Advances in precocity research of the Chinese mitten crab Eriocheir sinensis

Precocity has been observed in fishes and crustaceans. However, mechanisms underlying precocity have not been well documented in crustaceans and are thought to be influenced by both genetic and environmental factors. Also, precocity is generally considered to have negative effects on crustaceans. The Chinese mitten crab Eriocheir sinensis, a catadromous species endemic to China, is a high valued commodity and in the recent past is being extensively cultured to meet the growing demand by the restaurant trade. The mitten crab is an ideal candidate for precocity studies because of their large size, distinct secondary sex characters, wide distribution and abundant availability from commercial farms. In this article, progress in several aspects of precocity of E. sinensis is reviewed, including the phenomena of precocity and its effect, identification of precocious crabs, factors related to precocity (temperature, salinity, light, nutrition, stocking density, and germplasm), relationships between precocity and neuro-endocrine system, steroid hormones or hepatopancreas, prevention and control methods of precocity. In addition, possible future directions for the study of precocity are suggested.