The Herpetological Bulletin

https://doi.org/10.33256/hb171.1219

AUTHORS: CHRISTOPHER J. MICHAELS & JOSÉ ALFREDO HERNÁNDEZ DÍAZ

ABSTRACT: The Lake Alchichica salamander Ambystoma taylori is a Critically Endangered, neotenic inhabitant of a single, hyposaline lake in Puebla, Mexico. Between 2015 and 2018, initial field data were collected for this understudied species, to inform future conservation action. Using unbaited submerged passive traps at depths of 0–<10, 10–<20 and 20–30 m, we captured 240 salamanders (137 males, 82 females, 18 juveniles) over 32 visits, for which length and mass were collected, and which were individually identified. Generalised linear models showed that males were captured at greater rates than females, and capture rates were lower in the dry-warm and wet-cold seasons than the wet-warm and dry-cold seasons. Salamanders were more likely to be captured at depths of 20 and 30 m than 10 m, but this effect was not detected when using only presence/absence data, suggesting clustering of animals in the lake. No evidence was found that depth of capture was predicted by size, sex or season. No eggs and only a small number of juveniles were detected, which were found in all seasons and without a clear trend in size across the year, meaning that a clear breeding season could not be identified. It is noteworthy that hatchling larvae would be able to escape the traps due to mesh size. Adult mass had a significant, positive cubic relationship with SVL, but females were heavier for their lengths, especially at larger sizes. Conversely, males were slightly but significantly longer than females for their weight (despite shorter absolute SVLs than females). These trends are typical in salamanders and likely associated with investment in eggs. Approximately 12% of animals carried an unidentified ectoparasitic burden and endoparasites Hedruris siredonis were detected in opportunistically encountered dead animals that were necropsied. Data reported here provide an initial insight into the biology and phenology of this species, as well as offering viable survey methods in a challenging environment.