Diet composition and trophic niche overlap between two sympatric species of Physalaemus (Anura, Leptodactylidae, Leiuperinae) in a subtemperate forest of southern Brazil (original) (raw)
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Diet of three sympatric Physalaemus (Anura: Leptodactylidae) from the Brazilian semiarid region
2021
Studies on the use of food resources and trophic niche of different species can help understand ecological relationships. In this study, we evaluated the diet of three sympatric species of Physalaemus from the Brazilian semiarid. We analyzed a total of 264 individuals, being 100 specimens of Physalaemus albifrons, 93 of P. cicada, and 71 of P. cuvieri. Seven prey categories were recorded: three for P. cicada and P. albifrons, and six distinct categories for P. cuvieri. The orders Coleoptera, Isoptera and the family Formicidae were the most representative categories in the diet of P. cicada, P. cuvieri, and P. albifrons, respectively. Although there is a high trophic niche overlap, differences in preference for food categories may reduce potential competition in these frog species from the Caatinga.
Diet of the Neotropical frog Leptodactylus mystaceus (Anura: Leptodactylidae)
Leptodactylus mystaceus is distributed throughout Brazil and no information is available about its diet. Here, we analyzed the diet of L. mystaceus from Novo Progresso, Pará, Brazil. We extracted the stomachs of 25 specimens. For each prey category, we calculated the frequency (Fi%), volume (Vi%) and Feeding Index (IAi). Among the specimens analyzed, seven (28%) had empty stomachs and the other ingested eight prey categories (Araneae, Blattodea, Coleoptera, Dermaptera, Diptera adults, Diptera larva, Formicidae, and Lepidoptera), and large amounts of plant material. This suggests that L. mystaceus is a generalist species and Dermaptera was the most representative component of its diet.
Acta Herpetologica, 2023
Despite the current increase in studies on the diet of neotropical anurans, few of them take a comparative approach between syntopic species. The objective of this study was to compare the diet of four syntopic species of the genus Physalaemus. The collections occurred between November 2014 and January 2016 in a preserved area of the subtropical Atlantic Forest in southern Brazil. We compared the gastrointestinal content of 109 individuals distributed in the species Physalaemus biligonigerus, P. cuvieri, P. gracilis and P. henselii. We measured the Index of Relative Importance of each prey category and calculated trophic niche breadth using the Levins’ index (Bsta) and trophic niche overlap using the Pianka’s index (Ojk). We also applied compositional analysis to evaluate feeding specializations. Formicidae was the most important prey category for P. biligonigerus (IRI = 88.5%) and P. gracilis (IRI = 39.1%). For P. henselii and P. cuvieri, the most important category was Isopoda (IRI = 51.7% and 57.9%, respectively), followed by Formicidae (IRI = 34.9% and 24.8%). Isopoda was also important in the diet of P. gracilis (IIR = 28.6%), followed by Araneae (IIR = 22.6%). The trophic niche breadth of the four species was narrow, all smaller than 0.32, and the lowest was recorded for P. biligonigerus (0.04). The trophic niche overlap was higher between P. biligonigerus and P. cuvieri (96%), and between P. gracilis and P. henselii (95%). Only P. gracilis presented a significant level of feeding specialization. The differences in their diets suggest different uses of the resources, which could relate to different ways of exploring the microhabitat.
Food niche overlap between two sympatric leaf-litter frog species from Central Amazonia.pdf
We studied the feeding habits and similarities in the diet of two sympatric and syntopic Amazonian frog species, Anomaloglossus stepheni (Aromobatidae) and Leptodactylus andreae (Leptodactylidae) in a forested area in Central Amazonia. The breadth of the trophic niche of these species was 5.89 and 3.75, respectively, and approximately 85% of their diets were similar. Ants were main food item in the diets of both frog species. The coexistence between these frog species may be facilitated by the significant differences in the size of their mouths. This difference allows them to consume preys items of different sizes.
Herpetology Notes, 2015
Physalaemus Fitzinger, 1826 is the most speciose genus of Leiuperinae frogs, with more than 40 recognized species. They are widely distributed in the Neotropical region, especially in open areas, and are among the most abundant species in several anuran communities. Nevertheless, our comprehension of the diet composition and trophic relationships of these species remains poor. In this study, we describe and compare the diet of sympatric and syntopic populations of Physalaemus gracilis and P. biligonigerus that inhabit the southernmost coastal zone of Brazil. The stomach content analyses revealed 13 distinct prey categories in the diet of P. gracilis and 12 in the diet of P. biligonigerus. On one hand the diet compositions of the species were significantly different according to both numeric and volumetric evaluations. On the other hand, Coleoptera and Formicidae were the most important prey for both species. The niche breadth was higher for P. gracilis than P. biligonigerus, and niche overlap was relatively low for both species (28%). Our results indicate that P. biligonigerus has a less generalist diet than P. gracilis, with a remarkable consumption of ants. Although both species are morphologically similar and sympatric, they appear to present different feeding strategies or preferences based on the low values of niche overlap.
Food niche overlap between two sympatric leaf-litter frog species from Central Amazonia
Zoologia (Curitiba), 2012
We studied the feeding habits and similarities in the diet of two sympatric and syntopic Amazonian frog species, Anomaloglossus stepheni (Aromobatidae) and Leptodactylus andreae (Leptodactylidae) in a forested area in Central Amazonia. The breadth of the trophic niche of these species was 5.89 and 3.75, respectively, and approximately 85% of their diets were similar. Ants were main food item in the diets of both frog species. The coexistence between these frog species may be facilitated by the significant differences in the size of their mouths. This difference allows them to consume preys items of different sizes.
Intrapopulation Diet Variation in Four Frogs (Leptodactylidae) of the Brazilian Savannah
Copeia, 2007
Age and sex-based as well as individual-level diet variation are known to occur in many natural populations, and may have important ecological and evolutionary implications. In the case of individual-level diet variation, most examples come from species-poor, temperate communities, and it is currently believed that it results from population niche expansion following interspecific competitive release. We investigated and measured the intrapopulation diet variation in four species of frogs, Leptodactylus (=Adenomera) sp., Eleutherodactylus cf. juipoca, L. fuscus, and Proceratophrys sp., that are part of species-rich frog communities of the Brazilian Cerrado. Specifically, we investigated age and sex-related, as well as individual-level, diet variation. We measured individual-level diet variation with the IS index of individual specialization, which is a measure of the degree of overlap between individual niches and the population niches. We found no ontogenetic shifts or sex-related differences in the types of prey consumed. However, we found evidence of individual-level diet variation in the four studied species (IS~0.2-0.5). There was a negative correlation between IS and the population niche width (r = -0.980; P < 0.0001), indicating that interindividual diet variation is more pronounced in more generalized populations. This pattern suggests that individual niche widths remain constrained even when population niche breadth is wide, consistent with the presence of functional trade-offs. We found no evidence that these trade-offs arise from morphology, since there was no diet-morphology correlation. We hypothesize that trade-offs have a behavioral or physiological basis, which needs further investigation. This is the first documented case of individual-level diet variation in a diverse tropical community, indicating that this phenomenon is not restricted to competitive release-driven niche expansion in temperate, depauperate communities.
Feeding ecology of endemic frogs of the Atlantic Forest in southern Brazil
Anais da Academia Brasileira de Ciências, 2022
Our objective was to describe and compare the diet of endemic anurans of the Atlantic Forest, as well as to evaluate the influence of biotic factors on the trophic ecology of the species. We conducted the study in Mananciais da Serra (Piraquara-PR), a transition region between mixed and dense ombrophilous forest, between January 2019 and February 2020. In this work, we describe the diet of eight species: Aplastodiscus albosignatus, Boana semiguttata, Bokermannohyla circumdata, Ischnocnema henselii, Leptodactylus notoaktites, Proceratophrys boiei, Rhinella abei and Scythrophrys sawayae. Coleoptera were important prey in the diet of most species, except for B. circumdata and L. notoaktites. All species showed potential selection for some category of prey. We observed a correlation between the size of the individuals and the volume of consumed prey in I. henselii. In general, the niche overlap between species was low, and most species had a broad trophic niche.
Diet of the South American frog Leptodactylus ocellatus (Anura, Leptodactylidae) in Uruguay
Iheringia. Série …, 2004
The diet of Leptodactylus ocellatus (L., 1758) was studied in specimens collected at Maldonado Department (Uruguay), where monthly surveys were made between August 1998 and March 2000. A total of 143 frogs were collected, measured, sexed, and dissected, to assess stomach contents. The anurans were grouped into three age classes and four categories (considering sex and capture date). The trophic amplitude for each age class and sex-season category was quantified using Shannon-Weaver Index, and the trophic niche overlap between ages and categories by using the Pianka Index. Comparisons among treatments were made by G-tests. The most important prey items were coleopterans (IRI = 2547), and significant correlations were found between predator and prey sizes. The major differences on diet composition were found between extreme age classes (froglets and adults). Significant differences were also detected between sexes in the cold season but not in the warm season. Any of these changes in diet may be related with the availability of prey.