Larval growth in three sympatric Ambystoma salamander species: species differences and the effects of temperature

Abstract

Differences in the larval growth of three Ambystoma salamander species that breed in close proximity to each other in space and time in north Florida were investigated under standardized regimes of controlled food levels and temperature. The order of species growth rates was as follows: Ambystoma tigrinum > A. talpoideum > A. opacum. This order is exactly the reverse of the order in which the species breed. Growth of A. talpoideum larvae was strongly dependent on temperature, whereas A. opacum larval growth was only weakly affected by temperature. Based on these growth rate differences, it is unlikely that A. talpoideum larvae could survive to metamorphosis without special behavioral mechanisms for predator avoidance in habitats with the rapidly growing predatory A. tigrinum larvae. Furthermore, A. opacum larvae would be favored in their growth over those of A. talpoideum at low temperature, while the reverse would be true at higher temperature.