金线鲃属鱼类的起源及其适应演化

THE ORIGIN AND ADAPTIVE EVOLUTION OF THE GENUS SINOCYCLOCHEILUS

根据地史和东亚地区鱼类区系演化史 ,推测了金线属鱼类的起源时代及其与当时古地质和古气候事件的关系 ,认为该类群的原始祖先可能在第三纪晚期已经存在于云贵高原一带 ;较系统地研究了金线属鱼类的洞穴适应演化趋势 ,表明该类群在穴居适应过程中既表现出穴居鱼类的共同演化趋势 ,也表现出其独特的穴居适应方式。

This paper discusses the origin of the genus Sinocyclocheilus in relation to ancient geology and climates. It was considered that the primitive ancestral of the genus might have occurred on the Yungui Plateau in the Tertiary. The adaptations to caves were also studied systematically in the genus. The genus exhibited not only the common adaptive features of all cave dwellers in Cyprinidae such as the degeneration of eyes, the disappearance of melanin, the development of barbels and the descent of swimming ability, but also some special ones of its own such as special protrusion on the head or the back and the presence of many short sensory canals on the sides of lateral lines.