怒江上游三种裂腹鱼类摄食及消化器官比较研究

Comparative Study of Three Species of Schizothoracine on Feeding and Digestive Organs in Upper Nujiang River

于2017年5和6月以及9和10月在怒江西藏段收集了怒江裂腹鱼(Schizothorax nukiangensis)194尾、裸腹叶须鱼(Ptychobarbus kaznakovi)152尾,热裸裂尻鱼(Schizopygopsis thermalis)117尾。综合运用3种多元分析方法分析3种鱼类摄食及消化器官形态的种间差异,结果显示,主要种间差异部位为头部及肠道;种间形态指标均为显著性差异(P <0.05);3种裂腹鱼的头部形态已有了一定程度的分化。鱼类食物组成及食物竞争情况研究表明,怒江裂腹鱼和裸腹叶须鱼属杂食性偏动物食性鱼类,两者食物重叠指数较高(0.91);热裸裂尻鱼属杂食性偏植物食性鱼类。食物多样性指数的种间差异明显。3种裂腹鱼营养及空间生态位均有分化,摄食与水温、流速和海拔等环境因素密切相关。

We have sampled 194 Schizothorax nukiangensis,152 Ptychobarbus kaznakovi and 117 Schizopygopsis thermalis in Tibet section of the Nujiang River between May and October 2017(Fig.1,2;Table 2)in order to compare the morphological characteristics of digestive organs including feeding and digestive organs among the three Schizothoracinae fish species.Three methods of multivariate analysis were applied to analyze the morphological difference of feeding and digestive organs.The results showed that major parts of interspecific variation were the cephalic and enteral characteristics(Fig.3,4;Table 5,6),and the morphological indexes of different species were significantly different among the three species(P<0.05)(Table 3).The cephalic morphology of the three species was with differences.Analysis on the enteral inclusion under microscopes was applied to understand their food competition.The results indicated that Schizothorax nukiangensis and Ptychobarbus kaznakovi belonged to the omnivore and partial carnivore fish(Fig.6),and the Schoener overlap index between two species was high(0.91).Schizopygopsis thermalis belonged to the omnivore and partial herbivore fish.The indexes of diversity of dietary composition among three species of fishes were apparently different(Table 8).Feeding habits of the three fishes were closely related to environmental factors,such as water temperature,flow rate and altitude(Table 1).