Genetic Evidence for the Asexual Origin of Small Individuals found in the Coelenteron of the Sea Anemone Actinia bermudensis McMurrich

Some sea anemone species brood small individuals in their coelenteron. This paper studies the genetic relationship between brooding and brooded individuals in the tropical sea anemone, Actinia bermudensis, to verify whether the offspring was produced asexually or not. Horizontal starch gels were stained for 14 enzymes, two of which showed high gel resolution and were polymorphic for some brooding anemones. Those anemones were analyzed again along with their offspring to see whether their genotype was identical to that of the brooding adults. As observed in other species of the genus, a total genotypic agreement was found between brooding and brooded A. bermudensis. The probability of this result occurring by chance if the young were produced sexually was at most 1.1 × 10⁻³⁵. It was concluded therefore, that the young anemones found in the coelenteron of A. bermudensis are produced asexually. This suggests that asexual brooding may be more common in sea anemone species than it was previously thought.