earticle

영어

In teleosts fish, a number of species perform spectacular migrations between seawater and freshwater environmental conditions. Japanese eel, Anguilla japonica is a commercially important species and catadromous fish that grows in fresh water, and moves to the sea to spawn. This study investigated the histological changes of organs of A. japonica based on acclimated to the aquatic environment of the seawater. To understand histological changes of organs tissue of A. japonica based on fresh water condition and seawater condition, 6 specimens (mean TL 62±2 cm, mean BW 578±43 g) were used for comparative observation using gills and skin. A large amount of mucous cells were found and chloride cells were rarely observed in the gills in fresh water condition. However, mucous cells were not observed and chloride cells were increased in seawater condition. In the skin, mucous cells were observed in each layer of epidermis from fresh water condition. On the other hand, mucous cells of seawater condition were decreased in each layer of epidermis. In the future, additional comparative studies on environmental characteristics related to the aspect of artificial sex maturation by hormone treatment, another organ tissue changes and osmotic pressure will be necessary.