Evidence for endogenous rhythmicity in cirral activity of the intertidal barnacle Fistulobalanus albicostatus.

ABSTRACT: Most intertidal invertebrates align feeding and reproduction with the tidal cycle. However, it is unknown to what extent biological clocks are involved in these activities. We focused on the internal and external regulation of cirral activity in Fistulobalanus albicostatus, an intertidal barnacle. Barnacles were subjected to a light-dark cycle (LD) for 14 days, constant darkness (DD) for 14 days, or constant light (LL) for 13 days, while monitoring the changes in cirral activity under laboratory conditions. LD individuals showed a major peak in activity repeating in 24 h, while DD and LL caused two peaks per day repeating at approximately 12 h. The 24 h day-active or day-inactive rhythm under LD often disappeared or showed no clear circadian component after transition to DD. Rayleigh's tes

SUBMITTER: Katayama A 

PROVIDER: S-EPMC12714779 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature