Physiological and ecological aspects of low-temperature tolerance in embryos of the wood frog, Rana sylvatica

摘要: Wood frogs (Rana sylvatica) breed in late winter temporary ponds, where eggs are deposited communal surface rafts. Subsequently, developing embryos may face subzero temperatures. In the laboratory, individual supercooled moderately (to –4.2°C for their jelly capsules; to –5.0°C removed from capsule) when chilled absence of external ice nuclei, but did not resist inoculative freezing contact with ice. They survived acute episodes (1–18 h) supercooling temperatures between ca. –0.5 and –2.0°C. Stage-12 (six six) 1 h at –2.0°C, only one six a 3.5-h episode same temperature. Stage-13 -14 4.5 –1.0°C survived) 18 –0.5°C survived), respectively. field, were monitored every 5 min 21 d embryo masses wood Jefferson salamanders (Ambystoma jeffersonian...