团头鲂肌间骨发育的形态学观察

DEVELOPMENTAL AND MORPHOLOGICAL OBSERVATION OF INTERMUSCULAR BONES IN MEGALOBRAMA AMBLYCEPHALA

研究利用整体骨骼染色、形态学解剖和X光透射的方法,对团头鲂(Megalobrama amblycephala)仔稚鱼肌间骨的出现时期、形态以及成鱼肌间骨数目、形态、分布和长度变化进行了观察与分析。结果表明:团头鲂的肌间骨在孵出后20d(体长为1.33 cm)骨化出现,首先出现在尾部,然后向头部方向依次出现,到第40天(体长为2.36 cm)基本全部出现;肌间骨出现与分化的时间受生长发育的影响大于日龄的影响。团头鲂肌间骨数目在108—129,平均为119根,其中躯干部轴上肌中的肌间骨数目最多(40—45根),尾部轴上肌与轴下肌中的肌间骨数目相近(32—39根)。肌间骨形态包括"1"形、"卜"形、"y"形、一端多叉形、两端多叉形和"("形6种类型,各种形态的肌间骨均是从"1"形发展而来;肌间骨越靠鱼体前端形态越复杂。团头鲂躯干轴上肌中的肌间骨显著长于尾部肌肉中的肌间骨(P<0.05),躯干轴下肌中的肌间骨最短,并且肌间骨长度与个体体重与体长呈正相关。研究结果为今后揭示团头鲂肌间骨发生与发育的分子机制,抑制团头鲂肌间骨骨化,培育无肌间骨的团头鲂提供了形态学基础。

To investigate the emergent periods and morphogenesis of Megalobrama amblycephala intermuscular bones, the modified bone clearing and X-ray transmission methods were conducted to study the number, morphology, distribu-tion and length of intermuscular bone of M. amblycephala with different sizes. The results showed that initial inter-muscular bones were ossified at 20 days post hatching (dph) with the body length of 1.33 cm, which first appeared in the tail and then turned toward the head. When the fries were 40 dph with the body length of 2.36 cm, all the intermuscular bones were basically appeared. The average number of intermuscular bones of M. amblycephala was 119 with the range from 108 to 129. The number of intermuscular bones in both body sides was not absolutely equal, although the number of each side was quite close. There were more intermuscular bones in the front dorsal part than rear part, and the number of intermuscular bones was almost equal in rear dorsal and rear abdominal parts. There were 6 kinds of intermuscular bones, including “1” “卜” “y”, one-end-multifork, two-end-multifork, and “(” types. Various types of intermuscular bones were evolved from the“1”shape, and more complex shapes were formed in the front part of body. The length of intermuscular bones in front dorsal part was significantly longer than that in tail part (P<0.05), while the intermuscular bones in the front abdominal part were shorter than others. The length of intermuscular bones of M. amblycephala was positively related with the body weight and body length. The emergence and differentiation of intermuscular bones was more related to the body size than to the age in M. amblycephala. The result from this study will contribute to under-stand the molecular mechanisms of intermuscular bone occurrence and development, the research on the inhibition of the intermuscular bone ossification as well as the breeding of M. amblycephala without intermuscular bone.