Ultrastructural Characterization of Branchial Muscle Myogenesis in Silver Carp (Hypophthalmichthys Molitrix)

Understanding fish muscle development is vital for improving aquaculture food production. This study examined branchial muscle development in carp, identifying skeletal myoblasts by their distinct sarcolemma, which separates neighboring sarcoplasm while maintaining cytoplasmic connections containing electron-dense cytoskeletal components. Three myoblast stages were observed: pregranular (lacking granules but containing mitochondria, ribosomes, fibrils, and early myofilament assembly), granular (featuring granules, ribosomes, smooth endoplasmic reticulum, and minimal rough endoplasmic reticulum), and striated (characterized by sarcoplasmic reticulum, myofilaments, granular materials, and striated myofibrils). Sarcoplasmic vacuolation was observed near developing myofibrils, with cytoplasmic regions showing Z-disc formation and myofibril growth. The findings reveal unique skeletal myogenesis events in silver carp, highlighting the importance of molecular regulation in muscle development. These insights can enhance aquaculture efficiency by optimizing muscle growth and meat yield. Research on skeletal myogenesis in aquatic species provides a foundation for improving fish farming practices, ultimately supporting sustainable and increased fish meat production. This study contributes to a deeper understanding of muscle formation in carp and offers potential applications for selective breeding and aquaculture advancements.