Cyclaspis vargasae, Petrescu, Iorgu & Heard, Richard W., 2004

Petrescu, Iorgu & Heard, Richard W., 2004, Three new species of Cumacea (Crustacea: Peracarida) from Costa Rica, Zootaxa 721, pp. 1-12 : 5-8

Cyclaspis vargasae n. sp. ( Figures 2 , 3 )

Material examined. Holotype.–Subadult female ( UCRZM 2382­02). Type locality: NW coast of Costa Rica, Station 8, off San José Island, Islas Murciélago, dredge, fine sand­silt substratum, 35 m depth, 0 8 May1999. Paratypes: 1 male (UCR 8382­01), 1 female ( MGAB CUM 1448), same collection data as holotype.

Diagnosis. Carapace with surface pitted, oblique ridge extending from mid dorsal carapace towards anterior corner. Maxilliped 3 with numerous plumose setae on outer margin of basis, merus with strongly serrate inner margin. Pereopod 1 with propodus longer than carpus and dactylus. Uropodal peduncle 1.5 times longer than last pleonite, with equal rami.

Description. Female. Body ( Figure 2 A,B): elongate, 6 mm in length, with well­calcified integument.

Carapace. Surface pitted with oblique ridge extending from mid dorsal region towards anterior corner, another ridge extending from ventral posterior corner toward pseudorostrum. Median dorsal keel extending from ocular lobe posteriorly. Abdomen with each pleonite having parallel dorsal and ventral crests; pleonites 1–5 each with short lateral crest ending anteriorly in subacute process or tubercle at articulation of each segment. Pleonite 6 with lateral crest present, but lacking anterior process.

Maxilliped 2. Lost during dissection.

Maxilliped 3 ( Figure 2 C): basis longer than remaining articles combined, bearing numerous plumose setae on outer margin, and with strongly serrate inner margin; outer process almost reaching mero­carpal articulation, ischium, merus, and carpus with serrated inner margin; merus with process exceeding extremity of carpus, with strong teeth on inner margin, carpus longer than propodus, propodus little longer than dactylus.

Pereopod 1 ( Figure 2 D): basis less than half length of entire pereopod, distal half with margins irregularly serrate; ischium with spinose dorsal margin; merus longer than dactylus, carpus shorter than propodus.

Pereopod 2 ( Figure 2 E) basis half length of entire pereopod, plumose setae on outer margin, merus longer than carpus, with two plumose setae on inner margin, carpus with two stout setae on inner distal corner, dactylus twice as long as propodus, with short simple setae.

Pereopods 3–5 ( Figure 2 F–H): basis becoming progressively shorter, with plumose setae on inner margin, merus as long as carpus, carpus with a long stout seta on distal end, dactylus fused with its terminal short stout seta.

Uropod ( Figure 2 I): peduncle with margins serrate (as in other species of the genus), about twice as long as rami. Exopod with two small subterminal setae and robust terminal seta; endopod as long as exopod, with subterminal seta, one stronger terminal seta, one seta on inner serrated margin.

Male. Body elongate, narrower than female, 5.8 mm in length.

Carapace ( Figure 3 A): much lower and longer than female, only ventral oblique crest present and extending along pleon.

Pereopod 1 ( Figure 3 B). Basis slender with six stout setae on inner margin, carpus subequal with propodus, dactylus shorter than propodus.

Uropod ( Figure 3 C): peduncle with numerous plumose setae, 1.5 times longer than last pleonite and twice as long as rami. Exopod with two short subterminal setae and one longer terminal seta. Endopod about equal in length with exopod, with terminal robust seta and three microserrate setae and four simple setae on inner margin.

Etymology. The species is named in honour of Rita Vargas, who participated in the collection of the type material, in recognition of her work on the malacostracan Crustacea of Costa Rica.

Remarks. Cyclaspis vargasae n. sp. has some similarities with Cyclaspis alba Roccatagliata & Moreira, 1986 and C. variabilis Roccatagliata & Moreira, 1986 , which are both known from the western Atlantic. It differs from these two species by having (1) a carapace with oblique dorsal crests, (2) a lateral ridge running anteriorly from the posteroventral margin of the carapace to end just above the antennal notch, and (3) a uropod with fewer setae on the endopod.

Cyclapsis vargasae co­occurred with a diverse group of invertebrates, including mollusks, polychaetes, and a variety of crustaceans including tanaidaceans ( Leptochelia sp.), amphipods, brachyuran crabs, caridean shrimps, and the diastylid cumacean, Diastylis californica Zimmer, 1936 .

Figures

FIGURE 2. Cyclaspis vargasae n. sp. Subadult female. A, lateral view; B, cephalothorax, dorsal view; C, maxilliped 3; D, pereopod 1; E, pereopod 2; F, pereopod 3; G, pereopod 4; H, pereopod 5; I, uropod. Scale 1 = 1 mm (A, B); Scale 2 = 0.5 mm (C, E – I); Scale 3 = 0.5 mm (D).

FIGURE 3. Cyclaspis vargasae n. sp. Adult male. A, lateral view; B, pereopod 1; C, uropod. Scale 1 = 1 mm (A); Scale 2 = 0.5 mm (B); Scale 3 = 0.5 mm (C).