Abstract
Ascidian tadpole larvae settle and metamorphose after a free-swimming period, and one of the typical morphological changes during metamorphosis is tail resorption. Halocynthia roretzi larvae cannot metamorphose for 6hrs after hatching even in the presence of metamorphosis inducers, which suggests that some internal changes occur in the larvae during this period. Larval protein synthesis was examined as one possibility by using a protein synthesis inhibitor, emetine. When tadpole larvae just after hatching were incubated with 5-10μM emetine, tail resorption did not occur. In contrast, larvae that were treated after a free-swimming period of 8 or 24hrs underwent tail resorption, although some were abnormal. These results suggest that protein synthesis during the swimming period is necessary for tail resorption.
