Evidence of brood parasitism in the sea anemone Aulactinia stella

Abstract

Monitoring of the sea anemone Aulactinia stella over several weeks provided evidence of interindividual reciprocal tentacle contacts. Closer examination of images revealed instances where a tentacle either hovered over or entered the mouth of a conspecific and remained there for minutes to hours. These observations align with previous data on reproductive and offspring biology in the same species to suggest deliberate transfer of larvae and/or juveniles across individuals, which would explain how genetically different offspring can be found in brooding females according to the literature. This unique interaction between conspecific sea anemones shows striking similarities with the intraspecific brood parasitism tactics described in insects and birds.