Eucalliaxiopsis Sakai, 2011

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 : 127-128

Eucalliaxiopsis Sakai, 2011

Calliaxina .— Ngoc-Ho, 2003: 493–494 (partim).— Sakai, 2011: 497–498 (partim).— Sakai and Türkay, 2014: 191 (partim).— Ngoc-Ho, 2014: 549 (partim).— Poore and Dworschak, 2017: 120 (partim).

Eucalliaxiopsis Sakai, 2011: 503–504 .— Sakai, 2018: 742–743.

Calliaxiopsis Sakai and Türkay, 2014: 192 .— Sakai, 2018: 741– 742 (type species, Calliaxiopsis madagassa Sakai and Türkay, 2014 , by original designation and monotypy) syn. nov.

Bakercalliax Sakai, 2018: 738 (type species, Callianassa aequimana Baker, 1907 , by original designation) syn. nov.

Heardcalliax Sakai, 2018: 743 (type species, Calliax jonesi Heard, 1989, by original designation and monotypy) syn. nov.

Manningcalliax Sakai, 2018: 743 (type species, Eucalliax mcilhennyi Felder and Manning, 1994 , by original designation) syn. nov.

Type species. Eucalliax cearaensis Rodrigues and Manning , 1992, by original designation and monotypy .

Diagnosis. Anterior dorsal carapace smooth, or with median ridge posterior to rostrum and submedian pair of oblique ridges; cardiac sulci present. Pleomere 1 without sternal plates, or with pair of sternal plates anterior to pleopods 1. Maxilliped 3 ischium and merus less than twice as long as wide at their articulation. Male major cheliped with palm about twice as long as carpus, 1.5 times as long as wide; minor chela slightly smaller, with elongate fingers or both chelipeds with palms as long as wide in both sexes, minor slightly smaller if at all (rarely). Male pleopod 1 article 2 longer than article 1, parallel-sided, setose, or article 1 with distal long setae, article 2 blade like, with bifid apex (sometimes obscure), or article 1 with distal long setae, article 2 much shorter, digitiform (sometimes fused); without appendix interna. Male pleopod 2 appendix interna digitiform; appendix masculina a lobe fused to appendix interna attached midway on endopodal margin, reaching or exceeding tip of endopod. Telson convex-sided, widest near midpoint; posterior margin slightly excavate or obscurely excavate between rounded posterolateral corners; with transverse crest on dorsal surface.

Remarks. Eucalliaxiopsis is most easily recognised by the telson having a transverse ridge and convex lateral margins. The male pleopod 1 lacks an appendix interna. The appendix masculina reaches or exceeds the tip of the endopod of pleopod 2. Eucalliaxiopsis shares with Eucalliax absence of a maxilliped 3 exopod (with one exception, E. madagassa ) and a telson widest near its midpoint and having a sharp transverse crest. Eucalliaxiopsis differs in having an oval rather than rhomboid uropodal endopod. The presence of cardiac sulci is assumed for the type species; it is present in all others illustrated. The generic synonymy is discussed above under the family heading.