Effects of salinity on the growth and survival of tadpoles of the Puerto Rican Crested Toad (Peltophryne lemur)

Abstract

Aquatic habitats play an important role in the reproduction of adult amphibians and in the development of their larvae. In these habitats, the interactions of biotic and abiotic factors influence tadpole ecology. Tadpole growth rates, duration of larval period, size at metamorphosis and survival to metamorphosis can be influenced by the physical environment (Alford 1999). In the case of tadpoles, abiotic parameters like desiccation risk, water temperature, dissolved oxygen concentration, pH, and salinity are a major concern for the success of a breeding event (Ultsch et al. 1999). Salinity is an abiotic factor that has raised concern for the management group in charge of ensuring the conservation of the Puerto Rican Crested Toad (Peltophryne lemur), the only endemic toad in Puerto Rico, currently listed as a threatened species. P. lemur breeds at the Tamarindo Pond, the main natural breeding pond in Puerto Rico. This pond has been influenced in the past by salt intrusion events and it is believed that this may affect negatively the development of the tadpoles.