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. Members of the subfamily Asthenognathinae have a trapezoidal carapace that is wider than long and has regions generally not well defined (Casadío et al. 2004). Members of the genus Pinnotheres have the ischium of the external maxillipeds fused with the merus to form a single large joint that closes the buccal cavity.
Characters (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 [Pinnotheridea, Pinnotheroidea]
`--AsthenognathinaeCA04
|--Tritodynamia Ortmann 1894CA04
`--Asthenognathus Stimpson 1858CA04
|--*A. inaequipes Stimpson 1858CA04
|--A. atlanticus Monod 1933CA04
|--A. cornishorum Schweitzer & Feldmann 1999CA04
|--A. gallardoi Serène & Soh 1976CA04
|--A. globosa (Karasawa 1990) [=Tritodynamia globosa]CA04
|--A. hexagonum Rathbun 1909CA04
|--A. microspinus Casadío, de Angeli et al. 2004CA04
`--A. urretae Schweitzer & Feldmann 2001CA04
Pinnotheridae incertae sedis:
Pinnixa White 1846CA04
| i. s.: P. chaetopteranaK-M02
| P. eocenica Rathbun 1926BWW93
| P. fabaFM96
| P. petersi Bott 1955B55
| P. rathbuni (Sakai 1934)G10
| P. retinens Rathbun 1918B55
| P. richardsoni Glassel 1936B55
| P. salvadorensis Bott 1955B55
| P. sayanaB64
`--P. (Palaeopinnixa Via 1966)BWW93, CA04
`--P. (P.) porornata Collins & Morris 1976BWW93
Dissodactylus Smith 1870B55
|--D. glasselliB55
|--D. lockingtoniB55
|--D. meyerabichi Botts 1955B55
`--D. nitidus Smith 1870 [incl. D. smithi Rioja 1944]B55
Pinnotheres Latreille 1802L02
|--*P. pisum (Linnaeus 1767)L02, KK03 [=Cancer pisumL02]
|--P. boninensis Stimpson 1858HS15
|--P. edwardsi De Man 1887HS15
|--P. glaberrimusB64
|--P. hickmani (Guiler 1950)J90
|--P. laquei Sakai 1962FM96
|--P. latipes Jacq. & Lucas 1835B64
|--P. latreiliiR26
|--P. montaguiR26
|--P. mytilorum [=Grapsus (Pinnotheres) mytilorum]G20
|--P. novaezelandiae Filhol 1886B64
|--P. parvulusGLT03
|--P. pholades de Haan 1839B64
|--P. pisoides Ortmann 1894B64
|--P. placunaeFM96
|--P. schauinslandi Lenz 1901B64
|--P. spinidactylus Gordon 1936J90
`--P. veterumR26
Mortensenella Rathbun 1909CA04
Hapalonotus de Man 1879CA04
Viapinnixa Schweitzer & Feldmann 2001CA04
Nannotheres mooreiMD01
ClypeasterophilusMD01
Xanthasia murigera White 1846TSH09
Arcotheres spinidactylus (Gordon 1936)HS15
Holotheres danielae Ahyong 2010HS15
NepinnotheresHS15
|--N. cardii (Bürger 1895)HS15
|--N. pinnotheres (Linnaeus 1758)KK03
`--N. villosulus (Guerin-Meneville 1831)HS15
*Type species of generic name indicated
References
[B64] Bennett, E. W. 1964. The marine fauna of New Zealand: Crustacea Brachyura. New Zealand Department of Scientific and Industrial Research Bulletin 153: 1–120.
[B55] Bott, R. 1955. Dekapoden (Crustacea) aus El Salvador. 2. Litorale Dekapoden, außer Uca. Senckenbergiana Biologica 36: 45–70.
[BWW93] Briggs, D. E. G., M. J. Weedon & M. A. Whyte. 1993. Arthropoda (Crustacea excluding Ostracoda). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 321–342. Chapman & Hall: London.
[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).
[FM96] Feldmann, R. M., D. I. MacKinnon, K. Endo & L. Chirino-Galvez. 1996. Pinnotheres laquei Sakai (Decapoda: Pinnotheridae), a tiny crab commensal within the brachiopod Laqueus rubellus (Sowerby) (Terebratulida: Laqueidae). Journal of Paleontology 70 (2): 303–311.
[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.
[G20] Goldfuss, G. A. 1820. Handbuch der Naturgeschichte vol. 3. Handbuch der Zoologie pt 1. Johann Leonhard Schrag: Nürnberg.
[G10] Grigoryeva, N. I. 2010. Seasonal dynamics of the crab larvae in Minonosok Inlet (Posyet Bay, Peter the Great Bay, the Sea of Japan) in 2000–2004. In: China-Russia Bilateral Symposium: Proceedings of the China-Russia Bilateral Symposium of “Comparison on Marine Biodiversity in the Northwest Pacific Ocean”, 10–11 October 2010, Qingdao (China) pp. 155–164. Institute of Oceanology, Chinese Academy of Sciences; A. V. Zhirmunsky Institute of Marine Biology, Far East Branch of the Russian Academy of Sciences.
[HS15] Hosie, A. M., A. Sampey, P. J. F. Davie & D. S. Jones. 2015. Kimberley marine biota. Historical data: crustaceans. Records of the Western Australian Museum Supplement 84: 247–285.
[J90] Jones, D. S. 1990. Annotated checklist of marine decapod Crustacea from Shark Bay, Western Australia. In: Berry, P. F., S. D. Bradshaw & B. R. Wilson (eds) Research in Shark Bay: Report of the France-Australe Bicentenary Expedition Committee pp. 169–208. Western Australian Museum.
[K-M02] Klein-MacPhee, G. 2002. Croakers, drums, and weakfishes. Family Sciaenidae. In: Collette, B. B., & G. Klein-MacPhee (eds) Bigelow and Schroeder’s Fishes of the Gulf of Maine 3rd ed. pp. 435–446. Smithsonian Institute Press: Washington.
[KK03] Kocataş, A., & T. Katağan. 2003. The decapod crustacean fauna of the Turkish seas. Zoology in the Middle East 29: 63–74.
[L02] Latreille, P. A. 1802. Histoire Naturelle, générale et particulière des crustacés et des insectes vol. 3. Familles naturelles des genres. F. Dufart: Paris.
[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.
[R26] Risso, A. 1826. Histoire naturelle des principales productions de l’Europe méridionale et particulièrement de celles des environs de Nice et des Alpes maritimes vol. 5. F.-G. Levrault: Paris.
[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.
Hi Chris,
It's probably my fault, having missed something, but I haven't figured out how or from where the sort-of-cladograms you include are generated, and I also don't understand the alphanumeric codes. I love the diversity you include, and am a regular reader. I'm only commenting this time because I did my masters on pinnotherids (Dissodactylus)and was a coauthor of Clypeasterophilus. Of course I want to know more about how they all fit in.
Keep up the great work,
Hugh
Hi Hugh,
Thanks for commenting! The dendrograms* I put together myself by hand from what I've found in the literature. Because (a) the sources I've incorporated into them so far may not necessarily be the most up-to-date ones, and (b) even if they are up-to-date, there's every possibility I've misunderstood them, the results are of varied reliability. You can probably see just from looking at it that this page's tree, for instance, is certainly not one of the best.
*(My preferred term [meaning 'tree diagrams'] for these things, as not all of them are meant to represent phylogeny. Many of them simply represent taxonomic groupings.]
The alphanumeric codes indicate the source of each component of the dendrogram, generated from the initials of the authors and the date of publication. So, in the tree above, 'CA04' against a name indicates that I sourced it from Casadío, de Angeli et al. 2004. The source indicated by each code is labelled as such in the reference list.
hi, Chris
many of the pinnotherids you include are NOT pinnotherids anymore. Check Ng et al. (2008) at http://decapoda.nhm.org/pdfs/27562/27562.pdf
But you probably know that by now (I just notice this is more than two years old ;-) )
Thanks for that, Emma. I have the publication you recommended on the to-do list :-)