Anomalous tadpoles in a Brazilian oceanic archipelago: implications of oral anomalies on foraging behaviour, food intake and metamorphosis (original) (raw)
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Herpetological Journal
Rhinella jimi (Anura, Bufonidae) is an introduced species in the archipelago of Fernando de Noronha, north-eastern Brazil. It is known as one of the greatest amphibian anomaly hotspots in the world, with almost half of the adult individuals in the population having external anomalies, but tadpoles from this population have not previously been examined. Therefore, we evaluated the presence of anomalies in tadpoles of this population, described their types and identified possible handicaps of anomalous tadpoles in foraging behaviour and food intake. We found anomalies in 52.5% of all tadpoles inspected, mostly involving labial teeth. Anomalous tadpoles, when compared to normal individuals, spend less time foraging and have a lower foraging efficiency. We also observed that anomalous toadlets originate both from normal and anomalous tadpoles. We suggest that the reduced feeding fitness may result in a reduced growing rate, longer time spent until metamorphosis, higher predation risk, d...
Biota Neotropica, 2021
Abstract: Tadpoles are abundant in the environments in which they occur and remain in aquatic habitats for longer periods than adults, being relatively easier to collect. Despite the increase in tadpole research in the past decade, our understanding of its morphological diversity remains limited. Here, we provide morphological characterizations for larvae of 15 anuran species that occur at Emas National Park (ENP) and its surroundings, in Goiás, and compare them with descriptions available in the literature for other locations. We also present an update of the list of anuran species known to the ENP, based on tadpole sampling. We found tadpoles from 15 anuran species, of which five represent new records for the park. Many species showed variations in morphological characters when compared with descriptions available in the literature for other locations, reinforcing the importance of describing larvae from different populations. Through the exploration of morphological characters, i...
Scinax angrensis (LUTZ, 1973) is an endemic species, which occurs in low altitude hillside forests, distributed from the municipalities of Mangaratiba to Parati in the south of the state of Rio de Janeiro. The aim of this study was to compare the morphology of Scinax angrensis tadpoles in two different stages of development, and verify their feeding spectrum. The mouth morphology of the two stages studied (27 and 37) appeared similar, with an increase in the size of the oral opening as well as an increase in the dimensions of the body. The examined species presented a trophic spectrum comprised of algae, protozoan, rotifers, microcrustaceans, nematodes, vegetation and invertebrate remains, fungus hyphae, and sand grains. Significant differences were found between dimensions of the two stages, but not between diets, although a differentiated preference with regards to planktonic items has been verified. The results suggest that the partitioning of feeding resources is not only relate...
We present a comprehensive review of larval morphology in the Neotropical toad genus Melanophryniscus. The taxa studied included 23 species with representatives of recognized phenetic groups and different larval ecomorphological guilds: pond, stream, and phytotelm-dwelling tadpoles. Their external morphology variation is congruent with current phenetic arrangement based on adult features, but also reflects the habitat where larvae develop. Lotic tadpoles (i.e. M. tumifrons group and M. krauczuki) in general exhibit a more depressed body, a longer tail with lower fins, and larger oral discs than lentic forms (i.e. M. stelzneri group, M. moreirae, M. sanmartini, and M. langonei). Despite their peculiar, confined microhabitat, phytotelm larvae do not diverge markedly from non-arboreal species. The distinctive features of all species are the presence of a pineal end organ and the placement of the intestinal reversal point at the left of the abdomen in typical larval stages. The buccal cavity and musculoskeletal anatomy are quite conserved between species, yet some characteristics differ from those of other bufonids. The presence of one pair of subhyoid muscles is apparently an exclusive trait of Melanophryniscus among Bufonidae.
The plasticity of the anurans' development is probably related to their great ecological and geographic diversity. Therefore, the understanding of environmental occupation by tadpoles is related to their morphological peculiarities. We evaluated the morphologic development of the larval phases 23, 25, 30, 37, 39 and 42 of Rhinella icterica with the aim of establishing the ratio of growth, the increase in corporal mass in relation to growth and the isometry of the corporal variables for each evaluated stage. We submitted the corporal variables to the Multivariate Allometry and the relation between these variables was evaluated using the Principal Components Analysis. We verified the isometric growth and correlation between the different variables, evaluated the growth according to the body mass and established the proportionality ratio between the corporal regions. Each corporal region evaluated presented a fixed proportionality ratio, regardless of the stage, and the size of this portion was found when its proportionality index was multiplied by the tadpole's total length. This study demonstrates that the larval phase of R. icterica presents an isometric growth with proportional development of the corporal parts regardless of the evaluated stage.
Biota Neotropica, 2006
Difficulties in species identification and the absence of taxonomic keys are several of the obstacles in elaborating adequate conservation, management and habitat recovery programs. This study provides a taxonomic key, morphological characterization, and drawings for the 22 known anuran tadpoles from the northwestern region of São Paulo state, south-eastern Brazil. Specimens of all species analyzed are deposited in the scientific amphibian collection of Universidade Estadual Paulista (DZSJRP), São José do Rio Preto, SP.
Diets of tadpoles from a temporary pond in southeastern Brazil (Amphibia, Anura)
Revista Brasileira de Zoologia, 2004
The diet of tadpoles of 13 anuran species was determined to verify whether food resource partitioning occurs and whether the degree of diet similarity is related to taxonomic affinity. Tadpoles of all species studied were mainly herbivorous, except for these of Leptodactylus fuscus (Schneider, 1799) which were mycophagous. Although some species had exclusive items in their diet, most tadpole species ingested the same items, but differed in the amount of each item consumed. Two guilds were found: tadpoles that feed on diatoms on the pond bottom, and tadpoles that feed on Oedogonium Link, 1820 algae in midwater. Diet similarity was related to the taxonomic relationship, microhabitat and feeding behavior of tadpoles indicating that the community organization is complex and resulting from the interaction of several parameters.
Ferreira et al 2010 Amphibians of Vitoria
Salamandra Journal
Estudamos a composição da anfibiofauna do município de Vitória, uma área urbana no Sudeste do Brasil. O trabalho de campo foi realizado de fevereiro de 2004 a dezembro de 2005. Além disso, foram realizadas visitas a coleções científicas e pesquisa em literatura específica. Um total de 34 espécies de anfíbios foi registrado, estando distribuído em duas ordens: Gymnophiona, representada pela espécie Siphonops annulatus, e Anura, representada pelas famílias Bufonidae, Craugastoridae, Cycloramphidae, Hylidae, Leiuperidae, Leptodactylidae, Ranidae e Pipidae. A espécie invasora Lithobates catesbeianus foi registrada. A ampla distribuição geográfica da maioria das espécies demonstra predominância de espécies habitat-generalistas em Vitória. Mesmo assim, sugerimos um monitoramento constante e de longo prazo para garantir a sobrevivência das espécies dependentes de habitats florestais.