塔里木河水系2种裂腹鱼类形态特征和骨骼形态的差异比较

Comparative study on morphological and skeletal differences of two Schizothorax species in Tarim River system

【目的】比较研究塔里木河水系2种裂腹鱼类形态和骨骼系统解剖学的差异性,为高原鱼类的系统演化和地理分布格局提供科学参考。【方法】以新疆特有鱼类厚唇裂腹鱼和斑重唇鱼为研究对象,结合框架数据和传统可量数据进行形态特征和主成分分析;采用CT扫描法和煮沸剔肉法比较两者骨骼形态的差异。【结果】2种裂腹鱼31项性状中,1-2/体长(BL)差异显著(P<0.05),体宽/体长(BW/BL)等25项比例性状差异极显著(P<0.01);前2个主成分累计贡献率为56.74%,差异主要体现在机体头部和躯干前段。2种裂腹鱼的脑颅、咽颅和附肢骨骼数目相同,分别为42块、80块和132块;但两者的脊椎数和肋骨数存在一些不同:厚唇裂腹鱼脊柱4+42-43+1枚,肋骨20~21枚(2尾);斑重唇鱼脊柱4+34-35+1枚,肋骨17~18枚(2尾);尤其是第二前筛骨、蝶耳骨、翼耳骨、前颌骨、上颌骨、翼骨、中翼骨和咽骨上2种裂腹鱼的差异更明显。【结论】塔里木河水系2种裂腹鱼形态特征和骨骼形态差异较为明显,其差异和演化机制与青藏高原隆起有着密切联系,独特的形态进化特征和骨骼差异系统可作为鱼类分类鉴别的依据,丰富了其形态进化生物学资料。

【Objective】Comparative study on morphological and skeletal differences of two Schizothorax species in Tarim River system.The provide scientific reference for the systematic evolution and geographical distribution pattern of the plateau fish.【Methods】To study the external morphology and skeletal system of Schizothorax irregularis and Diptychus maculatus which are endemic to Xinjiang by anatomical comparison.Principal component analysis of morphological features was carried out by combining frame data and traditional quantifiable data and then the difference of bone morphology between CT scanning and boiling cutting was compared.【Results】Among 31 proportional traits of Schizothorax species,there were significant differences in 1-2/body length(BL)(P<0.05),body width(BW/BL)and other 25 proportional traits were significantly different(P<0.01);In the principal component analysis,the cumulative contribution rate of the first two principal components was 56.74%,and the difference was mainly reflected in the body head and the front torso.The number of cranial,pharyngeal and appendicular bones of the two Schizothorax species was the same,with 42,80 and 132,respectively.However,there were some differences in the number of vertebrae and ribs between the two Schizothorax species:there were 4+42-43+1 vertebrae and 20-21 ribs in S.irregularis(2 tails),and there were 4+34-35+1 spines and 17-18 ribs in D.maculatus(2 tails).On some bones,such as the 2nd preethmoid,sphenotic,pterotic,premaxilla,maxilla,pterygoid and mstapterygoid,especially in the pharyngeal,the differences between the two Schizothorax species were more pronounced.【Conclusion】The morphological and skeletal differences of the two Schizothorax species in the Tarim River system are obvious,and their evolutionary mechanisms are closely related to the uplift of the Qinghai-Tibet Plateau.The unique morphological and evolutionary characteristics and skeletal differences can be further served as the basis for the classification and identification of fish,which might enrich the biological data of their morphological and evolutionary evolution.