Comparison of reproductive performance and offspring quality of purple and greenblack Chinese mitten crab, Eriocheir sinensis

Colour plays a critical role in reproductive performance and egg quality in the crustacean. This study was designed to compare the reproductive performance, egg quality, colour, carotenoids, proximate, and fatty acid composition of purple and greenblack Eriocheir sinensis. The results showed that the survival rate, egg production, fecundity and reproductive effort for purple females were slightly higher than greenblack females, but not significant. The egg diameter, wet weight and dry weight of individual egg were similar between purple and greenblack. There was no significant difference for lightness (L*), redness (a*), yellowness (b*), colour difference (dE*), and total carotenoids content between purple and greenblack eggs. Purple eggs had a significantly higher astaxanthin and lutein than greenblack at 1 week (p < 0.05), while lower lutein content in purple eggs at 4 weeks (p < 0.05). The eggs produced by purple female had the significant higher C20:5n3 (EPA) than that of greenblack female. In conclusion, the astaxanthin and EPA content of purple were significantly higher than those of greenblack, but the reproductive performance, eggs colour and proximate composition were similar, which suggested that purple E. sinensis may have better high-quality egg than greenblack E. sinensis.