Population density and sexual maturity of Ambystoma lermaense, an endangered species in central Mexico
DOI:
https://doi.org/10.22201/ib.20078706e.2026.97.5617Keywords:
Ambystomatidae, Population structure, Paedomorphosis, Vitellogenic oocytes, Mature sperm, DeclineAbstract
Ambystoma lermaense, an endangered salamander species endemic to central Mexico, faces significant threats from habitat degradation, pollution, and human activities. This study evaluates the population density, structure, and sexual maturity of A. lermaense in Capilla Vieja, Estado de México, over 3 time periods: 2009, 2010, and 2020. Using visual encounter surveys along a 730-m stream transect, we recorded population densities of 0.021 individuals/m² in 2009, 0.070 individuals/m² in 2010, and 0.075 individuals/m² in 2020, reflecting relative stability despite anthropogenic pressures. Juveniles accounted for 87% of the population, with sexual maturity observed at a snout-vent length of 60 mm, supported by histological evidence of vitellogenic oocytes in females and mature sperm in males. Our study provides important insights into the population dynamics and sexual maturity of A. lermaense in the sampling locality, where this species had not been previously studied.
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