Haploops meloi, Valério-Berardo, Maria Teresa, 2008

Valério-Berardo, Maria Teresa, 2008, Six new species of deep water Ampeliscidae (Crustacea: Amphipoda) from Brazilian Coast, Zootaxa 1844, pp. 1-24 : 20-22

Haploops meloi sp. nov.

( Fig. 11–12 )

Material examined: Holotype: female, 4mm, 22°02’50,811”S – 39°52’24,1”W, 1050m, R/V Astro Garoupa, 14/XII/2002, MNRJ 20097; Paratype 2 females, 22°02’50,811”S – 39°52’24,1”W, 1050m, R/V Astro Garoupa, 14/XII/2002, MNRJ 20091

Etymology: named in tribute to Dr Gustavo Schmidt de Melo in recognition of his significant contribution to Brazilian carcinology.

Diagnosis: Head anterior margin slightly sinuous, anteroventral margin concave. Ocular lenses absent. Antenna 1 subigual in length to antenna 2 peduncle. Coxa 1 expanded distally. Pereopod 7 basis anterior and posterior margins parallels, posterodistal lobe reaching end of isquium, posterior margin with a row of plumose setae; basis shorter than distal articles combined; propodus with 1 robust seta on posterodistal margin; dactylus distal margin rounded with 3 apical setae. Pleosome 2–3 and urosome 1 with 2 short setae on posterodorsal margins. Uropod 1 rami subequal in length. Uropod 3 with both rami with apex blunt, outer ramus with long apical plumose setae, inner ramus inner margin with 2 robust setae and apical setae. Telso more than 2/3 cleft, apices lobes rounded, bearing 1 robust seta and 1 plumose seta each.

Description Holotype, female 4 mm. Head ( Fig. 11 ) shorter than to first three body segments combined; anterior margin slightly sinuous, anteroventral margin concave. Ocular lenses absent. Antenna 1 ( Fig. 11 ) subequal in length to antenna 2 peduncle, article 2 1.2X longer than article 1; flagellum with 5 articles, longer than peduncle. Antenna 2 ( Fig. 11 ) shorter than body length, peduncular article 5 1.3X longer than article 4; flagellum with 12 articles. Mandible ( Fig. 11 ) with 5 accessory setal row; mandibular palp article 2 elongate, with 1 seta on both margins, article 3 0.5 X article 2, with long seta on inner and apical margins. Maxilla 1 ( Fig. 11 ) inner plate bearing 1 distal pectinate seta; outer plate with 9 setal-teeth; palp article 2 provided with 3 distal cusps accompanied by 4 robust setae and 1 simple seta on distal margins. Maxilla 2 ( Fig. 11 ) both plates with apical plumose setae. Maxilliped ( Fig. 11 ) inner plate rectangular, with 1 robust seta and 4 simple setae on distal margin; outer plate bearing 3 chisel-shaped robust setae along medial margin, reaching the end of the palp article 2; palp article 4 insert at midlength of article 3.

Coxa 1 ( Fig. 11 ) expanded distally maximum width 0.58 X coxa length, with plumose setae along ventral margin. Coxa 4 ( Fig. 11 ) nearly transverse, posterior lobe bluntly rounded. Gnathopod 1 ( Fig. 11 ) basis posterior margin with simple setae; carpus subequal in length to propodus, both articles with posterior margins with pinnate setae; dactylus shorter than half of palm length, with setae on inner and distal margins. Gnathopod 2 ( Fig. 11 ) slender than gnathopod 1, basis with simple setae on anteroproximal and posterodistal margins; carpus longer than propodus (1.3 X), both articles with long plumose setae on posterior margins; dactylus with setae along inner margin. Pereopod 3 and 4 ( Fig. 11 ) similar in shape but the third is slightly more stout than fourth, both with dactyli subequal in length to carpus and propodus combined. Pereopod 5 ( Fig. 12 ) basis subovoid, anterior margin with 2 plumose setae; carpus subequal in length to propodus, with posterodistal corner produced into small lobe, with 5 robust setae and 1 long seta pectinate on distal margin. Pereopod 6 ( Fig. 12 ) basis subovoid, anterior margin with 2 long plumose setae, carpus subequal in length to propodus, posterior margin with a row of robust setae, posterodistal corner produced into a small lobe; dactylus short and curved. Pereopod 7 ( Fig. 12 ) basis anterior and posterior margins parallel, posterodistal lobe reaching to end of isquium, posterior margin with a row of plumose setae; length of basis shorter than distal articles combined; both margins of merus and carpus with robust setae; propodus shorter than carpus (0.3 X), with 1 robust seta on posterodistal corner; dactylus shorter than propodus (0.5 X), distal margin rounded with 3 apical setae.

Pleosome 2–3 and urosome 1 ( Fig. 12 ) with 2 short setae on posterodorsal margins. Epimera 1–3 ( Fig. 12 ) ventral margin setose, epimeron 3 posteroventral corner with a rounded spine. Uropod 1 ( Fig. 12 ) peduncle and rami unarmed, rami shorter than peduncle and both subequal in length. Uropod 2 ( Fig. 12 ) rami shorter than peduncle (0.7 X), both rami with 2 robust setae on outer margins, inner margins nacked. Uropod 3 ( Fig. 12 ) with rami longer than peduncle (1.5X), both rami with apex blunt, outer ramus with long apical plumose setae, inner ramus inner margin with 2 robust setae and 3 apical setae. Telson ( Fig. 12 ) more than 2/3 cleft, each lobe rounded at apex, each distal margin bearing 1 robust seta and 1 plumose seta each.

Remarks: Haploops meloi sp. nov. is similar to H. similis Stephensen, 1925 in presenting head anterior margin lightly sinuous and anteroventral corner concave; coxa 1 anteriorlly expanded; pleosome and urosome with 1 pair of short setae dorsal; pereopod 7 basis with posterodistal reaching the distal margin of the isquium; beyond the absences of eyes and dorsal carina in pleosome and urosome. However, the new species is differentiated for the shape of the basis of pereopod 7 and for the presence of setae in the posterior margin of this article; antenna 1 of same length that the antenna 2 peduncle, whereas in H. similis antenna 1 is subequal in length to antenna 2; uropod 1 rami subequal in length differentiating of H. similis that the inner ramus not exceeding 2/3 of the length of the outer ramus; beyond the coxa 4 anterior margin rounded, versus acute projection, a characteristic diagnostic of H. similis .

Figures

FIGURE 11. Haploops meloi sp. nov., holotype female, 4 mm (MNRJ 20097). Scale bars = 0.1 mm, unless indicated otherwise.

FIGURE 12. Haploops meloi sp. nov., holotype female, 4 mm (MNRJ 20097). Scale bars = 0.1 mm.