Cumella spinifera, 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 : 8-11

Cumella spinifera n. sp. ( Figures 4 , 5 )

Material examined. Holotype.–Subadult female (UCR 2383­01). Type locality: Costa Rica, southern Caribbean coast, Puerto Vargas, back reef, carbonate rock rubble washings, depth 1–1.5 m. Paratype: 1 subadult male (UCR 2383­02) same collection data as holotype.

Diagnosis. Female with 12 strong dorsal spines; spines also on dorsal side of pereon and first three pleonites. Male with dorsal margin of carapace armed with four spines, three on ocular lob. Pereonites 2–5 in both sexes having lateral margins with acute prolongations.

Description. Subadult female. Body (Fig A): elongate, about 2 mm in length. Integument spiny and finely setose, especially on carapace (spines disposed in almost parallel rows).

Carapace ( Figure 4 A): slightly more than 1/3 length of entire body, with 12 strong dorsal spines, three on posterior elevation and 5 on the frontal lobe (most of spines with broken tips); pseudorostrum long and spinose, notch distinct with strong tooth on anteroventral corner. Pereonites 2–4 each with short irregular, row of three­five spines on each side of dorsal crest (divide), two dorsal­most spines usually largest.

Antenna 1 ( Figure 4 B): peduncle with teeth on margins of article 2, third article 3 times longer than article 2.

Maxillipeds. Lost during dissection.

Pereopod 1 ( Figure 4 C): basis, ischium, and merus lacking distinct setae, carpus long and robust, longer than ischium and merus combined; propodus with two long simple setae on inner margin, more than twice as long as dactylus, slightly shorter than carpus; dactylus with long simple setae. Exopod small, not fully developed.

Pereopod 2 ( Figure 4 D): basis slightly longer than third of entire length of pereopod, merus with a simple seta on inner margin, carpus longer than ischium and merus combined, with two stout simple setae on distal end; dactylus twice as long as propodus, with long subterminal and terminal setae. Exopod small.

Pereopods 3–5 ( Figure 4 E–G): robust, with basis becoming progressively shorter; dactylus fused with robust, curved terminal seta.

Uropod ( Figure 4 H): peduncle slightly longer than last pleonite and about 1.3 times length of endopod, with long simple setae on both sides. Exopod slightly shorter than endopod, with stout terminal seta. Endopod curved, with two long sensory brush setae and two stout short seta on inner margin, one short terminal seta present.

Subadult male. Carapace. Dorsal margin armed with spine dorsal spines, three on ocular lobe ( Figure 5 A). Five pairs of incompletely developed exopods.

Pereonites 2–5 ( Figure 5 B): with lateral acuminate prolongations.

Uropod ( Figure 5 C): peduncle with six long marginal setae, two outer margin and four on inner margin; about 1.4 times longer than last pleonite and about equal in length to inner ramus (including terminal seta). Exopod about 7/10 length of endopod, with one long terminal seta, one small seta on outer margin and one large subdistal simple seta on inner margin. Endopod with outer margin lacking setae, inner margin with one small proximal seta, two sensory brush seta on shallow lobe mid­marginally, two short (spiniform) subdistal setae, and one large terminal seta (over 3/4 length of remaining part of endopod).

Etymology. The specific name refers to the spinose nature of the integument.

Remarks. Cumella spinifera n.sp. appears to be most similar and closely related to Cumella zimmeri Petrescu, Iliffe & Sarbu, 1994 described from Jamaican waters. The two species both have dorsal spines, a long pseudorostrum, similarly shaped pereonites with acuminate margins and spines, and nearly similar pereopods and uropod. Cumella spinifera differs from C. zimmeri by having (1) more numerous dorsal spines on the carapace of the female (10 versus 3 on C. zimmeri ), (2) the carapace of the female higher and more dorsally pronounced, and with thick rugous integument (versus smooth integument on C. zimmeri ), (3) dorsal spines on pereonites and pleonites, (4) the antennular peduncle spinose, and (5) the uropod with peduncle longer than last pleonite and endopod.

This small cryptic species occurred in rock washings, which contained a diverse invertebrate fauna, especially crustaceans. These included caridean shrimps, amphipods (many spp.), tanaidaceans, mysids ( Heteromysis sp.), and a variety of other cumaceans including Vaunthompsonia cf. cristata Bate, 1856 ; Elassocumella micruropus (Calman, 1911) ; Schizotrema agglutinanta (Băcescu, 1971) , and several other species of Cumella (see Petrescu et al., in press).

Figures

FIGURE 4. Cumella spinifera n. sp. Subadult female. A, lateral view; B, antenna 1; C, pereopod 1; D, pereopod 2; E, pereopod 3; F, pereopod 4; G, pereopod 5; H, uropod. Scale 1 = 0.5 mm (A); Scale 2 = 0.1 mm (B); Scale 3 = 0.3 mm (C – H).

FIGURE 5. Cumella spinifera n. sp. Subadult male (A) lateral view; (B) cephalothorax, dorsal view; (C) uropod. Scale 1 = 0.5 mm (A, B); Scale 2 = 0.3 mm (C).