Variación interpoblacional y ontogenética en la dieta de la rana llorona Physalaemus albonotatus (Anura: Leiuperidae)

Abstract

Resumen. Se analizó y comparó el espectro trófico de 2 poblaciones de Physalaemus albonotatus que habitan en ecosistemas diferentes: a) un terreno baldío urbano y b) un área protegida del valle aluvial del río Paraná Medio. La dieta de Physalaemus albonotatus está compuesta fundamentalmente de hormigas, coleópteros, colémbolos e isópodos, pero con numerosas presas secundarias. Al comparar 3 grupos etarios de los individuos en cada población (adultos, subadultos y jóvenes) se encontró una variación ontogenética relacionada con el volumen, cantidad y tipo de presa ingerida. Los anfibios adultos consumieron mayor cantidad de presas y más voluminosas, pero el nicho trófico de los jóvenes fue más amplio. Entre los adultos, la similitud de la dieta entre sexos fue muy elevada, aunque las hembras consumieron más hormigas que los machos. Si bien el solapamiento trófico entre las poblaciones fue elevado, la amplitud trófica resultó mayor en la población del humedal fluvial. Las diferencias en la alimentación encontradas entre las 2 poblaciones y lo registrado en otros trabajos realizados en diferentes ambientes reflejan la plasticidad trófica de este anuro, característica que le permite prosperar en hábitats diversos, incluso en los muy antropizados.Palabras clave: anuros, hábitats de forrajeo, ambiente urbano, humedal fluvial, plasticidad trófica, solapamiento trófico.Abstract. We analyzed and compared the feeding of 2 populations of Physalaemus albonotatus inhabiting different ecosystems: a) an urban vacant lot, and b) a protected area of Middle Paraná River floodplain. The diet of Physalaemus albonotatus is mainly composed by ants, beetles, springtails and woodlouses, but also included several secondary preys. While comparing adults, subadults and juveniles diet on each population, we found an ontogenetic diet variation related to changes in prey type and volume as well as in number of prey items per gut. Bigger frogs consumed a greater amount of prey and more voluminous arthropods, while juveniles had a larger trophic niche breadth. Despite the great similarity in diet between sexes, adult females consumed a larger amount of ants than males did. Although trophic niche overlap between both populations was high, trophic niche breadth was wider for Paraná River floodplain population. Feeding differences found between studied populations and populations inhabiting other environments as described on literature reflects the trophic plasticity of this species and its capacity to thrive at different habitats, including markedly anthropogenically impacted environments.

Diet of three sympatric Physalaemus (Anura: Leptodactylidae) from the Brazilian semiarid region

“…In our study, P. albifrons consumed three prey categories, being Formicidae the most frequent (45%) and important (42%) prey, corroborating the study of Cruz (2000) from São Francisco River sand dunes in the state of Bahia. Moreover, consumption of ants by P. cuvieri and P. albifrons (present study; M. Oliveira et al, 2015), P. cuvieri from Atlantic Forest (Santos et al, 2004;Leivas et al, 2018), P. ephippifer Steindachner, 1864, from the Eastern Amazon (Rodrigues & Santos-Costa, 2014), and P. albonotatus Steindachner, 1864 (Falico et al, 2012), and P. riograndensis Milstead, 1960(López et al, 2003, from Argentina, reinforces the importance of this prey category for this genus.…”

The roles of anurans in antagonistic networks are explained by life‐habit and body‐size

“…2009, 2015; Falico et al . 2012; Nadaline et al . 2019), and the forest floor is full of a great diversity of prey (Becker et al .…”

“…Foraging for food also increases the chances that an anuran encounters infective stages of parasites in the environment which are transmitted by physical contact (Campião et al 2016). As the diversity in amphibian's diet is heavily influenced by prey availability (Anderson et al 1999;López et al 2009López et al , 2015Falico et al 2012;Nadaline et al 2019), and the forest floor is full of a great diversity of prey (Becker et al 2007;Rafael et al 2012), anurans with terrestrial habits may encounter great variability of prey, and hence are more susceptible to a greater richness of parasite infections, as also found by Euclydes et al (2021).…”

Rainy Season Food Availability for Anurans of Kimboza Forest Reserve, Tanzania

“…This is different for the highly specialized species which become highly prone to slight or major changes in the environment resulting in their potential elimination and probably extinction [3]. In contrast, species having a broad range of food diets are more flexible and highly adapted to getting a variety of energy sources [4]. Allmon, [5] observed that the distribution patterns of forest leaf litter anurans were linked to prey availability.…”