Online Dictionary of Invertebrate Zoology Parasitology, Harold W

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln

Armand R. Maggenti Online Dictionary of Invertebrate Zoology Parasitology, Harold W. Manter Laboratory of

September 2005

Online Dictionary of Invertebrate Zoology: T

Mary Ann Basinger Maggenti University of California-Davis

Armand R. Maggenti University of California, Davis

Scott Gardner University of Nebraska-Lincoln, [email protected]

Follow this and additional works at: https://digitalcommons.unl.edu/onlinedictinvertzoology

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Maggenti, Mary Ann Basinger; Maggenti, Armand R.; and Gardner, Scott, "Online Dictionary of Invertebrate Zoology: T" (2005). Armand R. Maggenti Online Dictionary of Invertebrate Zoology. 5. https://digitalcommons.unl.edu/onlinedictinvertzoology/5

This Article is brought to you for free and open access by the Parasitology, Harold W. Manter Laboratory of at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Armand R. Maggenti Online Dictionary of Invertebrate Zoology by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. 889 On line Di ctio nar airborne sounds. y of Inv erte T taenia n. [Gr. taenia, band or ribbon]brAa band, such as of nerve te Z or muscle. ool ogy taeniate a. [Gr. taenia, band or ribbon] Having a broad longitudinal marking. tabula n.; pl. -ae [L. tabula, table] 1. (CNID: Anthozoa) Hori- taenidium n.; pl. -nidia [L. dim. taenia, band or ribbon] 1. zontal partitions across the vertical canals of corals. 2. (ARTHRO: Chelicerata) In Acari, a ribbon-like canal on the (ECHINOD: Asteroidea) A flat elevated dorsal plate of sea surface of the tegument. 2. (ARTHRO: Insecta) A circular or stars. spiral chitinous thickening, strengthening the inner wall of tabular a. [L. tabula, table] Arranged in a flat surface. the trachea. tachyauxesis n. [Gr. tachys, quick; auxesis, growth] Rapid taenioglossate radula (MOLL: Gastropoda) A radula with nu- growth; a part or structure that grows at a quicker rate merous transverse rows of lingual teeth, usually seven to a than the organism as a whole. see bradyauxesis, isauxe- row; median tooth frequently has cusps, the largest in the sis. middle, broad cuspidate admedians and narrow, hooklike tachyblastic a. [Gr. tachys, quick; blastos, bud] Referring to marginals. thin shelled eggs that begin cleavage immediately after tagma n.; pl. tagmata [Gr. tagma, an arrangement] 1. A oviposition and develop quickly; summer egg. see opsib- major division of body regions of a metamerically seg- lastic. mented animal, particularly arthropods. see pseudo- tachygen n. [Gr. tachys, quick; gennaein, to produce] An tagma. 2. (ARTHRO: Chelicerata) The prosoma and opist- evolutionary structure of abrupt origination. hosoma. 3. (ARTHRO: Insecta) The head, thorax, pedicel and gaster of Formicidae. tachygenesis n. [Gr. tachys, quick; genesis, beginning] The shortening or acceleration of embryonic development by tagmosis n. [Gr. tagma, an arrangement] The division of a omitting one or more developmental stages. see brady- body into groups of segments, forming distinct trunk sec- genesis. tions or tagmata. tachytelic a. [Gr. tachys, quick; telos, completion] Evolution at tail n. [A.S. taegel, tail] 1. (ARTHRO: Insecta) The cauda; in a faster rate than usual. see horotelic. some Lepidoptera and Neuroptera, the elongated processes on the hind wings. 2. (NEMATA) That portion of the body in -tactic a. [Gr. taktikos, comb. form] Used in adjectives formed vermiform adults posterior to the anus. from nouns ending in -taxis. tailfan see caudal fan tactile a. [L. tactus, touch] Pertaining to the organs of the sense of touch. tail valve (MOLL: Polyplacophora) The posterior valve. tactile combs (CNID: Hydrozoa) Patches of long stiff hairs on Takakura's duct (NEMER:Enopla) In Carcinonemertidae, a the bell margin of hydromedusae. common efferent canal in the male reproductive system that links the testes and discharges into the intestine near tactile sensillum see sensillum trichodeum the anus. tactoreceptors n.pl. [L. tactus, touch; receptor, receiver] talon n. [L. talus, heel] Shaped like a claw; unguiculate. Hairs, bristles, or other epidermal structures that function in touch where the organism comes in contact with the talus n. [L. talus, heel] (ARTHRO: Insecta) The juncture of the substratum, vibration of the substratum or high intensity tibia and tarsus. 890 891 Maggenti and Gardner On line Di ctio nar tandem a. [L. tandem, at length] One behind the other; two (ARTHRO: Insecta) The yfuosf ed tarsal segment and claw of Inve connected or attached together. many coleopteran larvae. rteb rate tangent a. [L. tangere, to touch] Touching; coming together at tarsus n. [Gr. tarsos, sole of foot] 1. The fZoooot. 2. (ARTHRO) The log a single point. most distal part of the leg, immediately bey ond the tibia, tangoreceptor n. [L. tangere, to touch; receptor, receiver] A usually subdivided into two to five segments, bearing the simple tactile sense organ, consisting of one sense cell. claws and pulvilli. tanylobous a. [Gr. tanaos, stretched; lobos, lobe] (ANN: Oli- taste bud (ARTHRO: Insecta) In Lepidoptera, specialized taste gochaeta) Pertaining to the tongue of the prostomium ex- cells located on the tarsi. tending through segment i to the groove between seg- tautonym n. [Gr. tautos, the same; onyma, name] In the bi- ments i and ii, dividing the peristomium dorsally. see nomial system, the same name given to a genus and one epilobous, prolobous, zygolobous. of its species or subspecies. tapetum n. [L. tapete, carpet] 1. A reflecting surface within an taxis n.; pl. taxes [Gr. taxis, arrangement] Movement of a eye. 2. (ARTHRO: Insecta) A light reflecting surface within motile animal in response to a source of stimulation. a. clear-zone eyes, formed by tracheae that run through the Positive taxis : toward the stimulus. b. Negative taxis : eye parallel with the ommatidia forming a layer around Away from the stimulus. each one, and reflecting the light back into the ommatidia. taxodont a. [Gr. taxis, arrangement; odon, tooth] (MOLL: Bi- tapetal a. valvia) With many short interlocking teeth, some or all tapinoma-odor (ARTHRO: Insecta) In Hymenoptera, a rancid transverse to the hinge margin; similar to prionodont. butter smell secreted from the anal glands of some ants of taxometrics see numerical taxonomy the Dolichoderinae. taxon n.; pl. taxa [Gr. taxis, arrangement] Any taxonomic Tardigrada, tardigrades n.; n.pl. [L. tardus, slow; gradus, group sufficiently distinct to merit being distinguished by step] A phylum of small, multicellular coelomates, com- name, i.e., phylum, class, order, etc. monly called water bears, or bear animaecules due to a lumbering, bearlike gait. taxon cycle A cycle of expansion and contraction of the geo- graphic range and population density of a species or higher tarsal a. [Gr. tarsos, sole of foot] Pertaining to the foot or tar- taxonomic category. sus. taxonomic a. [Gr. taxis, arrangement; nomos, law] Pertaining tarsal claw (ARTHRO) A claw at the apex of the tarsus; unguis. to the classification of organisms. tarsal comb see pedal stridulating organ taxonomist n. [Gr. taxis, arrangement; nomos, law] One who tarsal formula (ARTHRO: Insecta) Referring to the number of studies the theory and practice of classifying organisms. tarsal segments on the front, middle, and hind tarsi. taxonomy n. [Gr. taxis, arrangement; nomos, law] The study tarsal pulvillus see euplantula of the theory, procedure, and rules of classification of or- tarsation n. [Gr. tarsos, sole of foot] (ARTHRO: Insecta) Com- ganisms, based on similarities and differences. see classi- munication by touching with the tarsi. cal taxonomy, cytotaxonomy, numerical taxonomy, experimental taxonomy, classification, systematics. tarsomere, tarsite [Gr. tarsos, sole of foot] (ARTHRO) A sub- division or segment of the tarsus. tectiform a. [L. tectum, roof; forma, shape] Roof-like; sloping. tarsungulus n. [Gr. tarsos, sole of foot; L. dim. unguis, claw] tectostracum see cerotegument 892 893 Maggenti and Gardner On line Di ctio nar tectum n. [L. tectum, roof] 1. (ARTHRO: Chelicerata) In Acari, the dorsal region of the ychoef liceral frame extending from the Inv the blade-shaped prolongation of the exoskeleton to pro- cheliceral base to the rostrum.erte bra tect an organ or joint; epistome; cervix. 2. (ARTHRO: te Z tegumen n. [L. tegumen, cover] (ARTHRO: Ionoslecta) 1. Tegmen. ogy Crustacea) The central portion of the carina of barnacles. 2. (ARTHRO: Insecta) In male Lepidoptera, a dorsal roof or teeth n. [A.S. toth, tooth] 1. Hardened growths on mandibles, hoodlike structure of the genitalia. maxillae or stomatal walls. 2. (CNID: Hydrozoa) Deep or tegument n. [L. tegumentum, covering] 1. Any natural outer very shallow indentations on the hydrothecal margins; peg- covering. 2. (ACANTHO) The non-cellular body wall or cuti- like chitinous growths just inside the margins. 3. (MOLL: cle. tegumentary a. Polyplacophora) Portions of the articulamentum between the slits; may be pectinated or propped (outside edges tegumentary glands (ARTHRO: Chelicerata) In Acari, special- thickened), sharp and smooth. ized secretory glands, located in or immediately beneath the hypodermis. teges see seta tela n.; pl. -ae [L. tela, web] (BRACHIO) One of a pair of points tegillum n.; pl. -a [L. teges, mat] (ARTHRO: Insecta) In Scara- at the end of the beak ridges that project into and beyond baeoidea larvae, a paired patch of hooked or straight setae the pedicle opening. on each side of the venter of the tenth abdominal segment beside paired palidia; part of the raster. telaform larva (ARTHRO: Insecta) In certain heteromorphic Hymenoptera first instar larva, a sharp, tail-like caudal tegmen n.; pl. -mina [L. tegmen, cover] 1. A tegument or horn curved anteriorly, body constricted between a large covering. 2. (ARTHRO: Insecta) a. In Coleoptera, a single or anterior part (cephalothorax) and an elongated posterior divided sclerite proximad of the penis (phallobase); may be part. divided into basal piece and parameres. see tegumen. b. In some Orthoptera, Dictyoptera and Homoptera, the hard- telamon n. [Gr. telamon, strap] 1. A supporting band. 2. ened leathery fore wing. 3. (ECHINOD: Crinoidea) An oral (NEMATA: Secernentea) A thickening of the anterior cloacal wall covering the calyx cup. wall in the order Strongylida, that acts as an accessory guiding structure for the spicules; sometimes erroneously tegmentum n. [L. tegere, to cover] (MOLL: Polyplacophora) applied in plant parasites to the gubernacular capitulum. The outer, sometimes softer and porous calcareous layer of the valve below the periostracum. telegonic see panoistic ovariole tegula n.; pl. -lae [L. tegula, roofing tile] (ARTHRO: Insecta) 1. teleiochrysalis n. [Gr. teleios, perfect; chrysallis, golden A small convex, scalelike lobe overlying the base of the fore thing] (ARTHRO: Chelicerata) In Acari, the third stage wing; paraptera. 2. In Diptera, small anterior sclerites lo- nymph enclosed in the integument of the preceeding nym- cated in an incision of the lateral region of the notum. 3. In phal stage. Lepidoptera, well developed, and carried on a special telenchium n. [Gr. telos, end; enchos, spear] (NEMATA: Se- tegular plate of the notum, supported by a tegular arm cernentea) Sometimes used to denote the shaft of the arising from the base of the pleural wing process. stylet in plant parasites in the order Tylenchida. see tegular arms (ARTHRO: Insecta) Internal structures supporting metenchium. the tegular plate. teleoconch n. [Gr. teleios, complete, konche, shell] (MOLL: tegular plate (ARTHRO: Insecta) In Lepidoptera, a notal Gastropoda) The entire shell, excluding the protoconch. structure bearing the tegulae of the fore wings. teleodont a. [Gr. teleios, complete; odon, tooth] 1. (ARTHRO: tegulum n. [L. tegulum, roof] (ARTHRO: Chelicerata) In Acari, Insecta) In Coleoptera Lucanidae, referring to males bear- 894 895 Maggenti and Gardner On line Di ctio nar ing large mandibles. see amphiodont; priodont. 2. telopodite n. [Gr. telos, eynodf; pous, foot] (ARTHRO: Insecta) Inv (MOLL: Bivalvia) Hinge with cardinal and lateral teeth, but The primary shaft of a limb deristetal to the coxopodite; the bra with additional elements, as Venus. basipodite. te Z ool ogy teleology n. [Gr. teleios, complete; logos, discourse] A theory telorhabdions n.pl. [Gr. telos, end; rhabdos, rod] (NEMATA) in biology that evolution or nature is guided by a purpose. The posterior wall plates of the telostome. see rhabdion. teleotrocha see trochophore telostome, telostom n. [Gr. telos, end; stoma, mouth] telepod see telopod (NEMATA: Secernentea) The posterior part of a stoma. see protostome. telescope v.i. [Gr. tele, far; skopos, watcher] To have the ability to evert and invert a body part. telescopic a. telosynapsis, telosyndesis see acrosyndesis telioderma n. [Gr. teleios, complete; derma, skin] (ARTHRO: telotarsus n. [Gr. telos, end; tarsos, sole of foot] (ARTHRO) In Chelicerata) In Acari, the cuticle of the previous stage Chelicerata and Chilopoda, the distal of the two principal nymph (apoderma) covering the tritonymph. tarsomeres of the tarsus. teliophan see tritonymph telotaxis n. [Gr. telos, end; taxis, arrangement] Movement directed towards a goal, with a minimum of deviation in the telmophage n. [Gr. telma, pool; phagein, to eat] (ARTHRO) A path taken. see kinotaxis, tropotaxis. blood feeding arthropod that severs skin and blood vessels, causing a small blood hemorrhage so as to feed. telotroch n. [Gr. telos, end; trochos, wheel] 1. (ANN: Poly- chaeta) The preanal girdle of cilia near the posterior end. 2. telocentric a. [Gr. telos, end; kentron, center of circle] Chro- (PHORON) A ciliary ring on the posterior of the trunk, mosomes in which the centromere is terminal. see acro- probably a locomotor organ. centric. teletrocha see trochophore telodendria n. [Gr. telos, end; dendros, tree] The branching terminals of an axon. teletrophic ovariole (ARTHRO: Insecta) An ovariole in which all the trophocytes are terminal in the germarium, and telofemur n. [Gr. telos, end; L. femur, thigh] (ARTHRO: Cheli- connect to the egg by a slender trophic chord; acroptrophic cerata) In Acari, a distal segment of the femur separated ovariole; telotrophic egg tube. see polytrophic ovariole. from the basifemur by the basifemoral ring. telson n. [Gr. telson, end] 1. (ARTHRO) The terminal portion of telogonic see panoistic ovariole an arthropod body (not considered a true somite), usually telolecithal egg An egg cell with abundant yolk concentrated containing the anus; the periproct. 2. (ARTHRO: Chelicer- toward the lower side of the cell. see centrolecithal egg. ata) In scorpions, the distal stinging caudal spine. 3. (AR- telomitic see telocentric THRO: Crustacea) The posterior projection, sometimes with caudal furca; the last body unit/segment in which the anus telophase n. [Gr. telos, end; phasis, aspect] The final stages is not terminal; postsegmental region; style. 4. (ARTHRO: of mitosis during which the chromatids (daughter chromo- Diplopoda) The preanal ring. 5. (ARTHRO: Insecta) a. The somes) are formed and the cytoplasm divides. 12th abdominal segment of primitive insects and some in- telophragma see Z-band or disc sect embryos. b. In scale insects, the lateral cuticular ex- telopod n. [Gr. telos, end; pous, foot] 1. (ARTHRO: Crustacea) tension of the 8th segment. telosonic a. Part of an appendage distal to the coxa. 2. (ARTHRO: Diplo- template n. [F. dim. temple, used in weaving] 1. A pattern poda) In males, a modified leg, serving a copulatory func- from which objects are copied. 2. In genetics, a strand of tion, on one of the posterior segments. DNA acting as template for a strand of RNA, which in turn 896 897 Maggenti and Gardner On line Di ctio nar serves as a template for nucleic acids or proteins. tentacle sheath (BRYO) Thyaotf part of the body wall that sup- Inv ports and encloses the tentaecrtles when everted and re- temporal isolation Non-interbreeding between species as a bra tracted. te Z result of time differences, i.e., diurnal versus nocturnal. ool ogy temporal organs see organs of Tomosvary tentacular atrium (BRYO) A cavity inside the tentacle sheath, with tentacles retracted. temporary haplometrosis (ARTHRO: Insecta) In early colony development of social insects, a single female (queen) ini- tentacular bulb (CNID) Swelling at the base of a medusoid tiates development and is either joined by its offspring or tentacle that serves primarily in digestion and manufacture females from other colonies, producing a pleometrotic soci- of nematocysts and sometimes bears an ocellus or other ety. see functional haplometrosis, permanent sensory structure; ocellar bulb. haplometrosis. tentacular cirrus (ANN: Polychaeta) Sensory projection(s) of temporary parasite A parasite that comes in contact with its the peristomium or cephalized segment. host to feed and then departs; intermittent parasite; mi- tentacular club (MOLL: Cephalopoda) A terminal suckered pad, cropredator. comprised of carpus, manus and dactylus. temporary pleometrosis (ARTHRO: Insecta) In social insects, tentacular crown see branchial crown a colony in which two or more females share a nest that tentacular fold (MOLL: Bivalvia) The central fold of the oyster was founded by a single female; non-founding females do mantle edge that bears the tentacles in two rows. not cooperate in nest development, and later disperse and found individual colonies. see permanent pleometrosis. tentacular palp (ANN: Polychaeta) A grooved, food-gathering appendage in many sedentary species. temporary social parasitism (ARTHRO: Insecta) In Hymen- optera, a parasitic queen entering an alien nest replacing tentaculocyst see rhopalium the alien queen by killing or sterilizing it and eventually tentaculozooid n. [L. tentaculum, feeler; Gr. zoon, animal; dominating the nest. eidos, form] (CNID: Hydrozoa) A modified polyp in the form tenacipeds n.pl. [L. tenere, to hold; pes, foot] (ARTHRO: Chilo- of a single tentacle, usually found at the outermost part of poda) In Lithobiida, ambulatory legs of segments 14 and the colony; a protective zooid. see tentaculozooid, gas- 15, elongated and apparently used for mating and capture trozooid. of prey. tentilla n. [L. tentaculum, feeler] (CNID: Hydrozoa) In Si- tenaculum see retinaculum phonophora, lateral contractile tentacular branches. tenent a. [L. tenere, to hold] Adapted for clinging, i.e., hairs. tentorial bar (ARTHRO: Insecta) The right or left half of the tentorium, consisting mainly of the united anterior and teneral a. [L. tener, soft] (ARTHRO) A term applied to any posterior arms. newly emerged soft-bodied individual; callow worker. tentorial bridge (ARTHRO: Insecta) The apices of the two tensor a. [L. tendere, to stretch] A muscle that stretches a posterior arms fused medially; incomplete or absent in part of a body or renders it of use. most Diptera. tentacle n. [L. tentaculum, feeler] Any elongate flexible ap- tentorial fovea see tentorial pits pendage usually near the mouth. tentacular a. tentorial macula (ARTHRO: Insecta) The depressions or dark tentacle crown (BRYO) Tentacles expanded into an external spots marking the points of union of the dorsal tentorial position as for feeding. arms and the epicranal wall near the antennae. 898 899 Maggenti and Gardner On line Di ctio nar tentorial pits (ARTHRO: Insecta) External depressions on the tergal fissure (ARTHRO: Inysoefcta) In Symphyta and primitive Inv surface of the head marking points of union of the arms forms of many orders, a memebrrtaenous line from one lateral bra with the outer wall of the head; usually two in the epis- margin to the other, behind the anteerZior notal wing proc- ool tomal suture and one at the lower end of each postoccipital esses. ogy suture. tergal fold see epimere tentorium n.; pl. -oria [L. tentorium, tent] (ARTHRO: Insecta) tergal margin (ARTHRO: Crustacea) In Thoracica Cirripedia, Two anterior and two posterior apodemes (arms) that form the edge of the scutum adjacent to the tergum, or edge of the internal skeleton of the head, serving as a brace for the any plate abutting the tergum. head and for the attachment of muscles; in Culicidae, the right and left halves are not connected. tergal suture (ARTHRO: Insecta) In many larvae, a Y-shaped dorsal suture of the head. tenuous a. [L. tenuis, thin] Thin, slender, delicate. tergal valves see cercus teratocyte n. [Gr. teras, monster; kytos, container] (ARTHRO: Insecta) In Lepidoptera Pieridae, unicellular forms resulting tergite n. [L. tergum, back] (ARTHRO) A dorsal sclerite of a from the embryonic membranes of parasitic Braconidae. segment. teratogen n. [Gr. teras, monster; genes, producing] Any sub- tergolateral margin (ARTHRO: Insecta) In Cirripedia, in those stance that causes or increases the incidence of congenital possessing upper laterals, the angular edge of the scutum. abnormalities in a population. tergopleural a. [L. tergum, back; pleuron, side] Referring to teratogenesis n. [Gr. teras, monster; genesis, beginning] The the upper and lateral portion of a segment. production of monstrous fetuses or growths. tergopore n. [L. tergum, back; porus, pore] (BRYO: Stenolae- teratogyne n. [Gr. teras, monster; gyne, woman] (ARTHRO: mata) In Tubuliporina, a type of kenozooecium on the back Insecta) In Hymenoptera, the aberrant form of female in a side of a colony, having a polygonal aperture. Formicidae colony, characterized by overdeveloped legs tergum n.; pl. terga [L. tergum, back] (ARTHRO) The dorsal and antennae, and excess pilosity of the body or defective surface of any body segment. wings; formerly referred to as beta-females. see alpha- termen n. [L. terminus, boundary] (ARTHRO: Insecta) The female. outer, or distal margin of the wing. teratology n. [Gr. teras, monster; logos, discourse] The bio- terminal a. [L. terminus, boundary, end] At the end; forming logical study of structural malformations and monstrosities. the end of a series or part; at the extreme end. terebella see terebra terminal anecdysis When maximum size is reached, no more terebra n.; pl. -bras, -brae [L. terebra, borer] 1. A borer or ecdyses occur. see anecdysis. piercer. 2. (ARTHRO: Insecta) a. In Hymenoptera, the terminal arborizations Branching fibrils ending the axon and stylets and stylet-sheath. b. In Odonata and Hymenoptera, collateral ends. see telodendria. the gonapophyses of segments 8 and 9. 3. (MOLL) a. In Bi- valvia, the anterior margin of the valve. b. In carnivorous terminal cirri (ARTHRO: Crustacea) In Ascothoracica, cirri lo- Gastropoda, the radula. terebrant, terebrate a. cated at the posterior end of the thorax, except for first pair. teres n. [L. teres, rounded] Nearly cylindrical. terete a. terminal claw spines (ARTHRO: Crustacea) In Cladocera, terga pl. tergum toothlike projection, varying in size, at the concave end of tergal a. [L. tergum, back] Situated on the back. the postabdomen. 900 901 Maggenti and Gardner On line Di ctio nar terminal filament (ARTHRO: Insecta) A cellular end thread of chiferous. y of Inv the female ovariole that forms a common thread uniting erte test-cross see back-cross bra with that from the ovary of the opposite side. te Z ool testis n.; pl. testes [L. testis, testicle] Thaotgyportion of the terminal diaphragm (BRYO: Stenolaemata) A membranous or male reproductive system producing spermatozoa; a sper- calcified diaphragm that separates the body cavity from the mary. environment. testisac n. [L. testis; testicle; saccus, sac] (ANN: Hirudinoidea) terminalia n.pl. [L. terminus, boundary, end] Collectively, any The testis sac. terminal part or structure. testis sac (ANN: Oligochaeta) A membranous sac around the termitarium n.; pl. -ia [L. termes, woodworm] (ARTHRO: In- testis, seminal vesicle and the funnel to the vas deferens. secta) An elaborate nest wherein a colony of termites live. testudinate a. [L. testudo, tortoise] In the form of the shell of termitophile n. [L. termes, woodworm; philos, loving] A sym- a tortoise; arched; vaulted. biont of termites. tetanus, tetany n. [Gr. tetanos, stiffness] State of contraction terranes n.pl. [L. terra, earth] Fragments of former continents of a muscle caused by continuous stimulation either natural that make up the present day continents. or electrical. terrestrial a. [L. terrestris, of the earth] Belong to or living on tetracerous, tetracerate a. [Gr. tetra, four; keras, horn] Having the ground or earth; opposed to aquatic and arboreal. four horns. terricolous a. [L. terra, earth; colare, to inhabit] Soil inhabit- tetraclad n. [Gr. tetra, four; klados, branch] (PORIF) A megas- ing. clere desma with rays bearing terminal couplings, or based territory n. [L. territorium, domain] An area defended by an on a calthrops, or both; tetraclone . animal against other members of its own or other species. tetracladine, tetracrepid (PORIF) A tetraxonid desma. tertiary a. [L. tertius, third] Third in degree of standing in clas- tetracotyle n. [Gr. tetra, four; kotyle, cup-shaped] (PLATY: Tre- sification. matoda) A metacercaria in the family Strigeidae. tertiary parasite A parasite of a hyperparasite. tetractine see tetraxon tertiary reproductive (ARTHRO: Insecta) In Isoptera, an er- tetrad n. [Gr. tetra, four; -ad, collective noun] Any set of four. gatoid reproductive; a third-form reproductive. tetradelphic a. [Gr. tetra, four; delphys, womb] (NEMATA) tertibrach n. [L. tertius, third; brachium, upper arm] (ECHI- Having four uteri. NOD: Crinoidea) Any ray plate of the third branchitaxis; palmars. tertibrachial a. see postpalmars. tetramerous a. [Gr. tetra, four; meros, part] 1. Having a four jointed tarsus. 2. Having body parts arranged in fours. tessellate a. [L. tessellatus, mosaic] Marked or colored in the pattern of squares, or oblong areas; checkerboard-like. tetramorphic a. [Gr. tetra, four; morphe, form] (CNID: Hydro- zoa) Having four distinct forms in one individual. test n. [L. testa, a shell] A rigid external covering or supporting structure. tetraploid n. [Gr. tetraple, fourfold; eidos, like] A polyploid with four haploid chromosome sets. testaceology n. [L. testa, shell; logos, discourse] The study of shells; conchology. tetrapod n. [Gr. tetra, four; pous, foot] Having 2 pair of legs. see bipod. testaceous a. [L. testaceus, covered with a shell] Bearing a test or hard covering; of the nature of a shell. see con- tetrapterous a. [Gr. tetra, four; pteron, wing] Having 4 wings. 902 903 Maggenti and Gardner On line Di ctio nar tetrasomic a. [Gr. tetra, four; soma, body] Polysomic cells theory of probabilities A ymoaf thematical theory used by tax- Inv with one chromosome represented 4 times in a normal onomists, whereby they assumeertethat no two individuals will bra diploid; 2n+2. simultaneously have the same combitneaZtion of characters as ool ogy tetrathyridium n. [Gr. tetra, four; thyridion, window] (PLATY: those of a given species; in mathematics, the theory of Cestoda) A cysticercoid of Mesocestoides which has a solid chance. body and a scolex not surrounded by special membranes. thermocline n. [Gr. therme, heat; klinein, to slope] In the tetrathyridial a. strata of rapidly changing temperatures in lakes, the nar- tetraxon n. [Gr. tetra, four; axon, axis] (PORIF) A spicule of 4 row dividing stratum between the epilimnion and equal and similar rays meeting at equal angles; tetractine; hypolimnion. quadriradiate. tetraxonid a. thermophile n. [Gr. therme, heat; philos, loving] Living at thalassophilous a. [Gr. thalassa, sea; philos, loving] Inhabit- high temperatures; hot springs fauna. ing or dwelling in the sea; pelagic; thalassic. thermophobe n. [Gr. therme, heat; phobos, hate] An organ- thallus n. [Gr. thallos, young shoot] The body or colony of a ism that lives at low tempertures. compound animal. thermoreceptor n. [Gr. therme, heat; L. recipere, to receive] thamnophilous a. [Gr. thamnos, shrub; philos, loving] Inhab- A sensory receptor that reacts to temperature stimuli. iting thickets or dense shrubbery. thermotaxis n. [Gr. therme, heat; taxis, arrangement] A taxis thanatocoenosis n. [Gr. thanatos, death; koinos, common] in which heat is the response initiating stimulus; regulation An assemblage of fossils comprised of the remains of or- of body temperature. ganisms brought together after death. see biocenosis. thesocytes n.pl. [Gr. thesis, deposit; kytos container] (PORIF) thanatosis n. [Gr. thanatos, death] Feigning death; letisimu- In hibernating fresh water sponge gemmules, binucleate, lation. highly vitelline archaeocytes. theca n.; pl. thecae [Gr. theke, case] 1. A sheath or sac-like thickener cells (PORIF) Cells influencing ray thickness during covering or structure for an organ or organisms, as probos- secretion of calcareous spicules. cis, tubes, shells, pupa or larvae. 2. (ANN: Oligochaeta) thickness n. [A.S. thicce, thick] (MOLL: Bivalvia) 1. See infla- Spermatheca. 3. (ARTHRO: Insecta) A fold or sheath from tion. 2. Measurement from the inner to outer shell surface. phallobase enclosing the aedeagus. 4. (ECHINOD: Cri- thigmotaxis n.; pl. taxes [Gr. thigma, touch; taxis, arrange- noidea) The skeleton. thecal, thecate a. ment] The taxis of contact; stereotaxis. a. Positive thig- thelycum n. [Gr. thelykos, feminine] (ARTHRO: Crustacea) In motaxis: toward the contact. b. Negative thigmotaxis: some female Decapoda, an external pocket on the ventral away from the contact. thigmotactic a. side of the thorax, functioning as a seminal receptacle. thigmotropism n. [Gr. thigma, touch; tropos, turn] Tropism in thelygenous a. [Gr. thelys, female; genes, producing] Pro- which direction is determined by contact with a solid body; ducing mostly or only female offspring; arrhenogenous. stereotropism. thelygenesis n. third axillary (ARTHRO: Insecta) A Y-shaped sclerite of the thelyotoky n. [Gr. thelys, female; tokos, offspring] A type of wing, with a flexor muscle inserted into the crotch of the Y parthenogenesis in which unfertilized eggs develop into fe- and usually articulating with the posterior notal process males; thelytoica. thelyotokous a. see arrenotoky, and a group of anal veins. deuterotoky, amphitoky. third-form reproductive (ARTHRO: Insecta) In Isoptera, an 904 905 Maggenti and Gardner On line Di ctio nar ergatoid reproductive; a tertiary reproductive. thylacogen n. [Gr. thylax, syaocfk; genes, producing] A chemical Inv produced by parasites that caeurtsee hypertrophy of host tis- thoracic a. [Gr. thorax, chest] Associated with the thorax. bra sue. te Z ool thoracic ganglia (ARTHRO: Insecta) The first three ganglia of ogy the ventral nerve cord, one in each thoracic segment, con- thyridium n; pl. -ia [Gr. dim. thyris, window] (ARTHRO: In- trolling the locomotory organs. secta) 1. A small whitish spot in the wings of Neuroptera, Hymenoptera and Trichoptera. 2. In ichneumonid Hymen- thoracic glands see prothoracic glands optera, a scar-like area on each side of the second abdomi- thoracic region (ARTHRO: Insecta) The second of three regions nal tergite, between the middle and base; the third tergite of the embryonic trunk; the future locomotor center. rarely may have tyridia. thyridial a. thoracic squama (ARTHRO: Insecta) In some Diptera, one of thyroid n. [Gr. thyra, oblong shield] (ARTHRO: Insecta) In three membraneous lobes in the region of the wing base Diptera, a shield-shaped plate on the posterior wall of the appearing to be derived from the posterior margin of the beak. scutellum. see alula, alar squama. thysanuriform larva see campodeiform larva thoracomere n. [Gr. thorax, chest; meros, part] (ARTHRO: tibia n.; pl. -iae [L. tibia, shin] 1. (ARTHRO: Chelicerata) The Crustacea) A thoracic segment. fifth segment of a spider leg, between the patella and thoracopod(ite) n. [Gr. thorax, chest; pous foot] (ARTHRO: metatarsus. 2. (ARTHRO: Insecta) The fourth segment of Crustacea) Any appendage of the thoracic somite; a cor- the leg, between the femur and tarsus. mopod. see phyllopod, maxilliped, pereopod. tibial comb (ARTHRO: Insecta) A strigil or scraper. thorax n.; pl. thoraxes, thoraces [Gr. thorax, chest] 1. (AR- tibial epiphysis see epiphysis THRO: Chelicerata) In Arachnida, fused with the head to form the cephalothorax of spiders. 2. (ARTHRO: Crustacea) tibial process/thumb (ARTHRO: Insecta) In Anoplura Pedicu- The tagma between the cephalon and abdomen comprising lus , a delicate modification of the tibia as a holdfast the anterior part of the trunk; cormus; pereon. 3. (ARTHRO: against the powerful claw of the tarsus. Insecta) a. The body region behind the head, bearing the tibial spur (ARTHRO: Insecta) A large spine usually located on legs and wings and encompassing the pro-, meso- and the distal end of the tibia. metathorax. b. In Hymenoptera, the second tagma of the tibiotarsal organ (ARTHRO: Insecta) In Collembola Smin- body consisting of pro-, meso-, metathorax and the epi- thurides , a sac-like swelling and an enlarged hair occurring notum of Formicidae. near the distal ends of the tibiotarsus of the third pair of thread n. [A.S. thraed, twist] 1. A fine linear surface elevation. legs. 2. (MOLL: Bivalvia) A narrow elevation on the shell surface. tibiotarsus n. [L. tibia, shin; Gr. tarsos, sole of foot] (ARTHRO: 3. (MOLL: Gastropoda) The silky fibers of the byssus. Insecta) Fused tibia and tarsus; the tibiotarsal segment. thread capsule see nematocyst Tiedemann's bodies (ECHINOD: Asteroidea) Tiny, 9 spherical thread cell (CNID) The cnidoblasts. swellings on the inner wall of the ring canal that have been thread press see silk press reported to produce amebocytes. thylacium n. [Gr. thylax, sack] (ARTHRO: Insecta) An external tiled a. [ME. tile] Appearing as a tiled roof; transverse and lon- gall-like cyst in the abdomen of the host containing the gitudinal striae on the cuticle. Dryinidae parasitic larva. timbal see tymbal 906 907 Maggenti and Gardner On line Di ctio nar tinctorial a. [L. tenctorius, of dyeing] Of or pertaining to color, topochemical sense The seynosfe of smell. Inv i.e., staining. erte topogamodeme n. [Gr. topos, pblarace; gamos, marriage; te Z tine n. [A.S. tind, spike] Any slender, pointed, projecting part. demos, the people] Individuals inhabitinogol a particular geo- ogy tissue n. [F. tissu, tissue] A layer or group of cells of a par- graphic locality that form a deme. ticular type, or at most a few types, with intercellular ma- topomorph n. [Gr. topos, place; morphe, form] An environ- terial of essentially a particular type. mental morphologic variant. topomorphic a. tissue culture Tissues appropriated from animals and main- toponym n. [Gr. topos, place; onoma, name] The name of a tained or grown in vitro for more than 24 hours. location thought to be the place of origin of a plant or ani- titillae n.pl.; sing. titilla [L. titillo, tickle] (NEMATA) Small pro- mal. jections on the distal part of the protrusile gubernaculum. topotype n. [Gr. topos, place; typos, type] A specimen col- titillator n. [L. titillo, tickle] (ARTHRO: Insecta) A terminal, lected at the original type-locality. small process (spines or small plates) at the distal extrem- tori pl. of torus ity of the aedeagus. torma n.; pl. -mae [Gr. tormos, socket] (ARTHRO: Insecta) 1. tocopherol n. [Gr. tokos, birth; pherein, to carry] Vitamin E. In Diptera, sclerotic processes between the labrum and tocospermal a. [Gr. tokos, birth; sperma, seed] Direct trans- clypeus. 2. In Scarabaeoidae larvae, heavily chitinized fer of sperm between male and female. structures on the ends of the clypeo-lateral suture that extend toward the mesal line, sometimes meeting and tocospermia n. [Gr. tokos, birth; sperma, seed] 1. (ARTHRO: fusing on the mesal line. Chelicerata) A type of sperm transfer by the male chelicera (gonopod), to the female vagina. see podospermia. 2. tormogen n. [Gr. tormos, socket; genes, producing] (ARTHRO: (MOLL: Cephalopoda) The direct transfer of spermatophores Insecta) An epidermal cell associated with a seta that se- to the female vagina by the male gonopod. cretes the cuticle of the socket and bounds the receptor lymph cavity. tocostome, tokostome n. [Gr. tokos, birth; stoma, mouth] (ARTHRO: Chelicerata) In Acari, the female genital aperture. tornote n. [L. tornatus, rounded with a lathe] (PORIF) A diactinal monaxon, lance-headed at each end. tomentum n. [L. tomentum, stuffing of wool] Covered with closely matted scale-like hair or spines on the body or ap- tornus see anal angle pendages that cannot be separated; downy. tomentose a. torose a. [L. torus, elevation] A swelling into knobs; cylindrical tone see tonus and swollen at intervals; torous. tonic muscle (MOLL: Bivalvia) White, opalescent part of the torpid a. [L. torpidus, to be numb] Dormant; inactive. see adductor muscle that reacts slowly, but can hold for long aestivation, hibernation. periods of time; catch muscle. torqueate a. [L. torquatus, with a necklace] Having a ring or tonofibrillae n.pl [Gr. tonos, stretching; L. dim. fibra, fiber] collar. Fine connective fibrils extending from the ends of the torsion n. [L. torquere, to twist] 1. Spiral bending; twisting. 2. skeletal muscles into the cuticle. (MOLL: Gastropoda) The theory in ancestral gastropods that tonus, tone n. [Gr. tonos, stretching] 1. The normal, main- a 180-degree counterclockwise twisting occurred that tained nerve impulse traffic. 2. The normal prolonged caused the crossing of the pleural-visceral connectives in steady contracture of muscle fibers. tonic a. the nervous system to form a figure eight. see chiasto- neury, detorsion. 908 909 Maggenti and Gardner On line Di ctio nar tortuose a. [Gr. torquere, to twist] Twisting; winding; irregu- trabeculate a. [L. trabeculya,ofsmall beam] (ANN: Oligochaeta) Inve larly curved. Used to describe seminal vesicrlteesb that develop as connec- rate torulose a. [L. torulus, little bulge] Having knob-like swellings; tive tissue proliferations from a septuZmoothat have numer- log moniliform. ous irregular spaces that remain minute untyil spermatogo- nia begin to enter. trabeculated a. torus n.; pl. tori [L. torus, swelling] 1. A blunt, rounded, ridge or protuberance. 2. (ANN: Polychaeta) Low ridges provided trachea n.; pl. tracheae [L. trachia, windpipe] 1. The wind- with rows of acicular hooks or minute setae or uncini. 3. pipe. 2. (ARTHRO: Chelicerata) For Arachnida, see tube (ARTHRO: Insecta) In Diptera, the pedicel of the antenna. 4. trachae, sieve trachea. 3. (ARTHRO: Insecta) The larger (PORIF) A more or less doughnut-shaped space around the tubes of the respiratory system, lined with taenidia, open- organism, concerned with water circulation. ing to the outside through the spiracles and terminating internally in the tracheoles. 4. (MOLL: Gastropoda) see totipotent a. [L. totus, all; potens, capable] Said of isolated ctenidia. 5. (ONYCHO) In Peripatus, short tubes without blastomeres capable of becoming complete embryos. spiral thickenings, neither branching nor anastomosing, totomount n. [L. totus, all; mons, mountain] The mount of a opening externally through numerous minute spiracles. whole organism for microscopic study. tracheate a. toxa n. [Gr. toxon, bow] (PORIF) A bow-shaped diactinal micro- tracheal gills (ARTHRO: Insecta) In aquatic larvae and some sclere. aquatic pupae, filiform, lamellate structures supplied with toxicognath n. [Gr. toxikon, poison; gnathos, jaw] (ARTHRO: trachae and tracheoles, usually borne on the abdomen. see Chilopoda) The forcipulate poison fangs. spiracular gills, blood gills. toxicology n. [Gr. toxikon, poison; logos, discourse] The sci- tracheal system (ARTHRO) A system of cuticle-line tube ence of poisons. opening to the outside through spiracles, functioning in respiration. toxin n. [Gr. toxikon, poison] A poisonous substance in the secretions or excretions of a parasite. tracheoblast n. [L. trachia, windpipe; Gr. blastos, bud] (AR- THRO: Insecta) Cells derived from the epidermal cells lining toxinosis n. [Gr. toxikon, poison] A disease caused by the ac- the trachea, that give rise to the tracheoles. tion of a toxin. tracheoles n. [L. dim. trachia, windpipe] (ARTHRO: Insecta) toxoglossate n. [Gr. toxon, bow; glossa, tongue] (MOLL: Gas- The fine intracelluar terminal branches of the respiratory tropoda) Having a radula always enclosed in the radular tubes. tracheolar a. sac; marginal teeth harpoon-shaped, filled with venom and loosely arranged in two rows. trachychromatic a. [Gr. trachys, rough; chroma, color] Strongly staining. toxoid n. [Gr. toxikon, poison; eidos, form] A toxin released from its toxic properties, but not from its antigenic proper- tract n. [L. tractus, region] 1. An area, region or parts of a ties. system, as a bundle of nerve fibers between parts of the central nervous system. 2. (PORIF) A fascicular column of trabecula n.; pl. -lae [L. trabecula, little beam] 1. A small bar, spicules. rod, bundle of fibers, or septum together with other trabe- culae which form part of the framework of various organs. Tragardh's organ (ARTHRO: Chelicerata) In Acari, a long, coni- see internuncial process. 2. (MOLL: Cephalopoda) In cal hyaline protuberance of the articulation between the squid and cuttlefish, a support from the edge of the arm body of a chelicera, and its movable jaw; oncophysis. inward for the protection of membranes of the arm. tragus n. [Gr. tragos, goat] (ARTHRO: Insecta) In Diptera, a 910 911 Maggenti and Gardner On line Di ctio nar somewhat elaborate lobe on the rim of the pinna of a lati- transscutal suture (ARTHRyOo:f Insecta) 1. In many orders, a Inve corn trumpet of some culicid pupae. transverse suture connecting rtthebe lateral margins behind rate transad n. [L. trans-, across; Gr. ad, makes collective nouns] the anterior notal wing process, dividinZgoothe scutum into an log Closely related organisms separated by an environmental anterior and posterior region. 2. In some Hyymenoptera, a barrier. suture dividing the posterior part of the scutum into two posterolateral areas called the axillae. transcoxa n. [L. trans-, across; coxa, hip] (ARTHRO: Chelicer- ata) A term used instead of coxa in some groups. transstadial a. [L. trans-, across; stadium, stage] The reten- tion of microorganisms from one stage of the host to the transcurrent a. [L. trans-, across; currens, running] 1. Ex- next; may be part or all of the host's life cycle. tending transversely. 2. (MOLL: Gastropoda) Passing con- tinuously around whorls crossing growth lines. transtilla n.; pl. -lae [L. trans-, across; stilla, drop] (ARTHRO: Insecta) In Lepidoptera, a transverse bar, or variously transect n. [L. trans-, across; secare, to cut] A cross section shaped process, connecting dorso-proximal angles of the or profile of an area for study, as with organisms and/or male valva; part of the fultura superior; the anterior end of vegetation. the dorsal extension of the 9th sternum or the vinculum. transection n. [L. trans-, across; secare, to cut] Cut across or transverse a. [L. trans-, across; vertere, to turn] Crossing at transversely; a transverse section. right angles to the longitudinal axis; lying across or be- transformation zone In males, that part of the testis follicle tween. in which the spermatids develop into spermatozoa; known transverse band of crochets (ARTHRO: Insecta) In larva, cro- as spermiogenesis. see maturation zone. chets being arranged transversely or across the longitudi- transient a. [L. trans-, across; ire, to go] A passing phenome- nal axis of the body in a single uniserial or multiserial band, non; of short duration. or in two such bands. transient polymorphism Polymorphism existing in a breeding transverse costal vein (ARTHRO: Insecta) A wing cross vein in population during the period when an allele is being re- the costal cell. placed by a superior one. see balanced polymorphism. transverse cubital vein (ARTHRO: Insecta) A transverse wing transitional cell see chromophile vein connecting the marginal and cubital veins. translocation n. [L. trans-, across; locus, place] The shift of a transverse fission A form of asexual reproduction by division segment of a chromosome to another chromosome, not of an organism at right angles to the long axis. see binary changing the total number of genes present. fission. translucent a. [L. trans-, across; lucere, to shine] Allowing the transverse impression see genal groove passage of light, but not necessarily transparent; semi- transverse marginal vein (ARTHRO: Insecta) A wing cross transparent. vein in the marginal cell. transmission n. [L. trans-, across; mittere, to send] 1. Hori- transverse notal suture see prescutal sulcus zontal: the transfer of an infectious agent from one organism to another. 2. Vertical: transmission from one genera- transverse partition (BRYO) A wall separating members of a tion to another. successive line of zooids. transposed hinge condition (MOLL: Bivalvia) A condition of transverse plane A plane or section perpendicular to the lon- teeth usually found in the hinge of one valve being found gitudinal axis. on the opposite one. transverse radial vein (ARTHRO: Insecta) A transverse mar- 912 913 Maggenti and Gardner On line Di ctio nar ginal wing vein. with three rays shorter tyhoafn the fourth. Inv erte transverse septum (ARTHRO: Crustacea) In Cirripedia, the triage n. [F. a culling] The process ofbgrraading. te Z thin walled, normal to longitudinal septum, parallel to ba- ool triangle n. [L. triangulus, having three angleosg]y (ARTHRO: In- sis, dividing the parietal tubes into a series of cells. secta) In Odonata, a small triangular cell or group of cells transverse striation A circular groove or arc whose plane is near the base of the wing; discoidal triangle; cardinal cell. perpendicular to the longitudinal axis. triangulate a. transverse suture (ARTHRO: Insecta) In Diptera, a suture triangular plates (ARTHRO: Insecta) In Hymenoptera, the sec- across the middle of the mesonotum of some species; usu- ond of three pairs of movable plates associated with the ally incomplete in the center of the notum; in Tipulidae it is sting. see quadrate plates, oblong plates. V-shaped. triaulic a. [L. tres, three; aulos, pipe] (MOLL: Gastropoda) In transverse wall (BRYO: Gymnolaemata) One of a pair of walls opisthobranch hermaphroditic snails, the female part hav- separating individual zooids in a linear series; perpendicu- ing two separate openings and the male part one. see di- lar to direction of growth. aulic, monaulic. trapezium n. [Gr. trapezion, small table] A four-sided figure, triaxial symmetry A type of symmetry such as biradial- or having no two sides parallel; trapeziform. bilateral symmetry, with three axes known as sagittal, lon- trapezoid n. [Gr. trapezion, small table; eidos, shape] A plane gitudinal, and transverse. four-sided figure in which two sides are parallel and two triaxon n. [Gr. tries, three; axon, axle] (PORIF) A spicule with are not. trapezoidal, trapeziform a. three axes. trema n.; pl. tremata [Gr. trema, hole] (MOLL: Gastropoda) tribe n. [L. tribus, tribe] A taxonomic category containing a An orifice in the outer wall of some shells, excretory in group intermediate between the genus and the subfamily; function; may occur singly or in a series. names of tribes end in -ini. Trematoda n. [Gr. trema, hole; eidos, form] A class of Platy- tribocytic organ (PLATY: Trematoda) In Strigeiudea, a glan- helminthes, commonly call flukes; all are endoparasitic dular, pad-like organ behind the acetabulum. flatworms. trichite n. [Gr. trix, hair] (PORIF) Hair-like siliceous spicule. trenchant a. [OF. trenchier, to cut] Having a sharp edge. trichobothrium n.; pl. -ria [Gr. thrix, hair; bothros, pit] (AR- trepan n. [Gr. trypanon, borer] (ANN: Polychaeta) Part of the THRO: Chelicerata) A compound structure of many groups eversible pharynx containing chitinized teeth anteriorly, es- consisting of a small cavity (bothridium) and variously pecially Syllidae. shaped setae (bothridial setae) that function as vibro- and triact n. [Gr. treis, three; aktis, ray] (PORIF) A microsclere spi- anemoreceptors. cule with three rays. see regular triact, saggital triact. trichobranchia n.pl. [Gr. thrix, hair; branchia, gill] (ARTHRO: triactinal a. [Gr. treis, three; aktis, ray] (PORIF) Having a Crustacea) A gill with a series of filamentous lateral three-pointed or rayed spicule. see diactinal, tetractinal, branches arising from the main stem or branchial axis. monactinal. trichobranchiate a. triad n. [Gr. treis, three; -ad, forms collective noun] An ar- trichocerous a. [Gr. thrix, hair; keras, horn] (PLATY: Trema- rangement of three; a trinity. toda) Pertaining to cercaria having a tail provided with con- spicuous spines or bristles. triaene n. [Gr. triaina, trident] (PORIF) A tetraxonid spicule trichodes see tricomes 914 915 Maggenti and Gardner On line Di ctio nar trichodragmata n.pl. [Gr. thrix, hair; dragma, sheaf] (PORIF: taining to an appendagye,ofambulacrum, or claw with three Inv Desmospongiae) In Axinellidae ( Tragosia ), raphides ungues. see monodactyl, bidearctetyl. bra grouped into bundles. te Z trident a. [L. tres, three; dens, tooth] Hoaovl ing three teeth; ogy trichogen n. [Gr. thrix, hair; genes, producing] (ARTHRO: In- three-pronged. tridentate a. secta) An epidermal cell that secretes the cuticle of the trifid a. [L. tres, three; findere, to split] Having three clefts, seta or peg, the scolopale and the pore tubules. parts, or branches. trichoid a. [Gr. thrix, hair; eidos, form] Formed like a hair. trifid nerve (BRYO) A three-branched peripheral motor nerve trichoid sensilla see sensillum trichodeum connected to the retractor muscle, esophagus, and along trichomes, trichodes n.pl. [Gr. thrix, hair] 1. (ARTHRO: In- the tentacle sheath to the direct nerve. secta) Modified tufts or hair on certain myrmecophilous and trifurcate a. [L. tres, three; furca, fork] Having three branches non-myrmecophilous insects that aid in the dissemination or forks; trichotomous. of appeasement or pheromone substances. 2. (ARTHRO: triglycerides n.pl. [Gr. treis, three; glykys, sweet] Esters of Diplopoda) Hollow spines or setae of the bristly millipedes. fatty acids with glycerin that form fats and oils. trichophore n. [Gr. thrix, hair; pherein, to bear] (ANN) A sac- trignathan a. [Gr. treis, three; gnathion, jaw] (ARTHRO) Hav- like structure or cavity from which setae emerge. ing mandibles and two pair of maxillae, such as Chilopoda, trichopore n. [Gr. thrix, hair; poros, channel] (ARTHRO: In- Symphyla and Insecta. see dignathan. secta) A pore in the cuticle through which a sensory hair or trigonal a. [Gr. treis, three; gonia, angle] Pertaining to, or in bristle is formed. the form of a triangle. trichosors n.pl. [Gr. thrix, hair] (ARTHRO: Insecta) In Neurop- trigoneutism n. [Gr. treis, three; gonos, offspring] The pro- tera, thickenings of the wing margin bearing several hairs; duction of three broods in one season. a single trichosor between each pair of vein-endings in adults. trilabiate a. [L. tres, three; labium, lip] Having three lips. trichostichal bristles see metapleural bristles trilateral a. [L. tres, three; latus, side] Three-sided. trichotomous a. [Gr. tricha, in three parts; tome, a cutting] trilobate a. [Gr. treis, three; lobos, lobe] Bearing three lobes. Divided into three parts; three-forked. trilocular a. [L. tres, three; loculus, small place] With three trichroism n. [Gr. treis, three; chros, color] The condition of cavities or cells. having three color forms in different individuals of the same trimorphic a. [Gr. treis, three; morphe, form] Having three species. distinct forms in one individual, as certain hydrozoan colo- tricolumella see columella nies. trimorphism n. tricostate a. [Gr. treis, three; costa, rib] Having three ribs or Trinominal nomenclature An extension of the binominal ridges. system of nomenclature consisting of three words: the generic name, the specific name, and the subspecific name, tricrepid a. [Gr. treis, three; krepis, base] (PORIF) A triaxonid together constituting the scientific name of a subspecies. desma. triordinal crochets (ARTHRO: Insecta) Crochets of larvae with tricuspid, tricuspidate a. [Gr. treis, three; cuspis, a point] proximal ends in a single row, but distal ends of three al- Divided into three cusps or points. ternating lengths. see ordinal. tridactyl a. [Gr. treis, three; daktylos, finger] (ARTHRO) Per- tripartite a. [L. tres, three; partitus, divided] Divided into 916 917 Maggenti and Gardner On line Di ctio nar three parts, divisions or segments. oligopods. see planidiumy o.f Inv erte tripectinate a. [L. tres, three; pecten, comb] Having three trivial name An obsolete designationbrbay Linnaeus for the spe- te Z rows of comb-like branches. cific name; vernacular name. ool ogy triplet n. [L. tres, three; plus, more] Three successive nucleo- trivium n. [L. trivium, crossroads] (ECHINOD: Asteroidea) Col- tide base pairs that code for an amino acid. lectively, the three rays of a sea star farthest from the triploblastic a. [Gr. triploos, threefold; blastos, bud] Derived madreporite. see bivium. from three embryonic germinal layers: ectoderm, endo- trivoltine n. [L. tres, three; It. volta, time] (ARTHRO: Insecta) derm and mesoderm. Having three annual broods, especially in the silkworms of triploid a. [Gr. triploos, threefold] A cell or individual having Bombycidae. three haploid chromosome sets in their nuclei; a form of trixenic a. [Gr. treis, three; xenos, guest] The rearing of one polyploidy. or more individuals of one species in association with three triquetral, triquetrous a. [L. triquetrus, three sided] Having known species of organisms. see axenic, dixenic, mon- three angles or arms; triangular in section. oxenic, polyxenic, synxenic, xenic. triradiate(s) a. [L. tres, three; radius, spoke of wheel] 1. troch n. [Gr. trochos, wheel] A band of cilia found on troco- Having three radiating process. 2. (PORIF) Spicules having phores and related larvae. the three rays somewhat in the same plane. see sagittal trochal disc (ROTIF) Anterior ciliated disc functioning in loco- triradiates. motion and/or food ingestion. tritocerebral commissure see postesophageal commis- trochalopodous a. [Gr. trochos, wheel; pous, foot] (ARTHRO: sure Insecta) Refers to a posterior coxae having an articulation tritocerebral segment see tritocerebrum of a ball and socket joint. see pagiopodous. tritocerebrum n. [Gr. tritos, third; L. cerebrum, brain] (AR- trochantellus n. [Gr. dim. trochanter, runner] (ARTHRO: In- THRO) The posterior (third) small part of an arthropod brain secta) In Hymenoptera, the proximal end of the femur; that gives rise to nerves that innervate the labium, the di- sometimes appearing as a second segment of the tro- gestive tract (stomatogastric nerves), the chelicerae of chanter. chelicerates, and the second antennae of crustaceans. see trochanter n. [Gr. trochanter, runner] (ARTHRO) A segment or metacerebrum. segments of an insect or acarine leg that articulate basally tritonymph n. [Gr. tritos, third; nymphe, young woman] (AR- with the coxa and distally with the femur; a pivot or rock- THRO: Chelicerata) In Acari, the third stage nymph. ing joint; the first cheliceral segment. tritosternum n. [Gr. tritos, third; sternon, chest] (ARTHRO: trochanteral organ (ARTHRO: Insecta) In Collembola, a group Chelicerata) In Mesostigmata, a secondary, ventral, bristle- of short setae on the trochanter. like sensory organ just behind the gnathosoma. trochantin n. [Gr. trochanter, runner] (ARTHRO: Insecta) Any triturate v.t. [L. tritum, rub to pieces] To rub or grind to a fine small intercalated sclerite of an insect appendage. a. The powder; masticate; pulverize. basal segment of the trochanter when two-jointed. b. A small sclerite in the thoracic wall, just anterior to the base triungulin, triungulinid n. [L. tres, three; ungula, claw] (AR- of the coxa. THRO: Insecta) First-instar larva of some hypermetamor- phic Neuroptera, Coleoptera, Hymenoptera, and the Strep- trochiform a. [Gr. trochos, wheel; forma, shape] 1. Shaped siptera (triungulinid), which are active, compodeiform like a top. 2. (MOLL: Gastropoda) In Trochidae, a flat-sided 918 919 Maggenti and Gardner On line Di ctio nar conical shell, without a highly acute spire and rather flat at trophamnion n. [Gr. trophey,offood; amnion, membrane around Inve the base. the fetus] (ARTHRO: Insecta) Arntebenvelope surrounding the rate trochlea n. [Gr. trochilia, pulley] A pulley-like structure, short, embryonic mass in the polyembryonicZovoa of mainly para- log circular, compressed and contracted in the middle of the sitic Hymenoptera, formed by cytoplasm in tyhe egg associ- circumference. ated with the paranuclear mass, and functioning in relaying nutrients from the host. trocholophous a. [Gr. trochos, wheel; lophos, crest] (BRACHIO) A lophophore with a simple disk around the trophi n.pl.; sing. trophus [Gr. trophe, food] 1. (ARTHRO) The mouth, bearing usually a single row of unpaired filamentary mouth parts, especially of insects and barnacles, collec- appendages, rarely a double row of paired appendages. tively. 2. (ROTIF) The mastacatory apparatus of the mastax. trophal , trophic a. trochophore n. [Gr. trochos, wheel; phora, bearing] An invertebrate free-swimming larva found in many groups, trophic chord (ARTHRO: Insecta) In telotrophic ovarioles, slen- marine turbellarians, nemerteans, brachiopods, phoronids, der chords connecting the nurse cells to the eggs. bryozoans, mollusks, sipunculids, and annelids, commonly trophic egg (ARTHRO: Insecta) In Apis, an egg that is fed to pear-shaped and provided with a prominent equatorial the colony members, usually degenerate and nonviable. band of cilia and sometimes one or two accessory ciliary trophic sac/pouch (ARTHRO: Insecta) In Siphunculata (Ano- circlets. plura), a pouch opening off the cibarium housing three trochosphere see trochophore closely compressed stylets, with only the anterior end ex- trochus n.; pl. trochi [Gr. trochos, wheel] (ROTIF) The inner, posed, functioning in piercing the skin for blood meals. anterior circlet of coronal cilia along the margin of the api- trophic symbiosis A form of symbiosis between a social insect cal band; cingulum. and another organism; tended by the social insect for the troglobiont n. [Gr. trogle, hole; bios, life] A cave dwelling or- sake of the food or secretions they derive from them. see ganism; troglobite. trophallaxis, trophobiont. troglodytic a. [Gr. trogle, hole; dyein, to enter] Living under- trophidium n. [Gr. dim. trophe, food] (ARTHRO: Insecta) In ground only. Hymenoptera, the first larval stage of some Formicidae. troglophile n. [Gr. trogle, hole; philein, to love] 1. Cave-lov- trophobiont n. [Gr. dim. trophe, food; bios, life; ont, one who] ing. 2. (ANN: Oligochaeta) Many species of earthworms are (ARTHRO: Insecta) An organism living in a social species referred to in this manner, however, they are not obliga- nest, or cared for and protected by a social species in re- tory troglophiles. turn for secretions which are then consumed. see mutual- ism. trogloxene n. [Gr. trogle, hole; xenos, guest] 1. A cave guest. 2. Sometimes used to characterize organisms that do not trophobiosis n. [Gr. trophe, food; biosis, manner of life] A complete all of their life cycle in caves. form of symbiosis in which there is a mutual exchange of food; trophallaxis. trophobiotic a. see trophic symbio- tropeic a. [Gr. tropis, keel] Resembling a keel; cariniform. sis. trophallaxis n. [Gr. trophe, food; allaxis, exchange] (ARTHRO: trophocytes n.pl. [Gr. trophe, food; kytos, container] 1. Cells Insecta) The mutual or unilateral exchange of alimentary that provide nutritive material. 2. (ARTHRO: Insecta) Cells canal liquid, from the mouth or anus, among colony mem- of the fat body of the embryo. 3. (PORIF) In fresh-water bers of social insects or guests; trophobiosis. trophallactic sponges, nurse cells involved in the initial stages of gem- a. mule formation; archaeocytes. 920 921 Maggenti and Gardner On line Di ctio nar trophodisc n. [Gr. trophe, food; diskos, disc] (CNID: Hydrozoa) taxis in which an animalydoifrects itself in relation to a source Inv In the female gonophore, endodermal tissue that nourishes of stimulation by comparing tehreteamount of stimulation on bra sperm or ova. either side of it, i.e., spiders in thetierZweb retrieving their ool ogy trophogeny n. [Gr. trophe, food; genes, producing] (ARTHRO: prey. see klinotaxis, telotaxis. Insecta) In social insects, caste difference determined by trumpet n. [OF. trompe, trumpet] (ARTHRO: Insecta) In Dip- nutritional mechanism. tera, paired, usually movable respiratory structures, lo- trophoporic field (ARTHRO: Insecta) In social insects, the en- cated on the dorsal portion of the cephalothorax of culicid vironment from which the colony gains food. pupae. see laticorn trumpet, angusticorn trumpet. trophorhinium n. [Gr. trophe, food; rhine, rasp] (ARTHRO: In- truncate a. [L. truncus, cut off] Terminating abruptly; ending secta) In Hymenoptera, two striated plates located within squarely with a cut-off edge. truncation n. the mouth of Myrmeciinae larvae that grind their food pel- trunk n. [L. truncus, cut off] 1. (ANN) a. In Polychaeta, the lets. body between the peristomium and the pygidium. b. In Oli- trophosome n. [Gr. trophe, food; soma, body] 1. (CNID: Hy- gochaeta, the body between the peristomium and pe- drozoa) All of the asexual structures of a polyp or polypoid riproct. 2. (ARTHRO: Crustacea) The postcephalic portion of hydrozoan colony. see gonosome. 2. (NEMATA) A food the body. 3. (ARTHRO: Insecta) The thorax. storage area of certain parasitic nematodes formed by trypsin n. [Gr. tryein, to rub down; pepsis, digestion] An en- modification of the intestine. zyme that catalyzes the hydrolysis of proteins. tryptic a. trophotaxis n. [Gr. trophe, food; taxis, arrangement] A re- tryptophan, tryptophane n. [Gr. tryein, to rub down; pha- sponse to the stimulation of food. see telotaxis, klino- nein, to appear] An amino acid existing in proteins, from taxis. which it is set free by tryptic digestion, that gives a red or trophothylax n. [Gr. trophe, food; thylax, sack] (ARTHRO: In- violet color on oxidation; it is essential to animal life. secta) In Hymenoptera Formicidae, a specialized pouch of T-tubule Invaginations of the plasma membrane into the mus- Pseudomyrmecinae larvae located on the ventral part of cle fiber between the Z- and H-bands. the thorax just beneath the mouth parts that receives food tube n. [L. tubus, tube] Any hollow, cylindrical structure. pellets; a feed bag. tube-feet (ECHINOD) Small, fluid-filled tubes of the water vas- trophozooid see gastrozooid cular system functioning in locomotion, adhesion, food trophus see pl. trophi capture and transport to the mouth; some are sensory and tropis n. [Gr. tropus, keel] 1. (ARTHRO: Crustacea) In Ostra- may assist in respiration. cods, a heavy chitinous (or two unfused rods) connecting tubercle n. [L. dim. tuber, hump] 1. A small knoblike or the zygum to the sternix and pastinum. 2. (NEMATA: Ade- rounded protuberance. see torus. 2. (ARTHRO: Insecta) In nophorea) In Enoplida, a hollow tooth-like structure formed Diptera, sometimes used for an elongate facial swelling. by a subventral wall of the buccal capsule. tuberculate , tuberculose a. tropism n. [Gr. tropos, turn] A movement, orientation or lo- tubercula pubertatis (ANN: Oligochaeta) A glandular swelling comotion of a motile organism in response to a stimulus. a. near the ventrolateral margin of the clitellum of mature Positive tropism: toward the stimulus. b. Negative tropism: adult earthworms during copulatory phase; differs in size, away from the stimulus. see taxis. shape and continuity. tropotaxis n. [Gr. tropos, turn; taxis, arrangement] A type of tuberiferous a. [L. dim. tuber, hump; fero, bear] Bearing tu- 922 923 Maggenti and Gardner On line Di ctio nar bercles. tunic n. [L. tunica, garment]y oAf covering membrane or tissue. Inve tube tracheae (ARTHRO: Chelicerata) In Opiliones, Solifugae tunica n.; pl. -cae [L. tunica, garmretenbt] 1. A covering or envel- rate and most spiders, tube-like tracheae; usually unbranched oping membrane or tissue; a tunic. 2Z.oo(ARTHRO: Insecta) log ectodermal invaginations. see sieve tracheae. For Lepidoptera see diaphragm. y tubicolous a. [L. tubus, tube; colere, to dwell] Inhabiting a tunica adventitia Outermost fibro-elastic layer of various tu- tube; a tubular spider web. bular organs, such as vas deferens, esophagus, uterus, tubifacient a. [L. tubus, tube; facere, to make] Tube con- ureter, etc. structing. tunica intima An inner lining or membrane. tubule n. [L. dim. tubus, tube] A minute tube. tunica propria (ARTHRO: Insecta) In females, an elastic mem- tubulus n. [L. dim. tubus, tube] (ARTHRO: Insecta) In Lepi- brane, with or without fine fibrils, that encloses the ovariole doptera, a tubular, telescoping ovipositor. and terminal filament. tubus n. [L. tubus, tube] (NEMATA) A cuticular projection sur- tunicary a. [L. tunica, garment] Pertaining to a covering mem- rounding the spicules beyond the body outline; cloacal brane or a tunic. tubus. tunicate a. [L. tunica, garment] 1. Having a tunic. 2. (ARTHRO) tuft sensilla (ARTHRO: Crustacea) In Decapoda, small Applied to coupling joint of antennae. branched hairs over pores in the carapace with two or turbinate a. [L. turbo, a whirl] Top-shaped; nearly conical with three attached neurons, functioning in vibration and water a round base; turbiniform. movement detectors. turbinate eye (ARTHRO: Insecta) In male Baetidae Ephemer- Tullgren funnel Apparatus designed by A. H. Tullgren for ex- optera, eyes enlarged, divided into lower and outer pig- traction of animals from duff and litter; the sample is mented ovals and raised on a broad stalk, with larger up- placed on a sieve and heat is applied from above to drive per and inner portion usually pale with large facets. the animals downward into a funnel with a collecting vessel turgid a. [L. turgidus, swollen] Swollen; distended. below; similar to a Baerman funnel that uses a water in- terface between sample and collecting vessel. turreted a. [L. turris, a tower] Tower-shaped. tumefaction n. [L. tumere, to swell; facere, to make] Abnor- turriculate a. [L. dim. turris, tower] (MOLL: Gastropoda) Hav- mal tissue formations in invertebrates having characteris- ing an acutely conical spire comprised of numerous flattish tics in common with vertebrate neoplasms, however, pre- whorls; turriform; turrited. cise nature is unknown. tychoparthenogenesis n. [Gr. tyche, change; parthenos, vir- tumescence n. [L. tumescere, to swell up] Slightly tumid or gin; genesis, beginning] Unfertilized eggs that can occa- enlarged. sionally, or accidentally, develop through parthenogenesis. tumid a. [L. tumere, to swell] Swollen; enlarged; abnormally tylasters n. [Gr. tylos, knob; aster, star] (PORIF) A star- distended. shaped spicule with a small center and knobbed rays. tumulus n. [L. tumulus, mound] (ARTHRO: Insecta) In Apis, a tylenchoid bursa see bursa pile of earth at the mouth of an underground burrow. tylenchoid esophagus (NEMATA: Secernentea) An esophagus tun n. [L. tunica, garment] (TARDI) A cryptobiotic shriveled, with a narrow procorpus, a strongly formed median bulb state of tardigrades produced by evaporation of surround- (metacorpus), followed by a narrow typical isthmus and ing water film. terminating with a glandular basal bulb. 924 925 Maggenti and Gardner On line Di ctio nar tyloid n.; pl. tyloides [Gr. tylos, knob] (ARTHRO: Insecta) In tympanic pit (ARTHRO: Inyseocfta) In Diptera, a membranous Inv Trigonalidae and Ichneumonidae, any large indented, flat- area opening toward the baseeortfethe wing, enclosed by the bra tened or raised sensory area on the antennae. two lowermost arms of the tympanalteriZdge. ool ogy tylosis n.; pl. -es [Gr. tylos, knob] A hardening or thickening; tympanum n.; pl. -ana [Gr. tympanon, drum] (ARTHRO: In- a callous. secta) A vibrating membrane involved in hearing; typanic tylostyle a. [Gr. tylos, knob; stylos, column] (PORIF) A membrane; an auditory membrane. monactinal monaxon knobbed at the broad end and pointed Tyndall colors or scattering (ARTHRO: Insecta) Color of cer- at the other. see subtylostyle. tain insects resulting from interference of light reflected by tylote n. [Gr. tylos, knob] (PORIF) A diactional monaxon in granules cast upon an absorbing layer of dark pigment be- which both broad ends are knobbed. neath a more or less transparent cuticle; producing blue, green or white, depending upon the size of granules. tylus n.; pl. tyli [Gr. tylos, knob] (ARTHRO: Insecta) The distal part of the clypeal region of the head. type n. [Gr. typos, type] A zoological object that serves as the base for the name of a taxon. tymbal n. [F. timbale, kettledrum] (ARTHRO: Insecta) In Hemiptera (Cicadidae), an area of thin cuticle supported by type by absolute tautonomy see type by original desig- a cuticular rim and a series of dorso-ventral strengthening nation ribs; involved in sound production. see Pearman's organ. type by elimination A type designated when some of the tympanal air chamber (ARTHRO: Insecta) An air-sac or space, original species of a genus have been transferred to other usually posterior to the tympanal organ into which outside genera, the type of the genus selected from among the air is admitted by a spiracle allowing the tympanum to vi- original species that remain in the genus. ICZN brate freely. type by original designation A species designated as type in tympanal bullae see tympanal hood the original publication of a genus. a. If in the original publication of a genus, typicus or typus is used for any of the tympanal fossa (ARTHRO: Insecta) In Diptera, a largely mem- species. b. The species in a proposed new genus (mono- branous area between the suprasquamal ridge and the typical genus). c. In a genus containing a number of spe- lower margin of the postalar wall. cies, one original species has the generic name as its spe- tympanal frame (ARTHRO: Insecta) The supporting framework cific or subspecific name, whether a valid name or a of the tympanal membrane. synonym (type by absolute tautonomy). ICZN tympanal hood (ARTHRO: Insecta) In some Lepidoptera, one type by virtual tautonomy An original species of a genus that of a pair of tubercles or rounded prominences on the dorsal has a specific or subspecific name, either as a valid name surface at the base of the first abdominal segment. or a synonym, is virtually the same as the generic name, or tympanal organs (ARTHRO: Insecta) Specialized chordotonal of the same origin or meaning. ICZN organs that occur on prothoracic legs, mesothorax, type genus In families, the specific genus on which the family metathorax, or abdomen; the auditory organ or eardrum. is founded, not necessarily the first one described. tympanal pockets (ARTHRO: Insecta) In Lepidoptera, pockets type host A designated organism from which a type specimen in the tympanal frame, usually 4 in number. has been collected. tympanal ridge (ARTHRO: Insecta) In some Diptera, a rib-like type locality The area from which a holotype, lectotype, or sclerite forked anteriorly, forming a single or double Y that neotype was collected. encloses the tympanic pit. 926 Maggenti and Gardner type method The method by which the name for a taxon is unquestionably associated with a definite zoological object belong to the taxon. type species The species which was used by the author of a genus to designate as type of a nominal genus. typhlosole n. [Gr. typhlos, blind; solen, channel] A longitudinal infolding of the dorsal intestinal wall into the intestinal lumen. typologist n. [Gr. typos, type; logos, discourse] One who dis- regards variation and who considers the members of a population as replicas of the type. typolysis n. [Gr. typos, type; lysis, loosing] Phylogerontic; stage that precedes extinction of a type organism or group. typostasis n. [Gr. typos, type; stasis, standing] A static phase in evolution.