Sphaerium lacustre

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.

Sphaerium lacustre
Conservation status
Least Concern  (IUCN 3.1)[1]
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Bivalvia
Order:	Sphaeriida
Family:	Sphaeriidae
Genus:	Sphaerium
Species:	S. lacustre
Binomial name
Sphaerium lacustre (O. F. Müller, 1774)
Synonyms
List Calyculina clessini Clessin, 1882 Calyculina deformis (H. F. Carpenter, 1902) Calyculina hungarica Hazay, 1880 Calyculina jayensis (Prime, 1852) Calyculina lacustris (O. F. Müller, 1774) Calyculina lacustris var. septentrionalis Clessin, 1876 Calyculina raymondi J. G. Cooper, 1892 Calyculina rosacea (Prime, 1852) Calyculina ryckholti (Normand, 1844) Calyculina rykholtii Clessin, 1879 Calyculina rykholtii var. gallica Clessin, 1879 Cyclas (Securilla) lacustris (O. F. Müller, 1774) Cyclas calyculata Draparnaud, 1805 Cyclas calyculata var. compressa Middendorff, 1851 Cyclas creplini Dunker, 1845 Cyclas jayensis Prime, 1852 Cyclas rosacea Prime, 1852 Cyclas ryckholti Normand, 1844 Cyclas ryckholti var. mucronulata Moquin-Tandon, 1856 Cyclas steinii A. Schmidt, 1850 Cyclas strictum Normand, 1854 Cyclas terveriana Dupuy, 1849 Musculium (Musculium) clessini (Paulucci, 1882) Musculium (Musculium) compressum (Middendorff, 1851) Musculium (Musculium) creplini (Dunker, 1845) Musculium (Musculium) hungaricum (Hazay, 1880) Musculium (Musculium) lacustre (O. F. Müller, 1774) Musculium (Musculium) mucronulatum (Moquin-Tandon, 1856) Musculium (Musculium) ryckholti (Normand, 1844) Musculium (Musculium) steinii (A. Schmidt, 1850) Musculium (Musculium) strictum (Normand, 1854) Musculium (Musculium) terverianum (Dupuy, 1849) Musculium clessini (Paulucci, 1882) Musculium compressum (Middendorff, 1851) Musculium creplini (Dunker, 1845) Musculium declive Sterki, 1912 Musculium hungaricum (Hazay, 1880) Musculium lacustre (O. F. Müller, 1774) Musculium mucronulatum (Moquin-Tandon, 1856) Musculium pusillum Sterki, 1910 Musculium rosaceum (Prime, 1852) Musculium rosaceum var. fuliginosum Sterki, 1916 Musculium ryckholti (Normand, 1844) Musculium strictum (Normand, 1854) Musculium terverianum (Dupuy, 1849) Musculium winkleyi Sterki, 1909 Sphaerium (Musculium) lacustre (O. F. Müller, 1774) Sphaerium deformis H. F. Carpenter, 1902 Sphaerium hispanicum Bourguignat, 1870 Sphaerium lenticula Prime, 1862 Sphaerium maroccanum Pallary, 1899 Sphaerium raymondi J. G. Cooper, 1892 Tellina lacustris O. F. Müller, 1774 Tellina stagnicola Sheppard, 1825 Tellina tuberculata Alten, 1812

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:

• Algeria^[2]
• Belgium
• Czech Republic – in Bohemia, in Moravia,^[3] near threatened (NT)^[4]
• Slovakia^[3]
• Germany – (Arten der Vorwarnliste)^[5]
• Great Britain
• Ireland
• Nordic countries: Denmark, Finland, Sweden (but not in Faroes nor in Iceland)^[6]