Adhesiveness removal of common carp (Cyprinus carpio) eggs using tannic acid with metadata-based analysis

Egg adhesiveness poses a significant challenge in both large-scale hatchery operations of commercially important fish species and laboratory research, impacting hatching success and operational efficiency in fish reproduction. Despite various treatments aimed at reducing egg adhesiveness, reproductive outcomes remain inconsistent across fish species. This study addresses this issue through a comprehensive meta-analysis of existing fish egg de-adhesion techniques, highlighting the suboptimal performance observed in common carp (Cyprinus carpio). The meta-analysis reveals that elimination of egg stickiness techniques can effectively reduce egg adhesion, and enhance larvae survival rate and growth, especially in large-scale incubation systems. Additionally, the analysis underscores the need for further comparative studies on egg de-adhesion under both laboratory and practical conditions. Finally, to fill the data gaps identified in the meta-analysis, we conducted a series of experiments to develop a standardized protocol and assess the efficacy of tannic acid (TA) in reducing egg adhesiveness in C. carpio. Our findings demonstrate that 2 g/L TA applied after fertilization for 2-10 min followed by a 10 min egg swelling period, significantly reduces egg adhesiveness while maintaining high hatching and survival rates, presenting a practical solution to improve the efficiency of hatchery operations. This study contributes to optimizing fish reproduction practices and provides valuable insights into the potential large-scale application of TA-based de-adhesion techniques in common carp aquaculture, which successfully reduces de-adhesion time from 70 min to 10 min.