Neotrypaea Manning and Felder, 1991

Poore, Gary C. B., Dworschak, Peter C., Robles, Rafael, Mantelatto, Fernando L. & Felder, Darryl L., 2019, A new classification of Callianassidae and related families (Crustacea: Decapoda: Axiidea) derived from a molecular phylogeny with morphological support, Memoirs of Museum Victoria (Mem. Mus. Vic.) 78, pp. 73-146 : 96

Neotrypaea Manning and Felder, 1991

Notiax Manning and Felder, 1991

Neotrypaea Manning and Felder, 1991: 711–712 .

Nihonotrypaea Manning and Tamaki, 1998: 889–891 (type species, Callianassa japonica Ortmann, 1891 , by original designation) syn. nov.

Pseudobiffarius Heard and Manning, 2000: 70.— Sakai, 2005b: 26 (as synonym of Callianassa ).— Sakai, 2011: 286 (as synonym of Trypaea ) (type species, Pseudobiffarius caesari Heard and Manning, 2000, by original designation and monotypy) syn. nov.

Trypaea .— Sakai, 2011: 385–387 (partim; not Trypaea Dana,1852 ).

Type species. Callianassa californiensis Dana, 1854 , by original designation.

Diagnosis. Rostrum obsolete or obtusely triangular, flat, not reaching cornea. Pleomere 1 tergite undivided or with weak transverse step. Eyestalk distal lobes triangular, apices separate or contiguous, produced and tapering over distal half. Antennular peduncle length about 2.5–3 times the width of both eyestalks. Maxilliped 3 merus expanded distomesially as rounded lobe beyond articulation with ischium, wider at ischium-merus suture than long. Male major cheliped merus with prominent truncate hook armed with serrations along lower margin, excavate laterally at base; propodus distal margin with deep notch at base of fixed finger. Pereopod 3 propodus rectangular, lower margin deeply convex, leading to broadly rounded free proximal lobe. Male pleopod 2 absent. Uropodal endopod asymmetrical, at least as wide as long, distal margin truncate-convex, at right angles to straight anterior margin, with facial distal transverse row of short spiniform setae. Uropodal exopod distal margin clearly differentiated from anterior margin, anterodistal corner right-angled. Telson lateral margins convex; posterior margin slightly concave, sometimes with medial spine.

Remarks. Neotrypaea probably includes more species than any genus of Callianassidae . Species have a triangular distal lobe on the eyestalk, the appendix interna of pleopods 3–5 embedded in the endopod, or only slightly protruding, and the merus of maxilliped 3 projecting as a rounded lobe beyond the articulation of the carpus ( Manning and Felder, 1991) but not as much as in Trypaea . The uropodal endopod is asymmetrical, at least as wide as long, with the distal margin truncate-convex, at right angles to straight anterior margin.

Manning and Tamaki (1998) differentiated Nihonotrypaea with the appendix interna of pleopods 3–5 projecting from the endopod margin from Neotrypaea , in which the appendix interna is completely embedded in the margin. The same difference was used for erection of Pseudobiffarius by Heard and Manning (2000) but this difference is slight. Two clades were evident in the molecular analyses of Robles et al. (in press) but not in the morphological treatment. Species assigned to Nihonotrypaea were reported to differ from Neotrypaea in having the antennular peduncle shorter than the antennal peduncle ( Lin et al., 2007a) but this is true, or they are of similar lengths, in all species from both genera. Both Nihonotrypaea and Pseudobiffarius were synonymised with Trypaea by Sakai (2011).

Notiax Manning and Felder, 1991: 772–773 .— Sakai, 2005b: 18 (as synonym of Callianassa ).

Not Notiax .— Sakai, 2011: 381–382.

Type species. Callianassa brachyophthalma A. Milne-Edwards, 1870 , by original designation and monotypy.

Diagnosis. Rostrum acute, reaching middle of cornea, with ventral broad swelling. Pleomere 1 tergite undivided or with weak transverse step. Maxilliped 3 merus wider at ischium-merus suture than long; crista dentata absent (or few proximal spines only). Male major cheliped merus with prominent truncate hook armed with serrations along lower margin, excavate laterally at base; carpus and propodus flattened, upper and lower margins carinate, blade-like, submarginal mesial face especially of carpus deeply concave. Pereopod 3 propodus rectangular, lower margin deeply convex, leading to broadly rounded free proximal lobe. Male pleopod 2 present or absent. Uropodal endopod asymmetrical, at least as wide as long, distal margin truncate-convex, at right angles to straight anterior margin, with facial distal transverse row of short spiniform setae. Telson longer than wide, tapering evenly from near base; anterolateral lobe defined posteriorly by short transverse slit; transverse ridge with only fine setae; truncate or slightly convex between posterolateral angles.

Remarks. Manning and Felder (1991) differentiated Notiax from other callianassids because of its “rostral spine” but it is not the only genus with this feature. Notiax differs, at least as adults, in having a broad swelling under the rostrum not seen in others. The telson is longer than wide, tapering from its base, whereas it is more rectangular in similar genera such as Neotrypaea and Arenallianassa . The maxilliped 3 merus is not lobed as in Neotrypaea .

Sakai (2011) redefined Notiax to include, besides the type species,five species here included in Rayllianassa , Filhollianassa and Biffarius . His diagnosis included alternate states for the shapes of the maxilliped 3, male pleopods 1 and 2 and the telson. Nothing was given that would unify these five species.