black sea red data book - Department of Biology

Ostrea edulis (Linnaeus, 1758)
Synonyms: Ostrea taurica Krynicki, 1837; Ostrea adriatica Lam.-Middendorff,
1848.
Common names: Engl: European flat oyster, Bulg: Stridia; Rom: Stridie; Russ:
Ustritsa; Turk: Istiride.
Order CYRTODONTIDA
Family OSTREIDAE
Taxonomic description. Shell moderately light, irregularly ovate, without a distinct
hooked beak; patterned with delicate foliations and yellowish-brown in colour.
Outline of both valves identical; left valve fixed to the substrate, slightly cupped, with
corrugated borders; right valve flat and marked with inconspicuous, radiating folds.
Shell consists of a series of chalky layers which may include laminar, hollow
chambers. Size: maximum length 80 mm; width 26 mm.
IUCN Status
World level:
Black Sea Regional level: EN
Subregion level: EN (Romanian and Ukrainian sector), VU (Romanian sector)
Distribution. Mediterranean and Black Seas, Atlantic coast of Europe up to the
Norwegian coast. Introduced to the Atlantic coast of USA. In Ukraine, the largest
remaining colonies are encountered near Tarkhankut Cape, South Crimean coast
(Laspi Bay, near Sevastopol, Sudak and Kara-Dag). Near the Caucasian shores,
found at Utrish Cape.
Habitat type, Critical habitats, Limiting factors. Limited by oxygen deficiency,
siltation of habitats, rising turbidity and pollution. Scavenged by Rapana thomasiana.
Uncontrolled catches are frequent.
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