陆水水库鳜属鱼类食性及消化器官的比较研究

COMPARATIVE STUDIES ON THE FEEDING HABIT AND DIGESTIVE ORCANS OF SINIPERCA FISHES OF LUSHUI RESERVOIR

通过对陆水水库三种鳜属鱼类的食性及消化器官比较，结果表明，三种鳜都以摄食鱼虾为主，在鳜和大眼鳜的食物组成中，虾的出现率分别为８２．３５％和８１．０３％，鱼的出现率分别为４７．０６％和３１．２３％，斑鳜中鱼和虾的出现率分别为６３．０７％和５０．０７％，鱼虾出现率在不同月份变化较大。鳜摄食强度最大，大眼鳜次之，斑鳜最小。但它们摄食鱼的饱满分指数均大于虾。在消化器官中，鳜、斑鳜，大眼鳜的幽门盲囊的平均数量分别为２５０．８、１０８．２、８４．１。随着体长的增加，大眼鳜和斑鳜的肠长也相应增加，而鳜的肠长趋于稳定。本文还对三种鳜在食性上出现差异的原因进行了讨论，认为消化能力的大小、食物的可获得性、食物的选择性及对环境的要求等是出现差异的主要因素。

Investigation was made on Siniperca fishes in Lushui Reservoir from May, 1991 to April, 1992. There were three species in Siniperca, i. e. S. chuatsi, S. kneri and S. scherzeri. Stomach contents examination revealed that main food items consist of shrimps and various other fishes. The fre quency of occupancy of shrimps was 82. 35%, 81. 03% and 50. 07% respectively among the three spotes of Sinipeas, and that of fishes was 47 .06%, 31. 23% and 63. 07% respectively. But the full ness index of the fish fed on fishes were higher than that of the fish fed on shrimps for the three species The mean number of pyloric caeca was 250. 8, 108. 2 and M. 1 respectively. With the increase of body-length, the intestine length of S. kneri and S. scherzeri got longer and that of S. chualsi tended to be stable. The relationship could be expressed by formula as follows:S. kneri, LgLi=-0.4654 +0.9365LgL, R=0.8003;S. scherzeri, LgLi=-0.6817 + 1.0902LgL, R=0 .8417;S. chuatsi, Lg(Li/L)=1 .9258-0.8488LgL, R=0. 7683.The reason for different feeding habitS among the three species has beendiscussed. The digestive ability, food availibility, prey selection andenvironmental conditions are considered to be the main factors.