Callianassa Leach, 1814

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 : 91-92

Callianassa Leach, 1814

Callianassa Leach, 1814: 386 , 400.— Sakai, 2011: 359

(comprehensive synonymy).

Type species. Cancer (Astacus) subterraneus Montagu, 1808 , by original designation and monotypy.

Diagnosis. Rostrum obsolete or obtusely triangular, flat, not reaching cornea. Pleomere 1 tergite undivided or with weak transverse ridge. Maxilliped 3 merus distally oblique with obtuse angle between distal and lower margins, longer than wide at ischium-merus suture. Male major cheliped merus with simple proximal hook on lower margin. Pereopod 3 propodus rectangular, lower margin deeply convex, leading to broadly rounded free proximal lobe. Male pleopod 2 rarely present. Uropodal endopod ovoid, usually longer than wide, anterior margin straight or slightly convex, posterodistal margin evenly convex or asymmetrical, at least as wide as long, distal margin truncate-convex, at right angles to straight anterior margin. Uropodal exopod distal margin clearly differentiated from anterior margin, anterodistal corner right-angled.

Remarks. Callianassa differs from Paratrypaea , Arenallianassa , Filhollianassa and Trypaea , genera it most resembles in these analyses, in having the telson tapering evenly from near base, the merus of maxilliped 3 longer than wide and tapering, the major cheliped with simple proximal hook on its lower margin and absence of facial setae on the uropodal endopod.

Callianassa has been the common catch-all genus for many species whose systematic position was uncertain. Sakai (2011) restricted the genus to a single species but his diagnosis of few characters could refer to any of numerous callianassid genera. The name Montagua Leach, 1814 , is sometimes listed as a synonym. Montagua appears only in the index of Leach (1814: 436) referring to “Genus 44”, Callianassa in the main text. Gebios Risso, 1822 , was treated as a junior synonym of Callianassa by Sakai (2011) and in many earlier works. If anything, Gebios Risso, 1822 , is a synonym of Gilvossius and is discussed below.