THE ORIGIN AND ADAPTIVE EVOLUTION OF THE GENUS SINOCYCLOCHEILUS

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.