Morphological differentiation of Ambystoma dumerilii populations in captivity and wildlife conditions

Ambystoma dumerilii, known as "achoque", is a microendemic salamander from Lake Patzcuaro, considered as a critically endangered species according to the IUCN (2020). The main threats are high levels of water contamination, high levels of eutrophication in addition to the fact that invasive species can be found within the "achoque" habitat. For these reasons, an important conservation effort has been the maintenance of "achoque" in captivity. However, captivity is known to be a stressor derived from non-optimal conditions that can have important physiological consequences that are reflected in body conditions. Therefore, our objective was to evaluate the condition of A. dumerilii individuals through a morphological analysis using different parameters such as morphological character sizes, geometric morphometrics, fluctuating asymmetry and allometry, in individuals from Lake Patzcuaro and captivity. We found that almost all the traits have a negative allometric relationship with the body size in individuals from both conditions. Our results showed that individuals from the lake presented greater sizes, slimmer bodies and higher levels of fluctuating asymmetry than captive individuals, all results are consistent in the context of performance with greater potential adaptations to increase swimming performance than individuals from captivity.