Abstract
Supercooling ability of the house spider, Achaearanea tepidariorum, is depressed by exogenous ice nucleators ingested with prey animals. To characterize the ice nucleators, the effect of heat exposure on the ice nucleating activity of the nucleators was examined. Spiders that fed on a heated isopod's gut (80-90°C) had a lower supercooling point (SCP) or temperature of crystallization than those that fed on an unheated gut. This result suggests that the ice nucleators limiting the supercooling ability of the predator are organic in origin.
