Metridium senile: dispersion and small scale colonization by the combined strategy of locomotion and asexual reproduction (laceration)

The process of biotope occupation by the anenome Metridium sen~le in the absence of pelagic larvae has been investigated by an in situ monitoring experiment lasting from July 1981 to April 1982. This process is composed of several behavioral phases: dispersion of the anemones on the new substrate by h ~ g h locomotory activity, colonization of the 'chosen' habltat by intensive asexual reproduction and finally, a stationary phase. One characteristic of the particular ecological situation in the Flensburg fjord (Western Baltic) seems to be the absence in M senile of sexual reproduction and larvae resulting in a monoor oligoclonality of the Fjord population. This study shows that even if pelagic dispersal is missing, local dispersion and proliferation can be assured by locomotion and laceration.