ANNUAL REPRODUCTIVE CYCLES OF THE CHITONS, KATHERINA TUNICATA AND MOPALIA HINDSII

Abstract

1. The reproductive cycles of two species of chitons, Katherina tunicata and Mopalia hindsii, collected in Monterey Bay are recorded, the first for three years and the second for two. 2. Katherina breeds in the summer, Mopalia in the fall and winter. 3. In each case the gonad index (ratio of gonad volume to body weight times 100) rises gradually and falls rather precipitously as spawning occurs. Differences in onset of breeding occurred during the years for which records are available, suggesting timing of events by local conditions. 4. Blood protein, non-protein nitrogen, and reducing sugar vary during the year but it is not clear whether these variations are significantly correlated with reproductive condition.