CASA system을 이용한 뱀장어 정자의 활성 평가

Abstract

Anguilla japonica is an important eel species in the aquaculture industry of Asia, especially in Korea. However, techniques for the industrialization are still not completed all over the world. Healthy gametes, including egg and sperm, are essential to accomplish the stable seed production in any aquaculture systems that involves evaluation of the healthy gametes with suitable parameters and improvement of the quality. In this study, the factors to evaluate the quality of eel sperm were investigated using CASA system, and try to provide effective formula for artificial seminal plasma by regulation of inorganic composition. Sperm samples were first divided into four groups, (A) 0-10%, (B) 10-40%, (C) 40-70%, and (D) 0-100%, based on motility and progressive. In the observation of sperm velocity variations, curve motion velocity which is VCL showed significantly highest values in all groups, moreover the relative correlations with progressive and the velocity factors revealed strong as positive relations. The directional factor, BCF which is beat cross frequency was lower in higher activation groups showing opposite correlation with sperm activity. And the highest VCL and lowest BCF values were 207.1 μm/s and 43.35 Hz, respectively. The head sizes of spermatozoa in high activity groups were significantly bigger than lower active groups. Although several minerals showed significant variations with the changes of sperm activity, the Na+ and K ions were assumed important to be principal inorganic elements of seminal plasma in this species. Furthermore, the regulation of the elements in artificial seminal plasma presented effective formula improved than the existing composition, exhibiting composition of Na 120 mM and K 40 mM when preserve the sperm for a short time, and Na 120 mM and K 30 mM for long time. The results of this study establish the indicators for evaluation of eel sperm quality, moreover suggests novel compositions for the artificial seminal plasma which is probably useful to produce the healthy seeds for aquaculture industry.