Cumella Vulgaris Class: Malacostraca Order: Cumacea Family: Nannastacidae

Phylum: Arthropoda, Crustacea Cumella vulgaris Class: Malacostraca Order: Cumacea Family: Nannastacidae

Description Size: In the original description by Hart present, with an acute antero-lateral angle (1930) from Vancouver Island, an ovigerous (Fig. 1). The male carapace is slender, the female was 2.5 mm in length and a male, 3.0 antennal notch is not as deep as in females, mm long (Hart 1930). The illustrated and the dorsal carina is almost absent (Fig. specimens (from Coos Bay) include a female, 3). 2.5 mm long, and a young male, 2.1 mm in Rostrum: Two pseudorostral lobes length. Cumella vulgaris is one of the smallest (together called a pseudorostrum), or cumacean species (Sars 1900). extensions of the carapace, extend anteriorly Color: Males are dark brown except for but do not fuse in front of the head in lighter distal segments and appendages. The cumaceans (Watling 2007). The female carapace and sixth pleonite are dark pseudorostrum in female C. vulgaris is brown and the rest of the body is light brown relatively short, minutely serrate anteriorly and or white (Gonor et al. 1979). strongly pronounced (Fig. 1). In males, the General Morphology: Cumaceans are pseudorostral projection is shorter (Sars easily recognizable by a large and inflated 1900) (Fig. 3). carapace and a (relatively) slender, flexible Eyes: Conspicuous and circular in thorax and abdomen (Kozloff 1993; Gerken females (Gonor et al. 1979) (Fig. 1). In males and Martin 2014) (Fig. 1). Their bodies can a single central sessile eye, with seven equal be divided into these three major regions: the lenses, is more prominent (Gonor et al. 1979) cephalon (head) that is covered by a (Fig. 4). carapace and includes the first five pairs of Antennae: Female antennule is appendages (antennae, mandibles, maxillae, rather stout, not easily visible, and with collectively the mouthparts). Posterior to the rudimentary inner flagellum (Nannastacidae, cephalon is the pereon (thorax), usually Fage 1951). The second antenna in females consisting of five thoracic somites, followed by is with two large plumose setae (Hart 1930) the pleon (abdomen) with consistently six (not figured). pleonites. The fifth pleonite is usually the Mouthparts: Mandibles are not longest and the pleonites are lacking unique and the bases are not massive (Fage pleopods in female individuals. The 1951) (not figured). cumacean family Nannastacidae are Pereon: Consists of five thoracic somites, characterized by the lack of a free telsons and each with paired appendages (pereopods) uropod endopods that are uniarticulate (Figs. 1–3). (Watling 2007). (For general morphology of Pereopods: The first pereopods in C. vulgaris, see also Plate 229B, Watling females are with bases serrate on the outer 2007.) distal margin. The dactyl and propodus are Cephalon: A carapace covers the cephalon equal to the carpus in length. The second and first three thoracic somites and is pereopods are stout, and the dactyl is twice expanded on either side to form a branchial as long as the propodus. The exopodites are chamber (Watling 2007). present on the first two pairs of pereopods Carapace: Female carapace is large only (Cumella, Lie 1969). The last three and deep, with a smooth mid-dorsal carina pereopods are stout (Fig. 1). The first four (ridge) with a depression on each side (on pereopod bases in males are more dilated posterior margin). A deep antennal notch is than in females and exopodites are present

A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: http://hdl.handle.net/1794/12703 and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: [email protected] on the first four pereopods (absent on fifth) 2014). Cumaceans belong to the (Figs. 2, 3). Malacostraca, and are characterized by a Pleon: Long and narrow in males and stouter carapace that covers the first three or four in females. Consists of six articles or thoracic somites. They also have an anterior pleonites, and lacking pleopods (Figs. 1, 3). extension (pseudolobes), a telson that is Pleopods: All female cumaceans present or reduced and fused with the last lack pleopods (Fig.1) and males in the family pleonite, eyes that are united dorsally, a Nannastacidae also lack pleopods (Watling second antenna that is without an exopod and 2007) (Fig. 3). pleopods that are absent in females and can Telson: Telson short, not freely articulated be absent or reduced in males (Watling and fused to sixth abdominal article 2007). (Nannastacidae, Watling 2007) (Figs. 1, 3). The superorder Peracarida includes Uropods: The uropod peduncles in females cumaceans, mysids, isopods, tanaids and have inner margin with only one spine on the amphipods. Cumaceans can be separated inner distal angle (Gonor et al. 1979) (Fig. 6). from mysids by their single compound eye The uropod endopod is uniarticulate (particularly in the males), as mysids have (compare to biarticulate endopod in large stalked eyes. Mysids have a carapace Nippoleucon hinumensis), larger than exopod, which covers the entire thorax, while denticulate on inner margin, with two stout cumaceans have several posterior segments spines, and one strong apical spine. The exposed (e.g. Figs. 1, 3). Euphausiids belong exopod is with two articles (as in all to the superorder Eucarida (along with cumaceans), is ½ the width of the endopod, decapods) and are pelagic and marine, but and with one slender apical spine (Fig. 6) might occasionally be found in estuaries. (Gonor et al. 1979). The uropods of males They have biramous thoracic appendages are slim and the peduncle is denticulate, (cumacean pereopods are uniramous, with longer than rami (Fage 1951), and with three some thoracic exopodites). Additionally, distal spines. The endopod is with only a euphausiids have strong pleopods for single article (Nannastacidae, Watling 1979), swimming and cumacean pleopods, when while the exopod is with two articles (Fig. 5). present, are small. Sexual Dimorphism: Quite strong sexual The four local cumacean families can dimorphism is observed in C. vulgaris. be divided into those with a freely articulated Females are generally shorter and stouter telson and those without, the former comprise than males and mature individuals have a the Lampropidae and Diastylidae, while the brood pouch. The female eye lacks the latter comprise the Leuconidae and obvious large lenses found in males (Fig. 4). Nannastacidae (Watling 2007). Cumacean Female specimens have a broader carapace families that lack an articulated telson are and uropods, a strong carapace carina, and consistently monophyletic on molecular exopodites that appear only on the first two phylogenies and are likely derived within the pairs of pereopods. Males have a compound Cumacea (Haye et al. 2004). However, eye, are slim, lack a strong carapace carina morphological characters used to differentiate and have a very long second antenna. Males cumacean families (e.g. number of pleopods also have four pereopod exopodites and in males) may be homoplasious (see Haye et some uropod distinctions. al. 2004). The family Nannastacidae, in which Possible Misidentifications Cumella occurs, lack an independent telson, Cumaceans are very small (range 1 the males have no pleopods and the endopod mm–1 cm) shrimp-like crustaceans. Their of the uropod is uniarticulate. Pereopodal heads and thorax are fused to form a exopodites in the Nannastacidae are as carapace, the abdomen is tubular and the follows: males have five (rarely four or three) uropods are slender and biramous. There are pairs and females have three (rarely four or 1500 species worldwide, approximately 50 of zero) pairs (Watling 1979). Cumella vulgaris which occur on the Pacific coast of the United is the only species in this genus locally. States (Watling 2007; Gerken and Martin However, C. pygmaea, the European species

Hiebert, T.C. and L. Rasmuson. 2015. Cumella vulgaris. In: Oregon Estuarine Invertebrates: Rudys' Illustrated Guide to Common Species, 3rd ed. T.C. Hiebert, B.A. Butler and A.L. Shanks (eds.). University of Oregon Libraries and Oregon Institute of Marine Biology, Charleston, OR. is very like C. vulgaris in color and size. The including Anchicolurus and Diastylopsis (one female of C. pygmaea is stouter than C. local species each) and Diastylis (three local vulgaris, with a less inflated carapace and species) (Watling 2007). with a dentate crest on the carina. The male of C. pygmaea is similar to that of C. vulgaris, Ecological Information except that its pedigerous segments are more Range: Type locality is Puget Sound (Hart uneven (Hart 1930). The only other genus of 1930), known range from central California to Nannastacidae from our area is Campylaspis. Oregon (Watling 2007). In this genus, both males and females have Local Distribution: Known in occur in Coos exopodites only on the first pair of pereopods and Yaquina bays. (Lie 1969). The females have a bulbous Habitat: Cumacean species choose carapace with rounded anterolateral angles, substrates mostly based on food availability. unlike Cumella, which has an un-inflated Cumella vulgaris prefers fine sand (grains carapace and an acute anterolateral angles. with diameter less than 160 µm) and dislikes Campylaspis species have a carapace that dry sand (in lab experiments). Males can be extends posteriorly and overhangs the first found in sand with grains of 200 µm diameter few pereonites. Campylaspis canaliculata and smaller (Wieser 1956) and are also found has a smooth carapace and females with a on the water surface, near shore (Hart 1930). marginal anterior-posterior groove. Cumella vulgaris actively avoids habitats with Campylaspis hartae has a carapace with fast currents (McCauley et al. 1977). large ridges, but no bumps, and C. Applications of the insecticide Sevin caused rubromaculata has a carapace with a series significant decreases (90%) in C. vulgaris of bumps or tubercles and shallow ridges abundance (Simenstad and Cordell 1989). (Watling 2007). Salinity: Collected at salinities of 30 (in Coos The Leuconidae (like the Bay). Nannastacidae) lack an independent telson. Temperature: However, they always have a biarticulate Tidal Level: Intertidal and usually found uropod endopod, not a uniramous one as in below +1.5 meters MLLW down to -0.6 Nannastacidae. Members of the Leuconidae meters Wieser 1956). Individuals found on often have up to two pairs of male pleopods water surface and in standing water at low (there are none in Nannastacidae) and tide (Hart 1930). Subtidal populations are leuconid males have exopodites on all five reported as deep as 10 m (Jones 1961). pairs of pereopods (rarely on three). Associates: Leuconid females have exopodites on four Abundance: The most common cumacean (rarely on three) pairs of pereopods (Watling in Puget Sound and San Juan Islands, 1979). Thus, numbers of pereopodal Washington (Wieser 1956) and a common exopodites in both sexes are too alike in the intertidal species in central California. In families Leuconidae and Nannastacidae to Coos Bay, it was the second most abundant serve as dependable determining characters. crustacean (by numbers) found in a North Of the Leuconidae, the genera Eudorella, and Bend study site (Gonor et al. 1979). With Nippoleucon (see N. hinumensis, this guide) Nippoleucon hinumensis, it was found at up to occur on the Pacific Coast (each with one 5,600 individuals per square meter in South local species). Slough of Coos Bay (personal The Lampropidae and Diastylidae communication, M. Posey, OIMB). In Willapa have a freely articulated telsons and the Bay, C. vulgaris was the third most abundant former family has three or more terminal organism in Neotrypaea beds, ninth most setae on the telson while the latter has 0–2. abundant in Zostera beds, seventh most The Lampropidae includes six local species in abundant in oyster beds and twelfth most the genera Hemilamprops and Mesolamprops abundant in bare mud and sand (Ferraro and (each with one local species) and the Cole 2007). Lamprops (four local species, see L. quadriplicata, this guide). In the Diastylidae there are five local species in three genera

A publication of the University of Oregon Libraries and the Oregon Institute of Marine Biology Individual species: http://hdl.handle.net/1794/12703 and full 3rd edition: http://hdl.handle.net/1794/18839 Email corrections to: [email protected] Life-History Information Cumella vulgaris aggregates to feed (Watling Reproduction: Development in cumaceans 1979). is direct, where eggs hatch within a Predators: Cumella vulgaris have been marsupium, and development is thought to be observed in gut contents of the three-spined similar among cumacean genera (e.g. sticklebacks (Gasterosteus aculeatus) and Leucon, Lamprops and Pseudocuma, Gerken Northern anchovies (Engraulis mordax) and Martin 2014). Little is known about the (Rasmuson and Morgan 2013). The development of C. vulgaris, specifically. In introduced European green crab (Carcinus Manocuma stellifera, an Atlantic intertidal maenas) significantly reduced C. vulgaris cumacean, mating occurs at night in plankton populations (Grosholz and Ruiz 1995). (Gnewuch and Croker 1973; Watling 1979), Shorebirds feed on C. vulgaris, but have no during the short swarming period. Females notable impact on abundance (Wilson 1991). molt 12–96 hours before oviposition (in the Behavior: Females and juveniles are lab). Eggs are probably fertilized as they are capable of swimming at speeds of 0.25 to 1.5 released into the marsupium, where they are cm per second, while males are capable of carried to a manca stage. Some other higher swimming speeds (~5 cm s-1, King intertidal species have two breeding 1977). generations per year, one in summer and in fall (see Corey 1969, 1976 in Watling 1979). Bibliography Larva: Cumacean development proceeds from an egg to two manca stages, a subadult and, finally, an adult. The manca stage 1. FAGE, L. 1951. Cumacés. Faune de resembles the adult, but is defined by a lack France:1-136. of the fifth pair of pleopods (see Fig. 41.1F, 2. FERRARO, S. P., and F. A. COLE. Gerken and Martin 2014). The mancae of M. 2007. Benthic macrofauna-habitat stellifera molt three times and the young leave associations in Willapa Bay, the marsupium, molt several more times into Washington, USA. Estuarine Coastal subadult morphology, with mature gonads and Shelf Science. 71:491-507. and secondary sexual characteristics present 3. GERKEN, S., and J. W. MARTIN. (see Corey 1969, 1976 in Watling 1979). 2014. Cumacea, p. 216-218. In: Atlas Juvenile: of crustacean larvae. J. W. Martin, J. Longevity: In Atlantic intertidal cumaceans, Olesen, and J. T. Høeg (eds.). Johns longevity varies with reproductive time of Hopkins University Press, Baltimore, year: an early summer generation may live MD. five months, while late summer and fall 4. GNEWUCH, W. T., and R. A. broods will overwinter and live 12 and nine CROKER. 1973. Macrofauna of months, respectively (see Corey in Watling northern New England marine sand. 1. 1979). Biology of Mancocuma stellifera Growth Rate: (Zimmer, 1943) (Crustacea, Cumacean growth occurs in conjunction with Cumacea). Canadian Journal of molting where the exoskeleton is shed and Zoology. 51:1011-1020. replaced. Post-molt individuals will have soft 5. GONOR, J. J., D. R. STREHLOW, and shells as the cuticle gradually G. E. JOHNSON. 1979. Ecological hardens. During a molt, arthropods have the assessments at the North Bend airport ability to regenerate limbs that were extension site. School of previously autotomized (Kuris et al. 2007). Oceanography, Oregon State Food: A deposit feeder in fine sand and University, Salem, OR. mud. In coarse sand (>150 µm), it is an 6. GROSHOLZ, E. D., and G. M. RUIZ. epistrate feeder that scrapes food off 1995. Spread and potential impact of individual grains (Watling 1979; Kozloff 1993). the recently introduced green crab, Cumaceans feed while buried and swim to Carcinus maenas, in central California. new site when one site has been exploited. Marine Biology. 122:239-247.