Eimeria in the Xochimilco axolotl Ambystoma mexicanum

Coccidia are protozoal parasites that can cause coccidiosis, a disease linked to high mortality in young, stressed, and overcrowded animals. In the order Urodela, only 21 coccidia species have been registered, and none in the Critically Endangered Ambystoma mexicanum. The present study presents the detection and follow-up of Eimeria in A. mexicanum. The monitoring was conducted at CIBAC (Centro de Investigaciones Biológicas y Acuícolas de Cuemanco), analyzing fecal samples from 90 juveniles using sedimentation, Faust, and modified Zajíček McMaster techniques. An overall prevalence of 65.6% was observed, with median oocyst shedding values of 100 oocysts per gram (opg) from July to September and 27500 opg from October to December, suggesting a seasonal pattern. Nematode eggs from the Kathlaniidae family were also identified in 18.3% of samples, with no observed association with water source, time period, or mortality. Further research is needed to describe the life cycle of this Eimeria species and its potential pathological effects.