Reproductive Biology of Crabs: Molecular and Physiological Insights and Implications for Aquaculture

ABSTRACT Crab aquaculture is becoming increasingly important for global food security and economic growth, yet the complexities of crab reproduction present significant challenges. The reproductive physiology of crabs is a critical factor in the sustainability and productivity of crab aquaculture. This review comprehensively explores recent advances in the molecular and physiological mechanisms underlying crab reproduction, with a focus on both male and female reproductive systems. Specifically, the review examines the molecular mechanisms of spermatogenesis and oogenesis, with an emphasis on identifying key genes involved in these processes. Key topics include the genetic and molecular regulation of gonadal development, sex determination, reproductive pathways governed by hormonal and molecular factors, the regulatory role of microRNAs in reproduction, anti‐bacterial mechanisms in reproduction, and the use of transcriptomics and proteomics to uncover reproductive mechanisms. Special attention is given to recent advances in reproductive biotechnology and their practical implications for aquaculture. Male reproductive physiology is discussed in depth, covering seminal plasma composition, sperm morphology, sperm transport, spermatophore formation, the molecular regulation of the acrosome reaction, and sperm quality. Additionally, the review examines the impacts of environmental stressors, such as pollutants and climate change, on reproductive success. By identifying critical research gaps and proposing future directions—including genome editing and germplasm banking—this review aims to bridge knowledge gaps and offer actionable insights for improving reproductive performance in crab aquaculture. These advancements might be applicable for molecular breeding, monosex crab production, sustainable seed production, broodstock management, and enhancing the resilience of crab farming systems globally.