鲢肌间小骨发育的形态学观察

Developmental Morphology of the Intermuscular Bone in Hypophthalmichthys molitrix

分别利用形态解剖和整体骨骼染色的方法,对鲢(Hypophthalmichthys molitrix)成鱼肌间小骨的形态、分布,以及仔、稚鱼肌间小骨的形态发生和出现进行观察。结果表明,鲢肌间小骨有I形、卜形、y形、一端多叉形、两端多叉形和树枝形6种类型,肌间小骨越靠前端形态越复杂。肌间小骨在43dpf首先出现在尾部,然后往前依次出现,到55dpf全部出现。出现一枚髓弓小骨的仔鱼最小体长是10.50mm,出现一枚脉弓小骨的仔鱼最小体长是13.66mm。各种复杂形态的肌间小骨均是从I形发展而来。本文结果为今后研究肌间小骨发生的分子机制提供了形态学基础。

To further understand the development process of intermuscular bones in teleosts, a modified bone clearing and staining experiment was conducted to investigate morphological development of intermuscular bone in silver carp Hypophthalmichthys molitrix. It is showed that intermuscular bone has different shapes including I type, one-endunequal-bifork type （ 卜 type）, one-end-equal-bifork type （y type）, one-end-multifork type, two-end-muhifork type, and tree-branch type. Generally, the morphological complexity of most intermuscular bones in anterior body was more than that in posterior body. The initial ossification of intermuscular bone is observed in the posterior part of the body at 43 dpf, and then each of the intermuscular bones is ossified anteriorly, and the morphological characters at 55 dpf are the same as those found in adult fish. The minimum length of silver carp with first ossified epineural bone is 10.50 mm, and with first ossified epipleural bone is 13.66 mm. The primary morphology of intermuscular bone is I type, and more complicated morphology of ossified intermuscular bones are gradually derived from I type during ossifing process. This study provides some very important information about the morphological development of intermuscular bone in silver carp, which will be helpful for us to further understand the molecular mechanism underlying intermuscular bone development.