POSSESSION AND LOSS OF COLD TOLERANCE BY SPONGE GEMMULES - A COMPARATIVE STUDY

摘要

Gemmules of the freshwater sponges Eunapius fragilis, Ephydatia muelleri, and Spongilla lacustris from southern New England differ in their resistance to exposure to extremely low temperatures. Eunapius fragilis appears to be most tolerant, with greater than 80% of the gemmules surviving exposure to -70 degrees C for one hour. Ephydatia muelleri is slightly less tolerant, and Spongilla lacustris is the least tolerant with no gemmules surviving exposure to temperatures lower than -10 degrees C. Gemmules of both Eunapius fragilis and Ephydatia muelleri lose cold tolerance with storage at 3 degrees to 5 degrees C for more than a few months, most probably due to the loss of cryoprotectants such as sorbitol. [References: 10]