Autumn Growth and Mortality of Queen Scallop (Aequipecten opercularis L.) in Captivity: Results from a 3-month Experiment

Pectinidae species are prominent shellfish in the Adriatic Sea, valued for their commercial and ecological importance. Among them, the queen scallop, Aequipecten opercularis, has not yet demonstrated long-term viability in captivity, posing challenges for aquaculture. However, successful aquaculture of A. opercularis could reduce the adverse effects of fishing gear on sea bottoms. The objective of this study is to offer perspectives on how queen scallops adapt to captive conditions, examining their morphometric response and shell growth over three months under different seawater parameters. We assessed the growth rate and hemocyte count in the scallops’ hemolymph, observing growth rate lengths of 0.058±0.174 mm/day in October, 0.003±0.024 mm/day in November, and 0.022±0.026 mm/day in December. Correspondingly, the growth rate weights slightly decreased from 0.022±0.107 g/day in October to 0.003±0.043 g/day in November and 0.008±0.037 g/day in December. Additionally, the total hemocyte count increased significantly over time, peaking in December at 25.846±7.251×10*6 cells/mL. These findings suggest that optimizing environmental conditions, particularly maintaining a temperature around 15°C and ensuring high food quality, can enhance the shell growth and survival rates of queen scallops in captivity. This research identifies key opportunities to improve the culture practices for A. opercularis, contributing to more sustainable aquaculture methods.