Feeding habits of Lithobates megapoda (Anura: Ranidae), a threatened leopard frog used for human consumption, in Lake Chapala, Mexico

Abstract

The Big-footed Leopard Frog (Lithobates megapoda) is a threatened and endemic species from western Mexico. This species has aquatic habits and it is distinguished by its large size, particularly by the length of its legs, reason for which it is captured for human consumption. Also, knowledge about its natural history is scarce and incomplete. In this study, we analyzed the composition of the diet of L. megapoda on the shore of Lake Chapala, the largest lake in Mexico. A total of 69 adult individuals were collected lifeless in fishing nets, during the rainy season (June-October), of which 48 had stomach contents. A total of 96 prey items were identified, which correspond to 13 prey categories. Fish constituted the most dominant prey category in the diet in terms of number, volume, frequency of occurrence, and relative importance. No significant differences were found in the consumption by prey type (aquatic or terrestrial). However, the aquatic preys had a greater relative importance and were more voluminous than the terrestrial ones. The diversity of prey categories, in terms of prey volume, indicates males may have a higher dietary diversity than females, but we not evaluated possible bias. In addition, a significant effect was found in the interaction of size (SVL) of frogs with the average of prey volume. Females (that are larger than males) consumed prey within a wide volume range and, the larger they are, more voluminous are prey. In this way it is possible that intraspecific competition for trophic resources in the environment is reduced. This study helps us understand the trophic ecology of L. megapoda, a frog species that plays an important role in the food web where it lives, as a predator feeding on aquatic and terrestrial organisms.

Numerous uncertainties in the multifaceted global trade in frogs’ legs with the EU as the major consumer

“…There are numerous published examples that describe the domestic trade of amphibians and the impact it may have on local frog populations. Species harvested for consumption within national borders and across range States, are reported for Greece (Hatziioannou et al 2022), West and Central Africa (Mohneke et al 2009(Mohneke et al , 2010Akinyemi and Ogaga 2015;Efenakpo et al 2015), Burundi of eastern Africa (Verbanis et al 1993), India (Pandian and Marian 1986;Ahmed 2012; Talukdar and Sengupta 2020), Nepal (Shresta and Gurung 2019), PDR China (Zhang et al 2008;Chan et al 2014;Turvey et al 2021), Malaysia (Hardouin 1997), Vietnam (Nguyen 2000), Mexico (Barragán-Ramírez et al 2021) and the USA (Ugarte 2004;Ugarte et al 2005), as exemplars of some countries/regions. The proportion of national vs. international trade is of particular interest when some countries document high annual exports for the international frogs' legs industry on a regular basis, while ignoring the fact that some species have been consumed locally for decades/centuries (Angulo 2008;Onadeko et al 2011;Ahmed 2012).…”