| Popis: |
Autecology of most sponge species, including Suberites domuncula in the Adriatic Sea, is still unknown, as there are gaps in our knowledge of, for example, growth, migration, behavior, and symbiosis. The main objective of this study was to compile additional contributions on the contraction phenomena of S. domuncula. Specimens of S. domuncula were studied in situ and collected by a SCUBA diver at a site 2.7 km off Rovinj, northern Adriatic Sea, Croatia. We determined and compared, for the first time, the dimensions of sponge specimens in situ (>30 m depth) and in aquaria. Within 1hr after collection, contractions resulted in a decrease of volumes between 40.7 to 69.5%, with an average contraction of 52.1 ± 12.0%. Ex situ, permanent contractions to approximately half their size can change the consistency of the sponge, form, canal structure, water flow, including the disappearance of oscula. It is obvious, that this adaptive, stress protective phenomenon can have far-reaching consequences on the maintenance and life of S. domuncula specimens in aquaria. In the wild, in situ reversible contractions could have protective function by reducing water filtration, decreasing the input of harmful substances, and providing a mechanical strength shield against predators. |
