In vivo and rapid assessment of scallop muscle trait

Scallops are a popular seafood, prized for their large and delicious adductor muscles. As the important economic traits to be improved in scallop breeding, adductor muscle weight (AMW) and adductor muscle weight percentage (AMWP), are traditionally determined by weighing after dissection, which leads to low efficiency in measurement and failure to collect data in live scallops. The loss of reproductive opportunity in the measured individuals slows the progress of genetic improvement for scallop muscle mass. Thus, in vivo tools that avoid injury are required for muscle evaluation for high-quality scallop breeding and lifespan assessment of muscle growth. In this study, we propose a rapid and non-destructive method for assessing scallop muscle traits by using X-ray technology. This technique presents a clear image of the shell and adductor muscle cross-section for calculating adductor muscle area (AMA) and shell area (SA) in Patinopecten yessoensis and Chlamys farreri, the massively farmed scallop species in China. Further, we found that AMA and adductor muscle area percentage (AMAP, obtained by dividing AMA by SA) highly correlated with AMW (r = 0.891 for P. yessoensis and r = 0.920 for C. farreri, P < .01) and AMWP (r = 0.708 for P. yessoensis and r = 0.703 for C. farreri, P < .01), respectively, indicating that AMA and AMAP could be important parameters for assessing scallop muscle mass and percentage in vivo. In conclusion. we have developed a promising and rapid method for evaluating scallop adductor muscle traits in a non-invasive manner. To the best of our knowledge, this study represents the first report to assess soft tissue mass for bivalves in vivo.