A rod-shaped, translucent yellow-pigmented, Gram-negative bacterium, strain B390(T), was isolated from the bryozoan Schizobrachiella sanguinea collected in the Adriatic Sea, near Rovinj, Croatia. 16S rRNA gene sequence analysis indicated affiliation to the genus Tenacibaculum, with sequence similarity levels of 94.8-97.3 % to type strains of species with validly published names. It grew at 5-34 degrees C, with optimal growth at 18-26 degrees C, and only in the presence of NaCl or sea salts. In contrast to other type strains of the genus, strain B390(T) was able to hydrolyse aesculin. The predominant menaquinone was MK-6 and major fatty acids were iso-C(15 : 0), iso-C(15 : 0) 3-OH and iso-C(15 : 1). The DNA G+C content was 31.6 mol%. DNA-DNA hybridization and comparative physiological tests were performed with type strains Tenacibaculum aestuarii JCM 13491(T) and Tenacibaculum lutimaris DSM 16505(T), since they exhibit 16S rRNA gene sequence similarities above 97 %. These data, as well as phylogenetic analyses, suggest that strain B390(T) (=DSM 18961(T) =JCM 14633(T)) should be classified as the type strain of a novel species within the genus Tenacibaculum, for which the name Tenacibaculum adriaticum sp. nov. is proposed.