인공종묘 생산된 감성돔 Acanthopagrus schlegeli 치어를 잘 피밭에 방류하여 방류초기의 먹이섭취와 체성분 변화에 대하여 조사하였다. 방류어의 먹이섭취율(predation rate)은 1일째와 3일째 79%로 낮았으며, 7일과 10일째 100%로 증가하였으나 20일째와 30일에는 75%로 낮아졌다. 방류된 감성돔 치어는 단각류와 복족류(Gastropoda)를 주로 섭식하였다. 단각류(Amphipoda)의 섭취는 방류 초기와 30일째에 낮고, 15일째에 82.9%로 가장 높았다. 한편 복족류는 1일째 84.6%로 가장 높았으며, 20일째는 3.1%로 가장 낮은 값을 보였으며, 갑각류와 해조류는 채집 기간동안 20% 내외를 나타내었다. 소화기관 중량비는 방류 후 20일과 30일째 유의적으로 낮은 값을 보였다. 전어체 성분에서는 방류 후 시간 경과에 따라 조단백질과 조지방 성분이 유의적으로 감소하였으며, 지방산 중 DHA 조성이 증가하는 경향을 보였다. 본 연구결과 잘피밭은 자연 먹이의 공급장으로서 방류된 감성돔의 빠른 초기 먹이섭취 및 환경적응에 많은 도움을 준 것으로 판단된다.
Artificially-produced juvenile black sea bream Acanthopagrus schlegeli (total length $8.3{pm}1.0;cm$, body weight $11.2{pm}4.2;g$) were released in eelgrass, Zostera marina bed and their initial food organism and changes of body compositions were investigated for one month after release. Predation rates in fish sampled on 1st and 3rd days were 79%, increased up to 100% on 7th and 10th days, and then decreased on 30th days as 75%. Major prey organisms was composed of mainly Amphipoda and Gastropoda. Ratio of Amphipoda and Gastropoda in stomach were highest in fish sampled on 15th and 1st days after release, respectively. Crustacea and Algae were maintained about 20% during a sampling period. Visceral weight index (VWI) offish sampled 20th and 30th after release were significantly higher than that of initial. Carcass crude protein and lipid contents of released fish were showed significantly decreasing; however carcass n-3 HUFA composition was showed increasing tendency with the passage of time after release. Eelgrass bed was supposed to be helpful for the released fish to adjust their feeding habits and biochemical metabolism to the natural environment within a short period after release.
