Estimación del máximo crítico térmico para la palometa gasteropelecus maculatus (Characiformes: Gasteropelecidae). Una aproximación a su respuesta frente al cambio climático

Abstract

The objective of this research is estimate the critical thermal maximum for the Gasteropelecus maculatus, a freshwater fish that is distributed between Ecuador, Panamá, Venezuela and Colombia; in the search for an approximation of their response to climate change, using the methodology of the CTmax, a non-lethal physiological index used as an indicator of the thermal tolerance of aquatic organisms, which consists in exposing the fish to a rate of heating at 18 °C per hour, in this case for fish acclimatized at 22, 28 and 32 °C. The results of the estimation of the critical thermal maximum for the Gasteropelecus maculatus at different levels of acclimatization (20, 28 and 32 °C) were 30.38 ± 0.29 °C, 32.41 ± 0.22 °C and 36.26 ± 0.19 °C, respectively. The reduced intraspecific variation of thermal tolerance found in this species for each level of acclimation suggests a limited capacity to adapt to extreme thermal conditions and raises concerns regarding current global temperature changes. At the end it was possible to establish an experimental model applicable to other species of ornamental and conservation interest.