800 Maggenti and Gardner

sagittal triact (PORIF) A three-rayed megasclere spicule hav- S ing one ray very unlike others, generally T-shaped. sagittal triradiates (PORIF) Tetraxon spicules with two equal angles and one dissimilar angle. see triradiate(s). sagittate a. [L. sagitta, arrow] Having the shape of an arrow- sabulous, sabulose a. [L. sabulum, sand] Sandy, gritty. head; sagittiform. sac n. [L. saccus, bag] A bladder, pouch or bag-like structure. sagittocysts n. [L. sagitta, arrow; Gr. kystis, bladder] (PLATY: saccate a. [L. saccus, bag] Sac-shaped; gibbous or inflated at Turbellaria) Pointed vesicles with a protrusible rod or nee- one end. dle. saccharobiose n. [Gr. sakchar, sugar; bios, life] Sucrose. salient a. [L. saliens, leaping] Projecting outward; prominent. sacciform a. [L. saccus, bag] Having the shape of a sac or saliva n. [L. saliva, spit] The secretion of the salivary glands pouch; saccular. that moisten the mouth parts, the food, and begins diges- tion; in many it also contains active consti- saccule n. [L. dim. saccus, bag] 1. A small sac or pouch. 2. tutents. Sometimes applied to a small invagination of the cuticle. salivarium n. [L. saliva, spit] 1. (ARTHRO: Chelicerata) In sacculus n. [L. dim. saccus, bag] (ARTHRO: Insecta) In Lepi- Acarina, the chamber in the buccal cone into which the doptera, the inner basal process of the coxite of male ex- salivary ducts open. 2. (ARTHRO: Insecta) The small cavity ternal genitalia. behind the hypopharynx and between it and the labium saccus n. [L. saccus, bag] (ARTHRO: Insecta) In Lepidoptera, into which the salivary duct opens. an internal, midventral, cephalad invagination of the vin- salivary canal (ARTHRO: Insecta) 1. In Hemiptera, the mouth culum. apparatus having separate food and salivary canals; the sacoglossa n. [Gr. sakos, shield; glossa, tongue] (MOLL: Gas- posterior of the two situated between the opposed styliform tropoda) In Opisthobranchia, having a single toothed maxillae, through which salivary fluids are secreted by a . salivary pump. 2. In Diptera, a canal extending the length saddle n. [A.S. sadol] 1. (ANN: ) In Lumbricidae, of the hypopharynx for passage of saliva from the salivary the clitellum incomplete ventrally, extending from the back pump; the salivary outlet canal. to below the lateral setae. 2. (ARTHRO: Insecta) In Diptera, salivary chromosomes (ARTHRO: Insecta) In Diptera, a large sclerite on the dorsal and lateral surfaces of the polytene chromosomes found in the interphase nuclei of 10th abdominal segment of larval Culicidae and some other the salivary glands of the larvae. nematocerous insects. see annular. salivary ducts (ARTHRO: Insecta) In Diptera, tubes through Saefftigen's pouch (ACANTHO) An elongate genital pouch of which saliva passes from the salivary glands; anteriorly males inside the genital sheath, continuous with the spaces fused forming the common salivary duct opening into the of the bursal cap, that functions to inject fluid for eversion salivary pump. of the bursa. salivary gland 1. (ARTHRO: Insecta) Glands that open into the sagittae see penis valves mouth, esophagus or at the beginning of the alimentary sagittal a. [L. sagitta, arrow] Of or pertaining to the vertical canal, that secrete a digestive substance. see labial gland, median anteroposterior plane in a bilaterally symmetrical esophageal glands, peptonephridia. 2. (MOLL: Cephalo- . see parasagittal. poda) In Sepia and Octopus the second salivary glands se- Online Dictionary of 801 802 Maggenti and Gardner

crete proteolytic enzymes. simple organic nutrients from surrounding medium. salivary pump (ARTHRO: Insecta) A modified salivarium into saprozoite n. [Gr. sapros, rotten; zoon, animal] An animal which the common salivary duct opens at the base of the that lives on dead or decaying organic matter. see sapro- hypopharynx. phyte. salivary syringe see salivary pump sarcobelum n. [Gr. sarx, flesh; belos, sting] (MOLL: Gastro- saltation n. [L. saltare, to leap] An evolutionary process that poda) In Pulmonata, a glandular node projecting into the proceeds by leaps and bounds through the production of prepuce from the junction of the penis sheath and propuce. mutants that differ greatly from the progenitor(s). see sarcode n. [Gr. sarx, flesh] Protoplasm. anamorphosis. sarcolemma n. [Gr. sarx, flesh; lemma, covering] An outer Saltatoria n. [L. saltare, to leap] A name commonly misap- membrane enclosing the nucleated sarcoplasm in which the plied to grasshoppers, crickets and their allies. muscle fibers are embedded. saltatory a. [L. saltare, to leap] Adapted for leaping. see fur- sarcolysis n. [Gr. sarx, flesh; lyein, to loosen] Phagocytosis of cula. muscles. saltigrade a. [L. saltare, to leap; gradus, step] Leaping sarcolyte n. [Gr. sarx, flesh; lytos, broken] (ARTHRO: Insecta) movement as in insects and spiders. In Diptera, spherical bodies filled with muscle fragments in sanguine a. [L. sanguis, blood] Having the color of blood. the blood of the pupae during metamorphosis. sanguinivorous a. [L. sanguis, blood; vorare, to devour] sarcomere n. [Gr. sarx, flesh; meros, part] Any one of a series Feeding on blood. of units occurring at regular intervals along a muscle fiber, each unit encompasses the actin and myosin filaments; in sanidasters n.pl. [Gr. sanidion, small board; aster, star] (PO- most invertebrates each sarcomere is set-off by Z discs. RIF) Rod shaped streptasters; a small rod-like spicule with sarcomeric a. see I-bands, T-tubule. spines at intervals. sarcophagous a. [Gr. sarx, flesh; phagein, to eat] Feeding on sapphirine a. [Gr. sappheiros, sapphire] Sapphire blue. flesh. saprobe see saprobiont sarcoplasm n. [Gr. sarx, flesh; plasma, formed or molded] saprobic a. [Gr. sapros, rotten] Living on decaying organic The undifferentiated protoplasm of a muscle cell; between matter. the myofibrils. saprobiont n. [Gr. sapros, rotten; bios, life] Living in an envi- sarcoplasmic reticulum Endoplasmic reticulum in striated ronment rich in decaying organic matter and low in oxygen. muscle fibers; surrounding the myofibrils. saprobiotic a. sarcosomes n. [Gr. sarx, flesh; soma, body] Former name for saprophagous a. [Gr. sapros, rotten; phagein, to eat] Feeding mitochondria in muscle cells. on dead or decaying animal or plant materials. sarcostyle n. [Gr. sarx, flesh; stylos, pillar] (CNID: Hydrozoa) saprophyte n. [Gr. sapros, rotten; phyton, plant] A plant that The dactylozooid on a column; nematophore. lives on dead and decaying organic matter; sometimes in- sarcotheca n. [Gr. sarx, flesh; theke, case] (CNID: Hydrozoa) correctly extended to include as well as plants. The sheath of a sarcostyle; nematotheca. saprophytic a. see saprozite. sarothrum see scopa saprozoic nutrition 1. Feeding on decaying organic matter. 2. Deriving sustenance by absorption of dissolved salts and saw n. [A.S. sagu, saw] (ARTHRO: Insecta) a. In Symphyta, Online Dictionary of 803 804 Maggenti and Gardner

transverse ridges provided on the fused 2nd valvulae. b. In scalloped a. [OF. escalope, shell] Indented, cut at the edges Diptera, the anterior serrated plate of the spiracular appa- into rounded hollows or segments of circles; crenate. ratus of Mansoniini larvae. scalp n. [Dan. skalp, shell] (MOLL) A bed of shellfish, especially saw bristles (ARTHRO: Crustacea) A heavy row of setae be- of mussels or oysters. tween the molar and incisor process on the gnathal lobe of scalpellum see lancet the mandible. scalpriform a. [L. scalprum, chisel; forma, shape] Chisel- saxicavous a. [L. saxum, rock; cavus, hollow] Said of rock- shaped. boring mollusks. scanning electron microscope (SEM) A microscope with an saxicolous a. [L. saxum, rock; colere, to inhabit] Living among electron beam that scans the specimen producing an image rocky or stony areas. of the surface on a florescent screen. scabellum n. [L. scabellum, footstool] (ARTHRO: Insecta) In scansorial a. [L. scandere, to climb] Adapted for climbing or Diptera, the distal basal portion of the halteres. clinging. scabrous a. [L. scaber, rough] Rough; rugged; with little rigid scape, scapus n. [L. scapus, shaft] 1. A stem or shaft. 2. (AR- points or minute irregularities. THRO: Chelicerata) A structure associated with the epi- scalariform, scalaroid a. [L. scalaris, ladder; forma, shape] gynum of some female Arachnida, partially covering the Ladder-like; having transverse bars and spaces like a lad- vulva. 3. (ARTHRO: Insecta) The first or basal segment of der. an antenna; in Diptera, the two basal segments of the an- scales n.pl. [OF. escale, husk] 1. A small, more or less flat- tenna. 4. (CNID: Anthozoa) a. In Alcyonaria, the main stem tened, plate-like exterior covering. 2. (ARTHRO) a. In Cheli- of Pennatulacea. b. In Actinaria, the lower thick-walled re- , flattened, modified setae of Arachnida. b. In Crus- gion of the column. tacea, small calcareous plate on the peduncle of scaphe n. [Gr. skaphe, boat] (ANN: Polychaeta) In Amphicteni- lepadomorph . see scaphocerite. c. In Insecta, dae, a flattened caudal appendage bearing the anus. flat unicellular outgrowths of the body-wall; highly modified scaphiform, scaphoid a. [Gr. skaphe, boat] Boat-shaped. clothing hairs of all Lepidoptera, many Collembola, in some Thysanura, Coleoptera, Diptera and Hymenoptera. 3. scaphium n. [Gr. skaphe, boat] 1. A boat-shaped structure. 2. (MOLL) a. In , localized projections of the outer (ARTHRO: Insecta) In male Lepidoptera, a dorsal sclerotiza- shell; usually on a rib. b. In Polyplacophora, small calcare- tion of the genitalia, below the uncus, and above the anus. ous bodies decorating the dorsal side of the girdle, some- see subscaphium. times closely set, overlapping and of various shapes, being scaphocerite n. [Gr. skaphe, boat; keras, horn] (ARTHRO: smooth or with minute striations. 4. (NEMATA: Sacernentea) Crustacea) The flattened exopod of the antenna; a scale; a Thickened, retrorse modifications of the body annuli. squama. scalids n.pl. [Gr. skalidon, hoe] 1. (KINOR) Circlets and longi- scaphognathite n. [Gr. skaphe, boat; ganthos, jaw] (ARTHRO: tudinal rows of spines on the protrusible cone-shaped head Crustacea) In Decapoda, the exopod of the maxilla, often and neck. 2. (LORI) In Nanaloricus mysticus, many re- used to produce the respiratory current in the gill chamber; curved spines on the cone-shaped anterior end (introvert) bailer or gill bailer. on its lateral surface. 3. (PRIAP) Longitudinal riblike, conical Scaphopoda n. [Gr. skaphe, boat; pous, foot] A class of Mol- projections arranged in circles and longitudinal rows on the lusca containing the tusk or tooth shell that are bilaterally barrel-shaped anterior proboscis region (introvert). symmetrical with an elongate, gently curved, tubular shell Online Dictionary of Invertebrate Zoology 805 806 Maggenti and Gardner

open at both ends; an exclusively marine dweller. butterfly wing. see biochrome. scapula see parapsis schistosomula n.; pl. -lae [Gr. schizein, split; dim. soma, scapulus n.; pl. -li [L. dim. scapus, stem] 1. (CNID: Anthozoa) body] (PLATY: Trematoda) In Schistostomatidae, the post- In Actinaria, the short upper part of the scape/scapus. 2. penetration stage in the vertebrate definitive host; the ju- (NEMATA) The enlarged sensory portion of a metaneme. venile stage between a cercaria and an adult. scapus see scape schizeckenosy n. [Gr. schizien, to split; eckenos, empty out] (ARTHRO: Chelicerata) In Acari, a system of waste elimina- scarabaeiform larva (ARTHRO: Insecta) A grublike larva with tion with blindly ending midgut by a lobe from the ven- a well sclerotized head, and poorly sclerotized body, but triculus breaking free and being expelled though a split in well developed thoracic legs and abdomen, without prolegs, the posterodorsal cuticle. and is usually short-legged and inactive. schizochroal n. [Gr. schizien, to split; chroa, superficial ap- scarabaeoid a. [L. scarabaeus, beetle; Gr. eidos, like] 1. pearance] (ARTHRO: Trilobita) Bound isolated lenses that Scarab-like. 2. (ARTHRO: Insecta) In Coleoptera, a member form around semicircular facets. see holochroal. of the Scarabaeoidea; third and fourth instar larva of the Meloidae, the blister beetles. schizocoel, schizocele n. [Gr. schizein, to split; koilos, hol- low] A coelomic cavity formed from the splitting of the scarified a. [L. scarifico, to scratch] To scratch or cut. mesodermal band or plate. scariose a. [F. scarieux, membranous] Thin, dry and scaly. schizodont a. [Gr. schizein, to split; odous, tooth] (MOLL: Bi- scatophagous a. [Gr. skatos, dung; phagein, to eat] Eating valvia) With a two cusped-tooth. dung or excrement; merdivorous; coprophagous. schizogamy n. [Gr. schizein, to split; gamos, marriage] (ANN: scavenger n. [ME. skavawer, collector of a toll] Any organism Polychaeta) Fission into a sexual and an asexual individual. that feeds on dead plants or animals and decaying matter schizogenesis see fission or animal wastes. schizolophe n. [Gr. schizein, to split; lophos, crest] (BRACHIO) scent brush/tuft Hairs or scales that function in diffusion of A lophophore indented to form a pair of branchia bearing a odorous secretions. row of paired filamentous appendages. schizolophous a. scent glands (ARTHRO: Insecta) Glands that manufacture and schizopeltid n. [Gr. schizein, to split; pelte, shield] (ARTHRO: store for subsequent release, volatile, usually highly odorif- Chelicerata) The prodorsal shield (peltidium) subdivided by erous substances. see brush organs, pheromone. one or more transverse scissures, composed of pro- scent pore see ostiole peltidium, mesopeltidium and metapeltidium, or pro- scent scales (ARTHRO: Insecta) Scales distinguished from peltidium and postpeltidium. clothing scales by their extreme length, sometimes called schizopod larva see mysis stage hairs. see androconia. schizorhyses n.pl. [Gr. schizein, to split; rhysos, delivering] sceptrules n. [Gr. dim. skeptron, royal staff] (PORIF: Sclero- (PORIF) Canals in the dictyonal framework that runs longi- spongiae) Microscleric monactinal triaxonic spicules that in- tudinally or obliquely from gastroderm to the dermis and clude clavules with terminal umbels or smooth heads. are lined by flagellated chambers. schemochrome n. [Gr. schema, shape; chroma, color] (AR- Schmidt's layer (ARTHRO: Insecta) The zone of deposition of THRO: Insecta) Colors produced by physical or structural new cuticle during molting; the exact nature of this zone is surfaces, devoid of pigment, as the iridescent colors of a not known. Online Dictionary of Invertebrate Zoology 807 808 Maggenti and Gardner

Schwann cell (ARTHRO: Insecta) An elongate cell into which sclerotized a. motor axons sink and become suspended by a suspensory scoleces pl. of scolex fold; lemnoblast; neurilemma cell. scolecid, scoleciform, scolecoid a. [Gr. skolex, worm] scientific name The formal nomenclatural designation of a Scolex-like. taxon. scolex n. [Gr. skolex, worm] (PLATY: Cestoda) The head or scissorial area (ARTHRO: Insecta) In Coleoptera, the cutting holdfast organ. area on the mandible of a Scarabaeoidea larva; between the dentes and molar area. scolopale n.; pl. -ia [Gr. skolos, pointed object; L. palus, stake] (ARTHRO: Insecta) A variously shaped cup or cone scissure n. [L. scindere, to cut] 1. A cleft or split in a body or with longitudinal ridges and a central filament connecting surface. 2. (ARTHRO: Chelicerata) In Acari, a relatively with the process of a central nerve cell; may have a termi- narrow band of soft skin that cuts the sclerotized cuticle nal button; sensory cell of the scolopidium; scolops; cu- into plates. ticular sheath; corpus scolopale. sclerification see sclerotization scoloparium see proprioceptor sclerite n. [Gr. skleros, hard] 1. (ARTHRO) Any sclerotized area scolopidium n.; pl. -ia [Gr. dim. skolos, pointed object] A of cuticle limited by lines or flexible, membranous mechanoreceptor (part of a chordotonal organ) consisting portions of cuticle. 2. (BRYO) A thickened line in the oper- essentially, of three cells: sensory neuron (scolopale), en- culum, mandible or frontal membrane. 3. (CNID) A calcare- veloping cell, and an attachment, or cap cell; scolopo- ous skeletal member of the mesogloea. phore; sensillum scolopophorum. see myochordotonal scleritization n. [Gr. skleros, hard; facere, to make] (ARTHRO: organ. Insecta) The formation of sclerites. scolopoid sheath see scolopale scleroblasts n.pl. [Gr. skleros, hard; blastos, bud] (PORIF) scolopophore, scolophore n. [Gr. skolos, pointed object; Special amoebocytes in sponges responsible for secreting phoreus, bearer] (ARTHRO: Insecta) 1. Complex sensilla the skeleton; consisting either of spicules, fibers of spongin consisting of a bundle of sensory cells whose endings are or both. separated from the body by one or more accessory cells, sclerocyte n. [Gr. skleros, hard; kytos, container] (PORIF) that are receptive to mechanical stimuli; scolopidium. 2. A Cells that secrete spicules. sense organ perceiving continuous vibration. see tangore- sclerophagous see duraphagous ceptor. sclerosepta n.pl.; sing. -um [Gr. skleros, hard; , parti- scolopophorus organ see chordotonal organ tion] (CNID: Hydrozoa) Calcareous rods of corals projecting scolops see scolopale from the basal plate in a fan-like shape between the mes- scolus n.; pl. scoli [Gr. skolos, pointed object] 1. Thorny proc- enteries of the polyp. esses of the body-wall. 2. (ARTHRO: Insecta) a. In Coleop- sclerotin n. [Gr. skleros, hard] (ARTHRO) A colorless or tera, long branched projection of coccinellid beetles. b. In quinone tanned amber or brown material occurring in the Lepidoptera, characteristic of nymphalid and saturniid lar- cuticle that accounts for much of the stiffening of the sur- vae; sphingid larvae also have a similar process in the anal face structures. sclerotic a. horn. sclerotization n. [Gr. skleros, hard] Hardening by deposition scolytoid larva (ARTHRO: Insecta) A fleshy larva resembling of sclerotin or other substances in the cuticle. sclerotic, the larva of scolytid beetles. Online Dictionary of Invertebrate Zoology 809 810 Maggenti and Gardner scopa n.; pl. -ae [L. scopa, broom] (ARTHRO: Insecta) In Hy- Small secondary spines on the scrobicular tubercles of the menoptera, special hairs (pollen brush) or modified to form test. a corbicula (pollen basket). scopate a. scrobiculus n. [LL. dim. scrobis, ditch] A pit or depression. scopiform a. [L. scopa, broom; forma, shape] Formed like a scrobis n.; pl. -es [LL. scrobis, ditch] (ARTHRO: Insecta) In brush. Scarabaeoidea larvae, a sunken lateral mandibular region scopula n.; pl. -ae [L. dim. scopa, broom] A small, dense tuft defined by two apically converging lateral carinae. of hair; scopa. scrotal membrane (ARTHRO: Insecta) The peritoneal envelope scopules n.pl. [L. dim. scopa, broom] (PORIF) Sceptrules with covering the testes; sometimes pigmented. few spines arranged in a regular cluster. scrotiform a. [L. scrotum, pouch; forma, shape] Purse- or scopuliferous, scopuliform a. [L. dim. scopa, broom] Brush- pouch-shaped. like. scrotum see scrotal membrane scopulipedes a. [L. dim. scopa, broom; pes, foot] (ARTHRO: n. [L. sculptura, carving] The pattern or marking of Insecta) In Hymenoptera, bees with pollen gathering impressions or elevations on the surface of an animal. structures on the feet. sculptured a. scotopic see superposition eye scutal angle (ARTHRO: Insecta) In Diptera, an angular projec- scraper n. [A.S. scrapian, scraper] 1. Any structure or special- tion of the scutal margin anterior to the prescutal suture, ized part of a structure adapted for rasping or scraping. 2. or in front of the prespiracular area. (ARTHRO: Insecta) In Orthoptera, the sharpened anal angle scutal margin (ARTHRO: Crustacea) In thoracic barnacles, the of the front wing that functions as a stridulating mecha- edge of the tergum, articulating with the scutum or the nism. see file. edge of any other plate adjacent to the scutum. screening a. [OF. escren, barrier] Selective procedures to iso- scutate a. [L. scutum, shield] In the shape of a shield; es- late animals or chemicals from populations, complex mix- cutcheon; clypeate; peltate. tures, or background material. scute n. [L. scutum, shield] (ARTHRO: Insecta) An external screw dislocation (BRYO) Spiral growth resulting from lattice scale. defects in calcite crystals making up their skeletal units. scutel see scutellum scrobe n. [LL. scrobis, ditch] A groove or furrow for the recep- tion of an appendage. scutellar angle (ARTHRO: Insecta) The expanded wing angle of the elytra adjacent to the scutellum. scrobicula n. [LL. dim. scrobis, ditch] (ECHINOD: Echinoidea) A bare area surrounding a boss (base of a spine) on the test; scutellar bridge (ARTHRO: Insecta) In Diptera, a ridge on both areola. sides of the scutellum connecting with the scutum. scrobicular tubercles (ECHINOD: Echinoidea) Secondary tu- scutellar bristles (ARTHRO: Insecta) In Diptera, bristles along bercles with spines encircling the base of a spine on the the posterior margin of the scutellum. test. scutellate a. [L. dim. scutum, shield] Divided into small plate- scrobiculate a. [LL. dim. scrobis, ditch] Marked with pits or like areas. hollows. scutellum n.; pl. scutella [L. dim. scutum, shield] 1. (ARTHRO: scrobicules n. [LL. dim. scrobis, ditch] (ECHINOD: Echinoidea) Insecta) a. A sclerotic subdivision of the thoracic . b. In Coleoptera, Hemiptera, and Homoptera, the scutellum Online Dictionary of Invertebrate Zoology 811 812 Maggenti and Gardner

(mesoscutellum); large and usually triangular or subtrian- from a thin layer of resistant endochorion and a thick am- gular. c. In Diptera, a posterior rounded or triangular lobe. ber layer that joins the cap to the rest of the chorion. 2. (NEMATA: Secernentea) One of a pair of large caudal seam n. [A.S. seam] A visible line of juncture between parts; a chemosensory organs opening in the lateral fields in some suture. species of the Hoplolaiminae. seam cells (NEMATA) The central cell row in the lateral chords scutiform a. [L. scutum, shield; forma, shape] In the shape of that have no membranous extension beneath the cuticle. a shield; peltate. sebaceous a. [L. sebaceus, tallow] Pertaining to secretion, or scutigerous a. [L. scutum, shield; gerere, to bear] Having a composed of oily or fatty substances. shield-like structure. sebific duct/gland Tubes of the collaterial glands. scutoscutellar suture (ARTHRO: Insecta) The sulcus dividing the mesonotum into the scutum and scutellum; V of V- Secernentea, secereneteans n.; n.pl. [L. secernere, to shaped sulcus with arms diverging posteriorly. separate] One of the two major classes of the Nemata, including most of the plant- and animal-parasitic scutulis see scutellum nematodes; formerly Phasmidia. see Adenophorea. scutum n.; pl. scuta [L. scutum, shield] 1. Any long, horny or second antennae (ARTHRO: Crustacea) 1. Antennae of the chitinous plate. 2. (ARTHRO: Chelicerata) In Acari, the second cephalic segment. 2. Antennae of some males are large, anteriodorsal sclerite. 3. (ARTHRO: Crustacea) In uniramous; two-jointed structures used to clasp females thoracic barnacles, a paired plate or . a. In Lepado- during mating. morpha, one on each side of the occludent margin of the capitulum. b. In Verrucomorpha, a fixed scutum, one of 4 secondary fiber (PORIF) A fiber that connects primary fibers principal plates, and a movable scutum, 1 of 2 opercular and is not oriented to the surface. plates. c. In Balanomorpha, one of 4 opercular plates. 4. secondary host see intermediate host (ARTHRO: Insecta) The middle division of the thoracic no- secondary intergradation The intergradation or hybridization tum, anterior to the scutellum. a. In Hymenoptera, the of two distinct and previously isolated populations that major part of the dorsum of the mesothorax in winged have reestablished contact. see primary intergradation. Formicidae. b. In Diptera, sometimes referred to as the eunotum. 5. (BRYO: Gymnolaemata) In anascan secondary iris cells see accessory pigment cells Cheilostomata, a broad, flat, lateral, marginal spine over- secondary ocelli (ARTHRO: Insecta) Ocelli of the larvae of hanging the frontal area. holometabolous insects; lateral ocelli. scyphistoma n. [Gr. scyphos, cup; stoma, mouth] (CNID) A secondary pigment cells see accessory pigment cells polypoid larval stage attached to the bottom that secondary pleometrosis (ARTHRO: Insecta) In Hymenoptera, gives rise to free-swimming medusae; a strobila. see hy- a process in a colony in which a founding queen is later dra-tuba. joined by others to form a pleometrotic association. see scyphomedusae see pleometrosis. Scyphozoa, scyphozoans n.; n.pl. [Gr. scyphos, cup; zoon, secondary reproductive see nymphoid reproductive animal] An exclusively marine class in the Phylum , secondary riblet (MOLL: Bivalvia) A riblet appearing later in in which the medusoid stage predominates having 8 development, however, weaker than primary riblets. notches in the margin of the bell; . secondary segmentation Any form of body segmentation not sealing bar (ARTHRO: Insecta) In eggs, a structure formed conforming with the embryonic metamerism. Online Dictionary of Invertebrate Zoology 813 814 Maggenti and Gardner secondary setae (ARTHRO: Insecta) In some caterpillars, setae enclosing the 1st valvulae. of indefinite locations and numbers; usually not present on second vein (ARTHRO: Insecta) In Diptera, when present, lying first instar. immediately behind the subcostal vein, always united with secondary sexual characters Characters that distinguish the the radial sector vein. sexes, though not functioning directly in reproduction. secretion n. [L. secretio, separation] A substance or fluid pro- secondary shell layer (BRACHIO) Shell deposited by outer duced in the body by a cell or gland; the passage of this epithelium median of outer lobes. a. In Articulata, substance to the outside of the cell or gland. secretory a. secreted intracellularly as fibers. b. In Inarticulata, if pre- secretory granules (NEMATA) Proteinaceous granules pro- sent, never fibrous. duced in the salivary (esophageal) glands, then transported secondary sockets (BRACHIO) A pair of small depressions be- anteriorly to the gland ampullae where breakdown occurs; hind the cardinal process lobes that receive the secondary thought to release digestive enzymes to be injected into teeth. the food cell during feeding. secondary somatic hermaphrodite see gynandromorph section n. [L. sectare, to cut] 1. Pertaining to a subdivision of secondary spicules (PORIF) Microscleres distributed through- a taxon or a series of related elements in one portion of a out the mesenchyme. higher taxon. 2. A thin slice of an organism or part of one used for microscopic study. secondary teeth (BRACHIO) In Stropheodontidae, two projec- tions from the ventral process that fit into sockets of the sectorial cross vein (ARTHRO: Insecta) A cross vein between brachial valve. the two branches of the radial sector. second axillary (ARTHRO: Insecta) 1. A sclerite articulating secund a. [L. secundus, following] Having parts or organs on partly with the preceding sclerite and partly with the base one side only; pointed one way; unilateral. of the radius; submedia. 2. An articulation sclerite of an in- secundibracts n. [L. secundus, following; brachium, arm] sect wing along the first axillary that touches the base of (ECHINOD: Crinoidea) Brachials between the first and 2nd the radial vein anteriorly, with a ventral portion of the axillaries; dicostalia. sclerite set below the wing surface; intra-alare. securiform a. [L. securis, ax; forma, shape] Hatchet-shaped. second-form reproductive see nymphoid reproductive sedentary a. [L. sedere, to sit] Remaining in one place; sta- second longitudinal vein see second vein tionary. second maxillae 1. (ARTHRO: Chilopoda) The fourth pair of seductor gubernaculi see gubernaculum head appendages. 2. (ARTHRO: Crustacea) The fifth and seed n. [A.S. saed, seed] (MOLL: Bivalvia) A young oyster; not last pair of head appendages. 3. (ARTHRO: Insecta) The designated by a specific size range. third pair of gnathal appendages; united in the labium. seed galls (NEMATA) Seedheads converted to galls containing second trochanter (ARTHRO) The second segment of the leg; cryptobiotic nematode larvae or adults. prefemur; ischiopodite. segment n. [L. segmentum, piece] 1. A part or subdivision of a second valvifers (ARTHRO: Insecta) In the ovipositor, a basal body or appendage that is marked off or separate between pair of lobes or oblong plates supporting the base of the joints or articulations. 2. (ANN) A portion of the body, along second valvulae. the anteroposterior axis, between two consecutive in- second valvulae (ARTHRO: Insecta) In the ovipositor, a dorsal tersegmental furrows and the associated septa. 3. (AR- elongate pair of processes, uniting to form the sting sheath THRO: Crustacea) A podomere. see article. Online Dictionary of Invertebrate Zoology 815 816 Maggenti and Gardner segmental blood vessel (ANN) A blood vessel in the body self-cleansing (MOLL: Bivalvia) Removal and ejection of wall, connecting anteriorly from dorsal to ventral arteries, . and posteriorly by plexes around the gut. self-fertilization The union of gametes derived from the same segmental spines (ARTHRO: Insecta) In Diptera, 12 major individual; autogamy; automixis. see cross-fertilization. bristles occurring in transverse rows on each segment of selfing see self-fertilization syrphid fly larvae. self-sedimentation (MOLL: Bivalvia) In oysters, pseudofeces segmentation n. [L. segmentum, piece] 1. The division of a and feces that are ejected. jointed appendage or limb. 2. Cleavage. sellate a. [L. sella, saddle] Saddle-shaped. segmentation cavity see blastocoel seller groove (ARTHRO: Crustacea) In Decapoda, a short segmentation nucleus Nucleus formed by union of male and transverse groove on the carapace, dorsally anterior to the female pronuclei during fertilization. cervical groove of Nephropidae. segregate n. [L. segregare, to separate] An individual that selva n. [L. silva, wood] A tropical rain forest. differs in some genetic characters from the parental stock due to segregation of genes. selvage n. [A.S. self; edge, its own proper edge] (ARTHRO: Crustacea) In Ostracoda, the principal ridge of the contact segregation n. [L. segregare, to separate] 1. The act of plac- margin sealing the valves closed. ing apart; separation. 2. The separation of the two genes of an allelomorphic pair during meiosis. sematic a. [Gr. sema, sign] Functioning as a warning of dan- ger, as signalling colors of insects, or disagreeable odors of seizing jaws see grasping spines certain poisonous or dangerous animals. see allosematic, sejugal a. [L. se, apart; jugare, to join] Indicating the furrow antiaposematic, aposematic, parasematic, pseu- or interval separating divisions or segments of an inverte- dosematic, episematic, pseudepisematic, pseu- brate body. daposematic. selection see natural selection sematophore see spermatophore selection pressure The effect of the environment in selecting semelparity n. [L. semel, once; parere, to bear] Producing individuals best suited for survival and reproduction. see young only once in a lifetime. semelparous a. natural selection. semiaquatic a. [L. semis, half; aqua, water] Living in wet selenaster n. [Gr. selene, moon; aster, star] (PORIF) A micro- places, or partially in water. sclere similar to a stellaster, but based on a spiraster. semidominant see codominant seleniform a. [Gr. selene, moon; L. forma, shape] In the semifenestra a. [L. semis, half; fenestra, window] (NEMATA: shape of a full moon. Secernentea) In Heterodera one of a pair of openings in the seleniform cell see plasmatocytes vulval cone separating the vulval bridge. see circum- n. [Gr. selene, moon; zone, girdle] (MOLL: Gastro- fenestrate. poda) In dibranchiates, a spiral band of crescentric growth semigeographic speciation see parapatric speciation lines or threads (lunulae) on the shell surface due to the semilunar a. [L. semi, half; luna, moon] A half-moon shaped semicircular end of a notch or slit on the outer ; a slit marking with sharp ends. band; corresponds to the anal fasciole of some other groups. seminal a. [L. semen, seed] Pertaining to structures in which sperm are involved. Online Dictionary of Invertebrate Zoology 817 818 Maggenti and Gardner seminal bursa (PLATY: Turbellaria) A term used to describe the Semper's cells see cells of Semper sac for receiving sperm during copulation that will be Semper's larva (CNID: Anthozoa) In Zoantharia, pelagic larva stored for a period of time; bursa seminalis. see bursa with long cilia. copulatrix. Semper's rib (ARTHRO: Insecta) In Lepidoptera, a degenerate seminal canal (ARTHRO: Insecta) In female Coleoptera, a duct trachea present in the wing, alongside a functioning tra- or canal that connects the spermatheca with the vagina, chea within the vein cavity. functioning in sperm transport. senescence n. [L. senescere, to grow old] The gradual dete- seminal ducts see vas deferens rioration of function in an organism leading to an increased seminal funnel (ANN: Oligochaeta) The internal opening of the probability of death; the ageing process. vas deferens. senility n. [L. senex, old] Old age. seminal furrows/grooves (ANN) Referring to distinct mark- senior homonym The earliest published of two or more identi- ings in the epidermis associated with male, or prostatic cal names for the same or different taxa. see homonym, pores, through which sperm and/or prostatic secretions junior homonym. move at the time of copulation. senior synonym The earliest published of two or more avail- seminal receptacle Diverticulum of oviduct or pouch external able names for the same taxon. see synonym, junior to the oviduct for storing spermatozoa delivered by the synonym. male; receptaculum seminalis. see spermatheca, bursa copulatrix, copulatory pouch, copulatory sac, seminal sense club see rhopalium bursa, spermatheca. sense cone/peg (ARTHRO: Insecta) 1. A minute cone or peg, seminal vesicle 1. A male sac-, tube- or pouch-like structure sensory in function. 2. Sense cone of Hayes, see nesium. in which spermatozoa is stored before being discharged; sense organ A simple or multicellular receptor organ, com- seminal reservoir; vesicula seminalis. 2. (ANN) A pouch prised of at least one sensory cell and accessory structures. usually formed in a posterior septum of a testicular seg- sensilla n.; pl. -ae [L. sensus, sense] see sensillum. ment where the latter stages of spermatogenesis occur. sensilla candelari (ARTHRO: Insecta) In the fulgorid Pyrops semination n. [L. semen, seed] Discharge of sperm. see in- folded sensory plaque organs having numerous bipolar semination. neurons arranged in groups; may have evolved from a semiochemical n. [Gr. semeion, mark or signal; chemeia, cluster of basiconic sensilla. transmutation] Chemicals involved in the chemical interac- sensilla circumfila (ARTHRO: Insecta) Thin-walled chemore- tions between individual organisms, subdivided into two ceptors with pores on fine surface ridges of elaborately major groups, pheromones and allelochemics. looped sensilla on the antennae of cecidomyids. semipupa n. [L. semis, half; pupa, puppet] (ARTHRO: Insecta) sensilla pouch (NEMATA) An expansion of the amphidial tube, In hypermetamorphosis, the interpolated stage between containing the sensory elements of the sensilla situated the active larva and the true pupa; the stage preceding pu- posterior to the amphidial pouch; fusus amphidialis. pate; prepupa. sensillium see sensillum. semisocial a. [L. semis, half; scocius, ally] (ARTHRO: Insecta) In Hymenoptera, female bees of the same generation living sensillum n.; pl. -la [L. sensus, sense] 1. A receptor complex in a colony with some individuals being primarily egg layers composed of a sense cell or units of sense cells plus associ- and some primarily workers (auxiliaries). ated structures: innervated hair, flat sensory plate, or sen- Online Dictionary of Invertebrate Zoology 819 820 Maggenti and Gardner

sory pit. 2. A small epithelial sense organ or nerve ending; plates. a simple receptor complex. sensillum rhinarium see rhinarium sensillum ampullaceum A sense organ in which the sense sensillum scolopophorum see scolopidium cone is a flask- or pouch-shaped cavity with no external structure evident; ampullaceous sensillum; sensory flasks. sensillum styloconicum A sense organ having a terminal sensory cone, usually in a pit in the cuticle, innervated by sensillum auriforme (ARTHRO: Chelicerata) In Acari, a sense nerve fibers running to its tip; thought to be olfactory in organ with flattened disks, similar to sensillum campani- function; sensilla styloconica; terminal sensory cone. formium. sensillum squamiformium (ARTHRO: Insecta) A sense organ sensillum basiconicum A sense organ with an external proc- with a scale-like external appearance with nerve fiber end- ess in the form of a minute cone or peg; basiconic sensil- ings at its base; usually occurring on the wing veins and lum. abdomen; sensory scales. sensillum campaniformium A thin, flexible, dome-shaped sensillum trichodeum A sense organ bearing an elongate sense organ that has no pore or opening, sometimes oc- seta, articulated with the body wall by a membranous curring in groups, that respond to strains on the cuticle, as socket so that it is free to move; a mechanoreceptor or less opposed to individual muscle movement; sensory cupolum. often as a chemoreceptor; trichoid sensillum; a tactile sen- sensillum chaeticum A sense organ with an external process sillum. in the form of a spine- or bristle-like seta, tactile in func- sensitization n. [L. sensus, sense] The process or state of tion. sensitiveness or hypersusceptibility to specific substances sensillum coeloconicum A sense organ with an external in contact with the body tissues. process in the form of a thin-walled conical or peg-like sensorium n.; pl. -riums, -ria [L. sensus, sense] The sensory projection in a shallow pit below the surface of the body apparatus, comprising sense organs and their nerve cen- wall; coeloconic sensillum; sensory pit-peg. ters. sensillum coelosphaericum (ARTHRO: Insecta) Olfactory re- sensory a. [L. sensus, sense] Having communication with the ceptor, lacking pore tubules, found on the last antennal sensorium. segment of Nicrophorus, composed of a complicated net- work of filaments. sensory cell A unicellular receptor sensillum coleum A sense organ that is completely covered sensory cell, type I Bipolar nerve cells in or beneath the epi- with a sheath except for the internal canal. dermis of the body wall, or the epithelium of the ectoder- mal parts of the alimentary canal and their distal processes sensillum insiticum A sense organ that shows no evidence of are usually connected with specific ectodermal sense or- an external structure or pore, but the ciliary process or gans. modified cilia are embedded in the cuticle. sensory cell, type II Bipolar or multipolar sense cell in the sensillum opticum A light perceiving sense organ; an om- inner surface of the body and on the wall of the alimentary matidium of a compound eye. canal, their distal processes go to the epidermis, connective sensillum placodeum A sense organ in the form of a flat, tissue, somatic muscles, splanchnic muscles or alimentary plate-like external membranous cover over an enlarged epithelium. pore tubule, with the outer surface continuous with the sensory neuron A neuron that acts as a receptor or receives general surface; maybe olfactory in function; sensory excitation directly from a receptor that is not a neuron; an Online Dictionary of Invertebrate Zoology 821 822 Maggenti and Gardner

axonic connection usually to the central nervous system. septum. 2. (BRYO) An internal membrane of a communica- sensu lato L. In a broad sense; S.L. tion organ. see dietella. sensu proprio L. In the original sense; S.Pr. septum n.; pl. -ta [L. septum, partition] 1. Any dividing wall, membrane or partition separating cavities or masses of tis- sensu stricto L. In the strict sense; a limited sense; S.S. sue; a dissepiment. 2. (ANN) Two layers of peritoneal cells senti n.pl.; sing. sentus [L. sentire, to feel] (ARTHRO: Insecta) enclosing muscle fibers, and blood vessels that separate In Hemiptera, unbranched, cone-like projections of the adjacent segments. 3. (ARTHRO: Crustacea) For barnacles, body wall with a few short, stout setae on the trunk of lar- see transverse septum. 4. (BRACHIO) Long, narrow, ele- vae of coccinellids. vation of the secondary (shell) layer, usually bladelike. a. septa pl. septum In Articulata, within underlying floor of valve with high, narrow deflections of fibrous calcite starting near the pri- septal a. [L. septum, partition] Pertaining to a septum. mary layer. b. In Inarticulata, comparable deflections of septal filaments (CNID: Anthozoa) Thread-like processes ar- the shell lamellae. 5. (MOLL: Cephalopoda) A calcareous ranged along the free edges of the septa that contain gland tube that supports the . 6. (MOLL: ) A cells and nematocysts. transverse plate secreted with early formed whorls of shell. septalial plates (BRACHIO) Crural plates forming the floor of sere n. [L. serere, to join] A chain of communities that follow the septalium and joining with the earlier-formed part of one another in sequence, prisere (primary sere) to a climax the median septum. typical of a particular climate and geographical area. see septalium n. [L. septum, partition] (BRACHIO) Troughlike hydrosere, xerosere, lithosere. structure of the brachial valve between hinge plates, con- serial a. [L. series, a row of things] Pertaining to or consisting sisting of septial plates enveloping and supported by the of or arranged in a series or row. median septum. serial crochets (ARTHRO: Insecta) Crochets of larvae, the dis- septal plate (BRACHIO) When present, one of two plates that tribution of the bases or points of attachment. see unise- fuse forming the duplex median septa in the brachial valve rial circle, biserial crochets, multiserial crochets. and bearing the outer plate on their ventral surface. sericate a. [L. sericus, silken] Having short, thick, silky down; septasternum see pleurosternum sericeous. septate a. [L. septum, partition] Partitioned off into septa. sericin n. [L. sericus, silken] (ARTHRO: Insecta) In Lepidoptera, septiform a. [L. septum, partition; forma, shape] Having the a protein containing a high content of the amino acid ser- shape of an enclosure or septum. ine, that hardens in air to form the glue surrounding the threads emitted from the spinneret of the silkworm. septula pl. septulum sericose n. [L. sericus, silken; os, mouth] (ARTHRO: Insecta) In septula n.; pl. -ae [L. dim. septum, partition] (ARTHRO: In- Hymenoptera, the opening for the duct of the silk glands. secta) In Scarabaeoidea larvae, a narrow bare region of the raster: between a transverse palidium and base of the serictery, sericterium n.; pl. -teria, -teries [L. sericus, lower anal lip, or between a pair of oblique palidia diverging silken] (ARTHRO: Insecta) The spinning gland or glands. a. backward to the end of the anal slit, or between a pair of In ant larvae, used as shuttles in weaving nests. b. The backward diverging, or parallel, or curved palidia to the in- silk-producing glands of a caterpillar. see silk gland. side ends of the anal slit. series n. [L. series, succession] In , the sample septulum n.; pl. -tula [L. dim. septum, partition] 1. A small taken in the field by the collector, or the sample available Online Dictionary of Invertebrate Zoology 823 824 Maggenti and Gardner

for taxonomic study. see hypodigm. sessile n. [L. sedere, to sit] Incapable of movement from place serific glands (ARTHRO: Insecta) Glands of silk production that to place; attached directly, without a stem or petiole; per- secrete a viscous fluid that solidifies passing through the manently attached. orifice of the spinneret, emerging as two semi-crystalline sessoblast n. [L. sedere, to sit; Gr. blastos, bud] (BRYO: Phy- threads. lactolaemata) A statobast cemented to the substrate. serology n. [L. serum, whey; Gr. logos, discourse] The study seston n. [Gr. sesis, sifting] Microplankton; all organisms living of sera and the nature, and interactions of antigens and or dead, swimming or floating in aquatic habitats. see antibodies. nekton, neuston, . serosa n. [L. serum, whey] (ARTHRO: Insecta) The outer em- seta n.; pl. setae [L. seta, bristle] 1. A bristle, hair or filament bryonic envelope. process of the cuticle with which it articulates or through serosal cuticle (ARTHRO: Insecta) An embryonic covering in- which it protrudes. see poison seta, penial seta. 2. (ANN) corporating the vitelline membrane on the outside, and Chaeta. 3. (ARTHRO: Insecta) Hollow structures formed as consisting of a chitinous endocuticle (white cuticle), with an extensions of the epidermal layer; macrotrichia or scales. epicuticle (yellow cuticle) having a second wax layer. 4. (ARTHRO: Crustacea) In Cirripedia, a bristle or spine on trophi and cirri. setal, setate a. serotinal a. [L. serus, late] Appearing later in the season than is customary with related species. setaceous a. [L. seta, bristle] Bristlelike, slender. serous a. [L. serum, whey] Secreting a watery, colorless se- setal membrane The membranous floor of a hair socket. rum. setal sac (ANN: Polychaeta) A pocket of the parapodial rami serpentinous a. [OF. serpentine, greenish mineral] A dirty, containing a single cell at the base, that continually pro- dark green. duce new setae as the old are lost. serra n. [L. serra, saw] A saw-like structure. setate a. [L. seta, bristle] Provided with bristles. serrate a. [L. serra, saw] Marginal teeth or notches like a saw. setiferous a. [L. seta, bristle; ferre, to carry] Bearing setae or bristles; setigerous; chaetiferous. serration n. [L. serra, saw] A saw-like formation. setiform a. [L. seta, bristle; forma, shape] Having the shape of serratulate a. [L. serrula, small saw] Having little teeth or a bristle or seta. serrations. setigenous a. [L. seta, bristle; Gr. genitus, to produce] Giving serriform a. [L. serra, saw; forma, shape] Saw-toothed; hav- rise to setae. ing the form of a series of notches. setiger n. [L. seta, bristle; gerere, to bear] (ANN: Polychaeta) serrula n. [L. dim. serra, saw] (ARTHRO: Chelicerata) In spi- A segment carrying setae. ders, a serration on the lateral margin of each maxillary lobe for cutting into prey. setigeris n. [L. seta, bristle; gerere, to bear] (ARTHRO: In- secta) A structure on the protibia similar in form and use as serrulate a. [L. dim. serra, saw] Finely serrate; having small the strigil or scraper; the tibial comb. fine teeth or minute notches. setigerous a. [L. seta, bristle; gerere, to bear] Bearing setae; serum ; pl. -a n. [L. serum, whey] The liquid part of the blood; setiferous. the secretion of a serous membrane. setigerous lobe (ANN: Polychaeta) The lobe of the parapodium sesquiocellus n. [L. sesqui-, one and one half; dim. oculus, that bears the setae. eye] A large ocellate spot including a smaller one. Online Dictionary of Invertebrate Zoology 825 826 Maggenti and Gardner setigerous tubercles (ARTHRO: Insecta) In Diptera, bumps natural phenomena, pathology, or artificial means. occurring on the scutellum or legs, each bearing a spine or sexthecal a. [L. sex, six; Gr. theke, case] (ANN) Having 3 pairs bristle at the . of spermathecae. setireme n. [L. seta, bristle; remus, oar] (ARTHRO: Insecta) In sexual cell see gametes aquatic forms, the hairy, oar-like leg. sexual dimorphism The notable phenotypic difference be- setula n.; pl. -lae; setule n.; pl. setules [L. dim. seta, bris- tween sexes of the same species. see polymorphism. tle] (ARTHRO) Slender hair- or bristle- or thread-like, fragile setae. sexuales n.pl. [L. sexus, sex] (ARTHRO: Insecta) In the life-cy- cle of aphids and adelgids, apterous forms produced on the setulose a. [L. dim. seta, bristle; -osus, full of] Set with short, primary host; the eggs the females lay hatch in the au- blunt bristles. tumn, giving rise to nymphs of the apterous fundatrices. sex n. [L. sexus, sex] The physical characteristics by which an sexual hybrid A hybrid in which the DNA is recombined by the animal is classed as male or female. fusion of haploid nuclei of different mating types. sex cell see gametes sexual pore see gonopore sexual congress The association of males and females for sexual reproduction Reproduction involving the fusion of two sexually reproductive purposes. cells (gamete nuclei), resulting from meiosis. sex chromosome A special chromosome, not occurring in sexual zooid (BRYO) a. In Gymnolaemata, autozooid in which identical number or structure in the two sexes, usually de- sex cells develop, may or may not show skeletal modifica- termines sex; the X and Y chromosomes. see chromo- tion. b. In Cheilostomata, it may loose the feeding ability. some, autosome. sexupara n.; pl. -ae [L. sexus, sex; parere, to bear] 1. Pro- sex hormone A hormone that influences primary and secon- duction of male and female offspring by parthenogenesis dary sexual characters and sexual behavior. then available for sexual reproduction. 2. (ARTHRO: In- sex-limited character A character occurring in only one sex. secta) The later generation of parthenogenetic viviparous see secondary sexual characters, sex-linked charac- Aphididae females originating from alienicola. ter. shaft n. [A.S. sceaft, shaft] The cylindrical part of a limb or sex-linked character A character controlled by a gene located structure. in a sex chromosome. see sex chromosome. shagreened a. [Turk. saghri, crupper] Having numerous sex-linked genes Genes in the sex chromosomes, linked in tooth-like projections. heredity to the genes determining sex. sheath n. [A.S. sceth, shell or pod] A covering enclosing an sex mosaic Intersex; gynandromorph. organism, part or organ. sexprostatic a. [L. sex, six; Gr. pro-, before; stare, stand] sheath laminae (BRYO: Stenolaemata) A concentrically en- (ANN) Having 6 prostates in 3 consecutive segments. closed stylet core, continuous with zoarial sheaths, but sexradiate a. [L. sex, six; radius, ray] Having 6 radii; hexacti- normally at right angles to them. nal. sheath of penis see ligula sex ratio The percentage of males and females of a specified shell n. [A.S. scell, shell] A hard, rigid, calcareous or chitinous age distribution in a population. structure covering an animal or part of an animal. sex reversal To change from one sex to the other, either by shell fold 1. (ARTHRO: Crustacea) The part of the carapace be- Online Dictionary of Invertebrate Zoology 827 828 Maggenti and Gardner

hind the cephalon. 2. (MOLL: Bivalvia) The outer fold of the twisted. mantle edge that houses the periostracal glands at its sigmoid a. [Gr. the 16th letter, sigma; eidos, form] Shaped base. like the letter S; sigmoidal. shell gland 1. (ARTHRO: Crustacea) see maxillary gland. 2. sigmoid curve see logistic curve (MOLL) Specialized epithelium that secretes the shell man- tle. 3. (PLATY: Trematoda) Mehlis' gland. signa n.pl.; sing. signum [L. signum, sign] (ARTHRO: Insecta) In female Lepidoptera, spines or dentate or roughened shield n. [A.S. scyld, shield] 1. A dorsal cover; carapace; patches on the inner wall of the corpus bursae, thought to scutellum; scutum; clypeus. 2. (ARTHRO: Crustacea) In De- function in holding or breaking up spermatophores. capoda, the anterior part of the cephalothorax of Paguri- dae. 3. (ARTHRO: Diplopoda) The second tergite. 4. silicalemma n. [L. silex, flint; Gr. lemma, peel] (PORIF) A unit (NEMATA) The interlabium. membrane enclosing the axial filament of a siliceous spi- cule. shoulder a. [A.S. sculdor, shoulder] 1. Any obtuse angulation. 2. (MOLL: Gastropoda) The angulation of the shell whorls, siliceous, silicious a. [L. silex, flint] Of or pertaining to silica. forming the abaxial edge of the sutural ramp or shelf; silicoblasts n.pl. [L. silex, flint; Gr. blastos, bud] (PORIF) A cell shoulder angle. that secretes all or part of a siliceous spicule. shovel n. [A.S. scofl, shovel] (ARTHRO: Insecta) In Ephemer- siliquiform a. [L. siliqua, a pod; forma, shape] Having the optera, the expanded, flattened leg joints. shape of a silique; long, tubular and narrow like a pod. sibling species True species populations that are reproduc- silk n. [Gr. serikos, silk] 1. A secretion that hardens so rapidly tively isolated, but morphologically identical or nearly so; on extrusion that it may be produced as a long continuous cryptic species. thread. 2. (ARTHRO: Chelicerata) Secreted by specialized side n. [A.S. side, side] (MOLL: Gastropoda) The surface of a salivary glands in Acari; anterior of the abdomen in Ara- shell, when present, between the shoulder and abapical neae; the galea of Pseudoscorpionida. 3. (ARTHRO: Insecta) suture or margin of the base. Secreted from dermal openings on the abdomen in some Coleoptera; foretarsi in Embioptera and some empidid Siebold's organ see crista acoustica Diptera; malpighian tubes discharging at the anus in Neu- sieve area (PORIF) The area containing inhalant apertures. roptera, some Coleoptera and Hymenoptera; mouth cavity sieve plate 1. (ECHINOD) see madreporite. 2. (PORIF) A (usually modified salivary glands) in Psocoptera, Sipho- plate-like porous structure below the osculum. naptera, some Diptera, Trichoptera, Lepidoptera and Hy- menoptera. sieve tracheae (ARTHRO: Chelicerata) In Ricinulei, bundles of tracheae that arise from a tubule of an ectodermal invagi- silk glands Glands that secrete the liquids that produce silk on nation on the 8th somite. see tube tracheae. exposure to the air. sigillum n.; pl. sigilla (ARTHRO: Chelicerata) 1. In some spi- silk press (ARTHRO: Insecta) In Lepidoptera larvae, a structure ders, the impressed, suboval, clear areas on the sternum. similar to a typical salivary pump in which the silk is 2. In Acari, the external mark of a muscle insertion. molded to a thread; silk regulator; thread press. sigma n. [Gr. the 16th letter, sigma] 1. (ARTHRO: Insecta) See silvicolous a. [L. silva, forest; colere, to dwell] Inhabiting or furca. 2. (PORIF) A C-shaped diactinal microsclere. growing in forests or woodlands. sigmaspires n.pl. [Gr. the 16th letter, sigma; speira, twist] simple a. [L. simplex, simple] Without embellishment; not (PORIF) Diactinal microsclere sigmas that are spirally modified, forked, toothed, branched or divided. Online Dictionary of Invertebrate Zoology 829 830 Maggenti and Gardner simple eyes (ARTHRO: Insecta) The ocelli. ture. siphonal a. simple seta see unjointed seta siphonal area (MOLL: Bivalvia) The posterior sector of the shell simple skeletal wall (BRYO: Stenolaemata) Having the wall surface, usually demarcated anteriorly by the umbonal calcified only on edges and one side. ridge; secreted at the openings in the mantle edge or ele- vated to form siphons. simple velum (ARTHRO: Crustacea) In Ostracoda, a velate structure of flange- or ridgelike form. (MOLL: Gastropoda) A tubular or troughlike extension of the for the enclosure of the . simple-walled colony see fixed-walled colony siphonal fasciole (MOLL: Gastropoda) The curved growth lines sinciput n. [L. semi-, half; caput, head] 1. Upper or forepart of near the foot of the marking successive positions the head. 2. (ARTHRO: Insecta) The head area between the of the . vertex and clypeus, especially in Coleoptera. siphonal fold (MOLL: Gastropoda) A ridge corresponding to the single band of crochets see mesoseries siphonal notch that winds spirally around the columella. single-walled colony see fixed-walled colony siphonal notch (MOLL: Gastropoda) A narrow sinus of the ap- sinistral a. [L. sinistra, left] Pertaining to the left; to the left of ertural margin near the base of the columella functioning the median line. for protrusion of the inhalant siphon. sinistral gastropods (MOLL) Having the genitalia on the left siphonal retractor muscles (MOLL: Bivalvia) Muscles that re- side of the head-foot mass or pallial cavity, and commonly tract siphons into the shell. the shell, when viewed with the apex uppermost, with the siphonal tube (MOLL: Bivalvia) A tube composed of aggluti- aperture on the left. see dextral gastropods. nized particles derived from boring and fused to the si- sinistron n. [L. sinistra, left] The left side of the body. phonoplax. see chimney. sinistrorse a. [L. sinistra, left; vertere, to turn] An organism siphonoglyph n. [Gr. siphon, tube; glyphein, to engrave] spirally twisting to the left. see dextrorse. (CNID: Anthozoa) A special groove or canal from the mouth sinuate a. [L. sinus, curve] Wavy; tortuous; curving in and to the actinopharynx, functioning to circulate fluid through out. the coelenteron. sinuatolobate a. [L. sinus, curve; Gr. lobos, lobe] Sinuate and siphonoplax n. [Gr. siphon, tube; plax, plate] (MOLL: Bivalvia) lobed. A chitinous or calcareous structure secreted by the mantle diverging or fused to form a tube on the posterior margin sinuosity a. [L. sinus, curve] Series of curves or bends. of the valves; probably for protection of the siphons. sinupalliate a. [L. sinus, curve; pallium, mantle] (MOLL: Bival- siphonostomatous a. [Gr. siphon, tube; stoma, mouth] via) Having a pallial sinus or recess in the posterior part of (MOLL: Gastropoda) Having the apertural margin notched or the pallial impression due to the retraction of the siphons. formed with a canal for the protrusion of the siphon. sinus n. [L. sinus, curve] A depression; bend; embayment. siphonozooid n. [Gr. siphon, tube; zoon, animal; eidos, form] sinus gland (ARTHRO: Crustacea) Storage release site for (CNID: Anthozoa) A small, modified polyp with reduced or neurosecretory material synthesized within the cell bodies lacking tentacles, having a well developed siphonoglyph to containing hormones produced by x-organ and other sites propel water through the canal system of the colony. of the central nervous system. siphons see gastrozooid siphon n. [Gr. siphon, tube] Any tubular or siphon-like struc- siphuncle n. [Gr. dim. siphon, tube] 1. (ARTHRO: Insecta) see Online Dictionary of Invertebrate Zoology 831 832 Maggenti and Gardner

cornicle. 2. (MOLL: Cephalopoda) A tubular vascular ex- a. In Polyplacophora, an abrupt indentation in the insertion tension borne at the apex of the visceral hump, that runs plate. b. In Gastropoda, a shallow incision to deep fissue in through the outer chambers of the shell and se- the outer margin of the aperture. cretes gas into them for buoyancy. siphunculate a. slit band see selenizone Siphuncula, sipunculans, sipunculids n.; n.pls. [Gr. dim. slit ray (MOLL: Polyplacophora) A shallow groove or row of siphon, tube] A phylum of bilaterally, unsegmented, cylin- pores or pits beginning at a slit and extending to the apex drical, deposit-feeding, benthic marine worms, with tenta- of the valve on the ventral side. cles and mouth located at the anterior extremity of the in- trovert. slit sense organs see lyriform organs sistentes n. [L. sistere, to stop] (ARTHRO: Insecta) The first slit sensilla (ARTHRO: Crustacea) In Decapoda, small pits lying generation of apterous exules on the secondary host that just distal to the walking leg joints; insertions of the den- give rise to the alate sexuparae and apterous progredientes drites of the joint proprioceptors of Homarus. in the genus Adelges. slope-faced (MOLL: Bivalvia) Referring to the face of the shell, sitopore n. [Gr. sitos, food; poros, pore] (ARTHRO: Insecta) i.e., central, anterior or posterior slope. The basal part of the cibarial floor of the hypopharynx of snout n. [ME. snoute, snout] (MOLL: Gastropoda) In Proso- generalized chewing insects. branchia, a non-retractable, short, mobile eminence at the sitophore sclerite see esophageal sclerite anterior end on which the mouth is formed. situs n. [L. situs, place] The locality; site; situation; relative social facilitation (ARTHRO: Insecta) An increase of activity position. from seeing or hearing others engaged in the same activ- ity. skeletal duplicature (ARTHRO: Crustacea) In some Cephalo- carida, the outer chitinous body covering that is shed dur- social hierarchy see hierarchy ing ecdysis. social homeostasis (ARTHRO: Insecta) The steady state skeleton n. [Gr. skeletos, dried, body] A hardened frame work maintenance either by control of microclimate in the nest, of an organism functioning for support and protection of or the control of population density, behavior and physiol- softer parts; may be external or internal and solid or ogy of the society members. jointed. skeletal a. social hormones see pheromones skin n. [ON. skinn, skin] The cuticle; the covering. social insects (ARTHRO: Insecta) 1. The ants, termites and skin bodies (SIPUN) A group of glandular cells often present on some bees and wasps in which individuals of the same spe- the surface of the trunk. cies cooperate in caring for the young, a reproductive divi- sion of labor is present, and an overlap of at least two gen- skin gill see papula erations in life stages contributing to the colony; eusocial skin rings see annular insects. 2. A social insect that belongs to either a presocial skototaxis n. [Gr. skotos, darkness; taxis, arrangement] The or eusocial species. orientation of an organism towards darkness. social interaction (ARTHRO: Insecta) Relationships among in- slavery see dulosis dividuals of a colony in which the behavior of one or a few indivduals influences others in the colony; social facilitation slime tubes see Cuvierian organs and social homeostasis are two interactions. slit n. [A.S. slutan, to tear] 1. A long cut or incision. 2. (MOLL) social parasite (ARTHRO: Insecta) A symbiont found in the Online Dictionary of Invertebrate Zoology 833 834 Maggenti and Gardner

nests of social insects, that feeds upon the food stores of walls, and large open roots, on the palp or legs; sense the colony. function unknown. social parasitic castration (ARTHRO: Insecta) Pertaining to a soleniform a. [Gr. solen, pipe; L. forma, form] Shaped like a Formicidae colony becoming parasitic on another colony of razor handle. a different species and eliminating the reproductives of it's solenocyte n. [Gr. solen, pipe; kytos, container] Specially host colony. modified tubular, ciliated or flagellated cells occurring in social (ARTHRO: Insecta) The coexistence of two protonephridia and nephridia of some invertebrates and species of social insects in the same nest, in which one is lower chordates. a. In protonephridial systems called flame parasitically dependent on the other. see symphile. cells or flame bulb; collectively all the flame bulbs, their society n. [L. socius, companion] An organized cooperative collecting tubes, 'bladder' when present, and external ori- group of individuals of the same species; communication fices; present in such invertebrates as: platyhelminths, between members is implied. nemertines, priapulids, rotifers, kinorhynchs, gastrotrichs and some annelids; function uncertain, may be excretory, socii n.pl.; sing. -us [L. socius, companion] (ARTHRO: Insecta) osmotic pressure regulator or both. b. In nephridial sys- In male Lepidoptera, lightly sclerotized, paired, hairy pads tems of some invertebrates and lower chordates its func- on the caudal margin of the tegumen near the base of the tion is attributed to excretion; structure similar to flame uncus in the genitalia. For Odonata, see superior ap- bulb system, but supplied with blood vessels, to help filtra- pendages. tion and absorption from blood; archinephridium. sociobiology n. [L. socius, companion; bios, life; logos, dis- solenomerite n. [Gr. solen, pipe; meros, part] (ARTHRO: Dip- course] The study of all aspects of communication and so- lopoda) In Julida, the tubular part of the opisthomerite with cial organization. the sperm channel and flagellum channel or groove. sociotomy see colony fission solenophage n. [Gr. solen, pipe; phagein, to feed] (ARTHRO) A socket n. [OF. soket, plowshare] (MOLL: Bivalvia) A cavity in blood-feeder whose mouthparts pierce directly into a blood the hinge to receive the tooth of the opposite valve. vessel to feed. sodium pump A mechanism of neurones to move sodium ions solid ramose colony see dendroid out of the cell during the recovery phase. solitaria n. [L. solus, alone] (ARTHRO: Insecta) The low density soft-part polymorph (BRYO: Gymnolaemata) In Cheilosto- phase of locusts and some caterpillars. see gregaria, mata, a zooid with sexual features, brood chamber, or kentromorphism. elongate tentacles to produce exhalant currents with no in- solitary n. [L. solus, alone] Living alone or in pairs, not in creased skeletal covering. colonies or groups. soldiers n. [L. solidus, a coin solider's pay] (ARTHRO: Insecta) solute n. [L. solvere, to loosen] 1. In a solution; a substance In Isoptera, members of a worker subcaste specialized for dissolved in another. 2. Wholly separate; free. see adnate. colony defense. soma n. [Gr. soma, body] The body of an animal, with the ex- solenia n.pl.; sing. -ium [Gr. solen, pipe] (CNID: Anthozoa) ception of the germ cells. somatic a. Endodermal tubes connecting polyps in some colonies. somatic cells Any cells of the body of an individual, except the solenidion n.; pl. -ia [Gr. dim. solen, pipe] (ARTHRO: Chelicer- germ cells. ata) In Acari, a hollow, microcephalic, pili-, baculi- or claviform, seta-like formation of the tegument with thin somatic chaetae see somatic setae Online Dictionary of Invertebrate Zoology 835 836 Maggenti and Gardner somatic crossing-over Reciprocal chromatin exchange be- tome. tween homologous chromosomes during somatic mitosis. sonication n. [L. sonus, sound] The disruption of cells by somatic hybrid Non-sexual or vegetative hybrid. sound waves. somatic layer The external layer of the mesoderm. sonifaction n. [L. sonus, sound; facere, to make] The produc- somatic musculature 1. Muscles of the body. 2. (NEMATA) tion of sound; sonorific. Longitudinally oriented muscle cells, usually spindle- sordid a. [L. sorditus, dirty] Of a dirty or muddy color; dull. shaped, containing a noncontractile portion and a contrac- sorotrochous a. [Gr. soros, heap; trochos, wheel] (ROTIF) tile portion that control body movement. Bearing a compound wheel organ or trochal disc. somatic mutation Mutation in any cell other than a germ cell n. [L. spadix, palm frond] 1. (CNID: Hydrozoa) A central or its precursor. core on which the sex cells ripen on the blastostyle. 2. somatic setae 1. Any setae on the body. 2. (ANN) Setae of the (MOLL: Cephalopoda) In male Nautilus sp., tentacles that somatic segments that function in locomotion. form a specialized reproductive structure. somatoblast n. [Gr. soma, body; blastos, bud] A cell that spado n. [Gr. spadon, a eunuch] (ARTHRO: Insecta) In hymen- gives rise to somatic cells. opteran bees and ants, a worker or neuter individual. somatocoel n. [Gr. soma, body; koilos, hollow] (ECHINOD) The spanandry n. [Gr. spanios, rare; andros, male] Progressive posterior of the three regions of coelomic sacs of the em- decrease in number of males. bryonic coelom, anterior (axocoel), and middle (hydrocoel). spanogamy n. [Gr. spanios, rare; gamos, wife] Progressive somatocyst n. [Gr. soma, body; kystis, bladder] (CNID: Hy- decrease in females. drozoa) In Siphonophora, the beginning of the stem gas- spanogyny n. [Gr. spanios, rare; gyne, female] (ARTHRO: In- trovascular canal that may contain an oil droplet. secta) The disappearance of mosquito colonies requiring somatoderm n. [Gr. soma, body; derma, skin] (MESO) The blood meals when maintained on a plant food source. outer rings of cells around the body; jacket cells. sparganum n. [Gr. sparganon, swaddling band] (PLATY: somato-esophageal muscles Muscles common to the eso- Cestoda) A second stage larva of Pseudophyllidea, with an phageal region. elongated shape and lack of cystic cavity; a plerocercoid. somato-intestinal muscles Muscles found in the region of the spat n. [A.S. spaetan, to spit] (MOLL: Bivalvia) A microscopic intestine, extending from the body wall. larval stage. somatome n. [Gr. soma, body; tome, cutting] A somite. spatfall n. [A.S. spaetan, to spit; A.S. feallan, fall] (MOLL: Bi- somatoplasm n. [Gr. soma, body; plasma, formed or molded] valvia) The en masse settlement of larva. The body-tissues. spatha n. [Gr. spathe, blade] (ARTHRO: Insecta) In Hymenop- somatopleure n. [Gr. soma, body; pleura, side] The somatic tera, a dorsal lobe of the aedeagus. layer. spathulate see spatulate somatotheca n. [Gr. soma, body; theke, case] (ARTHRO: In- spatulate a. [L. spatula, spoon] Spatula-like in form; flat- secta) Area of pupa covering the abdominal rings. see tened, while broad apically and narrowed basally. gasterotheca. spear see stylet somite n. [Gr. soma, body] A division of the body; a body specialization n. [L. specialis, special] An animal or structure segment of a metamerically segmented animal; a soma- Online Dictionary of Invertebrate Zoology 837 838 Maggenti and Gardner

that has adapted to a habitat or condition during the course panal organ. c. The shiny areas of some caterpillars. d. In of evolution. ichneumonid Hymenoptera, a slight, polished or sculptured speciation n. [L. species, kind] The division of a phyletic line; prominence on the upper hind part of the mesepisternum. the process of species multiplication; the origin of disconti- sperm n.; pl. & sing. [Gr. sperma, seed] Any male gamete; nuities between populations resulting from the develop- spermatozoid; spermatozoa. ment of reproductive isolating mechanisms. see allopatry, spermaduct n. [Gr. sperma, seed; L. ducere, to lead] Any duct sympatric speciation. for carrying sperm; spermiduct; sperm duct; vas deferens. species n.; sing. & pl. [L. species, kind] A group of inter- spermagonium n.; pl. -ia [Gr. sperma, seed; gonos, off- breeding (or potentially interbreeding) natural populations spring] (NEMATA) The sperm-producing structure of a di- that are reproductively isolated from other such groups. gonic female. see subspecies, isolate. spermalege see ectospermalege, mesospermalege, Ri- species group A group of closely related species, usually with baga's organ partially overlapping ranges. spermary, spermarium n. [Gr. sperma, seed] The male go- species inquirenda A species of doubtful status due to inade- nad, in which the sperm cells are produced. quate description and lack of preserved specimens. spermatangium n. [Gr. sperma, seed; angon, jar] (MOLL: species name 1. A scientific name of a taxon at the rank of Cephalopoda) Evaginated spermatophores ready to release species. 2. A binomen, the combination of a generic name sperm; sperm sacs; sperm bladders; sperm bulbs. and a specific name. spermateleosis n. [Gr. sperma, seed; teleiosis, completion] species nova New species; sp. nov.; sp. n. Spermiogenesis. specific character A common feature or structure in all indi- spermatheca n.; pl. -ae [Gr. sperma, seed; theke, case] A viduals of a species. saccate genital structure in female invertebrates in which specific density see economic density sperm from the male is received and may or may not be specific epithet see specific name stored; seminal receptacle; copulatory sac; copulatory pouch; seminal bursa; seminal receptical; ectospermalege. specificity n. [L. species, kind] Condition of an individual or group of organisms being specific to a host, locale, etc. see spermathecal chaeta (ANN: Oligochaeta) In tubificids, chaeta host specificity. (seta) usually in ventral fascicles on segment x; shape is usually different from somatic chaeta. specific name The second name in a binomen and in a tri- nomen. spermathecal gland (ARTHRO: Insecta) A special gland open- ing into the duct of the spermatheca, or near the junction specophile see sphecophile of the latter with the vagina. spectrum n.; pl. spectra [L. spectrum, appearance] A statisti- spermatid n. [Gr. sperma, seed] One of four haploid cells of cal survey of species distribution. the male after the meiotic divisions; an immature sper- specular membrane see mirror matozoon. speculum n.; pl. -ula, ums [L. dim. specere, to look at] 1. An spermatocyst n. [Gr. sperma, seed; kystis, bladder] (MOLL: ocellus. see eyespots 2. (ARTHRO: Insecta) a. In Lepidop- Gastropoda) In some Opisthobranchiates, a sperm storage tera, the brilliant metallic markings, or transparent spots sac proximal to the bursa copulatrix. on the wing. b. The thin, delicate membrane of the tym- spermatocyte n. [Gr. sperma, seed; kytos, container] An Online Dictionary of Invertebrate Zoology 839 840 Maggenti and Gardner

auxocyte of males that give rise to the spermatids. spermatozeugma n. [Gr. sperma, seed; zeugma, join] United spermatodactyl n. [Gr. sperma, seed; dactylos, finger] (AR- by fusion of two or more spermatozoa. THRO: Chelicerata) In Acari, modification of the chelicera in spermatozoon n.; pl. -zoa [Gr. sperma, seed; zoon, animal] order for sperm transfer from the male's gonopore to the The matured and functional male sperm cell. female copulatory receptacles. sperm bladders/bulbs see spermatangium spermatogenesis n. [Gr. sperma, seed; genesis, beginning] sperm cell A small, usually motile gamete. The formation and development of spermatozoa. sperm conceptacles (ARTHRO: Insecta) In Hemiptera, paired spermatogonial cyst see sperm cyst enlargements of the wall of the common oviduct of female spermatogonium n.; pl. -ia [Gr. sperma, seed; gonos, off- Cimicidae. spring] The gonads of male animals that give rise to the sperm cyst (ARTHRO: Insecta) A cellular capsule within the spermatocytes. testis containing the spermatocytes. spermatolophis n. [Gr. sperma, seed; lophos, crest] (ARTHRO: sperm duct (ANN) Ducts or tubes conveying sperm from the Insecta) In certain Thysanura, sperm packets thought to be male funnels towards the exterior. see spermaduct, vas formed in the nongranular portion of the vas deferens. deferens. spermatophore n. [Gr. sperma, seed; pherein, to bear] A spermiducal glands 1. Glands associated with the sperm packet or capsule of spermatozoa for transfer from male to ducts of many invertebrates. 2. (ANN) see prostate female. glands. spermatophore cup (ARTHRO: Insecta) In some Orthoptera spermiducts n.pl [Gr. sperma, seed; L. ducere, to lead] The and Neuroptera, a cup-like cavity at the anterior end of the male gonoducts; spermaducts; spermoducts; vas deferens; ejaculatory duct; in recent literature called a mold. sperm ducts. spermatophore sac 1. (ARTHRO: Insecta) a. In male Caelifera, sperm induction (ARTHRO: Chelicerata) In Arachnida, the pas- the sac into which the gonopore opens. b. For Ensifera see sage of spermatozoa from the genital orifice beneath the endophallic cavity. 2. (MOLL: Gastropoda) In Prosobran- base of the abdomen into the receptacle in the male chia, Neritidae and Phenacolepadidae, a large spermato- palpus. phoric sac associated with the vagina. 3. (MOLL: Cephalo- poda) A large diverticulum of the male reproductive system spermiogenesis n. [Gr. sperma, seed; genesis, beginning] functioning in storage for spermatophores. The formation of spermatozoa from the spermatids pro- duced during the meiotic divisions of spermatocytes; sper- spermatophoric sac see Needam's sac/organ mateleosis. spermatophory n. [Gr. sperma, seed; pherein, to carry] A spermoduct see sperm duct type of fertilization in which stalked spermatophores are placed on the substrate for the females to take up into her spermora n. [Gr. sperma, seed; L. os, mouth] (ARTHRO: In- genital tract. see gonopody. secta) In Isoptera, the external opening of the spermathe- cal duct. spermatophragma see sphragis sperm sacs 1. (ANN) Seminal vesicles or testis sacs or sper- spermatopositor n. [Gr. sperma, seed; ponere, to place] (AR- mathecae. 2. (MOLL: Cephalopoda) see spermatangium. THRO: Chelicerata) In Acari, a small evaginable male organ for depositing spermatophores; penis. sperm web (ARTHRO: Chelicerata) In Arachnida, a web on which male spiders deposit the semen before taking it into spermatotheca see spermatheca Online Dictionary of Invertebrate Zoology 841 842 Maggenti and Gardner

the palpus. containing spherules reported to contain neutral or acid sphaeridium n.; pl. -idia [Gr. dim. sphaira, ball] (ECHINOD) mucopolysaccharide, glyco-mucroproteins, lipochrome, Minute, spherical bodies covered by ciliated epidermis, trosinase and sulfated sialomucin. see spherule cell. usually lodged in pits in the test or almost completely en- spherulous cell (PORIF) Cells with multiple, large vesicles closed; confined to the ambulacral areas around the mouth containing coarse granular material. or scattered along the entire ambulacra; believed to be sphincter n. [Gr. sphinkter, binder] Any ring-like muscle that gravity receptors. contracts, constricts, or closes an orifice. sphaeroclone n. [Gr. dim. sphaira, ball; klon, twig] (PORIF) A sphingiform larva (ARTHRO: Insecta) A larva with a cylindrical megasclere spicule with a subglobular desma produced by body with short or no setae, and a mediodorsal horn or swelling of the centrum. button on the 8th abdominal segment. sphecology n. [Gr. sphex, wasp; logos, discourse] The study sphragis n. [Gr. spragis, seal] (ARTHRO: Insecta) In some of wasps. Lepidoptera, a structure formed by male glandular secre- sphecophile n. [Gr. sphex, wasp; philos, love] (ARTHRO: In- tions or actual male genital parts remaining in the female secta) A symbiont of wasps; any organism that must spend after insemination that inhibits subsequent copulations of at least a portion of its life cycle in a wasp colony. the female; spermatophragma; mating plug. sphenoid a. [Gr. sphen, wedge; eidos, like] Wedge shaped; spicate a. [L. spica, spike] Spike-shaped; possessing spikes. cuneate; cuneiform. spiciform a. [L. spica, spike; forma, form] Spike-shaped, as spherasters n. [Gr. sphaira, ball; aster, star] (PORIF) A large- some setae. centered spicule with many definite rays. spicula pl. of spiculum spheres n.pl. [Gr. sphaira, ball] 1. Any globular body. 2. (PO- spicular sheath (NEMATA) A conical or tubular extension of the RIF) Rounded bodies in which growth is concentric around a cuticle distally sheathing the spicules beyond the body pro- center. file. spherocyte see spherule cell spicular muscles (NEMATA) Muscles for the protraction and spheroidocyte n. [Gr. sphaira, ball; eidos, form; kytos, con- retraction of the spicules. tainer] (ARTHRO: Insecta) Round hemocytes with fat-like spicular pouch (NEMATA) A cuticular lined pouch that contains droplets, granular and other inclusions and occasionally the spicules and is formed from the spicular primordia. crystals. spicule n. [L. spicula, small spike] 1. Any minute pointed spine spherula n. [Gr. dim. sphaira, ball] A small sphere. or process. 2. (MOLL: Polyplacorphora) The dorsal girdle spherular cell see spherule cell decorations of various size, shape and frequency. 3. spherulate a. [Gr. dim. sphaira, ball] Having one or more rows (NEMATA) Blade-like, sclerotized male copulatory organs, of minute tubercles. usually paired, located immediately dorsad to the cloaca. 4. (PORIF) An element of the sponge skeleton, composed spherule cell (ARTHRO: Insecta) Hemocytes, varying in shape, mainly of silica or calcium carbonate, and rarely spongin. that possess few to many, acidophilic inclusions, that may fill the whole cell. see spherulocyte. spicule hair (ARTHRO: Insecta) In Lepidoptera, irritative hair usually formed by one or more trichogen cells; size, shape, spherulocyte n. [Gr. dim. sphaira, ball; kytos, hollow] (AR- internal cell components, and body arrangement are vari- THRO: Insecta) Ovoid or round hemocytes, variable in size, able. see spine hairs. Online Dictionary of Invertebrate Zoology 843 844 Maggenti and Gardner spiculiferous a. [L. spicula, small spike; fero, bear] Provided chaeta) Composite seta with terminal blades tapering to with spicules. fine tips; spines. spiculiform a. [L. spicula, small spike; forma, shape] Spicule- spinigerous a. [L. spina, thorn; gerere, to carry] Spine-bear- shaped. ing. spiculose a. [L. spicula, small spike] Bearing spicules. spinneret n. [A.S. spinnan, to spin] 1. (ARTHRO: Chelicerata) spiculum n.; pl. spicula [L. spicula, small spike] Spicular In spiders, three pairs of glands at the subcaudal end of structures, as the spines of echinoderms and dart of certain the abdomen, covered with minute tubes. see fusula; snails. sericose. 2. (ARTHRO: Insecta) An external apparatus from which silk exudes and is spun; produced by dermal gland spigots n.pl. [L. spica, spike] (ARTHRO: Chelicerata) In Arach- openings on the abdomen in Coleoptera; fore tarsi in Em- nida, conical spinning tubes on the spinnerets. bioptera and some Diptera; by the Malpighian tubes dis- spiked-tail stage (NEMATA: Secernentea) In Heteroderidae, charging at the anus in Neuroptera, some Coleoptera and the pointed tail of the second stage larval cuticle retained Hymenoptera; discharged from the mouth cavity, usually during initial expansion of the vermiform body. modified salivary glands in Psocoptera, Siphonaptera, some spina n.; pl. spinae [L. spina, thorn] 1. A spine. 2. (ARTHRO: Diptera, Trichoptera, Lepidoptera and Hymenoptera; in lar- Insecta) a. The medium apodemal process of the spi- val bees, the salivarium. 3. (NEMATA: Adenophorea) The nasternum. b. The medium apodeme. terminal pore of the caudal glands; the cement glands. spinasternum n. [L. spina, thorn; sternum, breast plate] (AR- spinning bristle (ARTHRO: Insecta) In Embioptera, hollow, THRO: Insecta) An instersegmental sclerite of the thoracic seta-like silk ejectors on the ventral surface of the fore tar- venter bearing a spina, associated with or united with the sus. sternal sclerite immediately anterior to it; the intersternite. spinning glands 1. (ARTHRO) Glands that secrete a silky ma- spinate a. [L. spina, thorn] Bearing spines; spiniform. terial; silk glands. 2. (ANN: Polychaeta) Glands of the parapodia that secrete the tube forming material. spination n. [L. spina, thorn] The development or arrange- ment of spines. spinose, spinous a. [L. spina, thorn] Full of spines; beset with spines; armed with sharp spines. spindle n. [A.S. spinnal, to spin] 1. Fusiform; tapering gradu- ally at both ends. 2. (PORIF) A straight monaxial spicule. spinulate a. [L. dim. spina, thorn] Having very small spines. spindle cell see plasmatocytes spinule n. [L. dim. spina, thorn] A minute spine. spine n. [L. spina, thorn] A pointed process or outgrowth; spinulifer n. [L. dim. spina, thorn; ferre, to bear] (BRACHIO) A thorn-like. radulifer with laterally compressed crura. spine base (BRYO) A collar-like skeletal inflation at the base of spinulose, spinulous a. [L. dim. spina, thorn] Having small a spine. spines. spine hairs (ARTHRO: Insecta) Poisonous weapons of many spiracle n. [L. spirare, to breathe] (ARTHRO) A breathing pore caterpillars, usually of multicellular origin and provided with or orifice leading to the tracheal or respiratory system; pointed tips, that upon penetration into human skin are stigma. spiracular a. broken, causing irritation; primitive setalike normal hairs. spiracular area (ARTHRO: Insecta) In Hymenoptera, the first spiniform a. [L. spina, thorn] Resembling a spine in shape. pleural area. spiniger n. [L. spina, thorn; gerere, to carry] (ANN: Poly- spiracular atrium (ARTHRO: Insecta) A cavity from which the Online Dictionary of Invertebrate Zoology 845 846 Maggenti and Gardner

trachea extend into the body. cle-shaped. spiracular cleft (ARTHRO: Insecta) In some larvae, spiracles spiral n. [L. spira, coil] A curved line or surface extending out- found in a closed or open cleft; in closed cleft, one or two ward with continuously increasing radius of curvature. liplike structures are usually present; stigmatic cleft. spiral amphid (NEMATA: Adenophorea) A coiled amphid tube spiracular depressions (ARTHRO: Insecta) In Coccoidea, usu- beneath the cuticle that appears as a spiral. ally found on the margin at the base of the spiracular se- spiral cleavage A type of early embryonic cleavage in which, tae. after the first few divisions, the cells of the upper quartet in spiracular disk (ARTHRO: Insecta) In Diptera, a flat area on the eight-celled stage lie above and between the cells of the caudal segment containing the spiracular openings of the lower quartet and thus tend to form a spiral pattern. aquatic larvae. spiral conic (MOLL: Gastropoda) In Trochidae, an advancing spiracular gills (ARTHRO: Insecta) In some aquatic pupae, the spiral, winding around an axis and forming a cone shape. long processes formed by the peritreme and atrial regions spiralia n.pl.; sing. spiralium [L. spira, coil] (BRACHIO) Two of one or more pairs of spiracles; adapted both for aquatic spirally coiled supports of the secondary shell for the plec- and aerial respiration. tolophe or spirolophe. spiracular grooves see spiracular cleft spiral thread/filament see taenidium spiracular line (ARTHRO: Insecta) The colored or pigmented spiramen n. [L. spiramen, vent] (BRYO) A median pore, not line adjacent to or coinciding with the line of the spiracles connected to the ascus, in the frontal wall on the proximal of caterpillars. side of the orifice. spiracular muscles (ARTHRO: Insecta) The occlusor and dila- spirasters n.pl. [L. spira, coil; aster, a star] (PORIF) Spirally tor. twisted streptasters. spiracular plate see peritreme n. [L. spira, coil] (MOLL: Gastropoda) The complete series spiracular processes (ARTHRO: Insecta) In some Scara- of whorls of a spiral shell except the last. baeoidea, dendriform trabeculae that form the filter appa- spire angle (MOLL: Gastropoda) In plane through entire shell ratus. axis, angle between two straight lines that touch all the spiracular sclerite (ARTHRO: Insecta) In Diptera, a sclerite of whorls on opposite sides; these lines can only be drawn if the metapleuron below the metathoracic spiracle. the rate of the increase is constant. spiracular setae (ARTHRO: Insecta) In Coccoidea, setae of spirignath, spiritrompe see galea various shapes and sizes terminating each spiracular pore spirocyst n. [L. spira, coil; Gr. kystis, bladder] (CNID: Antho- band. zoa) In Zoantharia, a type of nematocyst with a thin, sin- spiracular sieve plate (ARTHRO: Insecta) A platelike sclerite gle-wall capsule that is acidophilic and contains a long, covering the spiracle that functions to exclude entry of dust spirally coiled, unarmed thread of uniform diameter. see or water into the tracheal system. nematocyst. spiracular spines (ARTHRO: Insecta) In Coccoidea, large seta spirogyrate a. [L. spira, coil; gyratus, circular] (MOLL: Bival- usually associated with each spiracular pore cluster. via) 1. Umbones coiled outward from the saggital plane. 2. spiraculate a. [L. spirare, to breathe] With spiracles. In oysters, having the beak in a distinct spiral. spiraculiform a. [L. spirare, to breathe; forma, shape] Spira- spiroid a. [L. spira, coil] Spiral-shaped. Online Dictionary of Invertebrate Zoology 847 848 Maggenti and Gardner spirolophe n. [L. spira, coil; Gr. lophos, crest] (BRACHIO) A spongioblasts see spongocyte lophopore with brachia spirally coiled and bearing single spongiocoel see spongocoel rows of paired filamentary appendages. spongioplasm n. [L. spongia, sponge; Gr. plasma, formed or splanchnic a. [Gr. splanchnon, entrail] Of or pertaining to the molded] The a, H, and I bands of fibrillar bundles of mus- viscera. cles. splanchnic layer (ARTHRO: Insecta) The inner layer of the spongiose a. [L. spongia, sponge] Sponge-like. mesoderm applied to the wall of the alimentary canal; splanchnopleure. spongocoel(s) n. [L. spongia, sponge; Gr. koilos, hollow] (PO- RIF) A canal(s) or cavity(ies) that conveys water from the splanchnic nerves (ARTHRO: Insecta) Nerves originating from flagellated chambers. the last abdominal ganglion and continuing to the hind in- testine and the reproductive system. spongocyte n. [L. spongia, sponge; Gr. kytos, container] (PO- RIF) A cell that secretes spongin. splanchnopleure see splanchnic layer spontaneous generation Abiogenesis. splendent a. [L. splendens, shining] Shining; glossy; reflecting light intensely. spoon see bouton, flabellum splicing a. [D. splissen, to split] Methods of attaching one sporadic a. [Gr. sporas, scattered] Occasional occurrence. piece of DNA to another; gene splicing. sporoblast n. [Gr. spora, seed; blastos, bud] A cell mass that split sense organs (ARTHRO: Chelicerata) In Arachnida, cu- will develop into a sporocyst within an oocyst. ticular sense organs of spiders responding to cuticular sporocyst n. [Gr. spora, seed; kystis, bladder] 1. A stage of stress and vibrations. sporozoan development, usually within a protective enve- splitter n. [MD. splitten, to split] In taxonomy, an individual lope; the oocyst. 2. (PLATY: Trematoda) An asexual stage who divides taxa expressing minute shades of difference of development. and relationship, through the formal recognition of sepa- sporogony n. [Gr. spora, seed; gonos, offspring] The multiple rate taxa and their elaborate categorical ranking. fission of a zygote; a sporont. spoil, spoile see exuvia sporont n. [Gr. spora, seed; on, a being] An undifferentiated spondylium n. [Gr. spondylos, vertebra, joint] (BRACHIO) A U- cell mass within an oocyst. shaped ridge formed by the fusion of the distal ends of the sporosac n. [Gr. spora, seed; sakkos, bag] (CNID: Hydrozoa) dental plates that accommodate the ventral muscles. In Siphonophora, gonophores held in place and not re- sponge n. [L. spongia, sponge) 1. The common name for the leased into the water during larval development. Porifera. 2. (ARTHRO: Crustacea) In Malacostraca, the usu- sporozoite n. [Gr. spora, seed; zoon, animal] The stage of de- ally orange egg mass brooded by female crayfish. velopment of a sporoblast which has divided and exited the spongicolous a. [L. spongia, sponge; colere, to inhabit] Living oocyst into the hemocoel and migration begins; the malar- in sponges. ial stage found in the salivary glands of insects. spongiform a. [L. spongia, sponge; forma, form] Sponge-like; spout n. [ME. spouten, to vomit] (MOLL: Gastropoda) A rudi- soft and porous. mentary siphonal canal. spongin n. [L. spongia, sponge] (PORIF) Collagenous material spraing n. [Scot. of Scand. origin, sprang, stripe] A bright of the skeleton formed of homogeneous fibers or plaques. streak or stripe. Online Dictionary of Invertebrate Zoology 849 850 Maggenti and Gardner spring tide A series of tides with a relatively large tidal range, squamul alaris see alar squama occurring at or soon after the new or the full moon. see squamulate, squamulose a. [L. dim. squama, scale] Having neap. small scales. spur n. [A.S. spora, spur] 1. A movable spine-like process. 2. squarrose a. [L. squarrosus, rough] Rough with projecting (ARTHRO: Crustacea) a. In Cirripedia, a pendent-like pro- scale-like processes, divided into upright and nonparallel jection from the basal margin of the tergum. b. In Ostra- with the plane. coda, a flattened spine-like projection in some dimorphic genera. squat a. [OF. esquatir, to press down] More broad in propor- tion than to height. spur fasciole (ARTHRO: Crustacea) In Cirripedia, a slight de- pression on the outer surface of the tergum to the apex in stabilamentum, stabilimentum n. [L. stabilis, firm; amen- line with the spur. tum, strap] (ARTHRO: Chelicerata) In Arachnida, one of a series of obvious zigzag lines at the hub of certain orb spi- spur furrow (ARTHRO: Crustacea) In Cirripedia, a groove on der webs that warn birds to avoid them. the outer surface of the tergum to the apex in line with the spur. stadium n.; pl. stadia [L. stare, to stand] 1. The stage or pe- riod in an animals life. 2. The interval between molts of a spurious a. [L. spurius, false] Morphologically untrue; false. larva; stade. see instar. spurious claw (ARTHRO) A false claw; a claw-like stout bristle. stage see stadium spurious legs see prolegs stalk n. [A.S. stel, stalk] A supporting structure, such as a spurious vein (ARTHRO: Insecta) A fold or thickening of the pedicel. wing membrane between two true veins. staphyla n.; pl. staphylae [Gr. staphyle, bunch of grapes] A squama n.; pl. -mae [L. squama, scale] 1. Any decumbent group of gongylidia used as food by Attine ants that grow scale. 2. (ARTHRO: Crustacea) A scale-like exopod of the the fungus. antenna. see scaphocerite. 3. (ARTHRO: Insecta) a. In stase n. [Gr. stasis, standing] (ARTHRO: Chelicerata) 1. One of Hymenoptera, a dorsolateral lobe of the phallobase; in the successive instars of the postembryonic development of ants, the first abdominal segment. b. In Hemiptera, the a specific species. 2. In Acari, an instar independent of fimbriate or spine-like marginal process of coccoids; plates; growing molts, that is distinct within a species and can be scaly hairs. c. In Lepidoptera, the scale-like structure cov- homologized with the corresponding instars of other spe- ering the wing base of the fore wings. see patagium. d. In cies. Diptera, the calypters; palpiger; alar squama; antisquama; alula; in mosquitoes, the short broad scales on the wing stasis n. [Gr. stasis, standing] The stopping of normal proc- veins; median scale; flat scale. e. In Odonata, the lateral esses, i.e., growth, fluid movement, etc. expansion of the . f. In Diaspidinae, see gland stasoid a. [Gr. stasis, standing; eidos, like] (ARTHRO: Chelicer- spines. 4. (MOLL: Bivalvia) A thin, long, concentric imbri- ata) The life cycles of some instars that cannot be homolo- cation. gized with corresponding instars of other species of the squamate, squamiform a. [L. squama, scale] Scale-like; same group. squamoid. statary phase (ARTHRO: Insecta) In Hymenoptera, a period in squamous, squamose a. [L. squama, scale] Covered with the army ant cycle in which the colony does not move from scales. site to site; the queen lays eggs, and the brood is mostly eggs and pupae. see nomadism. Online Dictionary of Invertebrate Zoology 851 852 Maggenti and Gardner static a. [Gr. statikos, to cause to stand] Pertaining to rest or stelliform a. [L. stella, a star; forma, form] Star-shaped. equilibrium. see dynamic. stelocyttarous a. [Gr. stele, pillar; kyttaros, partition] (AR- statis organ see THRO: Insecta) Pertaining to nests, especially of social statis sense The sense of balance or maintenance in the air or wasps, in which the brood combs are attached to the sup- water. port by pillars and not connected with the envelope. see astelocyttarous. statistical method Special mathematical methods for the elu- cidation of quantitative variations affected by a multiplicity stem see hydrocaulus of factors. stemapoda, stemapod n. [Gr. stema, penis; pous, foot] (AR- statoblast n. [Gr. statos, fixed; blastos, bud] (BRYO: Phylac- THRO: Insecta) In larval Noctuoidea, elongated anal pro- tolaemata) A sessile or free, ovoid or discoid chitinized bud, legs. with large yolky cells and organized germinal tissue, that stem cell see prohemocyte give rise to polypides; resting buds; winter eggs. see stemma n.; pl. stemmata, stemmatas [Gr. stemma, gar- floatoblast. land] (ARTHRO: Insecta) The lateral ocelli of larval holome- statocone n.; pl. -ia [Gr. statos, fixed; koni, dust] A minute tabolous insects that vary in number from one on each side calcareous granule in a statocyst. in tenthredinid larvae to 6 on each side in lepidopterous statocyst n. [Gr. statos, fixed; kystis, bladder] An organ of larvae; a simple eye; an ocellus. balance found in many invertebrates, variable in structure stem nematogen (MESO: Rhombozoa) A young nematogen from an open canal, vesicle, or closed chambers composed with the same number and arrangement of cells as the of one to many cells (lithocytes), that contains a concretion larva, but with many agamete cells that give rise to ordi- of granules of sand, lime, diatom shells or quartz grains nary nematogens. (statolith), or capsules of ciliated cells enclosing a fluid with stenobathic a. [Gr. stenos, narrow; bathys, depth] An organ- one or more statoliths suspended within; otocyst. ism restricted to a narrow vertical range of movement. see statocyte see lithocyte eurybathic. statolith n. [Gr. statos, fixed; lithos, stone] A movable concre- stenobenthic a. [Gr. stenos, narrow; benthos, depth of the tion of granules of sand, lime, diatom shells, or quartz sea] An organism living within a narrow range of depth of grains contained in a statocyst, that functions in equilib- the sea bottom. see eurybenthic. rium; lithite. stenocephalous a. [Gr. stenos, narrow; kephalon, head] statorhabd see rhopalium Having a narrow, elongated head. stauractine a. [Gr. stauros, cross; aktis, ray] (PORIF) A tet- stenogamous a. [Gr. stenos, narrow; gamos, union] (ARTHRO: ractinal spicule with all four rays in a single plane. Insecta) Pertaining to Culicidae that require only a small stegasimous a. [Gr. stege, roof] (ARTHRO: Chelicerata) In enclosure when mating in captivity. see eurygamous. Acari, having the prodorsal sclerite project over the cheli- stenogastric a. [Gr. stenos, narrow; gaster, stomach] With a cerae. see astegasimous. shortened abdomen or gaster. stellate a. [L. stella, a star] Star-shaped; resembling the rays stenoglossate a. [Gr. stenos, narrow; glossa, tongue] (MOLL: of a star. Gastropoda) Pertaining to the radula consisting of 1-1-1 or stellate cells Stelliform plasmatocyte-like cells often adhering 0-1-0 rows of teeth. to internal tissues. see plasmatocyte. stenohaline a. [Gr. stenos, narrow; halinos, saline] Any or- Online Dictionary of Invertebrate Zoology 853 854 Maggenti and Gardner

ganism capable of withstanding only slight variations of sa- narrow host range. linity in its environment; stenosalinity. see euryhaline. steppe n. [Russ. step', lowland] Short grass plains, generally stenohygric a. [Gr. stenos, narrow; hygros, moist] Pertaining treeless. to an organism tolerating only a narrow atmospheric hu- stercoral a. [L. stercus, dung] 1. Pertaining to excrement. 2. midity range. Living in or feeding on dung. Stenolaemata, stenolaemates n.; n.pl. [Gr. stenos, narrow; stercoral pocket (ARTHRO: Chelicerata) A dilated portion of laimos, throat] A class of "tubular bryozoans", exclusively the proctodeum of certain spiders in which fecal matter and marine, with circular lophophores lacking an epistome. excreta temporarily accumulate. stenomorphic a. [Gr. stenos, narrow; morphe, shape] 1. Gen- stereoblastula n. [Gr. stereos, solid; blastos, bud] An early, era with limited morphological characters. 2. Dwarfed. solid blastula larva, all of whose cells reach the external stenonoty n. [Gr. stenos, narrow; notos, back] A small thorax. surface. stenophagous a. [Gr. stenos, narrow; phagein, to eat] Exist- stereogastrula n. [Gr. stereos, solid; gaster, stomach] A gen- ing on only a limited variety of foods. see euryphagous, eral term for solid metazoan larvae. omnivorous. stereoisomer n. [Gr. stereos, solid; isos, equal; meros, part] stenopodium n. [Gr. stenos, narrow; pous, foot] (ARTHRO: Different three-dimensional configurations of organic mole- Crustacea) Slender, sometimes setose, elongate append- cules that have different light rotational properties. age, composed of rod-like segments. stereokinesis n. [Gr. stereos, solid; kinesis, movement] A re- stenopterous a. [Gr. stenos, narrow; pteron, wing] Having a flex sensitivity inhibition due to passive contact stimuli; narrow, complete wing. thigmotaxis. stenosaline see stenohaline stereom(e) n. [Gr. stereos, solid] 1. The rigid material of the stenosis a. [Gr. stenos, narrow] Constriction of vessels, ducts, invertebrate skeleton. 2. (BRYO: Stenolaemata) The extra- etc. zooidal skeletal deposits, additions to structural skeleton, or to the vesicle roof skeleton. stenotele n. [Gr. stenos, narrow; telos, the end] (CNID) A stinging nematocyst; a sprially coiled thread armed with stereotaxis n.; pl. -taxes [Gr. stereos, solid; taxis, arrange- spiral rows of projections that is provided at its distal end ment] The directive response of an organism to contact with a lid (); a penetrant. with solids; thigmotaxis. a. Positive stereotaxis: toward the contact. b. Negative stereotaxis: away from the contact. stenothermal a. [Gr. stenos, narrow; therme, heat] Confined stereotactic a. to living within a narrow range of temperatures. see eu- rythermal. stereotropism n. [Gr. stereos, solid; tropos, turn] A move- ment in direction determined by contact with a solid body. stenotopic a. [Gr. stenos, narrow; topos, place] Organisms a. Positive stereotropism: toward contact. b. Negative having a limited geographical distribution or occurring in stereotropism: away from contact. stereotropic a. restricted habitats. see eurytopic. sterile a. [L. sterilis, unfruitful] Incapable of producing viable stenovalent a. [Gr. stenos, narrow; L. valens, strong] An or- gametes. ganism restricted to few types of environmental conditions. see euryvalent. sterilization n. [L. sterilis, unfruitful] 1. Rendering an animal incapable of reproduction. 2. Rendering a substrate free of stenoxenous a. [Gr. stenos, narrow; xenos, host] Having a organisms. Online Dictionary of Invertebrate Zoology 855 856 Maggenti and Gardner sterinx n. [Gr. sterinx, support] (ARTHRO: Crustacea) In Ostra- tending from the coxal gland orifice, between coxae I and coda, one of a pair of connecting pieces lateral to the tropis II, to the subcapitular gutter. in the male copulatory apparatus. sternal verrucae (ARTHRO: Chelicerata) In Opilioacariformes, sterna pl. of sternum paired wart-like structures in the sternal region. sternacosta n. [Gr. sternon, chest; L. costa, rib] (ARTHRO: In- sternannum see basisternum secta) An internal transverse ridge connecting the bases of sternapophysis n. [Gr. sternon, chest; apo-, separate; phy- the sternal apophyses. sein, to grow] (ARTHRO: Chelicerata) In Acari, protuberance sternacostal suture (ARTHRO: Insecta) The external suture of (single, paired or three) in the sternal region of leg I. the thoracic sternum through the apophyseal pits separat- sternaulus n.; pl. -li, -lices [Gr. sternon, chest; aulos, tube] ing the basisternum from the sternellum. (ARTHRO: Insecta) In ichneumonid Hymenoptera, a hori- sternal a. [Gr. sternon, chest] (ARTHRO: Insecta) Pertaining to zontal groove on the lower edge of the mesopleurum from the sternum. the prepectal carina backwards, sometimes reaching the sternal apophyseal pits (ARTHRO: Insecta) In higher insects, base of the middle coxa; the dividing line between the an external indentation marking the point of origin of the mesosternum and mesopleurum. sternal apophysis. sternellum n. [Gr. dim. sternon, chest] (ARTHRO: Insecta) A sternal apophysis (ARTHRO: Insecta) One of a pair of lateral part of the eusternum posterior to the sternacostal suture. apodemal arms of the eusternum marked by pits joined by sternellar a. a sulcus, thus dividing the eusternum into a basisternum sternite n. [Gr. sternon, chest] (ARTHRO) The main ventral and a sternellum; in higher insects they arise in the midline sclerite of a somite. and separate internally, forming the Y-shaped furca. see sternopleural bristles (ARTHRO: Insecta) In Diptera, bristles pleural apophysis. on the sternopleuron. sternal canal (ARTHRO: Crustacea) In Decapoda, an internal sternopleurite n. [Gr. sternon, chest; pleuron, side] (ARTHRO: skeletal structure of some formed by the meeting of Insecta) The ventral sclerite of the thoracic pleuron that the sternal apodemes from opposite sides of the body articulates with the coxa and becomes fused with the ster- above the nerve cord; sternum canal. num; a sternopleuron. sternal coxal process (ARTHRO: Insecta) 1. A projection of sternopleuron see sternopleurite the sternum serving for the ventral point of articulation with the coxa. 2. In Culicidae, a winglike expansion of the sternum n.; pl. sterna [Gr. sternon, chest] 1. (ARTHRO) The meso- and metabasisterna; ventral process. primary ventral portions of the somites, or the composite ventral sclerite of a segment. 2. (ARTHRO: Chelicerata) The sternal laterale (ARTHRO: Insecta) A plate on each side of the sclerotized plate of spiders between the coxae marking the sternum or presternum in some lower insects. floor of the cephalothorax. sternal plastron see sternum sternum canal see sternal canal sternal process (ARTHRO: Crustacea) In Mysidacea, a projec- sterols n.pl. [Gr. stereos, solid] Alcohols of high molecular tion arising from the midsection of the sternite. weight containing benzene-rings found in plants and ani- sternal spatula see breastbone mals. sternal taenidium (ARTHRO: Chelicerata) In Opilioacariformes, sterrasters n. [Gr. sterrhos, solid; aster, star] (PORIF: Des- a surface canal in the sternal region of the podosoma ex- mospongiae) Large centered, globular spicules with rays Online Dictionary of Invertebrate Zoology 857 858 Maggenti and Gardner

reduced to small projections from the spherical surface. of larvae; spiracular disk; respiratory disk. see spiracular sterrula n. [Gr. sterrhos, solid] (CNID: Anthozoa) A solid free- line swimming larva of Alcyonaria; stereoblastula. stigmatal line see spiracular line stethidium n. [Gr. stethos, breast] 1. (ARTHRO: Chelicerata) In stigmatal spine (ARTHRO: Insecta) In larval Diptera, the ex- Acari, the nonsclerotized prodorsum. 2. (ARTHRO: Insecta) trusible structure (modified terminal spiracles) in the anal The thorax and its appendages. siphon. stethosoma n. [Gr. stethos, breast; soma, body] (ARTHRO: stigmatic cord (ARTHRO: Insecta) In some larvae, a delicate Chelicerata) In Acari, that part of the body from the cir- cord running from the scar of a nonfunctional spiracle to an cumcapitular furrow to the disjugal furrow; prosoma with- adjacent part of the tracheal system. out the gnathosoma. stigmatic scar (ARTHRO: Insecta) The mark on the surface Stewart's organs (ECHINOD: Echinoidea) In cidaroids, made by the ecdysial tube after molting. coelomic pouches associated with Aristotle's lantern, func- stigmatiferous a. [Gr. stigma, mark; L. ferre, to bear] (AR- tioning for interchange of gases. THRO: Insecta) Bearing spiracles or stigmata. stichic a. [Gr. stichos, row] Pertaining to a row parallel to the stigmergy n. [Gr. stigma, mark; mergere, to dive] (ARTHRO: longitudinal axis. Insecta) In social insects, the directing of work by individ- stichocyte n. [Gr. stichos, row; kytos, container] (NEMATA: ual colony members based on work previously accom- Adenophorea) An individual cell of a stichosome. plished as opposed to direct signals from nestmates. stichosome n. [Gr. stichos, row; soma, body] (NEMATA: Ade- stimulus n.; pl. stimuli [L. stimulus, a goad] Any change of nophorea) A longitudinal series of cells (stichocytes) that external or internal conditions resulting in a change in the form the posterior esophageal glands. activities of an organism. sticklac n. [A.S. sticca, stick; Skr. laksa, lac] (ARTHRO: In- sting apparatus (ARTHRO: Insecta) In female Hymenoptera, secta) Branches or twigs covered with the dried lac of scale the modified ovipositor of aculeates and many terebrantes, insects. see lac. usually containing the venom gland and one accessory stigma n.; pl. stigmata [Gr. stigma, mark] 1. A spiracle or gland, the Dufour gland; others may sometimes be pre- breathing pore. 2. (ARTHRO: Chelicerata) In Acari, a sclerite sent: the Koshevnikov or Koshewnikow gland, the Bordas' surrounding a spiracle. 3. (ARTHRO: Insecta) a. A colored gland, the sting sheath gland, or anal gland. wing spot. see monostigmatous. b. In Odonata, a tick- sting autotomy (ARTHRO: Insecta) In Hymenoptera, enlarged ening of the wing membrane along the costal border near barbs on the sting apparatus that remain at the sting site; the apex. c. In Diptera, An apodeme at the base of the autothysis. ventral surface of the postgenital lobe of female mosqui- stinging button (CNID) A group of nematocysts on a jellyfish toes; basal median (longitudinal) apodeme; a sclerite sur- tentacle, especially the Portuguese man-of-war. rounding a spiracle on a maggot. 4. (PLATY: Trematoda) In Schistosomatoidea, an operculum-like area of an eggshell sting sheath (ARTHRO: Insecta) In Hymenoptera, the cover of through which the miracidium hatches. the sting formed by the lateral halves of the third valvulae. stigmal vein (ARTHRO: Insecta) A short vein extending poste- sting sheath gland/sheath gland (ARTHRO: Insecta) In Hy- riorly from the costal margin of the wing; stigma. menoptera, a gland in the sting sheath valves of various bees, in the form of a high palisade gland epithelium be- stigmatal field (ARTHRO: Insecta) An area around the spiracles neath a strongly sclerotized strip on the outer sides of the Online Dictionary of Invertebrate Zoology 859 860 Maggenti and Gardner

sheaths; function unknown. oid. stipe n. [L. stipes, a stem] 1. A stem or stalk-like appendage. stoma n.; pl. stomata [Gr. stoma, mouth] 1. Any of various 2. (ARTHRO: Crustacea) In Eucarida, a stemlike basal part small, simple mouth openings of invertebrates. 2. (NEMATA) of an appendage with sometimes squamate or other- The mouth or buccal cavity, from the oral opening and shaped expopod, i.e., the second joint of the antenna-like usually includes the anterior end of the esophagus appendage. (=pharynx). stipes n.; pl. stipites [L. stipes, a stem] 1. (ARTHRO: Chelicer- stomach n. [Gr. stoma, mouth] The digestive cavity of inver- ata) The distal end of the embolus (copulatory organ) of tebrates. spiders. 2. (ARTHRO: Diplopoda) The lateral lobes of the stomata pl. of stoma gnathochilarium. 3. (ARTHRO: Insecta) a. The second seg- ment or division of a maxilla that bears endite lobes, the stomatal a. [Gr. stoma, mouth] Pertaining to the stoma. lacinea and galea on its inner apical angle and the telopo- stomate a. [Gr. stoma, mouth] 1. Bearing a mouth. 2. (ANN) A dite (palpus) laterally; may be combined with basi-, disti-, with a funnel; an open nephridium. etc. b. In Diptera, a rodlike structure located inside the stomatodaeum see stomodeum head ventral to the tentorial arms. 4. (ARTHRO: Pauropoda) One of the three articles of the first maxilla, along with stomatogastric see recurrent nerve, stomogastric nerv- cardo and lacinia. 5. (ARTHRO: Symphyla) Two pairs of ous system maxillae similar to those of insects, except lacking a joint stomatostyle, stomatostylet n. [Gr. stoma, mouth; stylos, separating the cardo and stipes. pillar] (NEMATA: Secernentea) A stylet or protrusible hollow stipiform a. [L. stipes, a stem; forma, shape] Resembling a spear found in fungus feeding plant parasitic and insect stalk. parasitic nematodes of the suborders Tylenchina and Aphelenchina, presumed to have evolved from the walls of stipital a. [L. stipes, a stem] Pertaining to the stipe(s). the stoma. stipple n. [D. stippelen, to spot] Numerous circles or dots; stomatotheca n. [Gr. stoma, mouth; theke, case] (ARTHRO: shading effects produced by dots, circles or small marks. Insecta) That part of the pupal covering over the mouth Stobbe's gland (ARTHRO: Insecta) In Lepidoptera, paired mul- structures. ticellular aphrodisiac pheromone producing glands in the stomoblastula n. [Gr. stoma, mouth; blastos, bud] (PORIF: second abdominal segment of male noctuids. Calcarea) A developmental period of the amphiblastula, stock n. [A.S. stocc, stem, race] (ANN: Polychaeta) The sexual when the blastula opens and ingests adjacent choanocytes. individuals from which other individuals arise asexually. stomocnide see injector stolon n. [L. stolo, a branch] 1. (ANN) Individuals that are stomodeal bridge (ARTHRO: Chilopoda) A commissure that budded or fragmented asexually off of other individuals. 2. anteriorly connects the tritocerebral glanglia. (BRYO: Stenolaemata) In Stolonifera, a tubular kenozooid or extension of an autozooid from which autozooids are stomodeal canal (CTENO) Paired canals lying parallel to the budded. 3. (CNID: Anthozoa) A stem-like structure from stomodeum or pharynx; the pharyngeal canal. which polyps arise. see hydrocaulus. stomodeal feeding (ARTHRO: Insecta) A mixture of salivary stolonate a. [L. stolo, a branch] Having stolons; stoloniferous. secretions and regurgitated intestinal contents received from another insect. see proctodeal feeding. stoloniferan n. [L. stolo, a branch; ferre, to bear] (BRYO: Stenolaemata) An autozooid budded from a single kenozo- stomodeal nervous system see stomatogastric sympa- Online Dictionary of Invertebrate Zoology 861 862 Maggenti and Gardner

thetic nervous system Gastropoda) Equivalent to chiastoneury. stomodeal valve see cardiac valve stria n.; pl. striae [L. stria, furrow] A groove or depressed stomodeum, stomodaeum n. [Gr. stoma, mouth; hodos, line. striate a. way, road] The anterior ectodermal portion of the alimen- striation n. [L. stria, furrow] A longitudinal ridge or furrow. tary canal; the fore-intestine or foregut. stricture n. [L. stringere, to bind tight] A binding or contrac- stomogastric nerve see recurrent nerve tion, as of a passage in a body. stomogastric nervous system (ARTHRO: Insecta) The nerv- stridulating organs The impact of some part of the body ous system directly connected to the brain, innervating the against the substratum; friction method, rubbing two parts fore and middle intestine, heart and certain other parts; of the body together; vibrating membrane; sound produced the esophageal nervous system; sympathetic system. by a pulsed air stream. stone canal (ECHINOD: Asteroidea) A vertical canal containing stridulation n. [L. stridere, to make a creaking or grating calcareous deposits in its wall, that descends to the oral noise] Any sound produced by a lower animal. side of the disc, joining a circular canal (the water ring) at stridulatory a. [L. stridere, to make a creaking or grating the inner side of the ossicles that ring the mouth. noise] Pertaining to or the nature of stridulation. storage pots (ARTHRO: Insecta) In Hymenoptera, containers striga n.; pl. strigae [L. striga, furrow] A narrow, transverse constructed of cerumen for food storage by social bees; a line or streak. honey pot. strigate a. [L. striga, furrow] Marked with fine, closely set strahl n.; pl. strahlen [Ger. strahl, ray] A ciliary process, ray grooves. or barbule. strigil n. [L. strigilis, scraper] (ARTHRO: Insecta) 1. A curved straight-hinge see protostracum structure at the apex of the fore tibia of many insects that strangulated a. [L. strangulare, to strangle] Constricted; con- functions as a scraper, a tibial comb or antenna cleaner. 2. tracted; held in. In some Hemiptera, a currycomb-like structure situated on strata pl. of stratum the dorsal surface of the abdomen. stratification n. [L. stratum, a cover; ficare, to make] Act or strigilation n. [L. strigilis, scraper] (ARTHRO: Insecta) In Hy- process of being made up of layers. menoptera, licking secretions from the body of another animal. stratum n.; pl. -ta [L. stratum, a cover] 1. A layer of tissue or cells that compose an organ. 2. A group of organisms in- strigilator n. [L. strigilis, scraper] One who licks the surface of habiting a particular geographical area. 3. A layer of vege- another to collect secretions from the body. tation, usually at the same stage of development. 4. A strigose a. [L. striga, furrow] Covered with strigae; marked layer of sedimentary rock or earth. with fine, closely set grooves. strepsilaematous a. [Gr. strepsis, twisting; laimos, throat] strigose ventral areas (ARTHRO: Insecta) In Hemiptera, the Having a pharynx rotated along its length. see euthylae- inner side of the hind tibiae containing wart-like tubercles, matous. each bearing a subapical tooth; rubbing against the femur streptasters n.pl. [Gr. strepsis, twisting; aster, star] (PORIF) produces an audible sound. Short, spiny, microscleric monaxon spicules. strigula n.; pl. -ulae [L. striga, furrow] A fine, short trans- streptoneury n. [Gr. strepsis, twisting; neuron, nerve] (MOLL: verse mark or line. Online Dictionary of Invertebrate Zoology 863 864 Maggenti and Gardner strike n. [OE. strican, to stroke, level out] (ARTHRO: Insecta) strongyloxea n. [Gr. strongylos, rounded; oxys, sharp] (PO- The deposition of Diptera eggs or larvae on a living host. RIF) A monactinal megasclere with one end rounded and string reef (MOLL: Bivalvia) Oysters crowded into a long, nar- the other pointed. row accumulation. strophe n. [Gr. strophos, twisted] (ARTHRO: Insecta) In males striola a. [L. dim. stria, furrow] Finely impressed parallel lines. of higher Diptera, spiral curling of parts of the postabdo- men into a protected position at rest. stripe n. [MD. strijp, stripe] A longitudinal color marking. structural colors Colors resulting from structure rather than strobila n.; pl. -lae [Gr. strobilos, anything twisted, pine cone] pigment. 1. An organism, or stage of an organism, from which suc- cessive annular disc embryos bud off. 2. (CNID: Scyphozoa) structural gene Any gene that determines the structure of a A scyphistoma larva of a jellyfish consisting of ephyrae. 3. polypeptide through the production of messenger RNA. (PLATY: Cestoda) A tapeworm, consisting of scolex, 'neck', structure n. [L. structus, build] Any organ, appendage or part immature, mature and usually gravid proglottids. of an organism. strobilation, strobilization n. [Gr. strobilos, anything twisted, struma n.; pl. -ae [L. struma, scrofulous tumor] (ARTHRO: In- pine cone] 1. The formation of a chain of body segmenta- secta) In most Coccinellidae larvae, distinct tubercles of the tion into zooids. 2. (CNID: Scyphozoa) The ephyrae of jelly- body wall bearing spines. strumose a. fish. see monodisk, polydisk. 3. (PLATY: Cestoda) The stupeous a. [L. stupa, coarse fiber of flax or hemp, tow] Cov- proglottids. ered with fiber-like filaments. strobilocercoid n. [Gr. strobilos, anything twisted, pine cone; stupulose a. [L. stupa, coarse fiber of flax or hemp, tow] Cov- kerkos, tail; eidos, like] (PLATY: Cestoda) In Schistotaenia , ered with coarse decumbent hairs. a cysticercoid that undergoes some strobilation. stylamblys see appendix interna strobilocercus n. [Gr. strobilos, anything twisted, pine cone; kerkos, tail] (PLATY: Cestoda) A simple cysticercus with stylate a. [Gr. stylos, pillar] With a style; stylelike. evidence of strobilation. style, stylus n.; pl. styli [Gr. stylos, pillar] 1. (ARTHRO: Cheli- stroma n.; pl. stromata [Gr. stroma, bed] Connective tissue cerata) The embolus of spiders. 2. (ARTHRO: Crustacea) see framework of an organ. telson. 3. (ARTHRO: Insecta) a. Any slender, tubular or spinelike appendage at the end of the abdomen. b. In some strombiform a. [Gr. strombos, a top, a spiral shell; L. forma, Diptera, a bristlelike process at the terminal segment of the shape] (MOLL: Gastropoda) Roughly biconical, with ex- antenna. 4. (BRYO: Stenolaemata) A general term for a panded outer lip; said of the shell of . rodlike skeletal structure forming a spinose projection on (MOLL: Gastropoda) In Strombus , a curve or the zoarial surface; canaliculus; stylet. see acanthopore. notch in the outer lip, above the anterior notch. 5. (CNID: Hydrozoa) A calcareous projection. 6. (MOLL) see strongylaster n. [Gr. strongylos, rounded; aster, star] (PORIF) crystalline style. 7. (PORIF) A monactinal spicule dissimi- A star-shaped spicule with small center and rays with lar at the two ends. stylate a. rounded edges. style sac (MOLL) The posterior conical region of the stomach, strongyle n. [Gr. strongylos, rounded] 1. (NEMATA: Se- lined with cilia, but devoid of chitin. cernentea) A common name for the order Strongylida. 2. stylet n. [Gr. stylos, pillar] 1. Any small rigid bristle or needle- (PORIF) A diactinal monaxon (spicule) rounded at both like appendage or organ. 2. (ARTHRO: Crustacea) see cau- ends. dal ramus. 3. (ARTHRO: Insecta) One of the piercing Online Dictionary of Invertebrate Zoology 865 866 Maggenti and Gardner

structures in the sucking mouth parts; the shaft of the ovi- small, longer than wide, projection on the parapodium. positor. 4. (BRYO: Stenolaemata) A rodlike skeletal struc- styloid a. [Gr. stylos, pillar; eidos, like] Long and slender; be- ture oriented almost perpendicular to the zoarial surface lonoid; aciform. and parallel to the zooecia. 5. (CNID) The large, lowermost thorn on the hampe (butt) of a stenotele nematocyst. 6. stylopization n. [Gr. stylos, pillar; ops, eye] (ARTHRO: Insecta) (NEMATA) A sclerotized, usually hollow, structure used for The endoparasitism by the coleopterous female Strepsip- feeding, releasing secretions and entering plants and ani- tera (Stylops), of other insects; stylopized. mals (Arthropoda); a spear. see stomatostyle, odon- stylose a. [Gr. stylos, pillar] Bearing a style or several styli. tostyle. 7. (NEMER) A nail-shaped structure on the end of stylostome n. [Gr. stylos, pillar; stoma, mouth] (ARTHRO: the proboscis that typically reaches 50-200 m, used in the Chelicerata) In acarid Trombiculidae, a hard, tube-like capture of prey. structure formed by the host's tissues under the influence stylet extension see of secretions by the feeding mites. stylet knobs (NEMATA) Various thickenings (apodemes) at the stylote a. of style base of the stylet, usually 3 in number, that serve as at- stylus n.; pl. styli [Gr. stylos, pillar] Style; stylet; a short tachment points for the protractor muscles. see basal slender, fingerlike process. knobs. subalar sclerite (ARTHRO: Insecta) A sclerite behind the pleu- styletocytes n.pl. [Gr. stylos, piller; kytos, container] (NEMER) ral process into which wing movement muscles are in- Large epithelial cells in which the stylets are formed. serted. stylet sac see trophic sac subalternate a. [L. sub, under; alternus, alternate] Not quite stylet sheath (ARTHRO: Insecta) In aculeate Hymenoptera, the opposite, yet not regularly alternate. dorsal part of the terebra. subanal lobe/appendage see catoprocess styli pl. of style and stylus subanal scale see anal scale styliferous a. [Gr. stylos, pillar; L. fero, bear] Having one or subantennal groove (ARTHRO: Insecta) In Diptera, a facial more styli. groove that facilitates the scape. styliform a. [Gr. stylos, pillar; L. forma, shape] Shaped like a subantennal ridge (ARTHRO: Insecta) In Diptera, the inner style or stylet; formed of parallel-sides and a pointed apex. supporting ridge of the subantennal suture of Culicidae. styliger plate (ARTHRO: Insecta) In Ephemeroptera, a sclerite subantennal suture (ARTHRO: Insecta) 1. Sutures ventral to on the posterior portion of sternum 9, variable in shape, the antennal socket. 2. In Culicidae larvae, a short line lat- which on the posterior margin gives rise to a pair of slender erally below the antennal prominence, associated with the and usually segmented appendages called forceps or clasp- subantennal ridge. ers; a subgenital plate. subapical lobe (ARTHRO: Insecta) In the genitalia of male Culi- stylocerite n. [Gr. stylos, pillar; keras, horn] (ARTHRO: Crusta- cidae, a mesal lobe found at or distal to the middle of the cea) A rounded or spiniform process on the outer part of gonocoxite. the proximal segment of the antennular peduncle; anten- nular scale. subapotorma n. [L. sub, under; Gr. apo, from; tormos, socket] (ARTHRO: Insecta) In Scarabaeoidea larva, a heav- styloconic sensilla see sensillum styloconicum ily sclerotized process extending forward from the stylode n. [Gr. stylos, pillar; eidos, like] (ANN: Polychaeta) A subtorma on each side mediad of the longitudinal row of Online Dictionary of Invertebrate Zoology 867 868 Maggenti and Gardner

inwardly directed, closely set, phobae of the hypopharynx. Located posterior to the cephalic region. subapterous see brachypterous subcerebral glands (ROTIF) Paired glands of the retrocerebral subassociation n. [L. sub, under; ad, to; socius, companion] organ/sac. This term has been used by various authors as a substitute subchela n. [L. sub, under; Gr. chele, claw] (ARTHRO: Crusta- for the term association when not in agreement with the cea) The distal end of a limb developed as a prehensile definition: a group assemblage of organisms, in a specific structure by the folding back of a dactyl against the propo- geographical area with one or two dominant species. dus or widest part of it; may arise from propodus folded subbasal a. [L. sub, under; Gr. basis, base] Just distad of the back against the carpus; gnathopod. base. subchelate a. [L. sub, under; Gr. chele, claw] 1. (ARTHRO) subbiramous a. [L. sub, under; bis, two; ramus, branch] Having an appendage in which the terminal podomere that (ANN: Polychaeta) Parapodia in which the notopods are re- can fold back like a pincer against the subterminal po- duced and neuropods are well developed. domere. 2. (ARTHRO: Crustacea) Provided with subchela. subbranchial a. [L. sub, under; Gr. branchia, gills] Beneath subclass n. [L. sub, under; classis, division] In classification, a the gills. major subdivision of a class, comprised of related orders. subbranchial region (ARTHRO: Crustacea) In Brachyura, the subclimax n. [L. sub, under; Gr. klimax, ladder] 1. The stage ventral part of the carapace beneath the gill area. preceding the climax in a complete sere. 2. A geographi- cally smaller area than that of a 'climax'. subcapitular a. [L. sub, under; capitalis, relating to the head] (ARTHRO: Chelicerata) In Acari, pertaining to the ventral subclypeal pump see cibarial pump surface of the infracapitulum. subclypeal tube see pseudotrachea subcapitular apodeme (ARTHRO: Chelicerata) In Acari, a subcolony n. [L. sub, under; colonia, farm] (BRYO: Stenolae- sclerotized continuation of the mentum internally, to which mata) A functional grouping within a colony, in which the several tendons are attached. skeletons may or may not be of the same structure. subcapitular gutter (ARTHRO: Chelicerata) In anactinotrichid subcosta n. [L. sub, under; costa, rib] (ARTHRO: Insecta) A Acari, the median taenidium on the ventral surface of the longitudinal vein between the costa and the radius. infracapitulum; the deutosternum. subcoxa n. [L. sub, under; coxa, hip] 1. (ARTHRO) A secondary subcarina n. [L. sub, under; carina, keel] (ARTHRO: Crustacea) proximal subdivision of the coxopodite. 2. (ARTHRO: Crusta- In Lepadomorpha, a small, unpaired plate below the carina. cea) see precoxa. subcarinate a. [L. sub, under; carina, keel] Shaped like a subcoxal pleurites 1. (ARTHRO: Insecta) Sclerites that are shallow keel. separated primitively or fused, that form the pleural sup- subcastes n.pl. [L. sub, under; castus, pure] (ARTHRO: In- port for the coxa. 2. (ARTHRO: Chilopoda) Small, variously secta) In Hymenoptera, the various forms of mature Formi- shaped sclerites associated with the bases of the coxa. cidae of a caste. see major worker, media worker, mi- subcutical n. [L. sub, under; cutis, skin] (ARTHRO: Insecta) nor worker. Newly secreted basal cuticle whose granular ultrastructure subcellular a. [L. sub, under; cellula, small cell] Applies to or- shows microfibrils that have not undergone orientation. ganelles in a cell. subdentate a. [L. sub, under; dens, tooth] Small teeth or subcephalic a. [L. sub, under; Gr. kephale, head] (NEMATA) notches. Online Dictionary of Invertebrate Zoology 869 870 Maggenti and Gardner subdiscal/subdiscoidal vein (ARTHRO: Insecta) The wing subgenital plate (ARTHRO: Insecta) A platelike sternite that vein forming the posterior margin of the third discoidal cell. underlies the genitalia, usually in the 9th abdominal ster- subdorsal a. [L. sub, under; dorsum, back] Pertaining to the num in males, and 7th or 8th in females; in some ichneu- sector between the dorsal and lateral surface. subdorsal monid Hymenoptera, the 7th sternite in males, the 6th in n. females; vulvar lamina. subdorsal keel/plate see dorsal plates subgenual organ (ARTHRO: Insecta) A cordotonal organ situ- ated in the proximal part of the tibia; when a two-part or- subdorsal line (ARTHRO: Insecta) In caterpillars, a subdorsal gan, the one more proximal is known as the "true sub- longitudinal line between dorsal and lateral; if addorsal line genual organ." present, between it and the lateral line. subgenus n.; pl. subgenera [L. sub, under; genus, tribe] The subdorsal ridge (ARTHRO: Insecta) In some Hymenoptera cat- name of an optional category between the genus and spe- erpillars, an elevated longitudinal line along the subdorsal cies; capitalized and placed in parentheses following the row of abdominal tubercles. genus name. subesophageal body (ARTHRO: Insecta) A number of large subhepatic carina (ARTHRO: Crustacea) In Decapoda, a nar- binucleate cells in the body cavity closely associated with row ridge extending posteriorly from the branchiostegal the inner end of the stomodeum in Orthoptera, Plecoptera, spine. Isoptera, Mallophaga, Coleoptera and Lepidoptera. subhepatic region (ARTHRO: Crustacea) In Decapoda, that subesophageal ganglion The nerve plexus below the esopha- part on the ventral surface of the carapace below the he- gus. patic region, bounded by the pterygostomial and suborbital subfamily n. [L. sub, under; familia, family] A category of the regions. family group containing related tribes or genera, and end- subimago n. [L. sub, under; imago, image] (ARTHRO: Insecta) ing in -inae. In Ephemeroptera, the first of two winged instars after it subfossorial a. [L. sub, under; fossor, digger] Adapted for emerges from the water surface, or underwater. subi- digging. maginal a. subgalea n. [L. sub, under; galea, helmet] (ARTHRO: Insecta) subjective synonym Two or more synonyms based on differ- An inner sclerite of the maxillary stipes; parastipes; some- ent types, but recognized as referring to the same taxon by times fused with the lacinia or merged into the stipes. taxonomists who hold them to be synonyms. subgenal areas (ARTHRO: Insecta) The narrow lateral marginal subliminal a. [L. sub, under; limen, threshold] A stimulus in- areas of the head setoff by the subgenal sulcus above the sufficient or inadequate to illicit a perceptible response. see mandibles and maxillae. liminal. subgenal ridge (ARTHRO: Insecta) A submarginal structure on sublingual gland see pharyngeal gland, ventral the inner surface of the head arising from the subgenal sul- sublittoral, sublittoral zone 1. A lake bottom too deep for cus. rooted plants to grow. 2. In oceans, a zone from the inter- subgenal sulcus (ARTHRO: Insecta) The lateral suture below tidal zone to the end of the continental shelf. the gena, and above the base of the mandibles and maxil- submalleate a. [L. sub, under; malleus, hammer] (ROTIF) A lae. modified malleate mastax. subgeneric name see subgenus submargin n. [L. sub, under; margo, margin] (MOLL: Bivalvia) Online Dictionary of Invertebrate Zoology 871 872 Maggenti and Gardner

One of the dorsal edges of the shell body which adjoins the submentapleural carina (ARTHRO: Insecta) In certain Hy- lower border of the auricle in Pectinacea. menoptera, the lower margin of the lower division of the submarginal a. [L. sub, under; margo, edge] Placed within the mesopleurum, between the bases of the middle and hind margin. coxae. submarginal area (ARTHRO: Insecta) In the hind wings, a subneural a. [L. sub, under; Gr. neuron, nerve] Under the section between the anterior (costal) margin and the first central nervous system or ventral nerve cord. strong vein. subocular sulcus (ARTHRO: Insecta) In smaller Ichneumoni- submarginal cell (ARTHRO: Insecta) In Hymenoptera, one or dae, a sharp groove extending from the base of the eye to more cells just behind the marginal cell. the mandibular socket. submarginal striae see proplegmatium suboesophageal see subesophageal submarginal tubercles (ARTHRO: Insecta) In Coccidae, round suborbital region (ARTHRO: Crustacea) In Brachyura, a nar- tuberacles, when present, variable in number, surrounding row region bordering the lower margin or orbit. a central invaginated tube, occurring in the dorsal submar- suborbital spine (ARTHRO: Crustacea) In a decapod carapace, ginal area of the body. a spine slightly below and posterior to the middle of the or- submarginal vein (ARTHRO: Insecta) In Chalcidoidea, a vein bit. just behind and paralleling the costal margin of the wing. subphylum n. [L. sub, under; Gr. phyle, tribe, race] A major submedia see second axillary subdivision in classification between phylum and class. submedian cell (ARTHRO: Insecta) In Hymenoptera, a cell be- subquadrangle n. [L. sub, under; quadri-, four; angulus, an- hind the median cell, in the basal posterior of the wing. gle] (ARTHRO: Insecta) In odonatan Zygoptera, a cell just behind the quadrangle. submedian denticle (ARTHRO: Crustacea) In Stomatopoda, the small projection(s) just laterad of the midline on the subradular organs (MOLL: Polyplacophora) Two eversible terminal margin of the telson (medial to submedian teeth). pads, probably of chemoreceptive function, at the base of the subradular sac. submedian groove (ARTHRO: Crustacea) In Decapoda, a lon- gitudinal groove in the submedian dorsal part of the cara- subradular sac (MOLL: Polyplacophora) A blind sac of the pace, contiguous with the postrostal carina. posterior wall of the buccal cavity containing cushion- shaped sensory structures (subradular organs) hanging submedian lobes (NEMATA: Secernentea) In the superfamily from the roof. Criconematoidea in Tylenchina, the paired, reduced, strongly modified subdorsal and subventral lips. subrostrum n. [L. sub, under; rostrum, beak] (ARTHRO: Crus- tacea) In Lepadomorpha Cirripedia, a single plate below the submedian tooth (ARTHRO: Crustacea) In Stomatopoda, the rostrum. strong spinelike or blunt projection just laterad of the mid- line on the terminal margin of the telson. subscaphium n. [L. sub, under; scaphium, hollow vessel] (AR- THRO: Insecta) In male Lepidoptera, a ventral sclerotization submentum n. [L. sub, under; mentum, chin] (ARTHRO: In- of the genitalia, below the anus; gnathos. secta) 1. The basal sclerite of a labium. 2. In some Col- eoptera, a distinct sclerite defined by a suture intervening subscutellum n. [L. sub, under; dim. scutum, shield] (AR- between the mentum and the gula; in others, has also THRO: Insecta) In some Diptera, especially Tachinidae, the been applied to the undifferentiated anterior margin of the anterior region of the mediotergite differentiated as a con- gula. submental a. vex, transverse ridge or lobe; often called postscutellum. Online Dictionary of Invertebrate Zoology 873 874 Maggenti and Gardner subsocial n. [L. sub, under; socius, companion] (ARTHRO: In- cells in the wing behind the triangle. secta) Applied to adults caring for their young for some pe- subtribe n. [L. sub, under; tribus, tribe] In classification, a riod of time. see presocial. rank below the tribe and above the genus. subsocies n.pl. [L. sub, under; socius, companion] A term subtylostyle n. [L. sub, under; Gr. tylos, knot; style, pillar] used by various authors when there is disagreement as to (PORIF) 1. A monactinal megasclere with a sub-apical ex- the definition of the word associes. pansion. 2. A tylostyle with an indistinct knob at one end subspecies n. [L. sub, under; species, kind] A subdivision of a and pointed at the other. see tylostyle. species inhabiting a geographic subdivision of the range of subulate a. [L. subula, awl] Shaped like an awl; slender and the species and differing taxonomically from other popula- tapering to a point, with sides convex. tions of the species. subumbrella n. [L. sub, under; dim. umbra, shade] (CNID) substitute see supplementary reproductive The concave oral surface of a medusa or jellyfish. see substitute king see supplementary reproductive exumbrella. substitute name A name proposed to replace a preoccupied subventral esophageal glands (NEMATA) Esophageal salivary name that assumes the same type and type-locality. glands lying in the subventral sectors of the posterior substrate n. [L. sub, under; stratum, bed] 1. A substance on esophagus. which an enzyme acts. 2. see substratum. subvibrissal setae/setulae (ARTHRO: Insecta) In Diptera, the substrate race A local race selected by nature to have a simi- setae/setulae along the anteroventral margin of the gena. larity of coloration with that of the substratum. succession see sere substratum n.; pl. substrata [L. sub, under; stratum, bed] succinct a. [L. sub, under; cingere, to gird] Compact; con- The ground or other surface in or upon which organisms tracted; reduced. live, walk, crawl or are attached. succursal nest (ARTHRO: Insecta) In social insects, a resting subsume n. [L. sub, under; sumere, to take] To include under; or hiding place constructed by workers, but not qualifying to put under another as belonging to it, i.e., in zoological as a true nest due to the absence of brood rearing. classification. sucker n. [A.S. sucan, to suck] An organ creating a vacuum, subtegular ridge (ARTHRO: Insecta) A transverse ridge near utilized by various invertebrates for locomotion, ingesting the upper edge of the mesopleurum, below the tegula and or holding food, or adhering to the substrate. base of the front wing. suctorial a. [L. sugere, to suck] Having vacuum organs; subtegulum n. [L. sub, under; tegulum, covering] (ARTHRO: adapted for sucking. Chelicerata) In Arachnida, one of the sclerotized plates that suffused a. [L. suffusus, to pour beneath] To overspread, as protect the hematodocha of the male papal organ of some with fluid or color; to cover the surface. suffusion n. spiders. sugent, sugescent a. [L. sugere, to suck] Suctorial. subtorma n. [L. sub, under; Gr. tormos, socket] (ARTHRO: In- secta) In Coleoptera, the heavily sclerotized, transverse, sulcate a. [L. sulcus, furrow] Having a groove or furrow. curved process of certain Scarabaeoidea larvae, located sulci n.pl. [L. sulcus, furrow] (ARTHRO: Insecta) Grooves of a near the proximal border of the hypopharynx. purely functional origin, such as strengthening ridges of the subtriangle n. [L. sub, under; tri, three; angulus, angle] (AR- head. THRO: Insecta) In Odonata Anisoptera, A cell or group of sulciform a. [L. sulcus, furrow; forma, shape] Being groove- Online Dictionary of Invertebrate Zoology 875 876 Maggenti and Gardner

like or groove-shaped. adults; paragnath. sulculus n. [L. dim. sulcus, furrow] (CNID: Anthozoa) In di- supermale n. [L. super, over; dim. mas, male] (ARTHRO: In- glyphic Actiniaria, having the second, sometimes small, si- secta) Abnormal male with one x-chromosome for 3 sets of phonoglyphs situated at the dorsal end of the pharynx. see autosomes in Drosophila. sulcus. supernumerary crossveins (ARTHRO: Insecta) Crossveins sulcus n.; pl. sulci [L. sulcus, furrow] 1. A furrow, groove or added to the normal number. fissure. 2. (ARTHRO: Insecta) A suture formed by an infold- supernumerary segment (ARTHRO: Insecta) In Cecidomyidae ing of the body wall. see sulci. 3. (BRACHIO) The major de- Diptera, a segment intercalated between the head and the pression of the valve surface, externally concave in trans- prothorax. verse profile and radial from the umbo. 4. (CNID: Anthozoa) A groove leading into the gullet. see siphonoglyph. 5. supero-marginal plates (ECHINOD: Asteroidea) Upper mar- (MOLL: Bivalvia) The radial depression of the shell surface. ginal plates that form the outline of the arm of sea-stars. see infero-marginal plates. sulcus, radial posterior (MOLL: Bivalvia) A groove that sets off the posterior flange from the main shell body. superoptimal stimuli Sensory stimuli reponse stronger than the natural stimuli for which the response had been se- sulcation n. [L. sulcus, furrow] 1. Scored by furrows or lected. grooves. 2. Encircled by channels. superorder n. [L. super, over; ordo, order] In classification, a summer egg A thin-shelled, rapidly developing egg; tachy- group below class and above order. blastic. see winter egg. superorganism n. [L. super, over; Gr. organon, organ] A col- summit n. [L. summum, the highest point] 1. The apex; the ony of social organisms, or organisms and their environ- top. 2. (MOLL: Bivalvia) The highest dorsal point of the shell ment, of interdependent relationships which may be stud- profile when the cardinal plane is horizontal. ied as though they were a single organism. superclass n. [L. super, over; classis, a division] In classifica- superposed a. [L. super, over; ponere, to place] Placed one tion, above the class and below the phylum. upon another; superimposed; placed directly over some superfamily n. [L. super, over; familia, family] In classifica- other part. tion, above the family and below the order. superposition eye (ARTHRO) In nocturnal or crepuscular ar- superfemale see metafemale thropods, an eye that permits the passage of light through superficial epicuticular layer see cerotegument the non-pigmented wall of one ommatidium to the iris of a neighboring one; an adaptation to protect sensitive photo- supergenus n. [L. super, over; genus, race] In classification, receptors from overstimulation during the day; clear-zone above the genus and below the family. eye. see apposition eye. superior appendages (ARTHRO: Insecta) In Odonata, lateral superposition image (ARTHRO) A less distinct but brighter im- movable, paired appendages on the 9th or 10th abdominal age due to the lens system focusing the light to the retina. segment; well developed in the males, reduced or vestigial see mosaic image. in females. supersedure n. [L. super, over; sedere, to sit] (ARTHRO: In- superior hemiseptum see proximal hemiseptum secta) In Hymenoptera, the replacement of an old or sick superlinguae n.pl. [L. super, over; lingua, tongue] (ARTHRO: queen by a new queen in a honeybee colony. Insecta) The two lateral lobes of the hypopharynx of superspecies n. [L. super, over; species, kind] A monophyletic Online Dictionary of Invertebrate Zoology 877 878 Maggenti and Gardner

group of mainly or entirely allopatric species that are mor- ventral umbo away from the apex of the delthyrium. phologically too different to be included in a single species suprabranchial a. [L. supra, above; Gr. branchia, gills] (MOLL) or are reproductive isolates; an artenkreis. Above the gills. supertribe n. [L. super, over; tribus, tribe] In classification, supracerebral glands see pharngeal glands, lateral below the subfamily and above the tribe. supracheliceral limbus (ARTHRO: Chelicerata) In Acari, an supplement n. [L. supplere, to fill up] 1. (ARTHRO: Insecta) In extension of part of the tegulum above the chelicera of Odonata, an adventitious vein formed by a number of Gamasida. crossveins lining up to form a continuous vein behind and more or less parallel to one of the main longitudinal veins. supraclypeal area see postclypeus 2. (NEMATA) Variously sized, often paired, papilliform sen- supraesophageal ganglion (ARTHRO) The brain; the nerve sory nerve terminations in the male ventral caudal area; mass above the esophagus. genital papillae. supraneural pore see coelomopores supplementary organs (NEMATA) Secondary sexual charac- supraneuston n. [L. supra, above; Gr. neustos, able to swim] teristics along the body of male nematodes either sensory Small animals living on the surface film of water. or glandular. see supplement. supraorbital carina see gastroorbital carina supplementary reproductive (ARTHRO: Insecta) In Isoptera, a queen or male, in the form of adultoid, nymphoid or er- supraspecific a. [L. supra, above; species, kind] Applied to a gatoid, that take over as a functional reproductive after the category or evolutionary phenomenon above the species removal of the primary reproductive of the same sex. level. supporting walls (BRYO) Zooidial walls that support orificial suprasquamal ridge (ARTHRO: Insecta) In Diptera, a ridge walls. between the base of the lower calypter to the anterolateral angle of the scutellum. supra adv. [L. supra, above] In scientific terms, a prefix, de- noting above or higher; on the dorsal side; opposite to in- supratidal a. [L. supra, above; A.S. tid, time] Pertaining to the fra. ocean; above the high tide mark; a subdivision of the neritic zone. supra-alar bristles (ARTHRO: Insecta) In Diptera, a longitudi- nal row of bristles on the lateral portion of the mesonotum, supratympanal organ see subgenual organ above the root of the wing. suranal a. [L. supra, above; anus] Above the anus; supra- supra-anal see superior appendages anal. supra-anal hook see uncus suranal plate (ARTHRO: Insecta) A heavily sclerotized area on the dorsum of the last abdominal segment; a plate or lobe supra-anal opening (MOLL: Bivalvia) The opening of the ex- dorsad of the anus; epiproct; anal plate. see ectoproct. current canal. surface ornamentation (MOLL: Bivalvia) A regular relief pat- supra-anal pad (ARTHRO: Insecta) The reduced epiproct, be- tern on the surface of many shells. low the posterior of the tenth tergum. surface pheromone A pheromone active only on or very close supra-anal plate (ARTHRO: Crustacea) In Notostraca, usually to the body; contact or near contact must be made. tongue-shaped, but may be spatulate to rounded, plate situated posteriorly on the dorsal side of the telson. surface tension Surface film on liquids caused by cohesion of the molecules of the liquid at the free surface. supra-apical foramen (BRACHIO) A pedicle foramen in the Online Dictionary of Invertebrate Zoology 879 880 Maggenti and Gardner surpedal area or lobe (ARTHRO: Insecta) In Hymenoptera, a sutural plate (MOLL: Polyplacophora) Lamina of the articula- lobe or area just above the prolegs and below and behind mentum across the jugal sinus of the intermediate and tail the spiracle on the abdomen of Symphyta larvae; su- valve, extending between the sutural laminae. prapedal area; postepipleurite. sutural shelf (MOLL: Gastropoda) A horizontally flattened band surstyli n.pl.; sing. -lus [L. supra, over; Gr. stylos, pillar] (AR- that may contact the adapical suture of the whorls. THRO: Insecta) In Diptera, paired appendages of the ninth sutural sinus see jugal sinus abdominal tergite (epandrium); suprastyli. sutural slope (MOLL: Gastropoda) An angle between the su- suspensor n. [L. sub, under; pendere, hang] 1. (ARTHRO: In- ture and plane perpendicular to the axis; sometimes secta) In Hymenoptera, a structure composed of carton or equated to the sutural angle. wax attaching the comb nests of bees and wasps. 2. (NEMATA: Adenophorea) Muscles associated with the spi- suture n. [L. sutura, seam] 1. Line of junction of 2 parts gen- cules, enclosing the distal part of the spicules of erally immovably connected. 2. (ARTHRO: Crustacea) In Paratrichodorus and other males in Diphtherophorina. Cirripedia, a line or seam at the juncture of two compart- mental plates; weakly calcified areas of the integument for suspensorium n.; pl. -ria [L. sub, under; pendere, to hang] 1. separation at ecdysis. 3. (ARTHRO: Insecta) Grooves mark- Anything that suspends a part. 2. (ARTHRO: Insecta) a. In ing the line of fusion of two former plates; a narrow mem- Blattoidea, a pair of linear sclerites extending toward the branous area between sclerites; line of juncture of elytra in lateral mouth angle on each side of the proximal half of the Coleoptera. 4. (MOLL: Gastropoda) The continuous spiral hypopharynx. b. In Coleoptera, extends from the adoral line on the shell surface where whorls adjoin. sutural a. face upwards to end in the lateral walls of the stomodeum; fultura. c. Suspensory ligaments that insert into the body swarming n. [A.S. swearm, swarm] (ARTHRO: Insecta) In so- wall or dorsal diaphragm suspending developing ovaries in cial insects: a. The departure of a queen and workers from the hemocoel. the parental nest to establish a new colony of highly euso- cial bees. b. In ants and termites, often applied to the suspensory fold of the Schwann cell see mesaxon mass departure of reproductive forms from the nests at the suspensory muscles see dilator beginning of the nuptial flight. sustentacular cells Supporting cells of organs as differenti- swimmeret n. [A.S. swimman, to swim] (ARTHRO: Crustacea) ated from the cells that provide the function of the organ. An abdominal appendage functioning as a swimming organ; sustentor/sustentator n. [L. sustinere, to sustain] (ARTHRO: pleopod. Insecta) One of two hooks on the posterior part of a but- swimming bell (CNID) Any bell or umbrella-shaped cnidarian terfly pupa; cremaster. that moves through the water by contractions, especially sutural angle see sutural slope Siphonophora; nectocalyx; nectophore. sutural edge (ARTHRO: Crustacea) In Cirripedia, the margin of swimming plate (CTENO) A short ridge bearing large fused the compartmental plate along the suture. cilia, arranged in eight meridional rows that function in lo- comotion. sutural laminae (MOLL: Polyplacophora) Apophyses plates; anterior plate-like projections of the articulamentum ex- switch gene The gene influencing the epigenotype to switch to tending from either side of an intermediate or tail valve; a different developmental pathway. may be separated by a sinus or partially joined by a lami- sycon n. [Gr. sykon, fig] (PORIF) A sponge in which the choa- nar extension of the articulamentum. nocyte layer shows folding accompanied by superficial thickening of the mesohyl. Online Dictionary of Invertebrate Zoology 881 882 Maggenti and Gardner sylleibid n. [Gr. syllektos, gathered together] (PORIF) An aq- sympatric a. uiferous system transitional between syconoid and leucon- symphile n. [Gr. syn, together; philein, to love] (ARTHRO: In- oid conditions, with elongate choanocyte chambers grouped secta) A symbiont that is accepted by a host colony as a around a common exhalant channel. member of their group and is licked, fed, protected, trans- sylvan, silvan a. [L. sylva, silva, forest] Pertaining to or in- ported or even reared with the host's own larvae; a true habiting the forests or woodland areas. guest. sylvatic, silvatic a. [L. sylva, silva, forest] In disease ecology, symphily n. [Gr. syn, together; philein, to love] (ARTHRO: In- a parasite existing normally in the wild and not in the hu- secta) In Hymenoptera, the relationship of ants and their man environment. see synanthropism. nest guests, that abide with them, with mutual benefit or symbiology n. [Gr. symbiosis, life together; logos, discourse] fondness; commensalism. symphilic, symphilous a. The study of symbioses. symphynote a. [Gr. symphysis, junction, seam; notos, back] symbion(t) n. [Gr. symbiosis, life together; on, being] Any (MOLL: Bivalvia) Having the valves firmly fixed or soldered organism that exists in a relationship of mutual benefit with at the hinge. another organism; a symbiote. symphysis n. [Gr. symphysis, junction, seam] A union be- symbiosis n. [Gr. symbiosis, life together] 1. The mutually tween two parts. beneficial living together of individuals of two different spe- symplesiomorphy n. [Gr. syn, together; plesios, near; mor- cies. 2. Interrelationship of different species of organisms, phe, form] Shared primitive homologous character states; ranging from beneficial, to neutral, to dehabilitating. sym- normally used in cladistic taxonomy. see plesiomorphy. biotic a. see mutualism, commensalism, parasitism. sympod, sympodite see protopod symbiote n. [Gr. symbiosis, life together] An organism living in symptomatology n. [Gr. symptoma, anything that has be- symbiosis; symbiont. fallen one; logos, discourse] A branch of medical science symmetry n. [Gr. symmetria, due proportion] The mode of concerned with symptoms of diseases. body organization. symmetical a. see bilateral symme- synanthropism n. [Gr. syn, together; anthropos, man] The try, radial symmetry. propensity of an organism to live in or around human sympathetic system 1. That portion of the autonomic nervous dwellings. system directly connected with the brain and innervating synapomorphy n. [Gr. syn, together; apo, separate; morphe, the fore and middle intestine, heart and certain other parts. form] The sharing of derived characters by several species. 2. (ARTHRO: Insecta) see stomogastric nervous system, see plesiomorphy. ventral sympathetic nervous system. synapse, synaptic junction, neurosynapse The central sympatric hybridization The production of hybrid individuals mechanism of intercommunication of nerve impulses pass- between two sympatric species. ing from neuron to neuron. synaptic a. sympatric speciation Speciation with geographic isolation; synapsis n.; pl. -ses [Gr. synapsis, union] The intimate con- the reproductive isolation occurring between segments of a junction of homologous chromosomes that occurs during single population. the prophase of the meiotic division. sympatry n. [Gr. syn, together; patria, native country] The synaptene n. [Gr. synapsis, union] The zygotene of meiosis. occurrence of two or more populations in the same area; usually referring to areas of overlap in species distributions. synaptic junction see synapse Online Dictionary of Invertebrate Zoology 883 884 Maggenti and Gardner synaptic knobs Swellings on the axon ends where contact is gether. 2. Synapsis. 3. A membrane connecting two sepa- made with dendrites of another nerve cell. rate parts permitting movement between them. synapticulum n.; pl. -la [Gr. synapsis, union] (CNID) One of syndiacony n. [Gr. syn, together; diakonos, servant] (ARTHRO: numerous conical or cylindrical calcareous processes con- Insecta) A form of commensalism between ants and plants necting the septa. synapticular a. with both obtaining benefit. synaptinemal complex Organelle present during pachytene syndrome n. [Gr. syn, together; dramein, to run] Signs and stage of eukaryote meiosis visable in electron micrographs. symptoms characteristic of a particular disease. synaptorhabdic a. [Gr. synapsis, union; rhabdos, rod] (MOLL: synecete see synoekete Bivalvia) Pertaining to ctenidia where filaments are con- synechthran n. [Gr. syn, together; echtos, hate] An insect nected at their interlamellar edges by strands of cellular guest that is persecuted by its host, and manages to stay tissue; organic interfilamentary junctions. see eleutheror- alive by greater speed and agility or the use of defensive habdic. mechanisms; an animal engaged in synechthry. see me- synaptychus n. [Gr. syn, together; apo-, away from; ptychos, tochy. fold] (MOLL: Cephalopoda) Double calcareous plates fused synechthry n. [Gr. syn, together; echtos, hate] The relation- with other paired plates. see anaptychus. ship between a symbiont, generally a scavenger, parasite syncerebrum n. [Gr. syn, together; L. cerebrum, brain] The or predator, that is treated in a hostile manner by the host; supraesophageal glanglia or brain of many invertebrates. metochy. synchronic speciation Speciation that occurs at the same synecology n. [Gr. syn, together, oikos, household; logos, dis- time level. see allochronic speciation. course] The relationship of populations and communities to synchronizer n. [Gr. syn, together; chronos, time] An envi- biotic factors in the environment. see autecology. ronmental factor that influences the phenomena of cir- synectic a. [Gr. syn, together; nektikos, habitual] Pertaining to cadian rhythm to conform to a daily cycle instead of wan- cells that retain their relative position during gastrulation. dering. synergism n. [Gr. synergos, associate] The cooperative action synclerobiosis n. [Gr. syn, together; keros, chance; bios, life] of two entities to effect a greater difference than both to- (ARTHRO: Insecta) In Hymenoptera, a temporary associa- gether, i.e., hormones, parasites, muscles. synergistic a. tion of two species of ants of independent colonies. syngamy n. [Gr. syn, together; gamos, marriage] 1. Union of synconoid grade (PORIF) A grade of construction intermediate male and female gametes following fertilization to form a between the asconoid and the leuconoid, in which each ra- zygote; gametogamy; hylogamy. see pseudogamy. 2. dial canal is subdivided into elongate-flagellate chambers Permanent union of both female and male reproductive grouped around a common excurrent channel. see leucon- units; male element sometimes greatly reduced and para- oid grade, asconoid grade. sitic in the female. syncyte n. [Gr. syn, together; kytos, container] A polyploid or syngenesis n. [Gr. syn, together; genesis, beginning] 1. Re- multinucleate cell. production between two sexually dimorphic parents; sexual syncytium n.; pl. syncytia [Gr. syn, together; kytos, con- reproduction. 2. The theory that the germ of the offspring tainer] A continuous mass of protoplasm with several or is derived from both parents, not from either alone. many nuclei; a multinucleate cell. syncytial a. syngenic see isogenic syndesis n. [L. syndesis, a binding together] 1. Binding to- syngonic a. [Gr. syn, together; gone, seed] The production of Online Dictionary of Invertebrate Zoology 885 886 Maggenti and Gardner

both sperm and eggs by the same gonad; hermaphroditic sponse favorable to both emitter and receiver. see al- reproduction. see digonic, amphigonic. lelochemic. synhaploid n. [Gr. syn, together; haploos, single] A condition synonyms n.pl. [Gr. syn, together; onyma, name] In nomen- derived from the fusion of two or more haploid nuclei. see clature, two or more names for the same taxon. see sen- double haploid. ior, junior, objective, subjective synonym. synony- synhesmia n. [Gr. syn, together; hesmos, swarm] A group of mous a. organisms swarming together in consequence of a repro- synonymy n. [Gr. syn, together; onyma, name] A chronologi- ductive drive. see androsynhesmia, gynosynhesmia. cal list of scientific names applied to a given taxon, includ- synistate a. [Gr. syn, together; histos, tissue] (ARTHRO: In- ing dates of publication and authors of the names. secta) In Neuroptera, referring to the ligula being reduced synopsis n.; pl. -es [Gr. syn, together; opsis, view] In taxon- to the condition of a median and sometimes slightly bilobed omy, a general summary of current knowledge of a group. process, or totally atrophied. synoptic a. [Gr. syn, together; opsis, view] Pertaining to synizesis n. [Gr. syn, together; hizein, to sit] The clumping of structures that upon comparison, are virtually identical. chromosomes in early prophase of the first meiotic divi- synoptical key The arrangement of the more essential char- sion; may be either normal or abnormal. acters in order to identify specific taxa by selecting only synkaryon n. [Gr. syn, together; karyon, nucleus] A zygote those that apply. nucleus formed by fusion of two gametic nuclei. synscleritous a. [Gr. syn, together; skleros, hard] (ARTHRO) synlophe n. [Gr. syn, together; lophos, crest] (NEMATA: Se- The joining of a tergite and a sternite to form a complete cernentea] In numerous Trichostrongylidae, an enlarged ring. see discleritous. longitudinal or oblique cuticular ridge on the body surface syntagma see tagma that serves to hold the nematodes in place on the gut wall. syntelic a. [Gr. syn, together; telos, fulfillment] In mitosis, synoecius, synoecious a. [Gr. synoikos, living in the same centromeres of the two chromatids of each chromosome if house] Producing both male and female gametes. they are oriented to the same spindle pole at the first mei- synoecy n. [Gr. synoikos, living in the same house] 1. Com- otic division. mensalism involving social insects where the guests are in- synthesis n.; pl. -ses [Gr. syn, together; titheni, to place] The differently tolerated by the hosts. 2. An association be- formation of a more complex substance from simpler ones. tween two species where one is benefited without harm to the other. see symphily, synechthry. synthetic a. [Gr. syn, together; titheni, to place] Combining the structural characters of two or more dissimilar groups synoekete n. [Gr. synoikos, living in the same house] A toler- or forms into one group or form. ated guest of a host colony. synthetic lethals Lethal chromosomes derived from normally synoenocytes n. [Gr. syn, together; oenos, wine colored; ky- viable chromosomes by crossing over. tos, container] (ARTHRO: Insecta) In dipteran Chironomi- dae, localization of oenocytes as distinctive organs. synthetic theory The evolutionary theory, with mutation and selection as the basic elements. synomone n. [Gr. syn, together; omone, mimics the ending of hormone] A chemical substance produced or acquired by synthorax n. [Gr. syn, together; thorax, chest] (ARTHRO: In- an organism, that upon contact with an individual of an- secta) The meso- and metathorax fused as a single unit of other species, evokes a behavioral or physiological re- wing-bearing insects; pterothorax. Online Dictionary of Invertebrate Zoology 887 syntrophy n. [Gr. syn, together; trophon, food] (ARTHRO: In- secta) In social insects, the accidental feeding of symphiles T or synoeketes during normal brood care. syntype n. [Gr. syn, together; typos, type] Every specimen in a type-series in which no holotype or lectotype was desig- nated. tabula n.; pl. -ae [L. tabula, table] 1. (CNID: Anthozoa) Hori- syntypic a. [Gr. syn, together; typos, type] Referring to the zontal partitions across the vertical canals of corals. 2. same type. (ECHINOD: Asteroidea) A flat elevated dorsal plate of sea stars. synxenic a. [Gr. syn, together; xenos, guest] The rearing of one or more individuals of a single species along with one tabular a. [L. tabula, table] Arranged in a flat surface. or more known species of organisms. see axenic, dixenic, tachyauxesis n. [Gr. tachys, quick; auxesis, growth] Rapid monoxenic, polyxenic, trixenic, xenic. growth; a part or structure that grows at a quicker rate synzoea n. [Gr. syn, together; zoe, life] (ARTHRO: Crustacea) than the organism as a whole. see bradyauxesis, isauxe- In Malacostraca, pelagic juvenile stages of Stomatopod lar- sis. vae. tachyblastic a. [Gr. tachys, quick; blastos, bud] Referring to syringe see salivary pump thin shelled eggs that begin cleavage immediately after oviposition and develop quickly; summer egg. see opsib- syringium n. [Gr. syrinx, pipe] (ARTHRO: Insecta) 1. The sali- lastic. vary pump in Hemiptera. 2. An organ for ejecting disagree- able fluids in some insect larvae. tachygen n. [Gr. tachys, quick; gennaein, to produce] An evolutionary structure of abrupt origination. systematics n.pl. [Gr. syn, together; histani, to place] Taxon- omy. tachygenesis n. [Gr. tachys, quick; genesis, beginning] The shortening or acceleration of embryonic development by systematist n. [Gr. syn, together; histani, to place] A student omitting one or more developmental stages. see brady- of taxonomy. genesis. systole n. [Gr. systole, contraction] The contraction of any tachytelic a. [Gr. tachys, quick; telos, completion] Evolution at contractile cavity, i.e., the heart. systolic a. see diastole. a faster rate than usual. see horotelic. syzygy n.; pl. syzygies [Gr. syzygos, united] 1. The combin- -tactic a. [Gr. taktikos, comb. form] Used in adjectives formed ing of organs without loss of identity. 2. (ECHINOD: Cri- from nouns ending in -taxis. noidea) Having each nodal columnal closely and rigidly jointed to the internodal columnal below it by short elastic tactile a. [L. tactus, touch] Pertaining to the organs of the fibers, and as such lacking flexibility. sense of touch. tactile combs (CNID: Hydrozoa) Patches of long stiff hairs on the bell margin of hydromedusae. tactile sensillum see sensillum trichodeum tactoreceptors n.pl. [L. tactus, touch; receptor, receiver] Hairs, bristles, or other epidermal structures that function in touch where the organism comes in contact with the substratum, vibration of the substratum or high intensity Online Dictionary of Invertebrate Zoology 889 890 Maggenti and Gardner

airborne sounds. tandem a. [L. tandem, at length] One behind the other; two taenia n. [Gr. taenia, band or ribbon] A band, such as of nerve connected or attached together. or muscle. tangent a. [L. tangere, to touch] Touching; coming together at taeniate a. [Gr. taenia, band or ribbon] Having a broad longi- a single point. tudinal marking. tangoreceptor n. [L. tangere, to touch; receptor, receiver] A taenidium n.; pl. -nidia [L. dim. taenia, band or ribbon] 1. simple tactile sense organ, consisting of one sense cell. (ARTHRO: Chelicerata) In Acari, a ribbon-like canal on the tanylobous a. [Gr. tanaos, stretched; lobos, lobe] (ANN: Oli- surface of the tegument. 2. (ARTHRO: Insecta) A circular or gochaeta) Pertaining to the tongue of the prostomium ex- spiral chitinous thickening, strengthening the inner wall of tending through segment i to the groove between seg- the trachea. ments i and ii, dividing the peristomium dorsally. see taenioglossate radula (MOLL: Gastropoda) A radula with nu- epilobous, prolobous, zygolobous. merous transverse rows of lingual teeth, usually seven to a tapetum n. [L. tapete, carpet] 1. A reflecting surface within an row; median tooth frequently has cusps, the largest in the eye. 2. (ARTHRO: Insecta) A light reflecting surface within middle, broad cuspidate admedians and narrow, hooklike clear-zone eyes, formed by tracheae that run through the marginals. eye parallel with the ommatidia forming a layer around tagma n.; pl. tagmata [Gr. tagma, an arrangement] 1. A each one, and reflecting the light back into the ommatidia. major division of body regions of a metamerically seg- tapetal a. mented animal, particularly arthropods. see pseudo- tapinoma-odor (ARTHRO: Insecta) In Hymenoptera, a rancid tagma. 2. (ARTHRO: Chelicerata) The prosoma and opist- butter smell secreted from the anal glands of some ants of hosoma. 3. (ARTHRO: Insecta) The head, thorax, pedicel the Dolichoderinae. and gaster of Formicidae. Tardigrada, tardigrades n.; n.pl. [L. tardus, slow; gradus, tagmosis n. [Gr. tagma, an arrangement] The division of a step] A phylum of small, multicellular coelomates, com- body into groups of segments, forming distinct trunk sec- monly called water bears, or bear animaecules due to a tions or tagmata. lumbering, bearlike gait. tail n. [A.S. taegel, tail] 1. (ARTHRO: Insecta) The cauda; in tarsal a. [Gr. tarsos, sole of foot] Pertaining to the foot or tar- some Lepidoptera and Neuroptera, the elongated processes sus. on the hind wings. 2. (NEMATA) That portion of the body in tarsal claw (ARTHRO) A claw at the apex of the tarsus; unguis. vermiform adults posterior to the anus. tarsal comb see pedal stridulating organ tailfan see caudal fan tarsal formula (ARTHRO: Insecta) Referring to the number of tail valve (MOLL: Polyplacophora) The posterior valve. tarsal segments on the front, middle, and hind tarsi. Takakura's duct (NEMER:Enopla) In , a tarsal pulvillus see euplantula common efferent canal in the male reproductive system that links the testes and discharges into the intestine near tarsation n. [Gr. tarsos, sole of foot] (ARTHRO: Insecta) Com- the anus. munication by touching with the tarsi. talon n. [L. talus, heel] Shaped like a claw; unguiculate. tarsomere, tarsite [Gr. tarsos, sole of foot] (ARTHRO) A sub- division or segment of the tarsus. talus n. [L. talus, heel] (ARTHRO: Insecta) The juncture of the tibia and tarsus. tarsungulus n. [Gr. tarsos, sole of foot; L. dim. unguis, claw] Online Dictionary of Invertebrate Zoology 891 892 Maggenti and Gardner

(ARTHRO: Insecta) The fused tarsal segment and claw of tectum n. [L. tectum, roof] 1. (ARTHRO: Chelicerata) In Acari, many coleopteran larvae. the blade-shaped prolongation of the exoskeleton to pro- tarsus n. [Gr. tarsos, sole of foot] 1. The foot. 2. (ARTHRO) The tect an organ or joint; epistome; cervix. 2. (ARTHRO: most distal part of the leg, immediately beyond the tibia, Crustacea) The central portion of the carina of barnacles. usually subdivided into two to five segments, bearing the teeth n. [A.S. toth, tooth] 1. Hardened growths on mandibles, claws and pulvilli. maxillae or stomatal walls. 2. (CNID: Hydrozoa) Deep or taste bud (ARTHRO: Insecta) In Lepidoptera, specialized taste very shallow indentations on the hydrothecal margins; peg- cells located on the tarsi. like chitinous growths just inside the margins. 3. (MOLL: Polyplacophora) Portions of the articulamentum between tautonym n. [Gr. tautos, the same; onyma, name] In the bi- the slits; may be pectinated or propped (outside edges nomial system, the same name given to a genus and one thickened), sharp and smooth. of its species or subspecies. teges see seta taxis n.; pl. taxes [Gr. taxis, arrangement] Movement of a motile animal in response to a source of stimulation. a. tegillum n.; pl. -a [L. teges, mat] (ARTHRO: Insecta) In Scara- Positive taxis : toward the stimulus. b. Negative taxis : baeoidea larvae, a paired patch of hooked or straight setae Away from the stimulus. on each side of the venter of the tenth abdominal segment beside paired palidia; part of the raster. taxodont a. [Gr. taxis, arrangement; odon, tooth] (MOLL: Bi- valvia) With many short interlocking teeth, some or all tegmen n.; pl. -mina [L. tegmen, cover] 1. A tegument or transverse to the hinge margin; similar to prionodont. covering. 2. (ARTHRO: Insecta) a. In Coleoptera, a single or divided sclerite proximad of the penis (phallobase); may be taxometrics see numerical taxonomy divided into basal piece and parameres. see tegumen. b. taxon n.; pl. taxa [Gr. taxis, arrangement] Any taxonomic In some Orthoptera, Dictyoptera and Homoptera, the hard- group sufficiently distinct to merit being distinguished by ened leathery fore wing. 3. (ECHINOD: Crinoidea) An oral name, i.e., phylum, class, order, etc. wall covering the calyx cup. taxon cycle A cycle of expansion and contraction of the geo- tegmentum n. [L. tegere, to cover] (MOLL: Polyplacophora) graphic range and population density of a species or higher The outer, sometimes softer and porous calcareous layer of taxonomic category. the valve below the . taxonomic a. [Gr. taxis, arrangement; nomos, law] Pertaining tegula n.; pl. -lae [L. tegula, roofing tile] (ARTHRO: Insecta) 1. to the classification of organisms. A small convex, scalelike lobe overlying the base of the fore taxonomist n. [Gr. taxis, arrangement; nomos, law] One who wing; paraptera. 2. In Diptera, small anterior sclerites lo- studies the theory and practice of classifying organisms. cated in an incision of the lateral region of the notum. 3. In Lepidoptera, well developed, and carried on a special taxonomy n. [Gr. taxis, arrangement; nomos, law] The study tegular plate of the notum, supported by a tegular arm of the theory, procedure, and rules of classification of or- arising from the base of the pleural wing process. ganisms, based on similarities and differences. see classi- cal taxonomy, cytotaxonomy, numerical taxonomy, tegular arms (ARTHRO: Insecta) Internal structures supporting experimental taxonomy, classification, systematics. the tegular plate. tectiform a. [L. tectum, roof; forma, shape] Roof-like; sloping. tegular plate (ARTHRO: Insecta) In Lepidoptera, a notal structure bearing the tegulae of the fore wings. tectostracum see cerotegument tegulum n. [L. tegulum, roof] (ARTHRO: Chelicerata) In Acari, Online Dictionary of Invertebrate Zoology 893 894 Maggenti and Gardner

the dorsal region of the cheliceral frame extending from the ing large mandibles. see amphiodont; priodont. 2. cheliceral base to the rostrum. (MOLL: Bivalvia) Hinge with cardinal and lateral teeth, but tegumen n. [L. tegumen, cover] (ARTHRO: Insecta) 1. Tegmen. with additional elements, as Venus. 2. (ARTHRO: Insecta) In male Lepidoptera, a dorsal roof or teleology n. [Gr. teleios, complete; logos, discourse] A theory hoodlike structure of the genitalia. in biology that evolution or nature is guided by a purpose. tegument n. [L. tegumentum, covering] 1. Any natural outer teleotrocha see covering. 2. (ACANTHO) The non-cellular body wall or cuti- telepod see telopod cle. tegumentary a. telescope v.i. [Gr. tele, far; skopos, watcher] To have the tegumentary glands (ARTHRO: Chelicerata) In Acari, special- ability to evert and invert a body part. telescopic a. ized secretory glands, located in or immediately beneath the hypodermis. telioderma n. [Gr. teleios, complete; derma, skin] (ARTHRO: Chelicerata) In Acari, the cuticle of the previous stage tela n.; pl. -ae [L. tela, web] (BRACHIO) One of a pair of points nymph (apoderma) covering the tritonymph. at the end of the beak ridges that project into and beyond the pedicle opening. teliophan see tritonymph telaform larva (ARTHRO: Insecta) In certain heteromorphic telmophage n. [Gr. telma, pool; phagein, to eat] (ARTHRO) A Hymenoptera first instar larva, a sharp, tail-like caudal blood feeding arthropod that severs skin and blood vessels, horn curved anteriorly, body constricted between a large causing a small blood hemorrhage so as to feed. anterior part (cephalothorax) and an elongated posterior telocentric a. [Gr. telos, end; kentron, center of circle] Chro- part. mosomes in which the centromere is terminal. see acro- telamon n. [Gr. telamon, strap] 1. A supporting band. 2. centric. (NEMATA: Secernentea) A thickening of the anterior cloacal telodendria n. [Gr. telos, end; dendros, tree] The branching wall in the order Strongylida, that acts as an accessory terminals of an axon. guiding structure for the spicules; sometimes erroneously telofemur n. [Gr. telos, end; L. femur, thigh] (ARTHRO: Cheli- applied in plant parasites to the gubernacular capitulum. cerata) In Acari, a distal segment of the femur separated telegonic see panoistic ovariole from the basifemur by the basifemoral ring. teleiochrysalis n. [Gr. teleios, perfect; chrysallis, golden telogonic see panoistic ovariole thing] (ARTHRO: Chelicerata) In Acari, the third stage telolecithal egg An egg cell with abundant yolk concentrated nymph enclosed in the integument of the preceeding nym- toward the lower side of the cell. see centrolecithal egg. phal stage. telomitic see telocentric telenchium n. [Gr. telos, end; enchos, spear] (NEMATA: Se- cernentea) Sometimes used to denote the shaft of the telophase n. [Gr. telos, end; phasis, aspect] The final stages stylet in plant parasites in the order Tylenchida. see of mitosis during which the chromatids (daughter chromo- metenchium. somes) are formed and the cytoplasm divides. teleoconch n. [Gr. teleios, complete, konche, shell] (MOLL: telophragma see Z-band or disc Gastropoda) The entire shell, excluding the . telopod n. [Gr. telos, end; pous, foot] 1. (ARTHRO: Crustacea) teleodont a. [Gr. teleios, complete; odon, tooth] 1. (ARTHRO: Part of an appendage distal to the coxa. 2. (ARTHRO: Diplo- Insecta) In Coleoptera Lucanidae, referring to males bear- poda) In males, a modified leg, serving a copulatory func- tion, on one of the posterior segments. Online Dictionary of Invertebrate Zoology 895 896 Maggenti and Gardner telopodite n. [Gr. telos, end; pous, foot] (ARTHRO: Insecta) serves as a template for nucleic acids or proteins. The primary shaft of a limb distal to the coxopodite; the temporal isolation Non-interbreeding between species as a basipodite. result of time differences, i.e., diurnal versus nocturnal. telorhabdions n.pl. [Gr. telos, end; rhabdos, rod] (NEMATA) temporal organs see organs of Tomosvary The posterior wall plates of the telostome. see rhabdion. temporary haplometrosis (ARTHRO: Insecta) In early colony telostome, telostom n. [Gr. telos, end; stoma, mouth] development of social insects, a single female (queen) ini- (NEMATA: Secernentea) The posterior part of a stoma. see tiates development and is either joined by its offspring or protostome. females from other colonies, producing a pleometrotic soci- telosynapsis, telosyndesis see acrosyndesis ety. see functional haplometrosis, permanent telotarsus n. [Gr. telos, end; tarsos, sole of foot] (ARTHRO) In haplometrosis. Chelicerata and Chilopoda, the distal of the two principal temporary parasite A parasite that comes in contact with its tarsomeres of the tarsus. host to feed and then departs; intermittent parasite; mi- telotaxis n. [Gr. telos, end; taxis, arrangement] Movement cropredator. directed towards a goal, with a minimum of deviation in the temporary pleometrosis (ARTHRO: Insecta) In social insects, path taken. see kinotaxis, tropotaxis. a colony in which two or more females share a nest that telotroch n. [Gr. telos, end; trochos, wheel] 1. (ANN: Poly- was founded by a single female; non-founding females do chaeta) The preanal girdle of cilia near the posterior end. 2. not cooperate in nest development, and later disperse and (PHORON) A ciliary ring on the posterior of the trunk, found individual colonies. see permanent pleometrosis. probably a locomotor organ. temporary social parasitism (ARTHRO: Insecta) In Hymen- teletrocha see trochophore optera, a parasitic queen entering an alien nest replacing the alien queen by killing or sterilizing it and eventually teletrophic ovariole (ARTHRO: Insecta) An ovariole in which dominating the nest. all the trophocytes are terminal in the germarium, and connect to the egg by a slender trophic chord; acroptrophic tenacipeds n.pl. [L. tenere, to hold; pes, foot] (ARTHRO: Chilo- ovariole; telotrophic egg tube. see polytrophic ovariole. poda) In Lithobiida, ambulatory legs of segments 14 and 15, elongated and apparently used for mating and capture telson n. [Gr. telson, end] 1. (ARTHRO) The terminal portion of of prey. an arthropod body (not considered a true somite), usually containing the anus; the periproct. 2. (ARTHRO: Chelicer- tenaculum see retinaculum ata) In scorpions, the distal stinging caudal spine. 3. (AR- tenent a. [L. tenere, to hold] Adapted for clinging, i.e., hairs. THRO: Crustacea) The posterior projection, sometimes with teneral a. [L. tener, soft] (ARTHRO) A term applied to any caudal furca; the last body unit/segment in which the anus newly emerged soft-bodied individual; callow worker. is not terminal; postsegmental region; style. 4. (ARTHRO: Diplopoda) The preanal ring. 5. (ARTHRO: Insecta) a. The tensor a. [L. tendere, to stretch] A muscle that stretches a 12th abdominal segment of primitive insects and some in- part of a body or renders it of use. sect embryos. b. In scale insects, the lateral cuticular ex- tentacle n. [L. tentaculum, feeler] Any elongate flexible ap- tension of the 8th segment. telosonic a. pendage usually near the mouth. tentacular a. template n. [F. dim. temple, used in weaving] 1. A pattern tentacle crown (BRYO) Tentacles expanded into an external from which objects are copied. 2. In genetics, a strand of position as for feeding. DNA acting as template for a strand of RNA, which in turn Online Dictionary of Invertebrate Zoology 897 898 Maggenti and Gardner tentacle sheath (BRYO) That part of the body wall that sup- tentorial pits (ARTHRO: Insecta) External depressions on the ports and encloses the tentacles when everted and re- surface of the head marking points of union of the arms tracted. with the outer wall of the head; usually two in the epis- tentacular atrium (BRYO) A cavity inside the tentacle sheath, tomal suture and one at the lower end of each postoccipital with tentacles retracted. suture. tentacular bulb (CNID) Swelling at the base of a medusoid tentorium n.; pl. -oria [L. tentorium, tent] (ARTHRO: Insecta) tentacle that serves primarily in digestion and manufacture Two anterior and two posterior apodemes (arms) that form of nematocysts and sometimes bears an ocellus or other the internal skeleton of the head, serving as a brace for the sensory structure; ocellar bulb. head and for the attachment of muscles; in Culicidae, the right and left halves are not connected. tentacular (ANN: Polychaeta) Sensory projection(s) of the peristomium or cephalized segment. tenuous a. [L. tenuis, thin] Thin, slender, delicate. tentacular club (MOLL: Cephalopoda) A terminal suckered pad, teratocyte n. [Gr. teras, monster; kytos, container] (ARTHRO: comprised of carpus, and dactylus. Insecta) In Lepidoptera Pieridae, unicellular forms resulting from the embryonic membranes of parasitic Braconidae. tentacular crown see branchial crown teratogen n. [Gr. teras, monster; genes, producing] Any sub- tentacular fold (MOLL: Bivalvia) The central fold of the oyster stance that causes or increases the incidence of congenital mantle edge that bears the tentacles in two rows. abnormalities in a population. tentacular palp (ANN: Polychaeta) A grooved, food-gathering teratogenesis n. [Gr. teras, monster; genesis, beginning] The appendage in many sedentary species. production of monstrous fetuses or growths. tentaculocyst see rhopalium teratogyne n. [Gr. teras, monster; gyne, woman] (ARTHRO: tentaculozooid n. [L. tentaculum, feeler; Gr. zoon, animal; Insecta) In Hymenoptera, the aberrant form of female in a eidos, form] (CNID: Hydrozoa) A modified polyp in the form Formicidae colony, characterized by overdeveloped legs of a single tentacle, usually found at the outermost part of and antennae, and excess pilosity of the body or defective the colony; a protective zooid. see tentaculozooid, gas- wings; formerly referred to as beta-females. see alpha- trozooid. female. tentilla n. [L. tentaculum, feeler] (CNID: Hydrozoa) In Si- teratology n. [Gr. teras, monster; logos, discourse] The bio- phonophora, lateral contractile tentacular branches. logical study of structural malformations and monstrosities. tentorial bar (ARTHRO: Insecta) The right or left half of the terebella see terebra tentorium, consisting mainly of the united anterior and terebra n.; pl. -bras, -brae [L. terebra, borer] 1. A borer or posterior arms. piercer. 2. (ARTHRO: Insecta) a. In Hymenoptera, the tentorial bridge (ARTHRO: Insecta) The apices of the two stylets and stylet-sheath. b. In Odonata and Hymenoptera, posterior arms fused medially; incomplete or absent in the gonapophyses of segments 8 and 9. 3. (MOLL) a. In Bi- most Diptera. valvia, the anterior margin of the valve. b. In carnivorous tentorial fovea see tentorial pits Gastropoda, the radula. terebrant, terebrate a. tentorial macula (ARTHRO: Insecta) The depressions or dark teres n. [L. teres, rounded] Nearly cylindrical. terete a. spots marking the points of union of the dorsal tentorial terga pl. tergum arms and the epicranal wall near the antennae. tergal a. [L. tergum, back] Situated on the back. Online Dictionary of Invertebrate Zoology 899 900 Maggenti and Gardner tergal fissure (ARTHRO: Insecta) In Symphyta and primitive terminal filament (ARTHRO: Insecta) A cellular end thread of forms of many orders, a membranous line from one lateral the female ovariole that forms a common thread uniting margin to the other, behind the anterior notal wing proc- with that from the ovary of the opposite side. esses. terminal diaphragm (BRYO: Stenolaemata) A membranous or tergal fold see epimere calcified diaphragm that separates the body cavity from the tergal margin (ARTHRO: Crustacea) In Thoracica Cirripedia, environment. the edge of the scutum adjacent to the tergum, or edge of terminalia n.pl. [L. terminus, boundary, end] Collectively, any any plate abutting the tergum. terminal part or structure. tergal suture (ARTHRO: Insecta) In many larvae, a Y-shaped termitarium n.; pl. -ia [L. termes, woodworm] (ARTHRO: In- dorsal suture of the head. secta) An elaborate nest wherein a colony of termites live. tergal valves see cercus termitophile n. [L. termes, woodworm; philos, loving] A sym- tergite n. [L. tergum, back] (ARTHRO) A dorsal sclerite of a biont of termites. segment. terranes n.pl. [L. terra, earth] Fragments of former continents tergolateral margin (ARTHRO: Insecta) In Cirripedia, in those that make up the present day continents. possessing upper laterals, the angular edge of the scutum. terrestrial a. [L. terrestris, of the earth] Belong to or living on tergopleural a. [L. tergum, back; pleuron, side] Referring to the ground or earth; opposed to aquatic and arboreal. the upper and lateral portion of a segment. terricolous a. [L. terra, earth; colare, to inhabit] Soil inhabit- tergopore n. [L. tergum, back; porus, pore] (BRYO: Stenolae- ing. mata) In Tubuliporina, a type of kenozooecium on the back territory n. [L. territorium, domain] An area defended by an side of a colony, having a polygonal aperture. animal against other members of its own or other species. tergum n.; pl. terga [L. tergum, back] (ARTHRO) The dorsal tertiary a. [L. tertius, third] Third in degree of standing in clas- surface of any body segment. sification. termen n. [L. terminus, boundary] (ARTHRO: Insecta) The tertiary parasite A parasite of a hyperparasite. outer, or distal margin of the wing. tertiary reproductive (ARTHRO: Insecta) In Isoptera, an er- terminal a. [L. terminus, boundary, end] At the end; forming gatoid reproductive; a third-form reproductive. the end of a series or part; at the extreme end. tertibrach n. [L. tertius, third; brachium, upper arm] (ECHI- terminal anecdysis When maximum size is reached, no more NOD: Crinoidea) Any ray plate of the third branchitaxis; ecdyses occur. see anecdysis. palmars. tertibrachial a. see postpalmars. terminal arborizations Branching fibrils ending the axon and tessellate a. [L. tessellatus, mosaic] Marked or colored in the collateral ends. see telodendria. pattern of squares, or oblong areas; checkerboard-like. terminal cirri (ARTHRO: Crustacea) In Ascothoracica, cirri lo- test n. [L. testa, a shell] A rigid external covering or supporting cated at the posterior end of the thorax, except for first structure. pair. testaceology n. [L. testa, shell; logos, discourse] The study of terminal claw spines (ARTHRO: Crustacea) In Cladocera, shells; conchology. toothlike projection, varying in size, at the concave end of testaceous a. [L. testaceus, covered with a shell] Bearing a the postabdomen. test or hard covering; of the nature of a shell. see con- Online Dictionary of Invertebrate Zoology 901 902 Maggenti and Gardner

chiferous. tetrasomic a. [Gr. tetra, four; soma, body] Polysomic cells test-cross see back-cross with one chromosome represented 4 times in a normal diploid; 2n+2. testis n.; pl. testes [L. testis, testicle] That portion of the male reproductive system producing spermatozoa; a sper- tetrathyridium n. [Gr. tetra, four; thyridion, window] (PLATY: mary. Cestoda) A cysticercoid of Mesocestoides which has a solid body and a scolex not surrounded by special membranes. testisac n. [L. testis; testicle; saccus, sac] (ANN: Hirudinoidea) tetrathyridial a. The testis sac. tetraxon n. [Gr. tetra, four; axon, axis] (PORIF) A spicule of 4 testis sac (ANN: Oligochaeta) A membranous sac around the equal and similar rays meeting at equal angles; tetractine; testis, seminal vesicle and the funnel to the vas deferens. quadriradiate. tetraxonid a. testudinate a. [L. testudo, tortoise] In the form of the shell of thalassophilous a. [Gr. thalassa, sea; philos, loving] Inhabit- a tortoise; arched; vaulted. ing or dwelling in the sea; pelagic; thalassic. tetanus, tetany n. [Gr. tetanos, stiffness] State of contraction thallus n. [Gr. thallos, young shoot] The body or colony of a of a muscle caused by continuous stimulation either natural compound animal. or electrical. thamnophilous a. [Gr. thamnos, shrub; philos, loving] Inhab- tetracerous, tetracerate a. [Gr. tetra, four; keras, horn] Having iting thickets or dense shrubbery. four horns. thanatocoenosis n. [Gr. thanatos, death; koinos, common] tetraclad n. [Gr. tetra, four; klados, branch] (PORIF) A megas- An assemblage of fossils comprised of the remains of or- clere desma with rays bearing terminal couplings, or based ganisms brought together after death. see biocenosis. on a calthrops, or both; tetraclone . thanatosis n. [Gr. thanatos, death] Feigning death; letisimu- tetracladine, tetracrepid (PORIF) A tetraxonid desma. lation. tetracotyle n. [Gr. tetra, four; kotyle, cup-shaped] (PLATY: Tre- theca n.; pl. thecae [Gr. theke, case] 1. A sheath or sac-like matoda) A metacercaria in the family Strigeidae. covering or structure for an organ or organisms, as probos- tetractine see tetraxon cis, tubes, shells, pupa or larvae. 2. (ANN: Oligochaeta) tetrad n. [Gr. tetra, four; -ad, collective noun] Any set of four. Spermatheca. 3. (ARTHRO: Insecta) A fold or sheath from phallobase enclosing the aedeagus. 4. (ECHINOD: Cri- tetradelphic a. [Gr. tetra, four; delphys, womb] (NEMATA) noidea) The skeleton. thecal, thecate a. Having four uteri. thelycum n. [Gr. thelykos, feminine] (ARTHRO: Crustacea) In tetramerous a. [Gr. tetra, four; meros, part] 1. Having a four some female Decapoda, an external pocket on the ventral jointed tarsus. 2. Having body parts arranged in fours. side of the thorax, functioning as a seminal receptacle. tetramorphic a. [Gr. tetra, four; morphe, form] (CNID: Hydro- thelygenous a. [Gr. thelys, female; genes, producing] Pro- zoa) Having four distinct forms in one individual. ducing mostly or only female offspring; arrhenogenous. tetraploid n. [Gr. tetraple, fourfold; eidos, like] A polyploid thelygenesis n. with four haploid chromosome sets. thelyotoky n. [Gr. thelys, female; tokos, offspring] A type of tetrapod n. [Gr. tetra, four; pous, foot] Having 2 pair of legs. parthenogenesis in which unfertilized eggs develop into fe- see bipod. males; thelytoica. thelyotokous a. see arrenotoky, tetrapterous a. [Gr. tetra, four; pteron, wing] Having 4 wings. deuterotoky, amphitoky. Online Dictionary of Invertebrate Zoology 903 904 Maggenti and Gardner theory of probabilities A mathematical theory used by tax- ergatoid reproductive; a tertiary reproductive. onomists, whereby they assume that no two individuals will thoracic a. [Gr. thorax, chest] Associated with the thorax. simultaneously have the same combination of characters as those of a given species; in mathematics, the theory of thoracic ganglia (ARTHRO: Insecta) The first three ganglia of chance. the ventral nerve cord, one in each thoracic segment, con- trolling the locomotory organs. thermocline n. [Gr. therme, heat; klinein, to slope] In the strata of rapidly changing temperatures in lakes, the nar- thoracic glands see prothoracic glands row dividing stratum between the epilimnion and thoracic region (ARTHRO: Insecta) The second of three regions hypolimnion. of the embryonic trunk; the future locomotor center. thermophile n. [Gr. therme, heat; philos, loving] Living at thoracic squama (ARTHRO: Insecta) In some Diptera, one of high temperatures; hot springs fauna. three membraneous lobes in the region of the wing base thermophobe n. [Gr. therme, heat; phobos, hate] An organ- appearing to be derived from the posterior margin of the ism that lives at low tempertures. scutellum. see alula, alar squama. thermoreceptor n. [Gr. therme, heat; L. recipere, to receive] thoracomere n. [Gr. thorax, chest; meros, part] (ARTHRO: A sensory receptor that reacts to temperature stimuli. Crustacea) A thoracic segment. thermotaxis n. [Gr. therme, heat; taxis, arrangement] A taxis thoracopod(ite) n. [Gr. thorax, chest; pous foot] (ARTHRO: in which heat is the response initiating stimulus; regulation Crustacea) Any appendage of the thoracic somite; a cor- of body temperature. mopod. see phyllopod, maxilliped, pereopod. thesocytes n.pl. [Gr. thesis, deposit; kytos container] (PORIF) thorax n.; pl. thoraxes, thoraces [Gr. thorax, chest] 1. (AR- In hibernating fresh water sponge gemmules, binucleate, THRO: Chelicerata) In Arachnida, fused with the head to highly vitelline archaeocytes. form the cephalothorax of spiders. 2. (ARTHRO: Crustacea) The tagma between the cephalon and abdomen comprising thickener cells (PORIF) Cells influencing ray thickness during the anterior part of the trunk; cormus; pereon. 3. (ARTHRO: secretion of calcareous spicules. Insecta) a. The body region behind the head, bearing the thickness n. [A.S. thicce, thick] (MOLL: Bivalvia) 1. See infla- legs and wings and encompassing the pro-, meso- and tion. 2. Measurement from the inner to outer shell surface. metathorax. b. In Hymenoptera, the second tagma of the thigmotaxis n.; pl. taxes [Gr. thigma, touch; taxis, arrange- body consisting of pro-, meso-, metathorax and the epi- ment] The taxis of contact; stereotaxis. a. Positive thig- notum of Formicidae. motaxis: toward the contact. b. Negative thigmotaxis: thread n. [A.S. thraed, twist] 1. A fine linear surface elevation. away from the contact. thigmotactic a. 2. (MOLL: Bivalvia) A narrow elevation on the shell surface. thigmotropism n. [Gr. thigma, touch; tropos, turn] Tropism in 3. (MOLL: Gastropoda) The silky fibers of the byssus. which direction is determined by contact with a solid body; thread capsule see nematocyst stereotropism. thread cell (CNID) The cnidoblasts. third axillary (ARTHRO: Insecta) A Y-shaped sclerite of the thread press see silk press wing, with a flexor muscle inserted into the crotch of the Y and usually articulating with the posterior notal process thylacium n. [Gr. thylax, sack] (ARTHRO: Insecta) An external and a group of anal veins. gall-like cyst in the abdomen of the host containing the Dryinidae parasitic larva. third-form reproductive (ARTHRO: Insecta) In Isoptera, an Online Dictionary of Invertebrate Zoology 905 906 Maggenti and Gardner thylacogen n. [Gr. thylax, sack; genes, producing] A chemical tinctorial a. [L. tenctorius, of dyeing] Of or pertaining to color, produced by parasites that cause hypertrophy of host tis- i.e., staining. sue. tine n. [A.S. tind, spike] Any slender, pointed, projecting part. thyridium n; pl. -ia [Gr. dim. thyris, window] (ARTHRO: In- tissue n. [F. tissu, tissue] A layer or group of cells of a par- secta) 1. A small whitish spot in the wings of Neuroptera, ticular type, or at most a few types, with intercellular ma- Hymenoptera and Trichoptera. 2. In ichneumonid Hymen- terial of essentially a particular type. optera, a scar-like area on each side of the second abdomi- nal tergite, between the middle and base; the third tergite tissue culture Tissues appropriated from animals and main- rarely may have tyridia. thyridial a. tained or grown in vitro for more than 24 hours. thyroid n. [Gr. thyra, oblong shield] (ARTHRO: Insecta) In titillae n.pl.; sing. titilla [L. titillo, tickle] (NEMATA) Small pro- Diptera, a shield-shaped plate on the posterior wall of the jections on the distal part of the protrusile gubernaculum. beak. titillator n. [L. titillo, tickle] (ARTHRO: Insecta) A terminal, thysanuriform larva see campodeiform larva small process (spines or small plates) at the distal extrem- ity of the aedeagus. tibia n.; pl. -iae [L. tibia, shin] 1. (ARTHRO: Chelicerata) The fifth segment of a spider leg, between the patella and tocopherol n. [Gr. tokos, birth; pherein, to carry] Vitamin E. metatarsus. 2. (ARTHRO: Insecta) The fourth segment of tocospermal a. [Gr. tokos, birth; sperma, seed] Direct trans- the leg, between the femur and tarsus. fer of sperm between male and female. tibial comb (ARTHRO: Insecta) A strigil or scraper. tocospermia n. [Gr. tokos, birth; sperma, seed] 1. (ARTHRO: tibial epiphysis see epiphysis Chelicerata) A type of sperm transfer by the male chelicera (gonopod), to the female vagina. see podospermia. 2. tibial process/thumb (ARTHRO: Insecta) In Anoplura Pedicu- (MOLL: Cephalopoda) The direct transfer of spermatophores lus , a delicate modification of the tibia as a holdfast to the female vagina by the male gonopod. against the powerful claw of the tarsus. tocostome, tokostome n. [Gr. tokos, birth; stoma, mouth] tibial spur (ARTHRO: Insecta) A large spine usually located on (ARTHRO: Chelicerata) In Acari, the female genital aperture. the distal end of the tibia. tomentum n. [L. tomentum, stuffing of wool] Covered with tibiotarsal organ (ARTHRO: Insecta) In Collembola Smin- closely matted scale-like hair or spines on the body or ap- thurides , a sac-like swelling and an enlarged hair occurring pendages that cannot be separated; downy. tomentose a. near the distal ends of the tibiotarsus of the third pair of legs. tone see tonus tibiotarsus n. [L. tibia, shin; Gr. tarsos, sole of foot] (ARTHRO: tonic muscle (MOLL: Bivalvia) White, opalescent part of the Insecta) Fused tibia and tarsus; the tibiotarsal segment. adductor muscle that reacts slowly, but can hold for long periods of time; catch muscle. Tiedemann's bodies (ECHINOD: Asteroidea) Tiny, 9 spherical swellings on the inner wall of the ring canal that have been tonofibrillae n.pl [Gr. tonos, stretching; L. dim. fibra, fiber] reported to produce amebocytes. Fine connective fibrils extending from the ends of the skeletal muscles into the cuticle. tiled a. [ME. tile] Appearing as a tiled roof; transverse and lon- gitudinal striae on the cuticle. tonus, tone n. [Gr. tonos, stretching] 1. The normal, main- tained nerve impulse traffic. 2. The normal prolonged timbal see tymbal steady contracture of muscle fibers. tonic a. Online Dictionary of Invertebrate Zoology 907 908 Maggenti and Gardner topochemical sense The sense of smell. tortuose a. [Gr. torquere, to twist] Twisting; winding; irregu- topogamodeme n. [Gr. topos, place; gamos, marriage; larly curved. demos, the people] Individuals inhabiting a particular geo- torulose a. [L. torulus, little bulge] Having knob-like swellings; graphic locality that form a deme. moniliform. topomorph n. [Gr. topos, place; morphe, form] An environ- torus n.; pl. tori [L. torus, swelling] 1. A blunt, rounded, ridge mental morphologic variant. topomorphic a. or protuberance. 2. (ANN: Polychaeta) Low ridges provided toponym n. [Gr. topos, place; onoma, name] The name of a with rows of acicular hooks or minute setae or uncini. 3. location thought to be the place of origin of a plant or ani- (ARTHRO: Insecta) In Diptera, the pedicel of the antenna. 4. mal. (PORIF) A more or less doughnut-shaped space around the organism, concerned with water circulation. topotype n. [Gr. topos, place; typos, type] A specimen col- lected at the original type-locality. totipotent a. [L. totus, all; potens, capable] Said of isolated blastomeres capable of becoming complete embryos. tori pl. of torus totomount n. [L. totus, all; mons, mountain] The mount of a torma n.; pl. -mae [Gr. tormos, socket] (ARTHRO: Insecta) 1. whole organism for microscopic study. In Diptera, sclerotic processes between the labrum and clypeus. 2. In Scarabaeoidae larvae, heavily chitinized toxa n. [Gr. toxon, bow] (PORIF) A bow-shaped diactinal micro- structures on the ends of the clypeo-lateral suture that sclere. extend toward the mesal line, sometimes meeting and toxicognath n. [Gr. toxikon, poison; gnathos, jaw] (ARTHRO: fusing on the mesal line. Chilopoda) The forcipulate poison fangs. tormogen n. [Gr. tormos, socket; genes, producing] (ARTHRO: toxicology n. [Gr. toxikon, poison; logos, discourse] The sci- Insecta) An epidermal cell associated with a seta that se- ence of poisons. cretes the cuticle of the socket and bounds the receptor toxin n. [Gr. toxikon, poison] A poisonous substance in the se- lymph cavity. cretions or excretions of a parasite. tornote n. [L. tornatus, rounded with a lathe] (PORIF) A diacti- toxinosis n. [Gr. toxikon, poison] A disease caused by the ac- nal monaxon, lance-headed at each end. tion of a toxin. tornus see anal angle toxoglossate n. [Gr. toxon, bow; glossa, tongue] (MOLL: Gas- torose a. [L. torus, elevation] A swelling into knobs; cylindrical tropoda) Having a radula always enclosed in the radular and swollen at intervals; torous. sac; marginal teeth harpoon-shaped, filled with venom and torpid a. [L. torpidus, to be numb] Dormant; inactive. see loosely arranged in two rows. aestivation, hibernation. toxoid n. [Gr. toxikon, poison; eidos, form] A toxin released torqueate a. [L. torquatus, with a necklace] Having a ring or from its toxic properties, but not from its antigenic proper- collar. ties. n. [L. torquere, to twist] 1. Spiral bending; twisting. 2. trabecula n.; pl. -lae [L. trabecula, little beam] 1. A small bar, (MOLL: Gastropoda) The theory in ancestral gastropods that rod, bundle of fibers, or septum together with other trabe- a 180-degree counterclockwise twisting occurred that culae which form part of the framework of various organs. caused the crossing of the pleural-visceral connectives in see internuncial process. 2. (MOLL: Cephalopoda) In the nervous system to form a figure eight. see chiasto- squid and cuttlefish, a support from the edge of the arm neury, detorsion. inward for the protection of membranes of the arm. Online Dictionary of Invertebrate Zoology 909 910 Maggenti and Gardner trabeculate a. [L. trabecula, small beam] (ANN: Oligochaeta) somewhat elaborate lobe on the rim of the pinna of a lati- Used to describe seminal vesicles that develop as connec- corn trumpet of some culicid pupae. tive tissue proliferations from a septum that have numer- transad n. [L. trans-, across; Gr. ad, makes collective nouns] ous irregular spaces that remain minute until spermatogo- Closely related organisms separated by an environmental nia begin to enter. trabeculated a. barrier. trachea n.; pl. tracheae [L. trachia, windpipe] 1. The wind- transcoxa n. [L. trans-, across; coxa, hip] (ARTHRO: Chelicer- pipe. 2. (ARTHRO: Chelicerata) For Arachnida, see tube ata) A term used instead of coxa in some groups. trachae, sieve trachea. 3. (ARTHRO: Insecta) The larger tubes of the respiratory system, lined with taenidia, open- transcurrent a. [L. trans-, across; currens, running] 1. Ex- ing to the outside through the spiracles and terminating tending transversely. 2. (MOLL: Gastropoda) Passing con- internally in the tracheoles. 4. (MOLL: Gastropoda) see tinuously around whorls crossing growth lines. ctenidia. 5. (ONYCHO) In Peripatus, short tubes without transect n. [L. trans-, across; secare, to cut] A cross section spiral thickenings, neither branching nor anastomosing, or profile of an area for study, as with organisms and/or opening externally through numerous minute spiracles. vegetation. tracheate a. transection n. [L. trans-, across; secare, to cut] Cut across or tracheal gills (ARTHRO: Insecta) In aquatic larvae and some transversely; a transverse section. aquatic pupae, filiform, lamellate structures supplied with transformation zone In males, that part of the testis follicle trachae and tracheoles, usually borne on the abdomen. see in which the spermatids develop into spermatozoa; known spiracular gills, blood gills. as spermiogenesis. see maturation zone. tracheal system (ARTHRO) A system of cuticle-line tube transient a. [L. trans-, across; ire, to go] A passing phenome- opening to the outside through spiracles, functioning in non; of short duration. respiration. transient polymorphism Polymorphism existing in a breeding tracheoblast n. [L. trachia, windpipe; Gr. blastos, bud] (AR- population during the period when an allele is being re- THRO: Insecta) Cells derived from the epidermal cells lining placed by a superior one. see balanced polymorphism. the trachea, that give rise to the tracheoles. transitional cell see chromophile tracheoles n. [L. dim. trachia, windpipe] (ARTHRO: Insecta) The fine intracelluar terminal branches of the respiratory translocation n. [L. trans-, across; locus, place] The shift of a tubes. tracheolar a. segment of a chromosome to another chromosome, not changing the total number of genes present. trachychromatic a. [Gr. trachys, rough; chroma, color] Strongly staining. translucent a. [L. trans-, across; lucere, to shine] Allowing the passage of light, but not necessarily transparent; semi- tract n. [L. tractus, region] 1. An area, region or parts of a transparent. system, as a bundle of nerve fibers between parts of the central nervous system. 2. (PORIF) A fascicular column of transmission n. [L. trans-, across; mittere, to send] 1. Hori- spicules. zontal: the transfer of an infectious agent from one organ- ism to another. 2. Vertical: transmission from one genera- Tragardh's organ (ARTHRO: Chelicerata) In Acari, a long, coni- tion to another. cal hyaline protuberance of the articulation between the body of a chelicera, and its movable jaw; oncophysis. transposed hinge condition (MOLL: Bivalvia) A condition of teeth usually found in the hinge of one valve being found tragus n. [Gr. tragos, goat] (ARTHRO: Insecta) In Diptera, a on the opposite one. Online Dictionary of Invertebrate Zoology 911 912 Maggenti and Gardner transscutal suture (ARTHRO: Insecta) 1. In many orders, a ginal wing vein. transverse suture connecting the lateral margins behind transverse septum (ARTHRO: Crustacea) In Cirripedia, the the anterior notal wing process, dividing the scutum into an thin walled, normal to longitudinal septum, parallel to ba- anterior and posterior region. 2. In some Hymenoptera, a sis, dividing the parietal tubes into a series of cells. suture dividing the posterior part of the scutum into two posterolateral areas called the axillae. transverse striation A circular groove or arc whose plane is perpendicular to the longitudinal axis. transstadial a. [L. trans-, across; stadium, stage] The reten- tion of microorganisms from one stage of the host to the transverse suture (ARTHRO: Insecta) In Diptera, a suture next; may be part or all of the host's life cycle. across the middle of the mesonotum of some species; usu- ally incomplete in the center of the notum; in Tipulidae it is transtilla n.; pl. -lae [L. trans-, across; stilla, drop] (ARTHRO: V-shaped. Insecta) In Lepidoptera, a transverse bar, or variously shaped process, connecting dorso-proximal angles of the transverse wall (BRYO: Gymnolaemata) One of a pair of walls male valva; part of the fultura superior; the anterior end of separating individual zooids in a linear series; perpendicu- the dorsal extension of the 9th sternum or the vinculum. lar to direction of growth. transverse a. [L. trans-, across; vertere, to turn] Crossing at trapezium n. [Gr. trapezion, small table] A four-sided figure, right angles to the longitudinal axis; lying across or be- having no two sides parallel; trapeziform. tween. trapezoid n. [Gr. trapezion, small table; eidos, shape] A plane transverse band of crochets (ARTHRO: Insecta) In larva, cro- four-sided figure in which two sides are parallel and two chets being arranged transversely or across the longitudi- are not. trapezoidal, trapeziform a. nal axis of the body in a single uniserial or multiserial band, trema n.; pl. tremata [Gr. trema, hole] (MOLL: Gastropoda) or in two such bands. An orifice in the outer wall of some shells, excretory in transverse costal vein (ARTHRO: Insecta) A wing cross vein in function; may occur singly or in a series. the costal cell. Trematoda n. [Gr. trema, hole; eidos, form] A class of Platy- transverse cubital vein (ARTHRO: Insecta) A transverse wing helminthes, commonly call flukes; all are endoparasitic vein connecting the marginal and cubital veins. flatworms. transverse fission A form of asexual reproduction by division trenchant a. [OF. trenchier, to cut] Having a sharp edge. of an organism at right angles to the long axis. see binary trepan n. [Gr. trypanon, borer] (ANN: Polychaeta) Part of the fission. eversible pharynx containing chitinized teeth anteriorly, es- transverse impression see genal groove pecially Syllidae. transverse marginal vein (ARTHRO: Insecta) A wing cross triact n. [Gr. treis, three; aktis, ray] (PORIF) A microsclere spi- vein in the marginal cell. cule with three rays. see regular triact, saggital triact. transverse notal suture see prescutal sulcus triactinal a. [Gr. treis, three; aktis, ray] (PORIF) Having a three-pointed or rayed spicule. see diactinal, tetractinal, transverse partition (BRYO) A wall separating members of a monactinal. successive line of zooids. triad n. [Gr. treis, three; -ad, forms collective noun] An ar- transverse plane A plane or section perpendicular to the lon- rangement of three; a trinity. gitudinal axis. triaene n. [Gr. triaina, trident] (PORIF) A tetraxonid spicule transverse radial vein (ARTHRO: Insecta) A transverse mar- Online Dictionary of Invertebrate Zoology 913 914 Maggenti and Gardner

with three rays shorter than the fourth. trichodragmata n.pl. [Gr. thrix, hair; dragma, sheaf] (PORIF: triage n. [F. a culling] The process of grading. Desmospongiae) In Axinellidae ( Tragosia ), raphides grouped into bundles. triangle n. [L. triangulus, having three angles] (ARTHRO: In- secta) In Odonata, a small triangular cell or group of cells trichogen n. [Gr. thrix, hair; genes, producing] (ARTHRO: In- near the base of the wing; discoidal triangle; cardinal cell. secta) An epidermal cell that secretes the cuticle of the triangulate a. seta or peg, the scolopale and the pore tubules. triangular plates (ARTHRO: Insecta) In Hymenoptera, the sec- trichoid a. [Gr. thrix, hair; eidos, form] Formed like a hair. ond of three pairs of movable plates associated with the trichoid sensilla see sensillum trichodeum sting. see quadrate plates, oblong plates. trichomes, trichodes n.pl. [Gr. thrix, hair] 1. (ARTHRO: In- triaulic a. [L. tres, three; aulos, pipe] (MOLL: Gastropoda) In secta) Modified tufts or hair on certain myrmecophilous and opisthobranch hermaphroditic snails, the female part hav- non-myrmecophilous insects that aid in the dissemination ing two separate openings and the male part one. see di- of appeasement or pheromone substances. 2. (ARTHRO: aulic, monaulic. Diplopoda) Hollow spines or setae of the bristly millipedes. triaxial symmetry A type of symmetry such as biradial- or trichophore n. [Gr. thrix, hair; pherein, to bear] (ANN) A sac- bilateral symmetry, with three axes known as sagittal, lon- like structure or cavity from which setae emerge. gitudinal, and transverse. trichopore n. [Gr. thrix, hair; poros, channel] (ARTHRO: In- triaxon n. [Gr. tries, three; axon, axle] (PORIF) A spicule with secta) A pore in the cuticle through which a sensory hair or three axes. bristle is formed. tribe n. [L. tribus, tribe] A taxonomic category containing a trichosors n.pl. [Gr. thrix, hair] (ARTHRO: Insecta) In Neurop- group intermediate between the genus and the subfamily; tera, thickenings of the wing margin bearing several hairs; names of tribes end in -ini. a single trichosor between each pair of vein-endings in tribocytic organ (PLATY: Trematoda) In Strigeiudea, a glan- adults. dular, pad-like organ behind the acetabulum. trichostichal bristles see metapleural bristles trichite n. [Gr. trix, hair] (PORIF) Hair-like siliceous spicule. trichotomous a. [Gr. tricha, in three parts; tome, a cutting] trichobothrium n.; pl. -ria [Gr. thrix, hair; bothros, pit] (AR- Divided into three parts; three-forked. THRO: Chelicerata) A compound structure of many groups trichroism n. [Gr. treis, three; chros, color] The condition of consisting of a small cavity (bothridium) and variously having three color forms in different individuals of the same shaped setae (bothridial setae) that function as vibro- and species. anemoreceptors. tricolumella see columella trichobranchia n.pl. [Gr. thrix, hair; branchia, gill] (ARTHRO: tricostate a. [Gr. treis, three; costa, rib] Having three ribs or Crustacea) A gill with a series of filamentous lateral ridges. branches arising from the main stem or branchial axis. trichobranchiate a. tricrepid a. [Gr. treis, three; krepis, base] (PORIF) A triaxonid desma. trichocerous a. [Gr. thrix, hair; keras, horn] (PLATY: Trema- toda) Pertaining to cercaria having a tail provided with con- tricuspid, tricuspidate a. [Gr. treis, three; cuspis, a point] spicuous spines or bristles. Divided into three cusps or points. trichodes see tricomes tridactyl a. [Gr. treis, three; daktylos, finger] (ARTHRO) Per- Online Dictionary of Invertebrate Zoology 915 916 Maggenti and Gardner

taining to an appendage, ambulacrum, or claw with three three parts, divisions or segments. ungues. see monodactyl, bidactyl. tripectinate a. [L. tres, three; pecten, comb] Having three trident a. [L. tres, three; dens, tooth] Having three teeth; rows of comb-like branches. three-pronged. tridentate a. triplet n. [L. tres, three; plus, more] Three successive nucleo- trifid a. [L. tres, three; findere, to split] Having three clefts, tide base pairs that code for an amino acid. parts, or branches. triploblastic a. [Gr. triploos, threefold; blastos, bud] Derived trifid nerve (BRYO) A three-branched peripheral motor nerve from three embryonic germinal layers: ectoderm, endo- connected to the retractor muscle, esophagus, and along derm and mesoderm. the tentacle sheath to the direct nerve. triploid a. [Gr. triploos, threefold] A cell or individual having trifurcate a. [L. tres, three; furca, fork] Having three branches three haploid chromosome sets in their nuclei; a form of or forks; trichotomous. polyploidy. triglycerides n.pl. [Gr. treis, three; glykys, sweet] Esters of triquetral, triquetrous a. [L. triquetrus, three sided] Having fatty acids with glycerin that form fats and oils. three angles or arms; triangular in section. trignathan a. [Gr. treis, three; gnathion, jaw] (ARTHRO) Hav- triradiate(s) a. [L. tres, three; radius, spoke of wheel] 1. ing mandibles and two pair of maxillae, such as Chilopoda, Having three radiating process. 2. (PORIF) Spicules having Symphyla and Insecta. see dignathan. the three rays somewhat in the same plane. see sagittal trigonal a. [Gr. treis, three; gonia, angle] Pertaining to, or in triradiates. the form of a triangle. tritocerebral commissure see postesophageal commis- trigoneutism n. [Gr. treis, three; gonos, offspring] The pro- sure duction of three broods in one season. tritocerebral segment see tritocerebrum trilabiate a. [L. tres, three; labium, lip] Having three lips. tritocerebrum n. [Gr. tritos, third; L. cerebrum, brain] (AR- trilateral a. [L. tres, three; latus, side] Three-sided. THRO) The posterior (third) small part of an arthropod brain that gives rise to nerves that innervate the labium, the di- trilobate a. [Gr. treis, three; lobos, lobe] Bearing three lobes. gestive tract (stomatogastric nerves), the chelicerae of trilocular a. [L. tres, three; loculus, small place] With three chelicerates, and the second antennae of . see cavities or cells. metacerebrum. trimorphic a. [Gr. treis, three; morphe, form] Having three tritonymph n. [Gr. tritos, third; nymphe, young woman] (AR- distinct forms in one individual, as certain hydrozoan colo- THRO: Chelicerata) In Acari, the third stage nymph. nies. trimorphism n. tritosternum n. [Gr. tritos, third; sternon, chest] (ARTHRO: Trinominal nomenclature An extension of the binominal Chelicerata) In Mesostigmata, a secondary, ventral, bristle- system of nomenclature consisting of three words: the ge- like sensory organ just behind the gnathosoma. neric name, the specific name, and the subspecific name, triturate v.t. [L. tritum, rub to pieces] To rub or grind to a fine together constituting the scientific name of a subspecies. powder; masticate; pulverize. triordinal crochets (ARTHRO: Insecta) Crochets of larvae with triungulin, triungulinid n. [L. tres, three; ungula, claw] (AR- proximal ends in a single row, but distal ends of three al- THRO: Insecta) First-instar larva of some hypermetamor- ternating lengths. see ordinal. phic Neuroptera, Coleoptera, Hymenoptera, and the Strep- tripartite a. [L. tres, three; partitus, divided] Divided into siptera (triungulinid), which are active, compodeiform Online Dictionary of Invertebrate Zoology 917 918 Maggenti and Gardner

oligopods. see planidium. conical shell, without a highly acute spire and rather flat at trivial name An obsolete designation by Linnaeus for the spe- the base. cific name; vernacular name. trochlea n. [Gr. trochilia, pulley] A pulley-like structure, short, trivium n. [L. trivium, crossroads] (ECHINOD: Asteroidea) Col- circular, compressed and contracted in the middle of the lectively, the three rays of a sea star farthest from the circumference. madreporite. see bivium. trocholophous a. [Gr. trochos, wheel; lophos, crest] trivoltine n. [L. tres, three; It. volta, time] (ARTHRO: Insecta) (BRACHIO) A lophophore with a simple disk around the Having three annual broods, especially in the silkworms of mouth, bearing usually a single row of unpaired filamentary Bombycidae. appendages, rarely a double row of paired appendages. trixenic a. [Gr. treis, three; xenos, guest] The rearing of one trochophore n. [Gr. trochos, wheel; phora, bearing] An in- or more individuals of one species in association with three vertebrate free-swimming larva found in many groups, known species of organisms. see axenic, dixenic, mon- marine turbellarians, nemerteans, brachiopods, phoronids, oxenic, polyxenic, synxenic, xenic. bryozoans, mollusks, sipunculids, and annelids, commonly pear-shaped and provided with a prominent equatorial troch n. [Gr. trochos, wheel] A band of cilia found on troco- band of cilia and sometimes one or two accessory ciliary phores and related larvae. circlets. trochal disc (ROTIF) Anterior ciliated disc functioning in loco- trochosphere see trochophore motion and/or food ingestion. trochus n.; pl. trochi [Gr. trochos, wheel] (ROTIF) The inner, trochalopodous a. [Gr. trochos, wheel; pous, foot] (ARTHRO: anterior circlet of coronal cilia along the margin of the api- Insecta) Refers to a posterior coxae having an articulation cal band; cingulum. of a ball and socket joint. see pagiopodous. troglobiont n. [Gr. trogle, hole; bios, life] A cave dwelling or- trochantellus n. [Gr. dim. trochanter, runner] (ARTHRO: In- ganism; troglobite. secta) In Hymenoptera, the proximal end of the femur; sometimes appearing as a second segment of the tro- troglodytic a. [Gr. trogle, hole; dyein, to enter] Living under- chanter. ground only. trochanter n. [Gr. trochanter, runner] (ARTHRO) A segment or troglophile n. [Gr. trogle, hole; philein, to love] 1. Cave-lov- segments of an insect or acarine leg that articulate basally ing. 2. (ANN: Oligochaeta) Many species of earthworms are with the coxa and distally with the femur; a pivot or rock- referred to in this manner, however, they are not obliga- ing joint; the first cheliceral segment. tory troglophiles. trochanteral organ (ARTHRO: Insecta) In Collembola, a group trogloxene n. [Gr. trogle, hole; xenos, guest] 1. A cave guest. of short setae on the trochanter. 2. Sometimes used to characterize organisms that do not complete all of their life cycle in caves. trochantin n. [Gr. trochanter, runner] (ARTHRO: Insecta) Any small intercalated sclerite of an insect appendage. a. The tropeic a. [Gr. tropis, keel] Resembling a keel; cariniform. basal segment of the trochanter when two-jointed. b. A trophallaxis n. [Gr. trophe, food; allaxis, exchange] (ARTHRO: small sclerite in the thoracic wall, just anterior to the base Insecta) The mutual or unilateral exchange of alimentary of the coxa. canal liquid, from the mouth or anus, among colony mem- trochiform a. [Gr. trochos, wheel; forma, shape] 1. Shaped bers of social insects or guests; trophobiosis. trophallactic like a top. 2. (MOLL: Gastropoda) In Trochidae, a flat-sided a. Online Dictionary of Invertebrate Zoology 919 920 Maggenti and Gardner trophamnion n. [Gr. trophe, food; amnion, membrane around trophodisc n. [Gr. trophe, food; diskos, disc] (CNID: Hydrozoa) the fetus] (ARTHRO: Insecta) An envelope surrounding the In the female gonophore, endodermal tissue that nourishes embryonic mass in the polyembryonic ova of mainly para- sperm or ova. sitic Hymenoptera, formed by cytoplasm in the egg associ- trophogeny n. [Gr. trophe, food; genes, producing] (ARTHRO: ated with the paranuclear mass, and functioning in relaying Insecta) In social insects, caste difference determined by nutrients from the host. nutritional mechanism. trophi n.pl.; sing. trophus [Gr. trophe, food] 1. (ARTHRO) The trophoporic field (ARTHRO: Insecta) In social insects, the en- mouth parts, especially of insects and barnacles, collec- vironment from which the colony gains food. tively. 2. (ROTIF) The mastacatory apparatus of the mastax. trophal , trophic a. trophorhinium n. [Gr. trophe, food; rhine, rasp] (ARTHRO: In- secta) In Hymenoptera, two striated plates located within trophic chord (ARTHRO: Insecta) In telotrophic ovarioles, slen- the mouth of Myrmeciinae larvae that grind their food pel- der chords connecting the nurse cells to the eggs. lets. trophic egg (ARTHRO: Insecta) In Apis, an egg that is fed to trophosome n. [Gr. trophe, food; soma, body] 1. (CNID: Hy- the colony members, usually degenerate and nonviable. drozoa) All of the asexual structures of a polyp or polypoid trophic sac/pouch (ARTHRO: Insecta) In Siphunculata (Ano- hydrozoan colony. see gonosome. 2. (NEMATA) A food plura), a pouch opening off the cibarium housing three storage area of certain parasitic nematodes formed by closely compressed stylets, with only the anterior end ex- modification of the intestine. posed, functioning in piercing the skin for blood meals. trophotaxis n. [Gr. trophe, food; taxis, arrangement] A re- trophic symbiosis A form of symbiosis between a social insect sponse to the stimulation of food. see telotaxis, klino- and another organism; tended by the social insect for the taxis. sake of the food or secretions they derive from them. see trophothylax n. [Gr. trophe, food; thylax, sack] (ARTHRO: In- trophallaxis, trophobiont. secta) In Hymenoptera Formicidae, a specialized pouch of trophidium n. [Gr. dim. trophe, food] (ARTHRO: Insecta) In Pseudomyrmecinae larvae located on the ventral part of Hymenoptera, the first larval stage of some Formicidae. the thorax just beneath the mouth parts that receives food trophobiont n. [Gr. dim. trophe, food; bios, life; ont, one who] pellets; a feed bag. (ARTHRO: Insecta) An organism living in a social species trophozooid see gastrozooid nest, or cared for and protected by a social species in re- trophus see pl. trophi turn for secretions which are then consumed. see mutual- ism. tropis n. [Gr. tropus, keel] 1. (ARTHRO: Crustacea) In Ostra- cods, a heavy chitinous (or two unfused rods) connecting trophobiosis n. [Gr. trophe, food; biosis, manner of life] A the zygum to the sternix and pastinum. 2. (NEMATA: Ade- form of symbiosis in which there is a mutual exchange of nophorea) In Enoplida, a hollow tooth-like structure formed food; trophallaxis. trophobiotic a. see trophic symbio- by a subventral wall of the buccal capsule. sis. tropism n. [Gr. tropos, turn] A movement, orientation or lo- trophocytes n.pl. [Gr. trophe, food; kytos, container] 1. Cells comotion of a motile organism in response to a stimulus. a. that provide nutritive material. 2. (ARTHRO: Insecta) Cells Positive tropism: toward the stimulus. b. Negative tropism: of the fat body of the embryo. 3. (PORIF) In fresh-water away from the stimulus. see taxis. sponges, nurse cells involved in the initial stages of gem- mule formation; archaeocytes. tropotaxis n. [Gr. tropos, turn; taxis, arrangement] A type of Online Dictionary of Invertebrate Zoology 921 922 Maggenti and Gardner

taxis in which an animal directs itself in relation to a source bercles. of stimulation by comparing the amount of stimulation on tube tracheae (ARTHRO: Chelicerata) In Opiliones, Solifugae either side of it, i.e., spiders in their web retrieving their and most spiders, tube-like tracheae; usually unbranched prey. see klinotaxis, telotaxis. ectodermal invaginations. see sieve tracheae. trumpet n. [OF. trompe, trumpet] (ARTHRO: Insecta) In Dip- tubicolous a. [L. tubus, tube; colere, to dwell] Inhabiting a tera, paired, usually movable respiratory structures, lo- tube; a tubular spider web. cated on the dorsal portion of the cephalothorax of culicid pupae. see laticorn trumpet, angusticorn trumpet. tubifacient a. [L. tubus, tube; facere, to make] Tube con- structing. truncate a. [L. truncus, cut off] Terminating abruptly; ending squarely with a cut-off edge. truncation n. tubule n. [L. dim. tubus, tube] A minute tube. trunk n. [L. truncus, cut off] 1. (ANN) a. In Polychaeta, the tubulus n. [L. dim. tubus, tube] (ARTHRO: Insecta) In Lepi- body between the peristomium and the pygidium. b. In Oli- doptera, a tubular, telescoping ovipositor. gochaeta, the body between the peristomium and pe- tubus n. [L. tubus, tube] (NEMATA) A cuticular projection sur- riproct. 2. (ARTHRO: Crustacea) The postcephalic portion of rounding the spicules beyond the body outline; cloacal the body. 3. (ARTHRO: Insecta) The thorax. tubus. trypsin n. [Gr. tryein, to rub down; pepsis, digestion] An en- tuft sensilla (ARTHRO: Crustacea) In Decapoda, small zyme that catalyzes the hydrolysis of proteins. tryptic a. branched hairs over pores in the carapace with two or tryptophan, tryptophane n. [Gr. tryein, to rub down; pha- three attached neurons, functioning in vibration and water nein, to appear] An amino acid existing in proteins, from movement detectors. which it is set free by tryptic digestion, that gives a red or Tullgren funnel Apparatus designed by A. H. Tullgren for ex- violet color on oxidation; it is essential to animal life. traction of animals from duff and litter; the sample is T-tubule Invaginations of the plasma membrane into the mus- placed on a sieve and heat is applied from above to drive cle fiber between the Z- and H-bands. the animals downward into a funnel with a collecting vessel below; similar to a Baerman funnel that uses a water in- tube n. [L. tubus, tube] Any hollow, cylindrical structure. terface between sample and collecting vessel. tube-feet (ECHINOD) Small, fluid-filled tubes of the water vas- tumefaction n. [L. tumere, to swell; facere, to make] Abnor- cular system functioning in locomotion, adhesion, food mal tissue formations in invertebrates having characteris- capture and transport to the mouth; some are sensory and tics in common with vertebrate neoplasms, however, pre- may assist in respiration. cise nature is unknown. tubercle n. [L. dim. tuber, hump] 1. A small knoblike or tumescence n. [L. tumescere, to swell up] Slightly tumid or rounded protuberance. see torus. 2. (ARTHRO: Insecta) In enlarged. Diptera, sometimes used for an elongate facial swelling. tuberculate , tuberculose a. tumid a. [L. tumere, to swell] Swollen; enlarged; abnormally distended. tubercula pubertatis (ANN: Oligochaeta) A glandular swelling near the ventrolateral margin of the clitellum of mature tumulus n. [L. tumulus, mound] (ARTHRO: Insecta) In Apis, a adult earthworms during copulatory phase; differs in size, pile of earth at the mouth of an underground burrow. shape and continuity. tun n. [L. tunica, garment] (TARDI) A cryptobiotic shriveled, tuberiferous a. [L. dim. tuber, hump; fero, bear] Bearing tu- state of tardigrades produced by evaporation of surround- ing water film. Online Dictionary of Invertebrate Zoology 923 924 Maggenti and Gardner tunic n. [L. tunica, garment] A covering membrane or tissue. tyloid n.; pl. tyloides [Gr. tylos, knob] (ARTHRO: Insecta) In tunica n.; pl. -cae [L. tunica, garment] 1. A covering or envel- Trigonalidae and Ichneumonidae, any large indented, flat- oping membrane or tissue; a tunic. 2. (ARTHRO: Insecta) tened or raised sensory area on the antennae. For Lepidoptera see diaphragm. tylosis n.; pl. -es [Gr. tylos, knob] A hardening or thickening; tunica adventitia Outermost fibro-elastic layer of various tu- a callous. bular organs, such as vas deferens, esophagus, uterus, tylostyle a. [Gr. tylos, knob; stylos, column] (PORIF) A ureter, etc. monactinal monaxon knobbed at the broad end and pointed tunica intima An inner lining or membrane. at the other. see subtylostyle. tunica propria (ARTHRO: Insecta) In females, an elastic mem- tylote n. [Gr. tylos, knob] (PORIF) A diactional monaxon in brane, with or without fine fibrils, that encloses the ovariole which both broad ends are knobbed. and terminal filament. tylus n.; pl. tyli [Gr. tylos, knob] (ARTHRO: Insecta) The distal tunicary a. [L. tunica, garment] Pertaining to a covering mem- part of the clypeal region of the head. brane or a tunic. tymbal n. [F. timbale, kettledrum] (ARTHRO: Insecta) In tunicate a. [L. tunica, garment] 1. Having a tunic. 2. (ARTHRO) Hemiptera (Cicadidae), an area of thin cuticle supported by Applied to coupling joint of antennae. a cuticular rim and a series of dorso-ventral strengthening ribs; involved in sound production. see Pearman's organ. turbinate a. [L. turbo, a whirl] Top-shaped; nearly conical with a round base; turbiniform. tympanal air chamber (ARTHRO: Insecta) An air-sac or space, usually posterior to the tympanal organ into which outside turbinate eye (ARTHRO: Insecta) In male Baetidae Ephemer- air is admitted by a spiracle allowing the tympanum to vi- optera, eyes enlarged, divided into lower and outer pig- brate freely. mented ovals and raised on a broad stalk, with larger up- per and inner portion usually pale with large facets. tympanal bullae see tympanal hood turgid a. [L. turgidus, swollen] Swollen; distended. tympanal fossa (ARTHRO: Insecta) In Diptera, a largely mem- branous area between the suprasquamal ridge and the turreted a. [L. turris, a tower] Tower-shaped. lower margin of the postalar wall. turriculate a. [L. dim. turris, tower] (MOLL: Gastropoda) Hav- tympanal frame (ARTHRO: Insecta) The supporting framework ing an acutely conical spire comprised of numerous flattish of the tympanal membrane. whorls; turriform; turrited. tympanal hood (ARTHRO: Insecta) In some Lepidoptera, one tychoparthenogenesis n. [Gr. tyche, change; parthenos, vir- of a pair of tubercles or rounded prominences on the dorsal gin; genesis, beginning] Unfertilized eggs that can occa- surface at the base of the first abdominal segment. sionally, or accidentally, develop through parthenogenesis. tympanal organs (ARTHRO: Insecta) Specialized chordotonal tylasters n. [Gr. tylos, knob; aster, star] (PORIF) A star- organs that occur on prothoracic legs, mesothorax, shaped spicule with a small center and knobbed rays. metathorax, or abdomen; the auditory organ or eardrum. tylenchoid bursa see bursa tympanal pockets (ARTHRO: Insecta) In Lepidoptera, pockets tylenchoid esophagus (NEMATA: Secernentea) An esophagus in the tympanal frame, usually 4 in number. with a narrow procorpus, a strongly formed median bulb tympanal ridge (ARTHRO: Insecta) In some Diptera, a rib-like (metacorpus), followed by a narrow typical isthmus and sclerite forked anteriorly, forming a single or double Y that terminating with a glandular basal bulb. encloses the tympanic pit. Online Dictionary of Invertebrate Zoology 925 926 Maggenti and Gardner tympanic pit (ARTHRO: Insecta) In Diptera, a membranous type method The method by which the name for a taxon is area opening toward the base of the wing, enclosed by the unquestionably associated with a definite zoological object two lowermost arms of the tympanal ridge. belong to the taxon. tympanum n.; pl. -ana [Gr. tympanon, drum] (ARTHRO: In- type species The species which was used by the author of a secta) A vibrating membrane involved in hearing; typanic genus to designate as type of a nominal genus. membrane; an auditory membrane. typhlosole n. [Gr. typhlos, blind; solen, channel] A longitudi- Tyndall colors or scattering (ARTHRO: Insecta) Color of cer- nal infolding of the dorsal intestinal wall into the intestinal tain insects resulting from interference of light reflected by lumen. granules cast upon an absorbing layer of dark pigment be- typologist n. [Gr. typos, type; logos, discourse] One who dis- neath a more or less transparent cuticle; producing blue, regards variation and who considers the members of a green or white, depending upon the size of granules. population as replicas of the type. type n. [Gr. typos, type] A zoological object that serves as the typolysis n. [Gr. typos, type; lysis, loosing] Phylogerontic; base for the name of a taxon. stage that precedes extinction of a type organism or group. type by absolute tautonomy see type by original desig- typostasis n. [Gr. typos, type; stasis, standing] A static phase nation in evolution. type by elimination A type designated when some of the original species of a genus have been transferred to other genera, the type of the genus selected from among the original species that remain in the genus. ICZN type by original designation A species designated as type in the original publication of a genus. a. If in the original pub- lication of a genus, typicus or typus is used for any of the species. b. The species in a proposed new genus (mono- typical genus). c. In a genus containing a number of spe- cies, one original species has the generic name as its spe- cific or subspecific name, whether a valid name or a synonym (type by absolute tautonomy). ICZN type by virtual tautonomy An original species of a genus that has a specific or subspecific name, either as a valid name or a synonym, is virtually the same as the generic name, or of the same origin or meaning. ICZN type genus In families, the specific genus on which the family is founded, not necessarily the first one described. type host A designated organism from which a type specimen has been collected. type locality The area from which a holotype, lectotype, or neotype was collected. 928 Maggenti and Gardner

valves, apical portion of either valve. see beak. 2. (AR- U THRO: Insecta) In Coleoptera, an elevated knob on the hu- meral angle of the elytra. 3. (BRACHIO) Apical portion of either valve containing the beak. 4. (BRYO: Gymnolaemata) In Cheilostomates, a blunt knob on the front wall of the uliginose, uliginous a. [L. uliginosus, swampy] Of or pertain- ovicell. 5. (MOLL: Bivalvia) That region of the valve sur- ing to mud; swampy. rounding the point of maximum curvature of the longitudi- nal dorsal profile; when not coinciding with the beak, ex- ultradextral a. [L. ultra, beyond; dexter, right] (MOLL: Gastro- poda) Having a shell appearing to be sinistral but soft parts tending to its base. umbonal a. organized dextrally; hyperstrophic. umbonal angle (MOLL: Bivalvia) In pectinoid shells, the angle of divergence of the umbonal folds; in other shells the di- ultrasinistral a. [L. ultra, beyond; sinister, left] (MOLL: Gas- tropoda) Having a shell appearing to be dextral but soft vergence of the posterodorsal and anterodorsal parts of the parts organized sinistrally; hyperstrophic. longitudinal profile. ultrasonic a. [L. ultra, beyond; sonus, sound] High frequency umbonal cavity (MOLL: Bivalvia) 1. Part of the valve interior sounds inaudible to the human ear. which lies within the umbo and under the hinge plate. 2. In oysters, that part of the left valve interior lying in the um- ultrastructure n. [L. ultra, beyond; struere, to construct] The bonal region beneath the ligamental area. fine structure of cells seen with an ultramicroscope or an electron microscope. umbonal depression (MOLL: Bivalvia) A depression at the umbo tip. umbel n. [L. umbella, a sunshade] 1. An arrangement in which a number of processes, nearly equal in length, spread from umbonal fold (MOLL: Bivalvia) In pectinoid shells, a ridge originating at the umbo and setting the auricle off from the a common center. 2. (CNID: Anthozoa) In Umbellulidae, polyps coming from a common center, forming a cluster, as shell body. in the anthocodia of Umbellula . 3. (PORIF) Processes ex- umbonal pole (MOLL: Bivalvia) The point of maximum curva- tending from the clavules. ture of the longitudinal profile of the dorsal valve. umbilical suture (MOLL: Gastropoda) In phaneromphalous umbonal reflection (MOLL: Bivalvia) The reflection of the dor- type shells, a continuous line separating successive whorls. sal margin of the valves anterior to and usually over the n.; pl. -lici [L. umbilicus, navel] 1. A navel, or na- umbos. vel-like depression 2. (MOLL: Gastropoda) A cavity formed umbonal region (MOLL: Bivalvia) The region of the umbo. around the shell axis between the faces of the adaxial wall umbonal spine (ARTHRO: Crustacea) In Conchostraca, a hol- of the whorls where these do not coalesce to form a solid low, curved, looped or nodular spinose projection of vari- columella. a. In conispiral shells opening at the base of the able size, sometimes covering the entire umbo. shell, excepting hyperstrophic type. b. Involute shells may have two umbilici, an upper or adapical and lower or abapi- umbone see umbo cal in asymmetrical types, and left and right in isostrophic umboniform a. [L. umbo, knob or boss; forma, shape] 1. Like types. umbilicate a. or shaped like an umbo. 2. (MOLL: Gastropoda) Having a umbo n.; pl. umbones, umbos [L. umbo, knob or boss] 1. low blunt or rounded spire, nearly lenticular in shape. see rotelliform. (ARTHRO: Crustacea) a. In Cirripedia, a portion of the plate from which successive growth increments extend. b. In bi- umbonuloid a. [L. umbo, knob or boss; Gr. eidos, like] (BRYO: Online Dictionary of Invertebrate Zoology 929 930 Maggenti and Gardner

Gymnolaemata) In cheilostomates, autozooids having radula of plant-eating gastropods. frontal shields formed by calcification of the basal side of uncus n.; pl. unci [L. uncus hook] 1. (ARTHRO: Insecta) a. In the epifrontal fold. some larvae, a hooked process on the distal inner margin umbo-veliger (MOLLL:Bivalvia) In oysters, the last larval of the maxillary mala, possibly a reminant of the lacinia. b. stage. In Lepidoptera, a process of the 10th abdominal tergum umbraculate, umbraculiferous a. [L. umbraculum, sun- overhanging the anus. 2. (ROTIF) One of a pair of the seven shade] Bearing an umbrella-like structure or organ. main pieces of the mastax. umbrella n. [L. dim. umbra, shade] 1. Any umbrella-shaped undate a. [L. unda, wave] Wavy, undulating. structure. 2. The ectodermal cells located anterior to the underbridge n. [A.S. under, below; bricg, bridge] (NEMATA: preoral band of cilia in the development of a trochophore Secernentea) In Heterodera cysts, a structure extending larva. 3. (CNID: Scyphozoa) The deep to shallow bowl like across the vulval cone below and parallel to the vulval body of a medusa or jellyfish; the bell. see exumbrella, bridge. subumbrella. 4. (MOLL: Cephalopoda) The velum or inter- undifferentiated a. [A.S. un-, not; L. differens, dissimiler] 1. brachial web interconnecting the head and arms of the fin- Immature or embryonic form; unspecialized; capable of ned octopods. differentiation into more specialized form. 2. With cells, umbrella organ see sensillum campaniformium meaning an embryonic cell that can develop into other unarmed a. [A.S. un-, not; L. arma, arms] Without armature types of cells. of any kind, i.e., shield, spurs, spines, plates, teeth, etc. undose a. [L. unda, wave] Undulating; nearly parallel depres- unarticulate a. [A.S. un-, not; L. articulare, to divide] Not sions blending more or less into each other. jointed or segmented. undulate a. [L. unda, wave] Having a wavy surface or margin. uncate a. [L. uncus, hook] Hooked; hamate. ungual a. [L. unguis, claw] Pertaining to the ungues or claws. unci pl. uncus unguiculus n.; pl. unguiculi [L. dim. unguis, claw] 1. A small unciform a. [L. uncus, hook; forma, shape] Hook-shaped. terminal claw or nail-like process. 2. (ARTHRO: Insecta) The smaller of the toothed tarsal claws of Collembola. ungui- uncinal plate see radula culate a. see unguis. uncinal seta (ANN: Polychaeta) Setae modified into hooks, unguifer n. [L. unguis, claw; ferre, to bear] (ARTHRO: Insecta) functioning in feeding or gripping. A median process of the last tarsomere, articulating with uncinate a. [L. uncinus, hook] 1. Hooked or barbed at the end; the pretarsal claws. unciniform. 2. (PORIF) Pertaining to megascleres, a fusiform unguiferate a. [L. unguis, claw; ferre, to bear] (PORIF) Per- oxea with thornlike spines. taining to a type of chelate microsclere with short and dis- uncinate mastax (ROTIF) A mastax with fulcrum and manubria crete teeth, often more than three at each end of the shaft. greatly reduced, stout rami, and large subunci; specialized unguiflexor n. [L. unguis, claw; flectere, to bend] (ARTHRO: for food laceration. Insecta) Muscles responsible for moving or extending the uncini n.pl; sing. uncinus [L. uncinus, hook] 1. (ANN: Poly- ungues. chaeta) Deeply embedded seta with only its multidentate unguiform a. [L. unguis, claw; forma, shape] Shaped like a head showing above the cuticle. 2. (MOLL: Gastropoda) claw. Numerous small teeth- or hook-like structures on the unguis n.; pl. ungues [L. unguis, claw] (ARTHRO) 1. The lat- Online Dictionary of Invertebrate Zoology 931 932 Maggenti and Gardner

eral claw of the pretarsus of several groups. 2. The larger ing one diverticulum. of the toothed tarsal claws of Collembola. ungual a. see uniflagellate a. [L. unus, one; flagellum, whip] With one fla- uguiculus, homodactyl. gellum; monociliated. unguitractor n. [L. unguis, claw; tract, to pull] (ARTHRO: In- unifollicular a. [L. unus, one; folliculus, small bag] Having one secta) A ventral sclerotized plate of the pretarsus from follicle. which arises the retractor muscles of the ungues or claws; also called unguitractor plate. unigeminal a. [L. unus, one; geminus, twin-born] 1. With one pair. 2. (ECHINOD: Echinoidea) Pertaining to one row of unguitractor tendon (ARTHRO: Insecta) The tendon serving pore pairs. for attachment of the unguitractor to the pretarsal depres- sor muscle; apodeme. unilabiate a. [L. unus, one; labium, lip] Having one lip. ungula see unguis unilaminate colony (BRYO) A colony consisting of a single layer of zooids opening in approximately the same direc- uniauriculate a. [L. unus, one; auricula, outer ear] Having a tion. single ear-like process. unilateral a. [L. unus, one; latus, side] On one side only. unibranchiate a. [L. unus, one; branchia, gill] Having one gill. unilocular a. [L. unus, one; loculus, small place] Having one unicameral a. [L. unus, one; , chamber] Having one cell or cavity. chamber. uniloculate a. [L. unus, one; loculus, small place] (ANN) Hav- unicapsular a. [L. unus, one; capsula, little box] Having only a ing only one seminal chamber, such as the spermathecal single capsule. diverticulum. unicarinate a. [L. unus, one; carina, keel] Having a single unimucronate a. [L. unus, one; mucro, sharp point] Having a ridge or keel. single sharp tip. unicellular a. [L. unus, one; cellula, small chamber] Consisting uninominal a. [L. unus, one; nomen, name] Having only one of only one cell. name; monominal. uniciliate a. [L. unus, one; cilium, eyelash] Having a single uninominal nomenclature The designation of a taxon above cilium or flagellum. species rank by a scientific name consisting of a single unicolonial a. [L. unus, one; colere, to dwell] (ARTHRO: In- word. secta) A population of social insects not recognizing nest uniordinal crochets (ARTHRO: Insecta) In larvae, crochets boundaries; multicolonial. arranged in a single row of uniform length or somewhat unicolorate a. [L. unus, one; color, tint] Having one color shorter towards the ends of the row. see ordinal. throughout. uniparous a. [L. unus, one; parere, to beget] Producing one unicornous a. [L. unus, one; cornu, horn] Having only one egg or young at a time. horn. uniplicate a. [L. unus, one; plicare, to fold] Having a single unicuspid a. [L. unus, one; cuspis, point of spear] Having a fold or line of folding. single tapering point; one tooth. unipolar a. [L. unus, one; polus, pole] Having one pole only. unidentate a. [L. unus, one; dens, tooth] Having only one unipolar cell A nerve cell with one fiber issuing from it. tooth. uniradiate a. [L. unus, one; radius, wheel spoke] One-rayed. unidiverticulate a. [L. unus, one; diverticulum, bypath] Hav- Online Dictionary of Invertebrate Zoology 933 934 Maggenti and Gardner uniramous a. [L. unus, one; ramus, branch] Having one an upwardly bent growth line covering a tear in the shell branch only. margin at the site of an injury. uniramous appendage (ARTHRO) An unbranched appendage. upper latus (ARTHRO: Crustacea) In Lepadomorph barnacles, uniramous parapodium (ANN: Polychaeta) A parapodium that the plate in the upper whorl between the scutum and ter- has only one part. gum or carina. uniseptate a. [L. unus, one; septum, partition] Having one upper lip see labrum partition. upsilon see furca uniserial a. [L. unus, one; series, row] Arranged in one row or uranidin see pterine serial. urate a. [Gr. ouron, urine] A salt of uric acid. uniserial circle (ARTHRO: Insecta) Referring to crochets of lar- urate cells (ARTHRO: Insecta) Special cells of the fat-body or in vae arranged in a single row or series with bases in a con- the epidermis or elsewhere that segregate the uric acid, tinuous line. see serial crochets. when not excreted through the Malpighian tubules. uniserrate a. [L. unus, one; serra, saw] One row of serrations. urceolus n. [L. dim. urceus, pitcher] A pitcher- or urn-shaped unisexual a. [L. unus, one; sexus, male or female sex] Indi- structure. viduals having separate sexes (dioecious, gonochoric) and urea n. [Gr. ouron, urine] A simple organic compound, CO(NH producing only one kind (male or female) of gamates, 2 ) 2 , a major nitrogenous waste product. therefore, being dimorphis. ureter n. [Gr. ureter] 1. (ARTHRO: Insecta) A discharging duct unispire a. [L. unus, one; spira, coil] A single turn of a spiral. of aggregate Malphigian tubules. 2. (MOLL: Gastropoda) A unit character A trait behaving as a unit in heredity, inherit- duct connecting the kidney with the mantle cavity. able independently of other traits. uric acid A nitrogenous waste product, more complex and usu- univalent a. [L. unus, one; valens, strong] One member of a ally formed in smaller amounts than urea. pair of homologous chromosomes. uricotelic a. [Gr. ouron, urine; telos, end] The excretion of ni- univalve a. [L. unus, one; valva, leaf of a folding door] (MOLL: trogen as uric acid. Bivalvia) Having a shell composed of one piece. urinary vessels see Malphigian tubules univariate analysis A biometric analysis of one character. urine n. [L. urina, urine] A solution of various waste products. univoltine a. [L. unus, one; It. volta, time] Having one gen- urite see cirrus eration a year; monovoltine. urn bodies 1. (MESO: Rhombozoa) An urn-like sac on the ven- unjointed seta (ANN: Polychaeta) A seta without a joint; a tral surface of infusoriform larvae of a dicyemid that con- simple seta. tains four germinal cells. 2. (SIPUN) Vase-shaped, multi- unmyelinated a. [A.S. un, not; Gr. myelos, marrow] Nerves cellular structures in the coelom. not covered with a myelin sheath. urocardiac ossicle (ARTHRO: Crustacea) In a decapodan gas- unspecialized a. [A.S. un, not; L. species, a particular kind] tric mill, a T-shaped plate running backwards and down- Lacking modifications for any special function or purpose. wards, sometimes bearing a U- or V-shaped median tooth. unsuitable host An immune or resistant animal or plant. urogastric groove (ARTHRO: Crustacea) A short transverse upcurved growth line (ARTHRO: Crustacea) In Conchostraca, groove in the median or submedian region of a decapod Online Dictionary of Invertebrate Zoology 935 936 Maggenti and Gardner

carapace posterior to the postcervical groove, sometimes abdominal tergite. joining the upper part of the postcervical groove. urstigmata n.pl.; sing. urstigma [Ger. ur, primitive; Gr. urogastric lobe or area (ARTHRO: Crustacea) In Decapoda, a stigma, mark] (ARTHRO: Chelicerata) In Acari, sense organs posterior division of the gastric region of a brachyuran between the coxae of the first and second pairs of legs; carapace; genital region. thought to be humidity receptors; Claparede organs. urogenital a. [L. urina, urine; gignere, to beget] Of or per- urticate v. [L. urtica, nettle] To sting or burn. urtication n. see taining to the urinary and genital system. nematocyst. urogenital opening (MOLL: Bivalvia) Opening through which urticating hairs (ARTHRO: Insecta) In some caterpillars and the gonadal products and excretory products are released adults, bristles with minute lateral points producing marked into the cloacal passage of the exhalant mantle chamber. irritation upon contact, whether due to mechanical action urogomphi n.pl.; sing. urogomphus [Gr. oura, tail; gomphos, alone or presence of poisonous secretion. club] (ARTHRO: Insecta) In Coleoptera larvae, a pair of out- urticator n. [L. uritica, nettle] (CNID) Cnidocytes; a nettle or growths of the tergum of segment 9 in the form of short sting cell. spines or multiarticulate processes; pseudocerci; corniculi. urzellen see prohemocyte uromere n. [Gr. oura, tail; meros, part] (ARTHRO) An abdomi- U-shaped notal ridge see scutoscutellar suture nal segment. ustulate a. [L. ustulatus, scorch or burn] Having the appear- uropatagium n.; pl. uropatagia [Gr. oura, tail; patagium, ance of being scorched or burned; brownish. border] (ARTHRO: Insecta) One of the paraprocts located on either side of the anus. uterine bell (ACANTHO) A bell-like or tubular structure of some females, that moves eggs from the pseudocoel to the uropod(ite) n. [Gr. oura, tail; pous, foot] (ARTHRO: Crustacea) uterus. 1. In Malacostraca, an appendage of the 6th abdominal somite, fanlike or reduced or modified. 2. In , uterine vagina see vagina uterina the last 3 pairs of abdominal appendages. uterus n. [L. uterus, womb] An enlargement of the lower end uropolar cells (MESO: Rhombozoa) In Dicyemida, somatoderm of the oviduct, in which eggs are retained temporarily or in cells at the posterior end of the trunk. which the embryo develops. uterine a. uropore n. [Gr. ouron, urine; poros, passage] (ARTHRO: Cheli- utricle n. [L. dim. uter, bag] A small bag or bladder. cerata) In Prostigmata and Tarsonemida, an external utriculus n. [L. dim. uter, bag] (ARTHRO: Insecta) In Lepidop- opening of the excretory duct in groups that have an in- tera, the larger lobe of the spermatheca; may be fused into complete gut. see anus. one organ. see lagena. urosome, urosoma n. [Gr. oura, tail; soma, body] 1. (AR- uvette n. [L. dim. uva, grape] (NEMATA: Adenophorea) The THRO) The abdomen. 2. (ARTHRO: Crustacea) That part of glandular region where the efferent tubes of the Demanian the body posterior to the major articulation, usually in- vessels meet before passing on to one or more exit pores cluding last 3 abdominal somites, bearing modified ap- in the body wall. pendages. urosternite n. [Gr. oura, tail; sternon, chest] (ARTHRO) The sternal or ventral part of the uromeres. urotergite n. [Gr. oura, tail; L. tergum, back] (ARTHRO) An 938 Maggenti and Gardner

plates of a mollusk, brachiopod or . 3. (ARTHRO: V Insecta) Certain external genitalia. valve coverage (MOLL: Polyplacophora) 1. Complete coverage Two contiguous valves with the rear edge of one covering the whole front edge of the one posterior to it. 2. Partial vacuole n. [L. vacuus, empty] A minute cavity within a cell, coverage A small part of the front edge of the next valve usually filled with a liquid product of protoplasmic activity. that is overlapped. 3. Jugal coverage With only the apical vacuolar a. part of a valve overlapping the next one. vagile a. [L. vagus, wandering] Freely wandering; motile. valvelet n. [L. dim. valva, leaf of a folding door] A small valve vagility n. see sessile. or fold. vagina n. [L. vagina, sheath] The terminal portion of the fe- valvifers n.pl. [L. valva, leaf of a folding door; ferre, to bear] male reproductive tract, that opens to the outside. vaginal (ARTHRO: Insecta) The basal plates of the ovipositor, de- a. rived from the basal segment of the gonopods; also known as the first and second gonocoxae. vaginate a. [L. vagina, sheath] Enclosed by a sheath. valvula n.; pl. valvulae [L. dim. valva, leaf of a folding door] vagina uterina (NEMATA) An inward extension of the vagina, 1. Any small valve-like process. 2. (ARTHRO: Insecta) In uniting with the distal part of the uterus, that histologically Hymenoptera, processes from the valvifers forming the resembles the vagina, but lacks cuticular lining. body of the ovipositor and the ovipositor sheath. vagina vera (NEMATA) The outermost part of the vagina, lined valvular a. [L. dim. valva, leaf of a folding door] Of or per- with cuticle. taining to a small valve or valvula. vaginipennate a. [L. vagina, sheath; penna, wing] (ARTHRO: valvular process see style Insecta) To ensheath a wing; having wings covered with a hard sheath. vannal fold (ARTHRO: Insecta) A radial line of folding of a wing, commonly between the cubital field and the first vaginula n. [L. dim. vagina, sheath] (ARTHRO: Insecta) The vannal vein; sometimes variable. covering of the terebra. vannal lobe (ARTHRO: Insecta) A lobe in the anal area of a vagus see stomogastric nervous system wing, immediately distad of the jugal lobe (when present). valency n. [L. valentia, strength] Power; important; value. vannal region (ARTHRO: Insecta) That part of the wing com- valid name An available name for a taxon that is not preoccu- prising the vannal veins, or veins directly associated with pied by a valid senior synonym or homonym. the third axillary; vannus. valva n.; pl. valvae [L. valva, leaf of a folding door] (ARTHRO: vannal veins (ARTHRO: Insecta) The veins of a wing in the Insecta) In Lepidoptera, a valve in the external male geni- vannal region, with basal association with the third axillary talia; the coxite and the stylus. see harpagones. sclerite. valvate a. [L. valva, leaf of a folding door] 1. Furnished with vannus see vannal region valves. 2. Hinged only at the margin. 3. Of or pertaining to variance n. [L. variare, to change] A sampling statistic relating a valve. to deviations from the mean. valve n. [L. valva, leaf of a folding door] 1. Any structure that variate n. [L. variare, to change] A variable quantity or char- limits or closes an opening. 2. One of the discrete shells or acter. Online Dictionary of Invertebrate Zoology 939 940 Maggenti and Gardner variation n. [L. variare, to change] Differences resulting from another. 2. In helminthic disease, an intermediate host that nongenetic responses of the phenotype to immediate en- seeks out the definitive host; as a mosquito. vironmental conditions; ecophenotype. vegetal pole In an early embryo, a region with large cells with varicellate a. [L. , dilation] Having small or indistinct much yolk; portion of egg or zygote with more yolk than varices. opposite end. varices pl. of varix vegetative functions All natural functions of living organisms varicose a. [L. varix, dilation] Bearing a varix or varices. that maintain life. variegated a. [L. variegatus, of different sorts] Marked by dif- vegetative reproduction The development of a new individual ferent shades or colors. from a group of cells in the absence of any sexual process. variety n. [L. variare, to change] An ambiguous taxonomic veinlets n.pl. [L. dim. vena, vein] Small veins. term for a heterogeneous group of phenomena including veins n.pl. [L. vena, vein] 1. Vessels conducting blood toward nongenetic variations of the phenotype, morphs, domestic the heart. 2. (ARTHRO: Insecta) The heavily sclerotized breeds, and geographic races. portion of wings that usually enclose small central tra- variole n. [F. variole, smallpox] A pock-like mark; fovea; cheae. fossa. variolate a. velarium n. [L. velarium, awning] (CNID) A velum-like struc- varix n.; pl. varices [L. varix, dilation] (MOLL: Gastropoda) ture having canals lined with endoderm; flaps on the edge Transverse elevations that occur on the outer shell surface; of the bell. more prominent than the costa and generally spaced more veliconch n. [L. velum, curtain; concha, shell] (MOLL: Bivalvia) widely; result of growth halt in which a thickened outer lip The shell of the veliger larva; prodissoconch. developed. veliger n. [L. velum, curtain; gerere, to bear] (MOLL) A larval vas n.; pl. vasa [L. vas, vessel] A small tubular vessel, duct or stage with a ciliated swimming membrane or membranes; canal, especially leading from the testis. a free-swimming young bearing a velum. vascula n.pl.; sing. -um [L. dim. vas, vessel] (BRACHIO) velum n.; pl. vela [L. velum, curtain] 1. A thin membranous Branches of the mantle canal system. covering. 2. (ANN: Hirudinoidea) A membrane separating vascular a. [L. dim. vas, vessel] Pertaining to vessels adapted the buccal cavity from the cavity of the oral opening. 3. for transmission or circulation of fluids. (ARTHRO: Crustacea) In Ostracoda, a ventral ridge, flange, or frill that may extend around part or all of the anterior vascular markings (BRACHIO) Impressions of the mantle ca- and posterior ends. 4. (ARTHRO: Insecta) The membrane nals on the inside of the shell; pallial markings. forming part of the apical and marginal areas of a pa- vas deferens sing.; pl. vasa deferentia 1. A sperm duct ramere. 5. (CNID) A shelf of tissue extending inward near leading away from a testis. 2. (ANN: Oligochaeta) A duct the margin of the bell of medusae. 6. (MOLL) a. In Bivalvia, carrying sperm from the male funnel to the male pore. the large, ciliated swimming disc of larval oysters. b. In vas efferens sing.; pl. vasa efferentia Tubule leading from Gastropoda, the swimming membrane consisting of two the testis to the vas deferens. large semicircular folds bearing cilia. 7. (NEMATA) The ven- tral membranous winglike extensions on the spicule of vasiform a. [L. vas, vessel; forma, shape] Vessel-shaped. some male nematodes. 8. (PLATY: Cestoda) The membra- vector n. [L. vehere, to carry] 1. Any carrier, particularly an nous posterior margin of a proglottid overlapping the ante- animal that transmits a disease organism from one host to rior of the following one. Online Dictionary of Invertebrate Zoology 941 942 Maggenti and Gardner velutinous a. [NL. vellutum, velvet] Clothed with very dense, ventral cirrus see neurocirrus upright short hairs. ventral comb (ARTHRO: Crustacea) In Cephalocarida, a row of venation n. [L. vena, vein] The complete system of veins. setae or bristles on the posteroventral margin of the last venom n. [L. venenum, poison] The secretion of the accessory abdominal somite. venom, or poison gland. venomous a. ventral cup (ARTHRO: Crustacea) An element of the nauplius venom apparatus 1. (ARTHRO: Insecta) The sting apparatus or eye. accessory glands. 2. (ANN: Polychaeta) The seta or venom- ventral diaphragm (ARTHRO: Insecta) A horizontal septum ous jaws. above the nerve cord separating the perineural sinus from venom gland 1. A gland secreting an irritating or lethal sub- the main perivisceral sinus. stance. 2. (ARTHRO: Chelicerata) In true spiders, a pair of ventral frontal organ (ARTHRO: Crustacea) Paired sensory glands situated in the cephalothorax; in others, on the che- structures associated with the nauplius eye. licerae with ducts traversing each claw with an oval slit ventral gland see prothoracic gland opening near the tip. 3. (ARTHRO: Insecta) In Hymenop- tera, the largest sting gland situated between the rectum ventral groove (ARTHRO: Insecta) In Collembola, a cuticular and vagina and ending in the aculeus. see apid venom channel down the middle ventral line of the body from the gland, braconid venom gland, vespid venom gland. labium to the anterior part of the ventral tube; thought to function in osmoregulation. venose a. [L. vena, vein] Having veins or lines that branch like veins. ventralia n. [L. venter, belly] (GNATHO) Paired sensory bristles found ventrally on the head of jaw worms. venous a. [L. venosus, full of veins] Having numerous veins. ventral membrane (ARTHRO: Insecta) In Diptera, skin-like tis- vent n. [L. findere, to split] The anus. sue connecting the tergites and the sternites along the venter n. [L. venter, belly] The ventral side; the entire under sides of the abdomen. surface of an animal. ventral muscles (ARTHRO: Insecta) Tergal and sternal longitu- ventilation tracheae (ARTHRO: Insecta) Tracheae, that are dinal abdominal muscles running between the interseg- subject to collapse, that respond to varying surrounding mental folds or on the antecostae of successive sterna. pressure. see diffusion tracheae. ventral nerve cord The primary nerve cord of all inverte- ventrad adv. [L. venter, belly; -ad, toward] Toward the venter, brates, except those of the Hemichordata and Chordata or underside of the body. see dorsad. phyla. ventral a. [L. venter, belly] 1. The lower or underside of the ventral pharyngeal gland see pharyngeal gland, ventral body. 2. (MOLL: Bivalvia) The edge remote from the hinge; ventral plate (ARTHRO: Insecta) 1. In embryology, a layer of opposite the umbones. columnar cells of the blastoderm on the ventral side of the ventral brush (ARTHRO: Insecta) In culicid larvae, a linear se- egg. 2. In Diptera, the floor of the cibarium. ries of irregularly paired setae, often divided into two ventral process see sternal coxal process groups, posteroventrally on the midline of abdominal seg- ment 10. ventral prolegs (ARTHRO: Insecta) Prolegs occurring ventrally on the abdominal segments of larvae, except the last seg- ventral cardo (ARTHRO: Crustacea) In Ostracoda, that portion ment that are called anal prolegs. of the peniferum that serves as a hinge by which it articu- lates with the zygum. ventral scale (ARTHRO: Insecta) In Diaspinae, the ventral part Online Dictionary of Invertebrate Zoology 943 944 Maggenti and Gardner

of the scale, composed of a thin layer of wax and the ven- ventriculus n. [L. dim. venter, belly] (NEMATA) Anterior part of tral exuviae that are interposed between the insect and the the intestine if cellularly different from the rest of the in- plant. testine; sometimes corrupted to mean glandular portion of ventral setae (ARTHRO: Insecta) In Culicidae, four small pe- the esophagus. ventricular a. see ventricular valve. glike cibarial setae located at the posterior margin of the ventrite n. [L. venter, belly] A ventral segment; ventral aspect cibarium. of annular rings. ventral sinus (ARTHRO: Insecta) The space of the body cavity ventrodorsal a. [L. venter, belly; dorsum, back] Extending below the ventral diaphragm, containing the nerve cord; from ventral to dorsal. the perineural sinus. ventrolateral a. [L. venter, belly; latus, side] Of or pertaining ventral stylet (ARTHRO: Insecta) In Siphunculata, the lower of to the area ventrally and to the side. 3 stylets (labium), toothed at the base for piercing. ventromedially adv. [L. venter, belly; medius, median] Of or ventral sympathetic nervous system (ARTHRO: Insecta) A pertaining to the median ventral line. pair of transverse nerves associated with the ganglia of the venulose a. [L. dim. vena, vein] Having many small veins. ventral nerve cord in each segment, passing to the spira- cles of their segment; may be connected to the perisym- verge n. [F. verge, rod] (MOLL: Gastropoda) In Prosobranchia, pathetic system. the penis. ventral thickening (ARTHRO: Insecta) In soft scales, two Vermes n. [L. vermis, worm] An obsolete term for animals that sclerotic, dorsal, internal processes that support the anal included all worm-like phyla. plates. vermian a. [L. vermis, worm] Worm-like. ventral tube (ARTHRO: Insecta) In all Collembola, a basal col- vermicide n. [L. vermis, worm; caedere, to kill] Any of various umn containing a pair of protrusible vesicles (shallow sacs therapeutic agents producing the death of a helminth; or long and tubular), on the ventral aspect of the first seg- anthelmintic. see vermifuge. ment; functioning in respiration, water absorption and/or vermiculate a. [L. dim. of vermis, worm] Resembling a worm, adhesive organ for mobility over smooth or steep surfaces. or having tracery simulating the tracks of a worm. ver- see ventral groove. miculation n. ventral vessel (ANN: Oligochaeta) A major blood vessel found vermiform a. [L. vermis, worm; forma, shape] Worm-shaped. in the mesentery ventral to the alimentary canal. vermiform cells see plasmatocyte ventricle n. [L. dim. venter, belly] A cavity or chamber of an organ, especially of the heart; receives blood from the vermiform embryos (MESO: Rhombozoa) In Dicyemida, the auricles. see heart chamber. young produced within the axial cell of adults. ventricose a. [L. dim. venter, belly] 1. Distended, inflated to- vermiform larva (ARTHRO: Insecta) A legless worm-like larva, ward the middle. 2. (MOLL: Gastropoda) In Harpidae, hav- lacking a well developed head. see pronymph. ing the whorls or valves swollen or strongly convex; in- vermifuge n. [L. vermis, worm; fugare, to drive away] A flated in the middle or on one side. therapeutic agent causing expulsion of a helminth, that ventricular valve 1. (ARTHRO: Insecta) see auricular valve. may or may not cause its death; anthelmintic. see vermi- 2. (NEMATA) A valve between the esophagus and the mes- cide. enteron proper; esophagointestinal valve. vernacular name The colloquial designation of a taxon. see scientific name. Online Dictionary of Invertebrate Zoology 945 946 Maggenti and Gardner vernal a. [L. vers, spring] Appearing or occurring in spring. highest point. 2. (ARTHRO: Insecta) A wing vein when both vernicose a. [NL. vernicosus, varnished] Appearing as though ends are equally distant from the wing base. varnished or brilliantly polished. vertical bristles (ARTHRO: Insecta) In Diptera, two pair of verricule n. [L. verriculum, net] A dense tuft of nearly parallel bristles, "inner and outer" behind the upper and inner cor- upright hairs. verriculate a. ners of the eyes; vertical cephalic bristles. Verrill's organ see funnel organ vertical classification Classification focusing on common de- scent, tending to unite ancestral and descendant groups of verruca n.; pl. verrucae [L. verruca, wart] 1. A wart or wart- a phyletic line into a single higher taxon, thereby separat- like prominence. 2. (ARTHRO: Chelicerata) In certain Acari, ing them from contemporaneous taxa having reached a a genital papilla, sternal prominence, or the genital cap- similar grade of evolutionary change. see horizontal clas- sule. 3. (ARTHRO: Insecta) In Lepidoptera larvae, a tubercle sification. bearing tufts of setae. 4. (CNID: Anthozoa) a. In Alcyonaria, a protuberance surrounding the base of polyps. b. In Ac- vertical triangle see ocellar triangle tiniaria, wart-like prominences on the body wall. verticillate a. [L. verticillus, small whorl] Whorled; provided verruciform cells (MESO) Somatic cells enlarged by lipoprotein with whorls of fine hairs; having spines arranged in nodes bodies. or whorls. verrucose a. [L. verruca, wart] Covered with minute warts or verticillate antenna (ARTHRO: Insecta) Antenna with whorls of tubercles. see papillate. hair at the joints or segments. versatile a. [L. versatilis, mobile, changeable] Moving freely. vertition n. [L. vertere, to turn] An idionymous organ observed unilaterally among specimens of the same species and versicolor a. [L. versicolor, to change color] Having many col- stage that has evolutionary significance. ors; changeable in color. vesica see preputial sac Versonian glands see Verson's glands vesicating a. [L. vesica, blister, bladder] Blister-like. Verson's cells see apical cell vesicle, vesicula n. [L. dim. vesica, bladder, blister] 1. A sac, Verson's glands (ARTHRO: Insecta) In Lepidoptera larvae, bladder, or cyst, frequently extensible. 2. (ANN: Oli- large paired, segmental epidermal glands that secrete a gochaeta) The anteriorly or posteriorly directed pockets of "cement layer" over the wax layer; dermal glands. a septum in which male germ cells mature; the reproduc- vertebra n.; pl. -ae [L. vertebra, turning joint] (ECHINO) 1. In tive system. vesiculate a. Asteroidea, the fused pair of opposite ambulacrals, articu- vesicular a. [L. dim. vesica, bladder, blister] Containing small lating with adjacent vertebrae by ball-and-socket joints. 2. cavities or vesicles. In Ophiuroidea, enclosed by a ventral arm plate and skin or a dorsal arm plate. vesicular cell (BRYO) A cell enclosing a large vesicle; found in peritoneal network and funicular strands. vertex n. [L. vertex, top] 1. The top; apex; summit; the high- est or principal point. 2. (ARTHRO: Crustacea) The top point vesicula seminalis see seminal vesicle of the head or cephalon. 3. (ARTHRO: Insecta) The top of vesparium n. [L. vespa, wasp; -arium, place for] (ARTHRO: In- the head, between the eyes and anterior to the occipital secta) In Hymenoptera, a natural or artificial colonial nest suture; the crown of the head. of vespine wasps. vertical a. [L. vertex, top] 1. Of or pertaining to the vertex; vespid venom gland (ARTHRO: Insecta) In Hymenoptera, a Online Dictionary of Invertebrate Zoology 947 948 Maggenti and Gardner

type of venom gland in which two tubes end in a distinct tles. 2. (ARTHRO: Insecta) For Diptera, see oral vibrissae. spherically formed reservoir whose wall has a strong mus- vibrissal ridge (ARTHRO: Insecta) In Diptera, a ridge arising on cular layer, but no glandular elements. each side of the face, inside the arms of the frontal suture; vespoid a. [L. vespa, wasp; -oid, like] Wasp-like. limited distally by the epistoma and the vibrissal angles; vessel n. [L. dim. vas, vase] A tubular structure that conveys facial ridge. fluid. vibrotaxis n. [L. vibrare, to vibrate; Gr. taxis, arrangement] vestibular organs (CHAETO) A transverse row of papillae, or An organism's response to mechanical vibrations. papillae on a ridge, just behind the teeth. vicarious a. [L. vicarius, deputy] 1. Taking the place of. 2. vestibular pit (CHAETO) A glandular depression behind the Closely related taxa in corresponding but separate envi- vestibular organs. ronments. vestibular wall (BRYO) The body wall surrounding the vesti- vicarious polymorph (BRYO: Gymnolaemata) A polymorph in bule and connecting the tentacle sheath to the wall of the a budding series that communicates with several zooids. orifice. vicinal a. [L. vicinus, neighbor] Neighboring; nearby. vestibule, vestibulum n.; pl. -bula [L. vestibulum, entrance vicinism n. [L. vicinus, neighbor] The propensity to variation hall] 1. A cavity forming an entryway to another cavity or due to proximity of related organisms. passageway. 2. (ANN) Containing a penis or male poro- villi pl. of villus phore and pore fissure. 3. (ARTHRO: Crustacea) In Ostra- coda, a space between the duplicature and outer lamella. villose a. [L. villus, tuft of hair] Covered with villi. 4. (BRYO) The area through which the lophophore passes. villus n.; pl. villi [L. villus, tuft of hair] Soft flexible hairs. see 5. (ROTIF;CHAETO) An opening leading to the mouth. 6. microvillus. (NEMATA) see stoma, cheilostome. vestibulate a. vinculum n.; pl. -la [L. vinculum, anything used for binding] 1. vestige n. [L. vestigium, footprint] A degenerate or imperfect Anything used to bond structures together. 2. (ARTHRO: In- remaining ancestral organ. secta) In male Lepidoptera, an U-shaped genital plate, dor- vestigial a. [L. vestigium, footprint] Pertaining to a small, de- sally articulating with the pedunculus and midventrally generate, nonfunctional organ that was ancestrally more forming a saccus. 3. (MOLL: Bivalvia) A shelly material be- fully developed or functional. tween the basic dental structures of the shell. vestiture n. [L. vestis, garment] The body covering, as scales vinous a. [L. vinum, wine] Wine-colored; vinaceous. or hairs. violaceous a. [L. viola, violet] Having a violet hue. vexillum n.; -illa [L. vexillum, flag] (ARTHRO: Insecta) In fos- virescent a. [L. virescere, to grow green] Greenish or turning sorial Hymenoptera, an expansion on the tip of the tarsi. green. viable a. [L. vita, life] Capable of living; the ability to grow and virga n. [L. virga, rod] (ARTHRO: Insecta) In Dermaptera, a develop. threadlike, sclerotized extension of the ejaculatory duct vibraculum n.; pl. vibracula [L. dim. vibrare, to vibrate] that guides the passage of the spermatophore into the (BRYO: Gymnolaemata) A heterozooid with the operculum spermatheca of the female in the form of a long bristle or seta between pivots, sup- virgalium n.; pl. -lia [L. virga, rod] (ECHINOD: Asteroidea) Os- posedly used to sweep away detritus and settling larvae. sicles lateral to and symmetrically placed on each side of vibrissa n.; pl. -sae [L. vibrissa, whisker] 1. Stiff hairs or bris- the ambulacral ossicles. Online Dictionary of Invertebrate Zoology 949 950 Maggenti and Gardner virgate a. [L. virga, rod] Rod-shaped. visceral sinus (ARTHRO: Insecta) A central cavity between the virgate mastax (ROTIF) With fulcrum and manubrium in the dorsal and ventral sinuses, containing the main internal or- shape of elongate rods; rami are triangular plates. gans. virgula organ (PLATY: Trematoda) Two pyriform sacs fused in visceral trachea (ARTHRO: Insecta) The median segmental the median line with forward pointed ends and placed near trachea beginning at a spiracle and branching to the ali- the posterior margin of the oral sucker. mentary canal, fat tissue, and reproductive organs. virgulate cercaria (PLATY: Trematoda) A Xiphidiocercaria visceral tracheal trunk (ARTHRO: Insecta) A longitudinal group with a ventral sucker smaller than the oral, tail with- trunk associated with the walls of the alimentary canal. out a fin and a virgula organ near the posterior margin of visceropallium see visceral hump or mass the oral sucker. viscid a. [L. viscidus, sticky] Having a thick or sticky consis- viridis a. [L. viridis, green] Green; greenish; viridescent. tency; adhesive. virion n. [L. virus, poison] The mature virus. viscosity n. [L. viscidus, sticky] The resistance of a fluid to virology n. [L. virus, poison; Gr. logos, discourse] The study of flow due to adherence of particles of one to another. vis- viruses. cous a. virulence n. [L. virulentus, fr. virus, poison] The state of being vital staining Staining of living cells and tissues by relatively pathogenic. non-toxic dyes; intravital staining. see intra vitam. virus n. [L. virus, poison] An intracellular obligate, infectious vitellaria larva (ECHINOD: Holothuroidea, Crinoidea, Ophiur- parasitic agent visible only under the electron microscope, oidea) A nonfeeding, barrel-shaped larva possessing cili- causing many diseases in man, animals and plants. viral a. ated bands with no arms. viscera n.pl. [L. viscera, entrails, flesh inside the body] Inter- vitellarium n.; pl. -ia [L. vitellus, yolk; -arium, place for] 1. A nal organs. visceral a. yolk gland; a zone of growth. 2. (ARTHRO: Insecta) That part of an ovariole that contains the developing eggs. 3. visceral ganglion 1. (MOLL: Bivalvia) Ganglion found near the (PLATY) Glands which produce yolk material and possibly posterior adductor muscle in the posterior viscera. 2. the eggshell. (MOLL: Gastropoda) Unpaired, median ganglion lying pos- teriorly and ventrally to the gut; may be fused with other vitelligenous a. [L. vitellus, yolk; gignere, to produce] Pro- ganglia in advanced forms. ducing yolk; sometimes applied to certain cells in the ova- ries. visceral hump or mass (MOLL) The main metabolic region of the body; contains the body organs; the visceropallium. vitelline a. [L. vitellus, yolk] Yellow like the yolk of an egg. visceral nervous system see stomogastric nervous sys- vitelline body see yolk nucleus tem or sympathetic system vitelline duct (PLATY: Turbellaria) One of paired ducts con- visceral pouch (MOLL: Bivalvia) A small extension of the vis- necting the vitelline glands to the common vitelline duct. ceral mass on the anterior side of the adductor muscle in vitelline membrane A membrane enclosing eggs of inverte- oysters. brates located within an egg shell. visceral segments (ARTHRO: Insecta) All abdominal segments vitellogenesis n. [L. vitellus, yolk; Gr. genesis, beginning] The anterior to the genital segments; only the anterior visceral production of yolk. segments are variously modified. vitellophages, vitellophags n.pl. [L. vitellus, yolk; Gr. Online Dictionary of Invertebrate Zoology 951 952 Maggenti and Gardner

phagein, to eat] Cells involved with the breakdown of the vulva fenestra (NEMATA: Secernentea) In some Heterodera, a yolk at all stages of development. vitellophagic a. thin transparent zone in the body wall of a white female vitellus n. [L. vitellus, yolk] The yolk of an egg. and the cyst wall; encircling or at the sides of the vulva. vitreous a. [L. vitrum, glass] Glassy; transparent. vulval bridge (NEMATA: Secernentea) In some Heterodera cysts, a narrow connection across the fenestra of the vulval vitreous body see crystalline cone cone, forming two semifenestrae. vitreous humor (MOLL: Cephalopoda) A jelly-like substance vulval flap/membrane see epiptygma filling the posterior chamber of the eye. vulvar lamina (ARTHRO: Insecta) In Odonata, a subgenital vitta n.; pl. -tae [L. vitta, band] A broad stripe or band. see plate of the 8th abdominal sternite. fascia, frontal vitta. vittate a. vitta frontalis see frontal stripe viviparous a. [L. vivere, to live; parere, to beget] Bringing forth living young. viviparity n. see oviparous, ovovivipa- rous. volant a. [L. volare, to fly] Capable of flying. volatile a. [L. volare, to fly] Passing away by evaporation. volsella n.; pl. -ae [L. volsella, pincers] (ARTHRO: Insecta) In Hymenoptera, the inner basal process of the gonocoxite. -voltine suff. [It. volta, time] Used with a prefix to denote the number of broods in a year; i.e., multivoltine. voluntary muscle Striated muscle capable of rapid contraction and relaxation; found in arthropods and other groups of animals. volute n. [L. volvere, to roll] (MOLL) A whorl or turn of a spiral shell. volution n. [L. volvere, to roll] (MOLL: Gastropoda) A complete coil of a helicocone. see whorl. volvent see desmoneme vomer n. [L. vomer, plowshare] (ARTHRO: Insecta) In the in- fraorder Phasmatidea or suborder Anareolatae, a movable sclerotized process that functions during copulation; vomer subanal. vulva n. [L. vulva, womb] The external opening of the female reproductive system. vulva cone (NEMATA: Secernentea) In some Heterodera cysts, the posterior protuberance on the posterior portion. 954 Maggenti and Gardner

wax-plate (ARTHRO: Insecta) A plate where the secretions of W the wax glands are deposited. wax scale (ARTHRO: Insecta) In Apis, thin plates of wax se- creted from the intersternal pockets of younger worker bees. web n. [A.S. webb] (ARTHRO) A network of threads spun by Wagener's larva (MESO: Rhombozoa) In Mycrocymea , a free spiders, mites and some insects. swimming larval stage that attaches to the host kidney tis- weighting n. [A.S. gewiht, weight] An evaluation of phyletic sue and transforms into a nematogen. content of a character and the evaluation of its probable waggle dance (ARTHRO: Insecta) A dance performed by hon- contribution to a sound classification. eybees indicating source and location of a good source. Weismann's ring see ring gland walking leg see pereopod wheel organ (ROTIF: Bdelloidea) Ciliated trochal discs, raised wall n. [L. vallus, a palisade] The encumbering sides of an or- on pedestals, functioning in locomotion and in the produc- gan or structure. tion of food currents; corona. warm-blooded see homoiothermal white body see Hensen's gland warning coloration Conspicuous colors of invertebrates white cuticle (ARTHRO: Insecta) The inner thick, tough, lami- causing predators to ignore them as food, either because nated endocuticle of an egg membrane secreted by the they are poisonous or distasteful or because they are mim- serosa, and containing chitin. see yellow cuticle. icking organisms possessing disagreeable qualities. see wholemount An intact specimen prepared for examination. sematic, aposematic, pseudaposematic. whorl n. [A.S. hweorfan, to turn] (MOLL: Gastropoda) 1. Any wart see verruca, tubercle complete coil of a helicocone. 2. The exposed surface of water pore see hydropore any complete coil of a helicocone. Waterston's organ (ARTHRO: Insecta) In Hymenoptera Cera- width n. [A.S. wid, broad] (MOLL) The maximum dimension phronidae, a medial patch of reticulum on the 5th gastric measured at right angles to the length or height of a shell. tergite; function unknown. wild type A strain, organism, or gene of the type predominat- water vascular system (ECHINOD) A unique system com- ing in nature; natural. prised of tube-like body wall appendages (tube-feet), and a wing n. [ME. winge, wing] 1. (ARTHRO) One of paired, thin, system of canals derived from the coelom. membranous reticulated organs of flight. 2. (MOLL) A pro- wax n. [A.S. weax, wax] (ARTHRO: Insecta) A substance se- jection, flattened, expansion, or earlike extension of a creted by various insects consisting of a complex mixture hinge line; auricle. see ala. of lipids, varying from species to species. winter egg Resting egg; where applicable, a type of egg with a wax gland Any gland in various parts of the body that secrete thick shell that protects the egg over winter; opsiblastic. a waxy product in the form of a scale, string or powder. see summer egg. wax layer (ARTHRO: Insecta) Wax secreted by oenocytes at or With's organs (ARTHRO: Chelicerata) In Acari, paralabial hy- near the surface or incorporated into the inner layers of the pertrophied setae mediad from the rutella. cuticle; responsible for waterproofing the cuticle. workers n.pl. [A.S. worc, work] (ARTHRO) 1. An individual of Online Dictionary of Invertebrate Zoology 955

the semisocial and eusocial Hymenoptera, nonreproductive, laboring caste. 2. In Isoptera, individuals which lack wings X and possess reduced pterothorax, eyes and genital appa- ratus. 3. In Formicidae, the ordinary sterile female, bearing reduced ovarioles and simplified thorax; includes both mi- nor workers and soldiers in species with two subcastes. xanthic a. [Gr. xanthos, yellow] Yellowish in color. worker jelly (ARTHRO: Insecta) In Apis, food given to larvae xanthophyll n. [Gr. xanthos, yellow; phyllon, leaf] An oxidised that causes them to become workers; bee milk. derivative of carotene found in the blood of some plant eating insects. xanthopterin, xanthopterine (ARTHRO: Insecta) A yellow pteridine pigment of some insects. X-chromosomes In most dioecious diploid organisms, sex chromosomes of which there are a pair in the female, but only one in the male. xenagones n.pl. [Gr. xenos, guest; agein, to lead] Substances produced by parasites that act upon the host. xenic a. [Gr. xenos, guest] The rearing of individuals of one species together with an unknown number of species of other organisms. see axenic, polyxenic, synxenic, trix- enic. xenobiosis n. [Gr. xenos, guest; bios, life] (ARTHRO: Insecta) A form of relation in which one species lives in and among the nests of another species, obtaining food from them by regurgitation or other means, but keeping their own brood separate. xenoecic a. [Gr. xenos, guest; oikos, house] Living in an abandoned shell of an unrelated species. xenogamy see cross-fertilization xenogenesis see heterogenesis xenomone see allelochemic xenomorphism n. [Gr. xenos, stranger; morphe, form] (MOLL: Bivalvia) Sculpture in the umbonal region of the unattached valve that resembles the substratum on which the attached valve was fixed. xenomorphic a. xenoparasite n. [Gr. xenos, guest; para, beside; sitos, sit] An ecosite that becomes pathogenic due to a weakened resis- tance on the part of its host. Online Dictionary of Invertebrate Zoology 957 xerarch succession A series of community changes from bare land to climax. Y xeric a. [Gr. xeros, dry] Arid; lacking in moisture; adaptation to dryness. xerophilous a. [Gr. xeros, dry; philos, loving] Living in dry places. Y-chromosomes A chromosome in the male, which pairs with the X-chromsome at synapsis. xerophobous a. [Gr. xeros, dry; phobos, fear] Intolerant of arid conditions. yellow body (ARTHRO: Insecta) An amorphous mass formed by shed larval epithelium of the midgut occurring in the lumen xerosere n. [Gr. xeros, dry; L. serere, to join] A sere arising at pupation. under dry conditions. see lithosere, hydrosere. yellow cells see chlorogogen cells xerothermic fauna Animals found in warm, dry conditions. yellow cuticle (ARTHRO: Insecta) A thin epicuticle of the egg xiphidiocercaria n. [Gr. xiphos, sword; kerkos, tail] (PLATY: membrane secreted by the serosa, that is highly imperme- Trematoda) Cercaria with a long tail and a stylet in the able to water and lacks chitin. see white cuticle. anterior rim of the oral sucker. see microcotylate cer- caria, microcercous cercaria. yolk n. [A.S. geoloca, yolk] Stored food substances in the egg cell. xiphiform a. [Gr. xiphos, sword; L. forma, shape] Sword- shaped. yolk cells Primary yolk cells that take no part in the blasto- derm formation. x-organ 1. (ARTHRO: Crustacea) In Decapoda, a neuro-secre- tory organ situated in the eye stalk, and the cephalon of yolk duct see vitelline duct sessile-eyed crustaceans; frontal organs in Anostraca. see yolk gland see vitellarium organ of Bellonci, frontal eye complex, frontal organ. yolk nucleus Intensely osmiophilic body located near the nu- 2. (KINOR) In female chaetonotoids that lack an oviduct, a cleus; vitelline body; Balbiani's body. sac-like structure through which the eggs pass to the sur- face of the body. Y-organs (ARTHRO: Crustacea) In Decapoda, paired nonneural glands in the antennary or maxillary segments that secrete xylanase n. [Gr. xylon, wood; -ase, enzyme] (ARTHRO: In- the molting hormone ecdysone. secta) In wood ingesting Cerambycidae, an enzyme that hydrolizes xylosan to xylose. Y-vein (ARTHRO: Insecta) Two adjacent veins fused distally forming a Y shape. xyloid a. [Gr. xylon, wood; eidos, like] Like or resembling wood; ligneous. xylophagous a. [Gr. xylon, wood; phagein, to eat] Wood-eat- ing. xylotomous a. [Gr. xylotomous, wood-cutting] The ability to cut or bore into wood. xyphus n. [Gr. xiphos, sword] (ARTHRO: Insecta) In Heterop- tera, a posteriorly directed triangular process of the mesosternum. 960 Maggenti and Gardner

larva. Z zoecium see zooecium zonate a. [L. zona, a belt] Marked with zones or concentric bands of color; ringed; belted. zone n. [L. zona, a belt] 1. An area having similar fauna and Z-band, disc, line [Ger. zwischenscheibe, intermediate] The flora. 2. A region of a body. 3. Area of the earth having zone of actin interaction between sarcomeres; the bound- similar climate; temperate zone; tropical zone. ary between muscle sarcomeres; Krause's membrane. zone of growth see vitellarium Z-chromosome A sex chromosome present in both sexes in female heterogametic reproduction. zonite, zoonite n. [Gr. zoon, animal] A body segment or so- matic divison of Kinorhyncha and Diplopoda, equivalent to zeitgeber see synchronizer arthromere or somite in Insecta. Zenker's organs (ARTHRO: Crustacea) In Ostracoda, an zonociliate a. [L. zona, a belt; cilium, eyelash] Banded with ejaculatory duct. cilia. zeugobranchiate a. [Gr. zeugos, a pair; branchia, gills] zooanthroponosis n. [Gr. zoon, animal; anthropos, man; (MOLL: Gastropoda) In Prosobranchia, pertains to paired nosos, disease] Any disease in man acquired from a lower symmetrical conditions of some structures of the pallial animal, including invertebrates; zoonosis. see anthropo- complex. zoonosis. zigzag n. [F. zigzag, alternately changing direction by sharp zoobiotic a. [Gr. zoon, animal; bios, life] Pertaining to an or- angles] 1. A series of short, sharp turns or angles. 2. Ziz- ganism that lives as a parasite on an another animal. zag evolution; anorthogenesis. zoocenose n. [Gr. zoon, animal; koinos, common] An animal zoaea see zoea community. zoanthella n. [Gr. zoon, animal; dim. anthos, flower] (CNID: zoochlorellae n.pl. [Gr. zoon, animal; dim. chloros, green] A Anthozoa) An elongate larval form of Zoanthinaria with a symbiotic intracellular algae on Cnidaria that are usually ventral band of very long cilia. see zoanthina, Semper's endodermal, from which cnidarians derive nutritive benefit larva. from the algal photosynthate. zoanthina n. [Gr. zoon, animal; dim. anthos, flower] (CNID: zoochromes n.pl. [Gr. zoon, animal; chromos, color] (ARTHRO: Anthozoa) An oval larval form of Zoanthinaria with a girdle Insecta) Biochromes acquired in the food that are metab- of long cilia near the oral pole. see zoanthella, Semper's olically handled and often modified. larva. zooea see zoea zoarium n. [Gr. zoon, animal; -arium, belonging to] (BRYO) A colony. zooecial compartment (BRYO) The body cavity of a zooid. zoea, zooea, zoaea n. [Gr. zoe, life] A larval stage in the de- zooecial lining (BRYO) The inner lining of a zooidal chamber. velopment of higher Crustacea. zoea I First zoeal stage zooecial wall (BRYO) The skeletal wall of a zooid. with paired compound eyes that are sessile. zoea II Secon- zooeciules n.pl. [Gr. zoon, animal; dim. oikos, house] (BRYO) dary zoeal stage with stalked compound eyes. zoea III Small to minute zooids; function unknown. Third zoeal stage that features the first appearance of uro- pods. see mysis, phyllosoma, protozoea, schizopod zooecium n.; pl. zooecia [Gr. zoon, animal; oikos, house] Online Dictionary of Invertebrate Zoology 961 962 Maggenti and Gardner

(BRYO: Stenolaemata;Gymnolaemata) 1. The skeleton of a zootomy n. [Gr. zoon, animal; temnein, to cut] 1. The dissec- zooid, comprised of calcareous layers of zooidal walls and tion of animals. 2. The anatomy of animals. connected zooidal structures. 2. In Phylactolaemata, com- zootoxin n. [Gr. zoon, animal; toxikon, poison] A toxic sub- prised of any nonliving secreted parts of the body. stance produced by animals. zoogamy n. [Gr. zoon, animal; gamos, marriage] Sexual re- zooxanthellae n.pl. [Gr. zoon, animal; dim. xanthos, yellow] production. Symbiotic intracellular algae that are usually endodermal, zoogenic a. [Gr. zoon, animal; genesis, origin] Pertaining to from which cnidarians derive nutritive benefit from the al- changes caused by animals or their activities; zoogenous. gal photosynthate. see zoochlorellae. zoogeography n. [Gr. zoon, animal; ge, earth; graphein, to z-organ (NEMATA: Adenophorea) In Xiphinema an undefined write] 1. The science of geographical distribution of ani- structure located between the oviduct and uterus. mals. 2. The environmental relationships that cause the zwitter n. [Ger. zwitter, halfbreed] (NEMATA) Nematode inter- distribution. sexes, sometimes mistakenly used as synonym of her- zooid n. [Gr. zoon, animal; eidos, like] 1. Any of the individual maphrodite. see gynadromorph. animals of a colonial or compound organism produced by zygocardiac ossicles (ARTHRO: Crustacea) In Decapoda, tri- asexual means. 2. (BRYO) A single member of a colony angular plates projecting into the cavity of the cardiac consisting of polypide and zooecium. zooidal a. stomach from each side usually bearing denticles; part of zoology n. [Gr. zoon, animal; logos, discourse] The study of the gastric mill. animals. zygogamy see isogamy zoonite see zonite zygogenetic, zygogenic a. [Gr. zygon, yoke; genesis, origin] zoonosis n.; pl. -ses [Gr. zoon, animal; nosos, disease] A dis- Product of fertilization. see parthenogenic. ease in man acquired from one of the lower animals. zygolobous a. [Gr. zygon, yoke; lobos, lobe] (ANN: Oli- zoonotic a. gochaeta) A prostomium lacking demarcation from the first zooparasite n. [Gr. zoon, animal; para, beside; sitos, food] 1. segment. A parasite of animals. 2. Any parasitic animal. zygolophous a. [Gr. zygon, yoke; lophos, crest] (BRACHIO) A zoophagous a. [Gr. zoon, animal; phagein, to eat] Feeding on lophophore with brachium consisting of straight or crescen- animals. tic side arm bearing 2 rows of paired filamentary append- zoophilous a. [Gr. zoon, animal; philos, loving] Animal loving. ages. zygolophus n. zoophyte n. [Gr. zoon, animal; phyton, plant] 1. A bryozoan. zygomorphic a. [Gr. zygon, yoke; morphos, shape] Bilaterally 2. Any non-motile plant-like animal. symmetrical. zooplankton n. [Gr. zoon, animal; plankton, wandering] Ani- zygonema n. [Gr. zygon, yoke; nema, thread] The chromo- mal plankton. some synapses of the 2nd stage of prophase I of meiosis; sometimes used as a synonym of zygotene. n.pl. [Gr. zoon, animal; semeion, signal] The analysis of animal communication. zygoneure n. [Gr. zygon, yoke; neurone, nerve] A nerve cell connecting other neurons. zoosuccivorous n. [Gr. zoon, animal; L. succus, juice; vorare, to devour] Any animal that sucks blood or other body-flu- zygoneury n. [Gr. zygon, yoke; neuron, nerve] (MOLL: Gastro- ids. poda) A connection between the main mantle nerve and the intestinal ganglial nerves and pallial nerves from the Online Dictionary of Invertebrate Zoology 963

pleural ganglia, usually on the left side, but may be on the right. see dialyneury. zygophase see diplophase zygosis n. [Gr. zygosis, a joining] 1. Conjugation. 2. (ARTHRO: Insecta) In coccids, the median lobes of the pygidium that are united basally by internal sclerotization. 3. (MOLL: Gas- tropoda) A neural connection between the supraintestinal ganglion and the pleural ganglion on the left side or be- tween the subintestinal ganglion and the pleural ganglion on the right side. see orthoneury. zygote n. [Gr. zygosis, a joining] A fertilized egg or egg nu- cleus. zygotene n. [Gr. zygon, yoke; tainia, ribbon] The 2nd stage in meiosis during prophase I, following the leptotene stage; homologous chromosomes (zygonema) begin to pair and coil about one another. see zygonema. zygum n.; pl. zyga [Gr. zygon, yoke] 1. (ARTHRO: Crustacea) In Ostracoda, a chitinous process of the male copulatory apparatus suspended in the posterior shell region by a system of chitinous rods, about which the peniferum arcs. 2. (ARTHRO: Insecta) In Scarabaeoidea larva, a convex cross bar forming the anterior margin of the haptomerum. zymogen n. [Gr. zyme, leaven; genesis, origin] Formerly a substance able to be transformed into an enzyme.