Temperature and salinity survival limits of the fluffy sea anemone, Metridium senile (L.), in Japan

Metridium senile, the fluffy (or plumose) sea anemone, is a circumboreal species adapted to the cold northern oceans. We performed a 40-day experiment on 108 individuals of M. senile collected from the Akkeshi-ko estuary in Japan to test their survivability in higher temperatures and their upper and lower salinity survivability limits. In addition to using survivorship to determine if there is a smaller tolerance range than the extreme limits of temperature and salinity, we used asexual reproduction via pedal laceration as an indicator of the most favorable environmental conditions for M. senile. The resulting limitations are used to both broaden our understanding of the biology of M. senile and to assess potential effects of changing oceanic conditions, since M. senile is unable to survive in warm water temperatures or in extreme salinities. Our results support the use of pedal laceration by M. senile as a way to quickly colonize an area with favorable environmental conditions in order to preserve a well-adapted phenotype.