Izinkala Griffiths, 1977

Lowry, J. K. & Stoddart, H. E., 2010, The family Izinkalidae fam. nov. (Crustacea: Amphipoda: Lysianassoidea) in Australian waters, Zootaxa 2532 (1), pp. 64-68 : 65-68

Izinkala Griffiths, 1977

Izinkala Griffiths, 1977: 115 . — Ledoyer, 1986: 768. — Barnard & Karaman, 1991: 492.

Diagnosis. With the characters of the family.

Included species. Izinkala includes 2 species: I. fihla Griffiths, 1977 ; I. griffithsi sp. nov.

Izinkala griffithsi sp. nov.

Figs 1–3

Type material. HOLOTYPE, male, 2.6 mm, AM P.70330, east of Newcastle , New South Wales, Australia, 32°53’S 152°35’E, 165 m, bottom tow, 15 August 1985, FRV Kapala stn K85-12-23.

Type locality. East of Newcastle , New South Wales, Australia, 32°53’S 152°35’E, 165 m depth .

Etymology. Named for Charles Griffiths in recognition of his work on the amphipod fauna of southern Africa. Diagnostic description. Head partially covered by coxae 1 and 2; lateral cephalic lobe subacute. Antenna 1 peduncular article 1 produced ventrodistally, narrowly rounded; peduncular article 2 produced dorsodistally into large lobe. Maxilla 1 vestigial. Maxilliped without inner and outer plates; palp article 1 about 3.5 x as long as broad, article 2 length about 2 x breadth; article 4 vestigial. Gnathopod 1 coxa vestigial, ischium about 8 x as long as broad; carpus rectolinear, about 7 x as long as broad; propodus rectolinear, about 5 x as long as broad, palm short with a large robust seta; dactylus short, truncated. Gnathopod 2 minutely chelate; coxa enlarged, as large as coxa 3, with a broadly rounded anterior margin; ischium about 5 x as long as broad; carpus subrectangular; propodus subovate with minute obtuse palm. Pereopod 5 basis expanded posteriorly; merus broadly expanded posteriorly, with sloping straight posteroproximal margin and straight posterodistal margin, posteroventral lobe extending halfway along propodus. Pereopod 6 basis expanded posteriorly; merus broadly expanded posteriorly, with sloping straight posteroproximal margin and straight posterodistal margin. Pereopod 7 basis large, posterodistal lobe extending slightly beyond carpus; merus expanded both anteriorly and posteriorly, posterodistal lobe extending to end of carpus. Epimeron 3 posterior margin smooth, posteroventral corner narrowly rounded. Urosomite 1 with a large rounded dorsal boss. Urosomite 2 with a smaller subtriangular dorsal boss. [Uropod 3 not clear.] Telson entire, with 4 robust setae.

Remarks. Unfortunately the mount of urosomite 3, with both of the third uropods and the telson, is very difficult to interpret. Our figure of uropod 3 shows what could be interpreted as a uniramous uropod with a large peduncle and a tiny single ramus. However, it corresponds well to what we have seen as the 2-articulate outer ramus of a biramous uropod 3 on the holotype of I. fihla . Ledoyer (1986) illustrated a 4 mm female with a 1-articulate outer ramus on a biramous uropod 3. Clearly, the true state of Izinkala uropod 3 is not yet resolved. It was not possible to illustrate the telson for I. griffithsi but the 4 large robust setae are clearly visible.

Izinkala griffithsi is very similar to I. fihla and if more material becomes known they might possibly be regarded as one species. However, at present the species can be distinguished by: antenna 1 peduncular article 1 ventrodistal lobe narrowly rounded (acute in I. fihla ); maxillipedal palp article 1 length about 3.5 x breadth (about 2.5 x in I. fihla ); pereopod 5 merus posteroventral lobe extending halfway along propodus (to end of carpus in I. fihla ); pereopod 7 merus expanded anteriorly (not expanded in I. fihla ).

Figures

FIGURE 1. Izinkala griffithsi sp. nov. Holotype, male, 2.6 mm, AM P.70330.

FIGURE 2. Izinkala griffithsi sp. nov. Holotype, male, 2.6 mm, AM P.70330. Scale for U3 represents 0.05 mm; remainder represent 0.1 mm.

FIGURE 3. Izinkala griffithsi sp. nov. Holotype, male, 2.6 mm, AM P.70330. Scales represent 0.2 mm.