Dulichiella anisochir ( Krøyer, 1845 )

Published, First, 2007, A revision of the tropical / temperate amphipod genus Dulichiella Stout, 1912, and the description of a new Atlantic genus Verdeia gen. nov. (Crustacea: Amphipoda: Melitidae), Zootaxa 1424, pp. 1-62 : 10-12

Dulichiella anisochir ( Krøyer, 1845)

( Figs 3–6)

Melita anisochir Krøyer, 1845: 317 , pl. II, fig. 1a–p. – Dana, 1852: 968, pl. 66, fig. 8a–d. – Ledoyer, 1986: 185.

Melita fresnelii . – Della Valle, 1893: 708 (in part), pl. 60, fig. 6. – Stebbing, 1906: 423 (in part).

? Gammarus (Maera) setipes Dana, 1852: 212 , 213.

? Gammarus (Maera) pilosus Dana, 1852: 212 , 213.

? Dulichiella appendiculata . –Wakabara, et al., 1991: 73. – Wakabara & Serejo, 1998: 574. – Serejo, 1998: 373.

Type material. Lectotype male, 10.7 mm, ZMUC CRU 3717 Rio de Janeiro, Brazil . Paralectotypes: 1 female, 11.8 mm, ZMUC CRU 9895 ; many specimens, ZMUC CRU 9896 ; 32 specimens (14 males, 18 females), ZMUC CRU 5339 ; 8 specimens (4 males, 4 females), AM P69546 , same locality .

Type locality. Rio de Janeiro, Brazil .

Additional material examined. 1 male, 1 female MNRJ 14035 , off Lagoa dos Patos, southern Brazil (32°25’00”S 51°35'00''W), 33 m, 4 December 1992 , stn 528. 2 males, MNRJ 4636 , Cabo Frio Island , Arraial do Cabo, Rio de Janeiro, Brazil, 16 Dec 1969 . 2 males, MNRJ 7699 , on signalization buoy, Coroa de Pedra , off Itaparica Island, Bahia, Brazil, P. Young & M.C. Brito, 3 Feb 1993 . 2 males, MNRJ 10388 , Massambaba Beach , Arraial do Cabo, Rio de Janeiro, Brazil, #III, 60 m, Aviso Pesqueiro Suboficial Oliviera, 21 June 1988 . 1 male, 2 females, MRJ 15963, Project Revizee Central 2, #23C (20°29'00''S 36°06'00''W), soft bottom, dredge, 60 m, RV Astrogaroupa, 8 November 1997 . 2 males, 2 females, MNRJ 15965 , Project Revizee Central 2, #34C (26°46'02''S 40°05'59''W), soft bottom, dredge, 55 m, RV Astrogaroupa, 3 November 1997 . 1 male, MNRJ 10400 , off Itapemirim , Espírito Santo, Brazil (21°18'58''S 40°28'63''), F.B. Pitombo .

Description. Based on lectotype male, 10.7 mm, ZMUC CRU 3717. Body large. Head eyes ovate; lateral cephalic lobe broad, truncated, anteroventral corner with slender seta. Antenna 1 peduncular article 1 shorter than article 2, with 3 robust setae along posterior margin. Antenna 2 peduncular article 2 cone gland not reaching to end of peduncular article 3; article 4 longer than article 5. Mandibular palp article 1 about as long as broad, inner margin article 1 produced distally; article 2 slightly shorter than article 3.

Gnathopod 1 coxa anteroventral corner produced, rounded, anterior margin concave, posteroventral corner notch present; carpus subequal in length to propodus; propodus "stout", palm convex, defined by posterodistal corner, without posterodistal robust setae. Gnathopod 2 coxa posteroventral corner notch present; (larger) propodus distolateral crown with 3 rounded indistinct spines, palm sinusoidal, posterodistal corner produced, upturned, posterodistal corner with dactylus overlapping corner; dactylus apically blunt; (smaller) merus with sharp posteroventral spine; palm straight, without robust setae, posterodistal corner with robust setae; dactylus with 4 setae on anterior margin. Pereopod 5 dactylar unguis anterior margin with accessory spine. Pereopods 6–7 basis, merus, carpus and propodus without bunches of long slender setae. Pereopod 6 basis posterior margin straight; dactylar unguis anterior margin with accessory spine. Pereopod 7 basis posterior margin slightly subsigmoid, tapering distally.

Pleonite/urosomite dorsal spine formula (9-9-9-5-6-2). Pleonites 1–3 with dorsal setae. Epimeron 1 posteroventral corner with small acute or subacute spine. Epimeron 2 posteroventral corner acute. Epimeron 3 posteroventral margin minutely serrate distally. Urosomite 1 with three dorsal spines. Urosomite 2 with two groups of 1–3 small dorsolateral robust setae. Urosomite 3 without dorsal setae, with 2 dorsal spines. Uropod 3 outer ramus very long, length about 2 x peduncle. Telson with dorsal robust setae.

Female (sexually dimorphic characters). Gnathopod 2 subequal in size, similar to smaller gnathopod 2 of male; palm straight; dactylus posterior margin crenulate. Pereopod 7 basis expanded, posterior margin slightly convex, tapering distally.

Habitat. Marine epibenthic, 0–30 m depth.

Remarks. There are two lots in the Zoological Museum, Copenhagen which contain material of D. anisochir from Rio de Janeiro, both collected at the same time, same location and by the same collector. One lot is labelled as syntypes and the other one is not. We are treating all of this material as syntypes (in agreement with Jørgen Olesen, Curator of Crustacea, ZMUC).

Dulichiella anisochir has been in synonymy since Della Valle (1893). It shares with four other species ( D. australis , D. oahu , D. spinosa and D. tulear ) three spines on the distolateral crown of male gnathopod 2. It appears to differ from all of those species in having a well produced anterodistal process on the coxa of gnathopod 1 and in having a restricted dorsal spine formula (9-9-9-5-6-2).

Distribution. Brazil. Rio de Janeiro to Lagoa dos Patos.