Abstract: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-end-unequal-bifork type (卜type), one-end-equal-bifork type (y type), one-end-multifork type, two-end-multifork 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.