Developmental effects of incubation temperature on hatchling pine snakes Pituophis melanoleucus

Abstract

1. 1. In this study pine snake eggs were incubated at different temperatures (21-32°C) to examine effects on physiological and morphological development. 2. 2. Snakes from eggs incubated at low temperatures (21-23°C) had significantly more morphological abnormalities, were shorter in body length, and had proportionally larger heads than those from eggs incubated at higher temperatures. 3. 3. At low temperatures most embryonic mortality occurred before two weeks and after 50 days of development. In the low temperature group most eggs that developed beyond 50 days but failed to hatch, had fully-formed snakes. 4. 4. The amount of yolk remaining unabsorbed was negatively correlated with total length. 5. 5. Incubation temperature affected the age at which shedding occurred in hatchlings maintained at the same temperatures. 6. 6. Snakes maintained at a temperature below their incubation temperature took longer to shed, while maintenance at a temperature greater than incubation temperature accelerated shedding. 7. 7. The results are consistent with a physiologic set point determined by incubation temperature, which then influences rates for at least some physiologic phenomena. © 1987.