Growth of Fenneropenaeus chinensis based on eye stalk microstructure

It is known to all that age and growth study of crustacean is a problem. However, this problem has been solved to some extent as growth increments were found in hard structures such as eyestalk and gastric mill of crustacean. Fenneropenaeus chinensis as one of important economic shrimp, the study of age and growth has been widely concerned. This paper collected 69 F. chinensis from the coastal waters of Nantong, Jiangsu Province. The microstructures of eyestalks of these F. chinensis were analyzed, and the relationship between growth bands of the eyestalks and the weight of F. chinensis was studied. Research shows that the eyestalks consists of four parts: epicuticle, exocuticle, endocuticle and membranous layer. Eyestalk has growth bands and growth increments obviously. Among 44 clear microstructure samples, there are 33 samples with 0 growth band, and 11 samples with 1 growth band. The number of growth increments in one growth band is 25 to 37. The number of growth increments and the length and weight of F. chinensis showed Logistic relation. We conclude that the formation of growth bands of eyestalk in F. chinensis is yearly. However, the formation of growth increments is not daily. Whether the formation period of growth increment is different from the individual differences and the growth environment differences of F. chinensis needs further experimental verification. The results not only lay the foundation for the future identification of F. chinensis, but also provide a new method for the domestic identification of shrimp and crabs and their growth.