Annual Cycle Of Gonadal Development In Sea Anemone, Entacmaea Quadricolor

Gonad is an organ of gametogenesis. Research on annual cycle of gonadaldevelopment not only help us to reveal the process of gametogenesis development andreproductive period, but also help us to evaluate fertility and development andutilization of its source.In this study, gonad development of annual cycle in sea anemone Entacmaeaquadricolor from two sites near Hongkong (Sharp Island and Tsim Chau) at5m and15m water depths was observed using histological technique. Results showed that,the E. quadricolor was dioecious, and a single annual cycle of gonad development,and spawning in batch mode. Gonad consisted of reproductive mesentery containinggastral layer and reproductive lobule. Based on the structure of both reproductivelobules and germ cells, the annual cycle of gonad development in E. quadricolor wasdivided into proliferating stage, growing stage, maturing and spawning stage, andresting stage, which occurred from March to May for proliferating stage, from May toAugust for growing stage, from August to October for maturing and spawning stage,and from October to the next February for resting stage at Sharp Island, while it wastwo months earlier in Tsim Chau than Sharp Island, respectively from January toMarch, from March to June, from June to August, and from August to the nextJanuary. Furthermore, it was different from the development and frequencycomposing of spermtogenic cysts in male mesenteries, and the frequency composingof oocyte diameter in female mesenteries among the different individuals and even inthe same individual, indicating that the gonadal development was asynchronyobviously. However, there was no difference from the annual cycle of gonaddevelopment among the samples of different water depths at the same site.Based on the data of environmental factors such as temperature, salinity, andbetween the two sites, Sharp Island and Tsim Chau, we found that temperature was the dominant factor to affect the development and mature of the E. quadricolorreproductive mesentery.