black sea red data book - Department of Biology

Donacilla cornea (Poli, 1791)
Synonyms: Mactra cornea Poli, 1791; Donax elliptica Krynicki, 1837; Mesodesma
donacilla Middendorff, 1849; Mesodesma cornea (Poli) Ostroumoff, 1893.
Common names: None.
Order VENERIDA.
Family MESODESMATIDAE.
Taxonomic description. Shell flattened, elongated, triangular, with small but
prominent umbo, slightly curved forward, without ribs; thin periostracum. Surface of
shell smooth, with fine concentric lines and discrete growth striations. Background
colour yellowish-white with rare brownish radiating pigment striations; some
specimens have yellowish, reddish or mauve pigment. Length 20-24 mm;
width 8 cm.
IUCN Status
World level:
Black Sea Regional level: EN
Subregion level: EN (Ukrainian sector)
Distribution, Habitat type, Critical habitats, Limiting factors. Inhabits coarse
sands in the midlittoral, sometimes found in the phreatic of supralittoral sands.
Present in the Azov Sea, Mediterranean Sea and along the European coasts of Atlantic
Ocean, north to England. Endangered by modifications in the structure of substrata
due to hydrotechnical works and by turbidity caused by sand extraction.
Biology. This species has no planktonic larvae, since these are incubated in the paleal
cavity of the female as an adaptation to the semiliquid environment in which they
live.
Population trends. On the Crimean littoral, densities of more than 3,000
individuals.m 2
occurred until the 1950s. On the southern Romanian littoral, it was
frequent till 1975-1980, in the coarse-sand littoral, forming a specific community with
195