CAJ | 학술논문

2009年8月和10月对渤海进行了底拖网调查,鲉对增殖放流种类之一的许氏平(Sebates schlegeli)进行了胃鲉含物分析和食物选择性的初步研究。结果表明许氏平共摄食7类20余种饵料,主要摄食虾类和鱼类,属虾/鱼食性鱼类。8月摄食的主要饵料为日本鼓虾和虾虎鱼类,10月摄食的主要饵料为疣背宽额虾和小黄鱼。与20世纪90年代的研究结果相比,鲉许氏平的摄食发生了显著的年间变化,摄食的虾类饵料增多,鱼类饵料减少；主要饵料种类发生改变,鳀鲉不再是其主要的饵料种类。食物选择性指数的计算表明许氏平摄食的主要饵料种类与喜食的饵料种类有一定差别；鲉许氏平的食物选择性并不完全是由环境中的饵料丰度决定的,说明其对食物的选择具有较强的主动性。结论认为,鲉许氏平的摄食和食物选择性的季节变化不仅受环境中饵料丰度的影响,也受鱼类自身营养需求和主动选择性摄食的影响。
2009년8월화10월대발해진행료저타망조사,유대증식방류충류지일적허씨평(Sebates schlegeli)진행료위유함물분석화식물선택성적초보연구。결과표명허씨평공섭식7류20여충이료,주요섭식하류화어류,속하/어식성어류。8월섭식적주요이료위일본고하화하호어류,10월섭식적주요이료위우배관액하화소황어。여20세기90년대적연구결과상비,유허씨평적섭식발생료현저적년간변화,섭식적하류이료증다,어류이료감소；주요이료충류발생개변,제유불재시기주요적이료충류。식물선택성지수적계산표명허씨평섭식적주요이료충류여희식적이료충류유일정차별；유허씨평적식물선택성병불완전시유배경중적이료봉도결정적,설명기대식물적선택구유교강적주동성。결론인위,유허씨평적섭식화식물선택성적계절변화불부수배경중이료봉도적영향,야수어류자신영양수구화주동선택성섭식적영향。
Based on bottom trawl surveys conducted in the Bohai Sea in August and October of 2009, stomach analysis and prey selectivity indices were used to study the feeding habits of Sebates schlegeli, which is a released fish species. The results showed that Sebates schlegeli fed on seven groups of more than 20 prey species, and mainly fed on shrimp and fish, accounting for 64.93%-76.59% of the total food composition, by percentage of occurrence. Thus, Sebates schlegeli belongs to the fish/shrimp predator fish. Alpheus japonicas and the gobiidae were the dominant prey species in August;however, Latreutes planirostris and small yellow croaker (Larimichthy polyactis) were the dominant prey spe-cies in October. Compared with the study performed in the 1990s, the feeding habits of Sebates schlegeli have varied significantly, feeding on a higher proportion of shrimp prey and fewer fish. The dominant prey species were also dif-ferent, and anchovy (Engraulis japonicus) was no longer the dominant prey species. <br> According to prey selectivity index, Sebates schlegeli preferred to feed on Alpheus japonicus, Latreutes anoplonyx, Leptochela gracilis and the gobiidae, but dislike small yellow croakers in August. In October, they prefer to feed on Alpheus japonicus, Apogon lineatus and small yellow croaker, but dislike Oratosquilla oratoria. Influenced by the abundance of prey in the environment, there is some difference between the favorite food species and dominant prey species. Prey selectivity of Sebates schlegeli is not entirely determined by the abundance of prey in the environment, but it does have a strong influence. The S. schlegeli showed a preference for prey with low abundance in the environ-ment, such as Leptochela gracilis, Latreutes anoplonyx and Syngnathus acus in August, and Apogon lineatus in October. It also selectively feeds on prey with high abundance in the environment, such as small yellow croaker and gobiidae. It can feed on Loligo japonica with a stable proportion in August and October;however, this is not related to their abun-dance. The results also indicated that seasonal variations in the food composition and prey selectivity of Sebates schle-geli is not only influenced by the abundance of prey in the environment, but also by nutritional requirements and prey selectivity of individual fish. <br> As a released fish species, the biomass of Sebates schlegeli increased slightly in recent surveys, and was restored to some extent by stock enhancement, yet its biomass is still less than 1%of the maximum historical biomass. Therefore, more could be released to restore biomass. The other important aim of this study was to evaluate scientifically and rea-sonably the ecological capacity for stock enhancement, based on food composition and prey selectivity of Sebates schlegeli. According to the results of this study, combined with its biomass and the evaluation of food consumption, Sebates schlegeli needs to feed on 1.7 t Alpheus japonicus, 2.2 t gobiidae and 1.9 t Loligo japonica in August. Thus, to evaluate the ecological capacity of Sebates schlegeli, the next study needs determine biomass and food consumption of those prey by other predators in the same nutritional niche.