Ampelisca moreirai Valério-Berardo & -, 2006, sp. nov.

Ampelisca moreirai sp. nov.

(Figs. 5–7)

Material examined: holotype, female, 7.7 mm, 25°35’S – 46°03’W, 136 m, mud and broken shell, R/V W. Besnard col., 29/05/71, MZUSP 16841. Paratypes: 25°13’S – 47°29’W, 32 m, fine sand, R/V W. Besnard col., 18/06/70, MZUSP 16843, 1 male; 23°03’S – 42 °19’W, 75 m, fine sand, R/V W. Besnard col. 05/06/70, MZUSP 16842, 2 females; 25°46’S – 46°30’W, 136 m, fine sand, R/V W. Besnard col. 20/06/70, MNRJ 19653, 2 specimens; 29°33’S – 48°46’W, 118 m, mud and broken shell, R/V W. Besnard col., 25/ 06/70, MNRJ 19654, 2 specimens.

Etymology: This species is named in recognition to Dr. Plinio Soares Moreira (Instituto Oceanográfico/ Universidade de São Paulo) for his innumerous contributions and dedication to marine benthic projects along the Brazilian coast.

Diagnosis: Head with antero­ ventral margin oblique. Antenna 1 shorter than antenna 2 peduncle. Antenna 2 shorter than body length. Coxa 1 with a notch on postero­ventral corner and distally widened. Pereopod 7, basis with plumose setae on ventral margin; merus postero­distal lobe extending 1/3 of propodus, lobe margin with long plumose setae; anterior margin of carpus with two robust setae; propodus longer than carpus, 2.2X longer than wide; dactylus shorter than propodus. Epimeron 3 postero­ventral corner rounded. Urosomite 1 dorsal margin produced posteriorly into a pointed carina upturned. Uropod 2 outer ramus with a long distal robust seta. Uropod 3 inner ramus wider and longer than outer ramus with setae along inner and distal margins; outer ramus with setae along outer margin. Telson deeply cleft apices lobes with 2 pair of setae.

Description: Holotype, female 7.7 mm. Head shorter than first 3 body segments combined, with antero­ ventral margin oblique. Ventral pair of the eyes at antero­ ventral corner of head. Antenna 1 shorter than antenna 2 peduncle, peduncular article 2 longer than article 1 and 3, without setae on ventral margin, flagellum of 5–7 articles. Antenna 2 shorter than body length, peduncular article 4 length subequal to article 5, flagellum with 8–9 articles. Left mandible with 9 accessory blades; mandibular palp article 2 slightly longer than article 3, not inflated, inner and outer margins with long simple setae, article 3 length 0.8X of article 2 with subapical and apical setae. Maxilla 1 inner plate with 2 apical setae, outer plate with 10 setal­teeth; palp aticle 2 with 3 distal cusps accompanied by 3 robust setae and 8 facial setae. Maxilliped inner lobe rectangular distally with 8 distal plumose setae; outer lobe reaching halfway of palp article 2, bearing 9 chiesel­shaped robust setae along margin; palp article 3 not clavate. Upper lip, lower lip and maxilla 2 with basic characters for the genus.

Coxae 1–4 longer than broad. Coxa 1 and 2 with marginal row of plumose setae on ventral margins. Coxa 1 with a notch on postero­ventral corner and distally widened. Gnathopod 1 basis posterior and anterior margins with a row of long simple setae; ischium and merus with setae on posterior margin; carpus 1.2X propodus length, both posterior margins with plumose setae; dactylus slightly curved. Gnathopod 2 slender than gnathopod 1, basis with few long setae on both margins, carpus elongate about 2.2X propodus length with long setae on posterior margin; propodus slender with plumose setae on posterior margin and simple setae on anterior margin; dactylus short, not curved, bearing 4 setules along inferior margin. Pereopod 3 and 4 similar in shape but the fourth is slightly more massive than third, both with elongate dactylus about 1.5X carpus and propodus length combined. Pereopod 3 merus with plumose setae along 2/5 posterior margin and apical long plumose setae on anterior margin, antero­distal corner produced. Pereopod 4 basis both margins with long simple setae; merus both margins with plumose setae, and about 2.7X as long as broad. Pereopod 5 basis subovoid, anterior margin with a row of setae; carpus length subequal to propodus and produced postero­distally, bearing 2 long setae and 2 short robust setae, posterior margin with 1 set of comb robust setae; dactylus short, with 5 apical cusps. Pereopod 6 basis subquadrate, anterior margin with short plumose and simple setae; carpus slightly longer than propodus and produced postero­distally bearing 4 long setae, posterior margin with 2 sets of comb robust setae, anterior margin with 4 robust setae; dactylus short, with 4 apical cusps. Pereopod 7, basis lobe obliquely rounded and surpassing carpus, with plumose setae on postero­distal margin; isquium length subequal to merus; merus postero­distal lobe extending 1/3 of propodus, lobe margin with long plumose setae; carpus anterior margin with two robust setae; propodus longer than carpus, not stout, 2.2X longer than wide; dactylus shorter than propodus and longer than carpus, curved antero­distally.

Epimeron 3 postero­ventral corner rounded. Urosomite 1 dorsal margin produced into a sharpened upturned carina. Uropod 1 extending beyond uropod 2 peduncle, peduncle shorter than rami, inner margin with 3 robust setae; inner ramus slightly longer than outer ramus with 3 robust setae on inner margin, outer ramus nacked. Uropod 2 peduncle length subequal to inner ramus and with 1 robust seta apical on inner margin; inner margins of both rami with robust setae; outer ramus shorter than inner ramus with a long apical robust seta. Uropod 3 rami lanceolate longer than peduncle, inner ramus wider and longer than outer ramus with setae along inner and distal margin; outer ramus with setae along outer margin. Telson deeply cleft, apices lobes blunt with 2 pair of setae.

Male, 5.0 mm. Differing from the female by antennal peduncles with brush setae; deeper notch of urosomite 1 antero­dorsal margin and rami of uropod 3 longer, with setules among all margins, except outer margin of outer ramus.

Remarks: Ampelisca moreirai sp. nov. belongs to the group of species bearing antenna 1 shorter than antenna 2 peduncle and pereopod 7 merus lobed posteriorly, characters shared with A. brevicornis (Costa, 1853); A. cavicoxa Reid, 1951; A. gibba Sars, 1882; A. pectenata Reid, 1951; A. pugetica Stimpson,1864; A. senegalensis Chevreux, 1925; A. uncinata Mills, 1971 and A. vervecei Bellan­Santini & Kaïm­Malka, 1977.

Within this group, Ampelisca moreirai sp. nov. is closer to A. pugetica and A. gibba in having head with antero­ventral margin oblique and uropod 3 rami lanceolate. However, the new species can be distinguished from those two species by pereopod 7 merus lobe surpassing carpus and urosomite 1 dorsal margin tapering into a pointed carina upturned. Ampelisca moreirai is also quite similar to A. senegalensis and A. cavicoxa in pereopod 7 merus lobe extending 1/3 of propodus, but may be distinguished by head margin anteroventral oblique, pereopod 7 basis obliquely rounded and uropod 2 with a long distal robust seta. Ampelisca moreirai sp. nov. differs from A. brevicornis, A. pectenata, A. uncinata and A. vervecei by pereopod 7 propodus rectangular, urosomite 1 dorsal margin upturned and lanceolate uropod 3 rami. In addition, Ampelisca moreirai sp. nov. can be distinguished from all those above species by epimera 3 postero­ventral corner rounded and without spine, while all other species present a small or large spine.