Breeding Phenology in the Polymorphic Mole Salamander, Ambystoma talpoideum, in Western Kentucky
Institution
Murray State University
Faculty Advisor/ Mentor
Howard Whiteman
Abstract
Ambystoma talpoideum, commonly known as the mole salamander, reaches the northern extremities of its range in western Kentucky. As a facultatively paedomorphic species, A. talpoideum presents an opportunity to study the comparative life histories and potential interactions of metamorphic and paedomorphic individuals within the same population. The initial focus of this research was to locate potential breeding sites of A. talpoideum in western Kentucky and to observe breeding patterns within these populations. Paedomorphic individuals have been confirmed at two sites in rural Calloway County and at one of eleven potential sites in Land Between the Lakes (LBL). Breeding activity (indicated by cloacal swelling and the presence of spermataphores) at the LBL site concluded by mid-February. Metamorphic individuals were discovered at the Calloway County sites in late December, and showed signs of breeding activity during the same time frame as paedomorphic individuals. Breeding continued throughout February and waned in early March in these populations. The timing of breeding is atypical because previous studies have shown that paedomorphic individuals generally begin and cease breeding earlier than metamorphic individuals. Exceptions have been noted when paedomorphic salamanders have only recently reached maturity, but individuals from the Calloway County sites were comparable in size to those from the LBL site. No LBL populations have been discovered which contain both paedomorphic and metamorphic individuals, but sampling will continue through the 2002-03 season.
Breeding Phenology in the Polymorphic Mole Salamander, Ambystoma talpoideum, in Western Kentucky
Ambystoma talpoideum, commonly known as the mole salamander, reaches the northern extremities of its range in western Kentucky. As a facultatively paedomorphic species, A. talpoideum presents an opportunity to study the comparative life histories and potential interactions of metamorphic and paedomorphic individuals within the same population. The initial focus of this research was to locate potential breeding sites of A. talpoideum in western Kentucky and to observe breeding patterns within these populations. Paedomorphic individuals have been confirmed at two sites in rural Calloway County and at one of eleven potential sites in Land Between the Lakes (LBL). Breeding activity (indicated by cloacal swelling and the presence of spermataphores) at the LBL site concluded by mid-February. Metamorphic individuals were discovered at the Calloway County sites in late December, and showed signs of breeding activity during the same time frame as paedomorphic individuals. Breeding continued throughout February and waned in early March in these populations. The timing of breeding is atypical because previous studies have shown that paedomorphic individuals generally begin and cease breeding earlier than metamorphic individuals. Exceptions have been noted when paedomorphic salamanders have only recently reached maturity, but individuals from the Calloway County sites were comparable in size to those from the LBL site. No LBL populations have been discovered which contain both paedomorphic and metamorphic individuals, but sampling will continue through the 2002-03 season.