Dulichiella Stout, 1912

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 : 9-10

Dulichiella Stout, 1912

Dulichiella Stout, 1912: 140 . – Karaman & Barnard, 1979: 152. – Karaman, 1981: 39. – Barnard & Barnard, 1983: 667. – Jarrett & Bousfield, 1996: 13.

Type species. Dulichiella spinosa Stout, 1912 , monotypy.

Diagnosis. Head anteroventral corner with several long, slender setae. Antenna 1 longer than antenna 2. Maxilla 1 inner plate long, narrow, tapering distally, with 2 well developed apical plumose setae. Maxilla 2 inner plate with oblique setal row. Gnathopod 2 male, asymmetrical, significantly unequal in size; palm in larger slightly obtuse; those of female equal in size. Pereopods 5–7 distal articles strongly to weakly setose; dactylar ungues with accessory spines. Pereopods 6 and 7 in males with bunches of long slender setae. Pereopod 7 basis in female fully expanded. Pleonites dorsally serrate. Uropod 3 inner ramus scale-like; outer ramus 4 to 5 x longer than wide, 2-articulate. Telson deeply cleft, lobes tapering distally to an acute point.

Included species. Dulichiella includes 14 species: D. anisochir ( Krøyer, 1845) ; D. appendiculata ( Say, 1818) ; D. australis ( Haswell, 1879) ; D. cotesi ( Giles, 1890) ; D. cuvettensis Appadoo & Myers, 2005 ; D. fresnelii ( Audouin, 1826) ; D. guinea sp. nov.; D. lecroyae sp. nov.; D. oahu sp. nov.; D. pacifica Lowry & Springthorpe, 2005 ; D. spinosa Stout, 1912 ; D. terminos sp. nov.; D. tomioka sp. nov.; D. tulear sp. nov.

Records of Dulichiella not attributable to any species. Some reports of Dulichiella cannot be placed with any current species, usually because they are not illustrated or poorly illustrated and are from an area where no species have been described. These include the following:

Melita exilii Müller, 1864: 6 , fig. In the text of Müller (1864) there are no diagnostic characters to distinguish D. exilii and no mention is made of type material or type locality. The text figure definitely shows a species of Dulichiella , but the illustration is too general to distinguish it as a particular species. Dulichiella exilii is considered to be an unidentifiable species.

Melita anisochir . — Walker, 1904: 270, pl. 4, fig. 28 ( Sri Lanka). Walker only illustrated a female and referred to Giles (1890) illustrations of the male of D. cotesi . We have seen Walker’s (1904) material. There are two microscope slides (363 and 364) which have deteriorated to the point where they are no longer useful for precise identification or illustration. However, the distolateral crown of male gnathopod 2 has four spines, which indicates that it is not D. anisochir . There are no dense dorsal setae on the pleon which indicates that it is not D. guinea . There appears to be only one accessory spine on the pereopodal dactyli, which puts it in a group with D. lecroyae , D. fresnelii and D. pacifica , but it is not possible to see the characters which distinguish these species.

Melita appendiculata . — Griffiths, 1973: 286 (Morrumbene Estuary and Inhaca Island, Mocambique). — Griffiths, 1974a: 191 ( South-west Africa — now Namibia). — Griffiths, 1974b: 237 (Natal; Durban Bay, South Africa). — Griffiths, 1976: 46, fig. 22a (illustration of D. oahu after J.L. Barnard, 1970). None of this material was illustrated and cannot be identified. We have tried to borrow Griffiths’ (1973, 1974a, b) material from the South Africa Museum, but unfortunately it is very difficult to borrow these collections for study.

Dulichiella appendiculata . — Jarrett & Bousfield, 1996: 13, figs 5, 6. The diagnosis is apparently not based on any material, but may be a composite based J.L. Barnard (1971) ( D. appendiculata [= D. oahu sp. nov.] from Hawaii) and Hirayama & Kikuchi (1979) ( D. appendiculata [= D. tomioka sp. nov.] from Japan). The figures are modified from those presented in these two publications. The British Columbian record of this species seems to be based on a questionable literature record of Melita appendiculata listed by Austin (1985) ( Jarrett & Bousfield, 1996).

Dulichiella appendiculata . — Ortiz & Lalana, 1997: 109. This record from Bontang, Indonesia appears in a checklist to the species of the area with no description and no illustrations.

Melita fresnelii . — Walker, 1909: 334 (Amirante; Cargados Carajos; Wasin; Suakim Harbour). —K.H. Barnard, 1916: 189, pl. 28, fig. 32 (Morewood Cove and Umholti River, Natal; off Durban, South Africa). — Shoemaker, 1935: 239 (Julia Cove, Guanica Harbour, Puerto Rico). — Pirlot, 1936: 304 (Paternoster Islands; Badjo Bay, Flores; Makassar; Borneo Bank; Ternate; Damar Island; Ambon; Banda; Aru; Saleh Bay). —K.H. Barnard, 1937: 159 (Red Sea; Gulf of Aden; Zanzibar). — Rudwick, 1951: 149 (Gulf of Aden). — Nayar, 1959: 22, pl. 7, figs 1—5 (as M. fresnalii, Madras , eastern India). — Nayar, 1966: 148, fig. 5f. — Sivaprakasam, 1968: 111 (Pamban and Tondi-Nambuthalai, eastern India). Of all these records, only K.H. Barnard (1916) and Nayar (1959) attempted to illustrate their specimens, but not well enough to allow identification.

Gammarus (Maera) valida Dana, 1852: 966 , pl. 66, figs 6a–c. ( Singapore). The illustration shows two distolateral spines on the male gnathopod 2. Only two species have this arrangement, D. cotesi and D. tomioka . Both species are in the right geographic area, but Dana’s illustrations are inadequate to make a positive identification.

Remarks. Dulichiella appears to be most similar to Abludomelita Karaman, 1981 and Verdeia gen. nov. It is similar to Abludomelita in the dorsal spination of the pleosome/urosome, but in Abludomelita the male second gnathopods are symmetrical and not so enormously enlarged. Dulichiella and Verdeia both have asymmetrical gnathopods, with one enormously enlarged, but the shapes of the palm are different and the dorsal spination of the pleosome/urosome is very weak in Verdeia . Dulichiella differs from both of these genera ( Abludomelita and Verdeia ) in having a tuft of slender setae on the anteroventral corner of the head, a well developed distolateral crown on the enlarged male gnathopod 2 propodus, accessory spines on the dactylar ungues of pereopods 3 to 7 and long, slender setae on the male pereopods 5 to 7.

Sexually dimorphic characters for Dulichiella include the asymmetrical, massively enlarged, male gnathopod 2; the shape of the palm of gnathopod 2 in the female; bunches of long, slender setae on pereopods 6 and 7 of the male; and the expansion of the female pereopod 7 basis.