西藏高原鳅、细尾高原鳅和异尾高原鳅消化道结构的比较

运用解剖学、组织学方法比较研究西藏高原鳅(Triplophysa tibetana)、细尾高原鳅(Triplophysa stenura)和异尾高原鳅(Triplophysastewarti) 3种高原鳅的消化道结构。结果表明: (1)3种高原鳅的消化道均由口咽腔、食道、胃、肠组成。胃“U”型, 无幽门盲囊, 肠道短, 可分为前、中、后三个部分。异尾高原鳅胃长与消化道长比值最大, 比肠长最短, 为0.51±0.07, 与西藏高原鳅比肠长0.64±0.08和细尾高原鳅比肠长0.70±0.06, 差异显著。(2)异尾高原鳅胃黏膜层相对高度大于西藏高原鳅和细尾高原鳅, 肌肉层相对厚度也比其他2种鱼厚。前肠黏膜层为异尾高原鳅相对高度最大, 肌肉层为西藏高原鳅相对最厚。中肠与后肠黏膜层相对厚度由大到小为异尾高原鳅>细尾高原鳅>西藏高原鳅。综上所述, 3种高原鳅的消化道结构均符合肉食性鱼类特征, 推测异尾高原鳅的结构特征适于消化更多的动物性饵料。

CHARACTERISTICS OF THE MORPHOLOGY AND HISTOLOGY OF DIGESTIVE TRACT OF TRIPLOPHYSA TIBETANA, TRIPLOPHYSA STENURA AND TRIPLOPHYSA STEWARTI

The study investigated the atomical and histological structures of the digestive tract of T. tibetana, T. stenura and T. stewarti, and found that the digestive tracts of three species fish were composed of oropharyngeal cavity, esophagus, stomach and intestine. All of them were " U” type stomach without pyloric caecum. The short intestines could be divided into three parts of foregut, midgut and hindgut. T. stewarti had the largest stomach length and digestive tract length ratio (SL/DL) but with the shortest intestine length and standard body length ratio (IL/DL) that was significantly difference with the other two species (P<0.5). The average intestinal coefficients ofT. tibetana, T. stenura and T. stewarti were 0.64±0.08, 0.70±0.06 and 0.51±0.07, respectively. Thickness of mucosa and muscle in stomach of T. stewartiwas were the greatest. Thickness of mucosa in foregut of T. stewarti was the highest, meanwhile, thickness of muscle in foregut of T. tibetana was the highest. Thickness of mucosa in midgut and hindgut of T. stewarti was the largest, following by T. stenura and T. tibetana. Overall, the digestive tract structures and characteristics of three species of fish indicate that they should be carnivorous fish.