SREL Reprint #2570




Does sex influence postreproductive metamorphosis in Ambystoma talpoideum?

Travis J. Ryan1,2 and Gabriel Swenson1

1Savannah River Ecology Laboratory, Drawer E, Aiken, South Carolina 29802, USA
2Division of Biological Sciences, University of Missouri, Columbia, Missouri 65211, USA

Introduction: The mole salamander, Ambystoma talpoideum, exhibits a life cycle polymorphism referred to as facultative paedomorphosis (Semlitsch, 1985a) or paedogenesis (Patterson, 1978; Reilly et al., 1997). Aquatic larvae may either undergo metamorphosis, becoming juveniles that will mature in terrestrial refugia surrounding aquatic breeding sites, or bypass metamorphosis and become mature branchiate adults that retain the larval morphology and remain in the aquatic environment. The life cycle polymorphism makes this species a model organism for understanding the ecology and evolution of complex and simple life cycles. Although the natural history of A. talpoideum has been well investigated (e.g., Patterson, 1978; Semlitsch, 1985a) and experimental approaches have led to a more thorough understanding of the factors controlling life cycle expression (e.g., Semlitsch and Wilbur, 1989; Ryan and Semlitsch, 1998), several aspects of the polymorphism remain poorly understood. For example, although branchiate adults may undergo postreproductive metamorphosis (Patterson, 1978; Semlitsch, 1985a; Winne and Ryan, 2001), there are few reliable data regarding the frequency of these transformations. Likewise, except for pond drying (Semlitsch, 1985a), the causes of postreproductive metamorphosis are not clearly known. . . .

SREL Reprint #2570

Ryan, T.J., and G. Swenson. 2001. Does sex influence postreproductive metamorphosis in Ambystoma talpoideum? Journal of Herpetology 35:697-700.

To request a reprint