Significant occurrence of Musellifer profundus Vivier, 1974 (Gastrotricha, Chaetonotida) in the Black Sea

Specimens of the gastrotrich genus Musellifer are recorded for the first time from the Black Sea. These specimens, identified as M. profundus Vivier, 1974, were found in sediment samples collected at various depths (22−135 m) and from waters characterized by low salinity (17.3−18.62‰) and varying levels of oxygen (2.43−299.59 μM). Three specimens were found from the Istanbul Strait (Bosphorus) outlet area of the Black Sea (Turkey) and 2 were found along the southern and southeastern shelf of the Crimean Peninsula (Russia), from the Yalta Gulf and the Feodosiya Gulf.