Sušac Island is small and remote island located in the central Adriatic. Bryozoans were sampled by SCUBA divers from the cliff exposed to the open sea, at 20 m depth. Within the quadrant frame sized 50 x 50 cm all biogenic substrate was carefully scraped from the carbonate rock. Altogether 60 bryozoan species were identified. Ten species are for the first time recorded in the central Adriatic, while two species of cyclostomes (Mecynoecia delicatula and Tubulipora notomale) are for the first time recorded in the Adriatic Sea. The most numerous bryozoans were Schizotheca serratimargo (23 colonies), Fenestrulina malusii (18 colonies) and Celleporina caminata (15 colonies), while 15 species were recorded by only one specimen. The dominant growth form of the colonies was encrusting, followed by erect and tubuliporiform, while the least number of species were reteporiform. Most of the species grew on carbonate rock and calcified algae (29), while the next favorable substrate was bryozoan S. serratimargo (12). Other substrates that bryozoans settled on were shells, green algae and polychaete tubes. Six bryozoans were found as epibionts on other bryozoan species. Is this indeed large bryozoan diversity on Adriatic cliff we cannot say, since it is the first time this sampling method has been applied in order to study bryozoan fauna. However, in other studies, where bryozoans were sampled haphazardly along the cliffs from surface to 40 m depth, 57 species were identified at nearby Lastovo Island (South Adriatic) and 50 on Prvić Island (North Adriatic). We argue which sampling method is better for the determination of bryozoan diversity.

Biologija