A COMPARATIVE STUDY ON THE AIR-BLADDER AND ITS BONY CAPSULE OF NOEMACHEILINE FISHES (COBITIDAE) IN CHINA

The present paper deals with the results of a comparative study on the air-blad ders and their bony capsules of Noemacheiline fiushes collected from China. 84 species and subspecies of 11 genera were observed.According to the degree of completeness of the posterior wall, the bony capsules may be divided into two patterns: 1, the uncovered pattern and 2, the covered pattern. The latter may further be divided into 2 subpatterns. normal-shaped and well-expanded. The uncovered pattern is more primitive than the covered pattern. On the basis of the developmental degree of the posterior vesicles, the air-bladders are also divided into 2 patterns: the double-vesicular pattern and the single-vesicular pattern.The posterior vesicle of the air-bladder is large and free in the abdominal cavity in some species. This vesicle is primary structure, not a secondary acquisition.The different patterns of the bony capsule and the degree of development as well as the different forms of the air-bladder have general phylogenetic significance.In this paper the relations between the different patterns of the air-bladder and the environmental adaption are also discussed.