Aparatanais, Bird & Bamber, 2013

BIRD, GRAHAM J. & BAMBER, ROGER N., 2013, New littoral, shelf, and bathyal Paratanaidae (Crustacea: Peracarida: Tanaidacea) from New Zealand, with descriptions of three new genera, Zootaxa 3676 (1), pp. 1-71 : 12

Aparatanais gen. nov.

Paratanais: Sieg (1981) : 1271; Gutu & Ramos (1995): 39; Larsen (2001, in part): 368; Larsen et al (2012): 34 .

Diagnosis. Female: Carapace entire or divided into plates. Pereonites all shorter than broad. Pleonites 1–4 with or without articulated epimeral pappose seta. Pleotelson not plate-like. Antennule four-articled, with or without distinct cap-like segment; with simple terminal setae. Antenna article-2 unexpanded or expanded, with or without superodistal apophysis; article-3 with superior spine; articles 2–4 without longitudinal ridge. Mandible body smooth; right incisor crenulate and weakly bifid. Maxilliped endite with two distal tubercles small; palp article-2 with one medial seta (or spine) heavily serrate or multifurcate on aboral margin. Cheliped palm with slender or broad [shaped like Ghurkha kukri knife] sinuate spine near articulation with dactylus; medial comb of one or two heavily serrate spines; fixed finger with one or two inferior seta. Pereopod-1 basis with superoproximal seta, or naked; merus elongate, up to six times ltb. Pereopods 2–3 basis with superoproximal seta; carpus with three distal spines, superior largest (excepting spinanotandus ); inferior pair of spines longer than broad, unequal. Pereopods 4– 6 ischium with two setae; carpus with elevated rows of spinules on inferior margin. Uropod visible from dorsal view, projecting beyond pleotelson; exopod present; rami not longer than peduncle.

Etymology. From the Greek negative particle ‘ a ’ – not, and Paratanais .

Gender. Male.

Type species. Paratanais spinanotandus Sieg, 1981 .

Composition. A. denticulatus (Gutu & Ramos, 1995) comb. nov.; A. intermedius ( Dojiri & Sieg, 1997) comb. nov.; A. malignus (Larsen, 2001) comb. nov.; A. spinanotandus comb. nov.; Aparatanais timutimu gen. et sp. nov. (See below); A. vicentetis ( Larsen, Nagaoka & Froufe, 2012) comb. nov.

Distribution. Eastern Australia (New South Wales), California, Colombia (Pacific coast), New Zealand, NW Africa ( Cape Verde), South Atlantic (Vema Seamount); eulittoral to 591 m ( A. intermedius ).

Remarks. Primarily, Aparatanais gen. nov. is characterised by the heavy serrate spine on the maxilliped palp article-2. Several other characters support it, although not all are expressed simultaneously in all the taxa transferred to the genus: small maxilliped endite tubercles, a kukri-shaped cheliped palm spine, a long pereopod-1 merus (extreme in A. timutimu sp. nov. and A. spinanotandus ), a relatively narrow pereopod-3 propodus, and short uropods (marginally longer in A. denticulatus ). It is not clear if A. spinanotandus lacks pleonal pappose setae or these were simply not recorded by Sieg (1981) but as A. denticulatus also only has simple epimeral setae, the absence is probably genuine. The general habitus tends to be robust and can sometimes help distinguish specimens from sympatric paratanaids. If the modified maxilliped palp seta (spine) and the kukri-shaped cheliped spine are true homologies, then Atemtanais is a closer sister genus than is Paratanais and these spines might therefore be synapomorphic. Atemtanais too is robust, lacks pappose epimeral setae, and has short uropods.

Five species previously classified in Paratanais are transferred to Aparatanais : P. denticulatus , P. intermedius , P. malignus , P. spinanotandus , and P. vicentetis (see above); the transfer of P. intermedius is provisional and more data are required to confirm this.