Euglesa casertanum, the pea cockle or pea clam, is a minute freshwater bivalve mollusc of the family Sphaeriidae.
Description The shell is broad, sub-triangular or oval and is ornamented with sculpture of faint concentric striations. The umbos are slightly behind the middle. The Periostracum is silky, scarcely glossy. In colour it is whitish to grey-brown and often the shell is coated with reddish-brown deposits.
The shell is of similar shape to Sphaerium novaezelandiae but is smaller as an adult, more inflated, with a deeper hinge-plate, stronger teeth, and the ligament is not visible externally.
Length is up to 4.5 mm, height 3.7 mm, and thickness 2.3 mm.
Distribution It has a cosmopolitan distribution and is perhaps the world's widely distributed non-marine mollusc.
British Isles - commonJanus, Horst, 1965. ‘’The young specialist looks at land and freshwater molluscs’’, Burke, London Ireland Czech Republic - in Bohemia, in Moravia, Horsák M., Juřičková L., Beran L., Čejka T. & Dvořák L. (2010). "Komentovaný seznam měkkýšů zjištěných ve volné přírodě České a Slovenské republiky. [Annotated list of mollusc species recorded outdoors in the Czech and Slovak Republics]". Malacologica Bohemoslovaca, Suppl. 1: 1-37. PDF. least concern (LC)Juřičková L., Horsák M. & Beran L., 2001: Check-list of the molluscs (Mollusca) of the Czech Republic. Acta Soc. Zool. Bohem., 65: 25-40. Slovakia Germany - distributed in whole Germany. High endangered (Stark gefährdet) in Hesse, critically endangered (vom Aussterben bedroht) in Saxony. Pisidium casertanum ponderosum endangered (gefährdet) in Brandenburg.Glöer P. & Meier-Brook C. (2003) Süsswassermollusken. DJN, pp. 134, page 109, Latvia Netherlands New Zealand - commonPowell A W B, New Zealand Mollusca, William Collins Publishers Ltd, Auckland, New Zealand 1979 Nordic countries: Denmark, Faroes, Finland, Iceland, Norway and Sweden Poland
References
External links Pisidium casertanum at Animalbase taxonomy, biology, status (threats), images Pisidium casertanum images at Consortium for the Barcode of Life photo