Sphaerium lacustre, also known as lake fingernail clam, is species of small freshwater clam, an aquatic bivalve mollusc in the family Sphaeriidae, the fingernail clams and pea clams.
Description The 8–11 mm. shell is oval to quadrangular in shape. The umbos which are capped by the juvenile shell are slightly in front of middle directed forwards. The posterior end is broad and truncated. The shell is fragile, fairly glossy and pearl grey to white in colour. The periostracum (surface) is ornamented with fine, even, concentric striation.
Distribution The native distribution of this species is Holarctic and occurs in islands and countries including: AlgeriaRamdini Ramdane, Dirk Van Damme, Sadouk Ghania & Medjdoub-Bensaad Ferroudja (2020). "Rediscovery of Armiger crista (Linnaeus, 1857) (Gastropoda Planorbidae) in Algeria". Biodiversity Journal 11(4): 821–824. Belgium 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. near threatened (NT)Red List of the molluscs (Mollusca) of the Czech Republic http://mollusca.sav.sk/malacology/redlist.htm Slovakia Germany – (Arten der Vorwarnliste)Glöer P. & Meier-Brook C. (2003) Süsswassermollusken. DJN, pp. 134, page 109, Great Britain Ireland Nordic countries: Denmark, Finland, Sweden (but not in Faroes nor in Iceland)
References
External links Musculium lacustre at Animalbase taxonomy, short description, biology, status (threats), images