Trachycaris restricta (A. Milne Edwards, 1878 )

Cardoso, Irene, 2006, Caridea (Crustacea, Decapoda) collected on the Brazilian (13 / 22 S) continental shelf and slope, Zootaxa 1364, pp. 1-44 : 21-26

Trachycaris restricta (A. Milne Edwards, 1878)

( Figs. 15–18 )

Hippolyte restrictus A. Milne Edwards, 1878: 231 .

Trachycaris restricta Holthuis, 1949: 233 ; Christoffersen, 1979: 362; Chace, 1972: 142; 1997: 58.

Material examined: 16o47´13” S, 38o 41´48” W, 50m, 4 female (1.3 to 3mm), MNRJ 19458.

Diagnosis: Carapace tuberculate, with teeth and tufts of setae; rostrum laterally flattened, as long as high, dorsal margin with 8–13 teeth, distal margin with 3–6 small teeth, lower margin with 3 broad teeth, dorsal carina with 5–7 teeth; antennal spine strong and acute, 2–3 small teeth on anterolateral angle. Stylocerite broad ending in 2 processes, proximal one acute and distal rounded, with strong teeth. Scaphocerite with small distal tooth, not overreaching blade.

Description: Carapace tuberculate, with teeth and tufts of setae; rostrum laterally flattened, as long as high, dorsal margin with 8 teeth, distal margin with 3 teeth, lower margin with 3 broad teeth, dorsal carina with 5 teeth; antennal spine strong and acute, 2 small teeth on anterolateral angle, without postorbital, branchiostegal and hepatic spines ( Fig. 15 A). Stylocerite broad ending in two processes, proximal one acute and distal rounded, with strong teeth ( Fig. 15 B). Scaphocerite with small distal tooth, not overreaching blade ( Fig. 15 C). Mandible, incisor process absent; molar process formed by two lobes, distal one formed by series of crests with serrate setae and serrate setae with broad, short denticles on lateral margins ( Fig. 16 A). Maxilla 1, broad distal endite with papposerrate setae on inner margin; basal endite slender, with 4 serrate setae on inner margin; palp with 2 plumose seta on tip ( Fig. 16 B). Maxilla 2, scaphognathite with plumose setae on all margins; endopod one fourth scaphognathite length; endite with 3 lobes, distal and median lobes, with serrate setae on inner margin and basal lobe, with plumose setae on inner margin ( Fig. 16 C). Maxilliped 1, exopodal lobe slender, with plumose setae on outer margin; exopod well developed, almost twice the exopodal lobe length, with plumose articulated setae on apex; endopod one third of exopod length, unsegmented, with a small rounded lobe at base; endite with two lobes, distal with serate setae on inner margin and basal with plumose setae on inner margin ( Fig. 16 D). Maxilliped 2, basis and ischium fused, propodus large, corresponding to basis-ischium, merus and carpus combined length, with serrate setae on inner margin; small, slender dactylus with plumose setae on inner margin ( Fig. 16 E). Maxilliped 3, ischiomerus with a distal outer tooth; carpus short; propodus-dactylus with 2 long cuspidate setae and 4 short cuspidate setae on outer margin, 2 short cuspidate setae on dorsal margin, and 2 long cuspidate setae on tip ( Fig. 16 F). Pereopod 1 longer and stronger than second; broad merus with distal dorsal tooth; propodus elongate with 2 broad cuspidate setae on tip, dactylus with 2 broad cuspidate setae ( Fig. 17 A). Pereopod 2 elongate, carpus subdivided in 2 articles; propodus elongate, with 2 cuspidate setae on tip; dactylar tip with 3 cuspidate setae ( Fig. 17 B). Pereopod 3, longer than the others, propodus with 5 stout setae on inner margin; dactylus with 2 cuspidate setae on inner and one large cuspidate seta on tip ( Fig.

17C). Pereopod 5 shorter than the others, propodus without cuspidate setae; dactylus with 2 cuspidate setae on inner margin and one large cuspidate seta on tip ( Fig. 17 D). Female endopod of pleopod 1 short and broad, with plumose setae on all margins ( Fig. 18 A). Female endopod of pleopod 2, appendix interna reduced to a small lobe with a plumose seta on tip ( Fig. 18 B). Telson with 3 pairs of dorsolateral cuspidate setae and 2 pairs oh distal cuspidate setae, the inner smallest ( Fig. 18 C). Endopod of uropod without diaresis; lateral margin ending in sharp triangular projection; without a posterolateral tooth ( Fig. 18 C).

Distribution: Western Atlantic: Bermudas, Florida, Yucatan, Cuba, Porto Rico, Curacao and Brazil (Pará to Espírito Santo). Eastern Atlantic: Cape Verde, Canary Islands and Gulf of Guine.

Remarks: The genus Trachycaris was described to fit Platybema rugosus Bate, 1888 a species that, until 1940, was known only in the Western Atlantic. Holthuis (1949) compared T. rugosa from Canary Islands, with specimens of Hippolyte restrictus A. Milne Edwards, 1878 from Curaçao, and concluded that both forms were one species, that he called T. restricta . Criales (1992) examined 19 mature females from Western Atlantic ( Colombia, Virgin Islands, Puerto Rico, Mexico, Cuba, Belize, Florida and South Carolina) and concluded that these specimens were T. rugosa . The main differences between these two species are, according to Criales (1992), that T. rugosa lacks of a palp in mandible; has 2 spines on basal antennal peduncle and has an endopod of maxilliped 1 with 2 segments, while T. restricta bears a 2-segmented mandibular palp; 3 spines on basal antennal peduncle and an unsegmented endopod on maxilliped 1. Criales (1992) affirmed that both T.restricta and T. rugosa are valid species, and that the first occurs in the Eastern Atlantic and the second in the Western Atlantic. However, the material herein examined (from Western Atlantic) agrees completely with Holthuis (1949) description of T. restricta , having all the three features that distiguish T. restricta from T. rugosa . So, I conclude that if both species are valid, T. restricta distribution isn’t limited to Eastern Atlantic as the present record shows.

Figures

FIGURE 15. Trachycaris restricta (A. Milne Edwards, 1878), female, 3 mm, MNRJ 19458; A. lateral view; B. right antennule, dorsal view; C. right antenna, dorsal view (as — antennal spine; st — stylocerite)

FIGURE 16. Trachycaris restricta (A. Milne Edwards, 1878), female, 3 mm, MNRJ 19458; A. left mandible; B. left maxilla 1; C. left maxilla 2; D. left maxilliped 1; E. left maxilliped 2; F. left maxilliped 3.

FIGURE 17. Trachycaris restricta (A. Milne Edwards, 1878), female, 3 mm, MNRJ 19458; A. right pereopod 1, lateral view; B. right pereopod 2, lateral view; C. right pereopod 3, lateral view; D. right pereopod 5, lateral view.

FIGURE 18. Trachycaris restricta (A. Milne Edwards, 1878), female, 3 mm, MNRJ 19458; A. endopod of right first pleopod, lateral view; B appendix interna, endopod of right second pleopod; C. telson and uropods, dorsal view.