The influence of daylength, temperature and season on the hatching rhythm of Homarus gammarus

Abstract

The release of larvae by female lobsters is confined to a few minutes at night, and is repeated at a similar time on each night over several weeks. The rhythm is shown to be partly controlled by an endogenous component in the female. Eggs in vitro have an exogenous, light-stimulated hatching rhythm, but are arhythmic in continuous light or darkness. In light/darkregimes the time of hatching is not influenced by daylength, but occurs sooner after sunset astemperature increases.