The potential for aquaculture of the bearded horse mussel (Modiolus barbatus) and Noah’s Ark shell (Arca noae) in southern Croatia

Abstract

To assess the potential of the bearded horse mussel (Modiolus barbatus) and Noah’s Ark shell (Arca noae) for aquaculture in southern Croatia, we analyzed their survival and growth rates under two experimental conditions—suspended culture and on-bottom culture. Furthermore, we investigated feeding on zooplankton by these two species in suspended culture conditions and compared them with previously published results of their feeding on zooplankton in the natural benthic environment. Experimental studies were conducted in Mali Ston Bay (Adriatic Sea) from December 2009 to December 2010. Differences were observed in terms of survival of tagged M. barbatus and A. noae—specimens of M. barbatus exhibited much better survival rates both in suspended culture and in on-bottom cages than did A. noae. Growth of A. noae under both culture conditions was essentially negligible, while M. barbatus grew several times faster in suspended culture than on the bottom. Values for the growth constant K and L inf for M. barbatus in suspended culture were 0.45 year−1 and 55.9 mm, while corresponding values for on-bottom culture were 0.09 year−1 and 58.6 mm, respectively. Zooplankters were present in the stomachs of 86.3 % of M. barbatus and 86.4 % of A. noae. Most abundant taxa were bivalve larvae followed by tintinnids, copepods, unidentified eggs and gastropod larvae. In conclusion, this study clearly shows that M. barbatus is a promising candidate for suspended aquaculture in southern Croatia.