Prevalence of Haematoloechus pulcher metacercariae (Digenea: Plagiorchioidea) in the crayfish Cambarellus montezumae in Salazar Lagoon, Estado de México

Crayfish can be intermediate hosts of larval digeneans. Cambarellus montezumae is a crustacean endemic of the Mexican plateau and is part of the diet of the inhabitants of Lerma; nonetheless, this municipality lacks parasitological studies on the species of hosts. This work is an analysis of 13 samples collected monthly proceeding from the lakeshore. Two hundred and twenty one crayfish were examined externally and internally. The metacercariae number per crayfish and per anatomical unit was registered. The prevalence, intensity and abundance were recorded each month. Ninety four crayfish were parasitized by metacercariae encysted mainly in the gills. The highest prevalence was observed in March, May and June. In spite of the slight difference in abundance between females (2.6) and males (2.4), there was no significant difference (U-Mann-Whitney test). The highest parasite burden was 26, with an average of 6 metacercariae per crayfish. In addition, all specimens with a size larger than 14 mm presented metacercariae, the only larval stage detected. C. montezumae could be considered a second intermediate host of the digenean Haematoloechus pulcher in the Salazar Lake in Mexico due to the prevalence and presence of this parasite throughout the year.