Pinnotheridae

Asthenognathus atlanticus, from here.

Belongs within: Brachyura.

The Pinnotheridae, pea crabs, are small crabs found living as commensals of other invertebrates such as bivalves, ascidians, etc. The free-living males are generally much smaller than the females.

Characters (from Davie 2002): Carapace typically more or less round or transversely oval, often poorly calcified (especially in commensal females); anterolateral margins smooth or laterally toothed; front narrow; orbits and eyes very small; cornea sometimes obsolescent. Antennules and antennae usually very small. Interantennular septum reduced to a thin plate or absent. Buccal cavern broad, short, usually semicircular. Third maxilliped with merus often very large; ischium usually smally, sometimes completely lost or fused with merus; exopod small, more or less concealed. Male genital openings sternal, but originally coxal; female openings sternal. Male abdomen narrow.

<==Pinnotheridae [Pinnotheroidea]
    |  i. s.: Pinnixa White 1846 CA04
    |           |--P. chaetopterana K-M02
    |           |--P. petersi Bott 1955 B55
    |           |--P. retinens Rathbun 1918 B55
    |           |--P. richardsoni Glassel 1936 B55
    |           `--P. salvadorensis Bott 1955 B55
    |         Dissodactylus Smith 1870 B55
    |           |--D. glasselli B55
    |           |--D. lockingtoni B55
    |           |--D. meyerabichi Botts 1955 B55
    |           `--D. nitidus Smith 1870 [incl. D. smithi Rioja 1944] B55
    |         Pinnotheres parvulus GLT03
    |         Mortensenella Rathbun 1909 CA04
    |         Hapalonotus de Man 1879 CA04
    |         Viapinnixa Schweitzer & Feldmann 2001 CA04
    |         Nannotheres moorei MD01
    |         Clypeasterophilus MD01
    |         Xanthasia murigera TSH09
    `--Asthenognathinae CA04
         |--Tritodynamia Ortmann 1894 CA04
         `--Asthenognathus Stimpson 1858 CA04
              |--*A. inaequipes Stimpson 1858 CA04
              |--A. atlanticus Monod 1933 CA04
              |--A. cornishorum Schweitzer & Feldmann 1999 CA04
              |--A. gallardoi Serène & Soh 1976 CA04
              |--A. globosa (Karasawa 1990) [=Tritodynamia globosa] CA04
              |--A. hexagonum Rathbun 1909 CA04
              |--A. microspinus Casadío, de Angeli et al. 2004 CA04
              `--A. urretae Schweitzer & Feldmann 2001 CA04

*Type species of generic name indicated

REFERENCES

[B55] Bott, R. 1955. Dekapoden (Crustacea) aus El Salvador. 2. Litorale Dekapoden, außer Uca. Senckenbergiana Biologica 36: 45-70.

[CA04] Casadío, S., A. de Angeli, R. M. Feldmann, A. Garassino, J. L. Hetler, A. Parras & C. E. Schweitzer. 2004. New decapod crustaceans (Thalassinidea, Galatheoidea, Brachyura) from the Middle Oligocene of Patagonia, Argentina. Annals of Carnegie Museum 73 (2): 25-47.

Davie, P. J. F. 2002. Zoological Catalogue of Australia vol. 19.3B. Crustacea: Malacostraca: Eucarida (Part 2). Decapoda—Anomura, Brachyura. CSIRO Publishing: Collingwood (Victoria).

[GLT03] Glenner, H., J. Lützen & T. Takahashi. 2003. Molecular and morphological evidence for a monophyletic clade of asexually reproducing Rhizocephala: Polyascus, new genus (Cirripedia). Journal of Crustacean Biology 23: 548-557.

[K-M02] Klein-MacPhee, G. 2002. Croakers, drums, and weakfishes. Family Sciaenidae. In Bigelow and Schroeder’s Fishes of the Gulf of Maine (B. B. Collette & G. Klein-MacPhee, eds) 3^rd ed. pp. 435-446. Smithsonian Institute Press: Washington.

[MD01] Martin, J. W., & G. E. Davis. 2001. An updated classification of the Recent Crustacea. Natural History Museum Los Angeles County, Science Series 39: 1-124.

[TSH09] Titelius, M. A., A. Sampey & C. G. Hass. 2009. Crustaceans of Mermaid (Rowley Shoals), Scott and Seringapatam Reefs, north Western Australia. Records of the Western Australian Museum Supplement 77: 145-176.