Callianassa sp.

Clark, Paul F., Ng, Peter K. L., Fransen, Charles H. J. M., McLaughlin, Patsy A., Dworschak, Peter C. & Baba, Keiji, 2008, A checklist of Crustacea Decapoda collected from Conic Island Cave and adjacent areas of Hong Kong, Journal of Natural History 42 (9 - 12), pp. 913-926 : 916-917

Callianassa sp.

Material examined

Long Kei Wan, 22 ° 219540 N 114 ° 239220E, Hong Kong; 1 „? ( NHM 2003.1058) , 1 ♀, 13.7 mm ( NHMW 19899 ), coll. 25 October 2002 .

Remarks

Both specimens are small, but the larger specimen (TL 55.3 mm, CL 51.5 mm) has a small rostral projection, uniramous pleopod1 and biramous pleopod2, the female gonopore being present. The two detached chelipeds ( PL 50.4 mm right, PL 50.27 mm left) probably belong to this specimen. The smaller specimen (TL 54.1 mm, CL 51.1 mm) has almost no rostrum projection and lacks pleopod1+2 and a female gonopore (so the sex is not known).

All chelipeds have a median meral spine, with small spines on the cutting edges of the fixed finger and the ischium is unarmed. The eyestalks are relatively large, with the cornea distinct and almost terminal in position (juvenile). The rostral projection is relatively short in the larger specimen and not visible in the smaller specimen. The third maxilliped is operculiform, with the merus slightly projecting beyond the articulation, the crista dentata with only a few spines (juvenile condition). The antenna peduncle is slightly longer than the antennule, with the antennular flagellum shorter than the peduncle. The specimens are juveniles (many characters are not yet fully developed: pleopods1+2, eyestalks, rostral projection, spination of pereiopod1 merus etc.) and too small to be identified.

Even assignment to one of the genera recognised by Manning and Felder (1991) and Poore (1994) for these specimens is difficult for the reason given above, and the fact that some genera are also weakly defined. As things remain, the specimens key out to Biffarius in Poore (1994) but do not fit exactly, as they will probably develop longer rostral projections when larger. The alternative would be Pseudobiffarius , a genus erected by Heard and Manning (2000), but specimens do not fit exactly with regards to the form of the antennae and pleopods1+2. Sakai (1999b) synonymised Biffarius (and all genera attributed to the subfamily Callianassinae ) with Callianassa . However, Callianassa [sensu lato] is considered to be a polyphyletic clade, with species included as listed in Tudge et al. (2000), but not in the sense of Sakai (1999b) – see Ngoc-Ho (2003) and Dworschak (2003). In any case the genera within the Callianassidae still require revision.