Valettiopsis Holmes, 1908

Serejo, Cristiana S. & Wakabara, Yoko, 2003, The genus Valettiopsis (Crustacea, Gammaridea, Lysianassoidea) from the southwestern Atlantic, collected by the RV Marion Dufresne, Zoosystema 25 (2), pp. 187-196 : 188-190

Genus Valettiopsis Holmes, 1908

TYPE SPECIES. — Valettiopsis dentata Holmes, 1908 , by original designation.

DIAGNOSIS (modified from Lincoln & Thurston 1983; Barnard & Karaman 1991). — Antennae 1 and 2 elongate, slender; antenna 1, flagellum with article 1 conjoint; accessory flagellum well developed. Mandible, incisor widely toothed; molar triturative; palp attached distal to molar. Maxilla 1, inner plate strongly setose medially; palp large and 2-articulate. Maxilliped with inner and outer plates well developed; palp strongly exceeding outer plate; dactylus well developed. Coxa 1 shortened and partly covered by coxa 2. Gnathopods 1 and 2 elongate and subchelate. Urosomite 1 with a dorsal tooth. Outer ramus of uropod 3, 2-articulate. Telson elongate, deeply cleft.

Valettiopsis macrodactyla Chevreux, 1909 ( Fig. 1 )

Valettiopsis macrodactyla Chevreux, 1909: 1 , figs 1, 2; 1935: 8-10, pl. 2, fig. 1. — Lincoln & Thurston 1983: 86-89, figs 1-3.

MATERIAL EXAMINED. — TAAF MD 55/Brazil, 1987, Marion Dufresne, stn 59 CB 99, 21°36’S, 39°58’W, 1190- 1295 m, 31. V.1987, 1 19.8 mm ( MNRJ 15696).

DISTRIBUTION. — Type locality: Azores , 1992 m, 38°17’40”N, 28°15’10”W ( Chevreux 1909) ; other localities: Bay of Biscay , 4300 m ( Lincoln & Thurston 1983) ; Brazil, off Espírito Santo coast, 21°36’S, 39°58’W, 1190-1295 m ( Fig. 5 ) .

DIAGNOSIS. — Cephalic lobe triangular. Pereon segments 5-7 and pleon segments 1-3 smooth. Urosomite 1 with well developed dorsal tooth. Gnathopod 1, carpus slightly longer than propodus; palm transverse. Gnathopod 2, carpus subequal in length to propodus; propodus robust; palm oblique. Coxa 4 shallowly excavate posteriorly. Basis of pereopod 7 narrowing on postero-distal margin. Outer ramus of uropod 3 with proximal article a little longer than twice the length of distal article. Telson cleft to about 5/6 of its length.

DESCRIPTION

Lateral cephalic lobe triangular; eyes absent ( Fig. 1A ). Antenna 1, peduncle robust; flagellum with 35+ articles, first article conjoint ( Fig. 1A, B ); accessory flagellum 10-articulate. Antenna 2 longer than antenna 1, flagellum with 46 articles. Mandible with incisor dentate; molar strongly triturative; palp 3-articulate, article 2 the longest with setae on inner margin. Lower lip, inner lobe absent; outer lobe marginally setose; mandibular lobe blunt and well developed. Maxilla 1, inner plate with a row of plumose setae on inner margin; outer plate with 11 denticulate spines distally; palp robust, 2-articulate. Maxilla 2, inner and outer plates densely setose; inner plate with a row of facial setae. Inner plate of maxilliped with 3 short apical spines. Coxa 1 subtriangular and shorter than the others; coxae 2-4 rectangular; coxa 4 weakly excavate posteriorly. Gnathopod 1, carpus slightly longer than propodus; carpus and propodus anterior margin sparsely setose, posterior margin densely setose; palm transverse; dactylus fitting palm. Gnathopod 2, carpus and propodus subequal in length; propodus robust, setose and distinctly wider than carpus; palm oblique; dactylus slightly shorter than palm. Basis of pereopod 5 oval. Pereopods 6-7, basis tapering distally, lacking postero-distal lobe, posterior margin weakly serrate. Epimera 2-3 acutely produced. Urosomite 1 with a well developed dorsal tooth ( Fig. 1C ). Uropod 1, peduncle with a strong disto-lateral spine; rami subequal in length, spinose. Uropod 2 with outer ramus shorter than inner ramus. Outer ramus of uropod 3 slightly longer than inner ramus and about 1.7 times the length of peduncle, proximal article a little longer than twice the length of distal article ( Fig. 1D ). Telson deeply cleft, each lobe with a distal notch and 2 apical spines ( Fig. 1E ).

REMARKS

Lincoln & Thurston (1983) provided an extensive redescription of V. macrodactyla so only a few diagnostic features of this taxon have been figured here. Our material is in close agreement with the descriptions of Chevreux (1909, 1935) and Lincoln & Thurston (1983). The callynophore is the fused proximal articles of the primary flagellum of antenna 1, which bear transverse rows of aesthetascs, present also in females, and herein illustrated ( Fig. 1B ). The body length varies, reaching 4 mm (female) in Chevreux’s (1909, 1935) material, 17 mm (male) in Lincoln & Thurston’s (1983) specimen, and 19.8 mm (female) in the material herein examined.

Figures

FIG. 1. — Valettiopsis macrodactyla Chevreux, 1909, 19.8 mm (MNRJ 15696); A, head with peduncles of antennae 1-2, above the length of antenna 1; B, callynophores of antenna 1 and flagellum accessory; C, pleon and urosome; D, uropod 3; E, telson. Scale bars: A, C, 1.0 mm; B, E, 0.3 mm; D, 0.5 mm.

FIG. 5. — Distribution of the genus Valettiopsis Holmes, 1908;, V. multidentata Barnard, 1961;, V. ruffoi n. sp.