Evaluation of the Efficacy and Effects of Stomach Flushing for Dietary Analysis on Five Frog Species found at Obafemi Awolowo University Nigeria


Dietary studies in anurans have commonly been done by sacrificing the animals and excising their stomach. In view of the declining populations of amphibians, studies which affect the biodiversity of organisms are being carried out with care. The stomach flushing technique was carried out on five frog species; Hoplobatrachus occipitalis, Xenopus laevis, Ptychadena aequiplicata, Rana galamensis and Hylarana albolabris with a view to determining its efficacy in retrieving ingested food items and the effect of the procedure on the species. Specimens were collected weekly for 32 weeks and stomach flushing was carried out not later than two hours after capture and returned to their capture sites. Recovery of 1,534 prey items from the stomachs of 264 specimens was successful for diet analysis and complete for most species after three replicates of the procedure with an average prey recovery rate of 87% and 98% in the first and second flushing sessions. This demonstrates the potential of the procedure in dietary studies of these species. Only four fatalities were observed. The mortality rate of 1.52% was accounted for mainly by H. albolabris with 1.14% while 0.38% was represented by X. laevis. Mortality was not observed for H. occipitalis, P. aequiplicata and H galamensis.

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