斑点鳟的外形特征与消化系统结构

【目的】研究斑点鳟Oncorhynchus mykiss外部形态特征与内部消化系统结构。【方法】观察并描述斑点鳟外部形态特征,测量30尾斑点鳟的外部形态参数,对其进行相关性分析;解剖观察斑点鳟的消化系统结构特征。【结果】斑点鳟外部形态参数全长(LT)与体长(LB)的相关关系为LT=1.21 LB-3.25(R2=0.948),体质量(W)与全长(LT)的关系为W=0.001 LT3.562(R2=0.754),其余几项形态参数之间相关性较低;可数性状背鳍、臀鳍、腹鳍、胸鳍、尾鳍的鳍条数分别为6~12、9~15、10~24、20~28、23~33;具有1条侧线;第1鳃弓鳃耙数为15~18。斑点鳟为典型的肉食性鱼类,其消化系统结构特征为口咽腔较小,颌齿发达;食道短粗;胃发达,呈V形,分化明显;肠在腹腔内呈两个盘曲,肠长/体长为0.503±0.09;幽门盲囊数为48~72个。【结论】该实验结果可为斑点鳟的消化生理研究以及养殖管理提供科学的理论依据。

Morphological Characteristics and Structure of Digestive System of Oncorhynchus mykiss

Objective] To study the external morphological characteristics and the structure of the digestive system of Oncorhynchus mykiss. Methods] The external morphological characteristics of Oncorhynchus mykiss were observed and described. The external morphological parameters of the 30 Oncorhynchus mykiss were measured and analyzed for correlation. The structural characteristics of their digestive system were observed by anatomic method. Results] The correlation equation of total length and body length was:L_T=1.21 L_B-3.25(R²=0.948). The correlation equation of weight and total length was:W=0.001 L_T^3.562(R²=0.754). The countable characters of the dorsal fin rays, anal fin rays, pelvic fin rays, pectoral fin rays, and caudal fin rays were 6-12, 9-15, 10-24, 20-28, 23-33 respectively. There was one lateral line. The left first gill arch raker was 15 to 18. Oncorhynchus mykiss was a typical carnivorous fish. Its digestive system was characterized by small oropharyngeal cavity, developed jaw teeth, short and thick esophagus, developed stomach, V-shaped, and distinct differentiation. The intestine had two curvatures in the abdominal cavity. The intestine length/body length was 0.503±0.09; the number of pyloric caecum was 48-72. Conclusion] The experimental results can provide a scientific theory basis for the study of digestive physiology and aquaculture management of Oncorhynchus mykiss.