Acoustic telemetry technique is one of useful tools to get behavioral information of the free-swimming fish. In this study, we conducted acoustic telemetry using coded acoustic transmitters to compare behavior characteristics between wild and cultured black seabream Acanthopagrus schlegeli, one of target species to promote resource in the marine ranching area. Two wild fish and five cultured fish were released in the marine ranching area after tagging surgically. Three of cultured fish were domesticated using the remote acoustic conditioning system for 3 weeks before being released. Two wild fish stayed at the released point for 2 hours and 9 days, respectively. One of wild fish was found about 10.8km away from the released point after 5 months. Two cultured fish stayed at the released point for 6 days and 75 days, respectively. One of acoustic conditioned fish stayed at the released point for 131 days and then was found about 10.1km away from the released point after 25 days. Others stayed at the released point during this study period(159 days).
Newly hatched black porgy larvae (Acanthopagrus schlegeli) swam to the surface, with the mouth and anus still closed and were 1.90–2.11 mm (mean, 2.0 mm) in total length (TL). The larvae were 2.71–2.94 mm TL (mean, 2.82 mm) on day 2 after hatching. At this time, about two-thirds of the yolk was absorbed, the bladder and intestines had formed, and the mouth and anus were open. Total length was 4.32–4.66 mm (mean, 4.45 mm) at the post-larval stage on days 5–6 after hatching, and the yolk and oil globule were almost absorbed. The end of the notochord began to flex, and 6–8 caudal fin rays were visible. The larvae were 15.37–16.1 mm TL (mean, 15.83 mm) at the juvenile stage on days 30–32 after hatching, and the number of rays in all fins was completely revealed.
The monthly variations of blood characteristics and RNA/DNA of black sea bream, Acanthopagrus schlegeli, habituated in Geojae costal area were analysed to determine health condition of natural stocks in terms of gonad maturation and spawning season from March 2010 to February 2011. Spawning season determinated by gonadosomatic index is from June to August. RNA/DNA ratio of black sea bream muscle was strongly correlated with spawning season. During the gonad maturation RNA/DNA ratio in dorsal muscle tissue was decreased contrast to rapid increase during spawning season. Blood composition factors increased in terms of gonad maturation are aspartate aminotransferase, cholesterol, triglyceride, total protein, glucose, globulin, alkaline phosphatase and inorganic phosphate. Other blood factors increased during spawning season are alanine aminotransferase, blood urea nitrogen, uric acid and lactate dehydrogenase.
웅성 선숙형 해산 어류인 감성돔에게 를 경구 투여하여 성스테로이드인 testosterone(T), 및 cortisol 수준의 변화와 생식소 발달을 조사하였다. 외인성 는 사육 60일째 감성돔의 혈장 T의 수준을 유의하게 상승시켰으나, 혈장 및 난모세포의 크기에는 영향을 미치지 못하였다. 또한 처리는 생식소 내 정소 발달과 정자 형성과정을 촉진시켰으며, 정자 방출 기간을 연장하는 것으로 나타났다. 를 처리한 실험구에서 60일째에 혈장 cortisol 수준