Survival of the gemmules ofAnheteromeyenia ryderi(Potts) following aerial exposure during winter in New England

摘要

Gemmules ofAnheteromeyenia ryderisurvived 24 h exposure to air temperatures as low as −20 °C under laboratory conditions. Drying the gemmules ofA. ryderiat 5 °C under laboratory conditions resulted in a reduced viability and a slower germination rate following rehydration compared with undried control gemmules. Only 25 of the gemmules germinated after drying for one month. Up to 25 of the gemmules ofA. ryderithat were tested survived aerial exposure from early November to early April when a pond in Connecticut inhabited by this sponge was drained. During this period air temperatures dropped to as low as −16 °C. Continued aerial exposure of the gemmules during the summer resulted in nearly complete gemmule mor