Oocyte analysis of species Arca noae Linnaeus, 1758 (Mollusca: Bivalvia) from Adriatic Sea

Abstract

Noah’s ark shellfish is a commercially important species in the Adriatic Sea, but its populations are overexploited. The objective of this study was to complete the information on reproduction for potential commercial breeding. Previous attempts at ark cultivation resulted in high post-transfer mortality due to mechanical stress from individuals’ detachment from the natural environment. A different approach involving the culture of broodstock for aquaculture operations should be considered. Accurate prediction of spawning events and comparison of the main spawning season and peak in several populations could help to identify a favorable location and period for the collection of hatched gametes and transfer to growing sites. Thus, females of two distinct populations from the Middle Adriatic Sea were investigated. The range of oocyte size at each gonadal developmental stage, the monthly distribution of oocyte frequency and the variation in the monthly mean value of oocyte diameter during 2013 and 2014 were determined. Gametogenesis was not fully synchronous between localities. The period of spawning in Pasman Channel lasts longer and new gametes develop faster. Based on the results we could estimate the periods of gamete release in the studied sites, which may indicate a favorable location and period for the collection of hatched gametes for aquaculture purposes.