Spatio-temporal infection and diversity indices of gastrointestinal helminths in Xenopus species from Lake Victoria Basin, Kenya

Xenopus frogs (Pipidae) are aquatic anurans widely distributed across Africa, where they play important ecological, biomedical, and cultural roles. However, populations are increasingly threatened by a range of stressors, including habitat degradation, climate change, and parasitic infections. This study investigated spatio-temporal infection and diversity indices of gastrointestinal helminths in Xenopus borealis and X. victorianus from the Lake Victoria Basin, Kenya. A total of 480 individuals (240 per species) were collected between June 2024 and January 2025 from selected streams and ponds using baited traps and seine nets. Spatio-temporal variations in environmental conditions were recorded using a YSI multiparameter meter. Standard parasitological techniques were employed for the recovery, fixation, and identification of parasites. Three helminth genera were recorded: the intestinal cestode Cephalochlamys sp., and two nematodes, Contracaecum sp. (intestinal) and Paracamallanus sp. (stomach). Prevalence ranged from 23% to 90%, and mean intensity from 1.0 to 8.3, depending on parasite taxon and host species. Nematodes were the most prevalent and diverse group across all localities. Diversity metrics, including Shannon-Wiener, Margalef richness, Berger-Parker dominance, and Simpson's index, showed variation between hosts and sampling sites. Analysis of variance (ANOVA) revealed no significant spatial differences in infection indices (p > 0.05), but temporal differences were significant (p < 0.05) for Contracaecum infections in X. borealis and Paracamallanus in X. victorianus. These findings provide the first baseline data on helminth fauna from Xenopus species in Kenya and support the need for molecular analyses to clarify taxonomy and better understand host-parasite-environment interactions.