Mucrollichirus, Poore & Dworschak & Robles & Mantelatto & Felder, 2019

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 : 113-114

Mucrollichirus gen. nov.

http://zoobank.org/urn:lsid:zoobank.org:act:B57E69B6-D096-

459C-B4AF-0D278A73B557

Type species. Callianassa mucronata Strahl, 1862 , by present designation and monotypy.

Diagnosis. Anterior branchiostegal lobe sclerotised, well produced anteriorly beyond junction with oblique branchiostegal ridge with which it articulates by means of a virtual condyle. Rostrum spine-like. Pleomere 1 tergite undivided or with weak transverse step. Maxilliped 3 ischium and merus narrow, more than twice as long as wide at their articulation; propodus about as wide as long, free distal margin clearly oblique. Male major cheliped merus lower margin convex, or blade like, especially proximally, with small denticles. Male minor cheliped half or more as wide as major, carpus as long as or shorter than palm, fingers as long as or longer than palm. Pereopod 3 propodus oval, lower margin convex, not proximally lobed. Pereopod 4 subchelate. Male pleopod 1 consisting of 2 articles, article 2 ovoid, with shallow apical notch between rounded subdistal lobe and curved acute apex. Male pleopod 2 appendix interna absent or reduced to obsolete distomesial lobe. Female pleopod 2 endopod 2–3 times as long as wide. Pleopods 3–5 appendices internae barely emerging from endopod margin. Uropodal endopod with convex anterior margin, acute-rounded apex, straight-slightly curved posterior margin, longer than wide. Telson converging to about half basal width from near anterior width over most of length to rounded posterolateral corners, posterior margin straight or with slight medial lobe, smooth dorsally.

Etymology. An alliteration of the name of the type species and Callichirus , type genus of the family.

Remarks. Mucrollichirus has a more weakly lobed propodus on pereopod 3 than all other genera except Calliapagurops . The new genus differs from Neocallichirus (see Sakai, 1988), Corallianassa (see Komai et al., 2015) and other similar genera in having a shorter telson. Both the morphological and molecular analyses placed Mucrollichirus mucronatus on a clade sister to Corallianassa (Robles et al., in press). The similarity to Neocallichirus , the genus in which the species was most recently placed ( Sakai, 2011), is more remote.

The molecular analysis of Robles et al. (in press) found no difference between individuals from Papua New Guinea and the Philippines but illustrations of Mucrollichirus mucronatus vary (De Man, 1888, 1928; Dworschak, 1992; Poore and Griffin, 1979; Sakai, 1999a; Sakai et al., 2014; Tirmizi, 1977).