The influence of individuality on performance traits in mussels: Assessments based on defensive behavior and physiology

Abstract

Cultured Mytilus coruscus fall-offs regularly led to the reduction of harvest yields of suspension-cultured mussels. High temperature and marine pollutants affect mussel physiological health, which increases the risk of mussel fall-offs and results in yield declines. In this study, we classified mussels into proactive and reactive groups based on their self-organizing behavior after air exposure stress and investigated the differences in defense performance of different group mussels. Proactive mussels were found to have a significantly higher byssus number, adhesion area, and gene expression in the mussel foot protein mfp5 and the byssus collagen preCOL-P. Exposure of mussels to high temperature and different concentrations of BDE-47 revealed a decrease in byssus performance and byssus gene expression in both proactive and reactive groups, but the decreased level of expression of the proactive mussel foot proteins mfp5 and mfp6 was significantly less than that of the reactive mussels. Our study found that proactive mussels have more and better byssuses, better adhesion and defense ability, and greater adaptability under higher temperature and pollutant-exposed conditions. The performance of byssus is correlated with the individuality of stress coping, providing a new direction for future mussel selection breeding and aquaculture.