A preliminary study on relationship between eyestalk and growth of Charybdis japonica in offshore waters of Jiangsu

We collected 57 individuals of Charybdis japonica from the offshore waters of Nantong, Jiangsu Province, China to analyze their eyestalk microstructure, explore their age and growth, and establish a corresponding growth model. The results show that the eyestalk microstructure of C. japonica consists of four parts: epicuticle, exocuticle, endocuticle and menbranous. The growth lines that can be used for research mainly exist in endocuticle. By analyzing the biological data and growth pattern, in addition to application of AIC method, we found that in seven commonly used growth functions, a linear function relationship is presented between carapace length and carapace width, and a power function relationship is presented among carapace length, carapace width and body mass. However, the relationship among growth lines and carapace length, carapace width as well as body mass is expressed by logistic function relationship.