An Examination of Morphometric Variations in a Neotropical Toad Population (Proceratophrys cristiceps, Amphibia, Anura, Cycloramphidae)

Abstract

The species Proceratophrys cristiceps belongs to the genus Proceratophrys within the family Cycloramphidae. These amphibians are found exclusively in South America in the morphoclimatic domain of the semi-arid depression zones in northeastern Brazil known as the Caatinga. We examined intrapopulational variation using univariate and multivariate statistics with traditional and geometric morphometrics, which supported the existence of two morphotypes of this species. Our results indicated significant degrees of variation in skeletal characteristics between some natural populations of this species. Careful analyses of variability levels are fundamental to avoid taxonomic errors, principally in populations that demonstrate characteristics intimately associated with their area of occurrence, as is the case of Proceratophrys cristiceps.

Geometric morphometrics in herpetology: modern tools for enhancing the study of morphological variation in amphibians and reptiles

“…Similarly, species of newts studied show generally congruent patterns, the skull base and rostral portion being the areas more profoundly modified throughout ontogeny (IvAnovIć et al, 2007(IvAnovIć et al, , 2008. However, while general trends appear relatively uniform, allometric trajectories frequently vary among closely related species (LArSon, 2005;IvAnovIć et al, 2007IvAnovIć et al, , 2008, providing a potentially important mechanism of morphological differentiation, both in extant and extinct taxa (wITzMAnn et al, 2009). The same is true for body shape variation before and through metamorphosis in newts (vAn BUSkIrk, 2009;IvAnovIć et al, 2011), although further studies should investigate the generality of the results obtained for Triturus, since remarkable variation of allometric patterns has been observed in some cases (vAn Figure 3: yearly evolution of the number of publications using GM methods to analyse morphological variation in extant and extinct amphibians and reptiles.…”

Patterns of Cranial Development in Larval Rana macrocnemis: Chondrocranial Size and Shape Relationship With Pelophylax bedriagae (Anura: Ranidae)

“…GMM is widely used for analysis of skeletal shape, especially cranial skeleton, among anurans. Its successful application in anurans has been reported for limited studies (Larson, 2002(Larson, , 2005Stayton and Ruta, 2006;Vieira et al, 2008;Ponssa and Candioti, 2012). There is no published study that addresses chondrocranial shape differences of the ranids, R. macrocnemis and P. bedriagae by using GMM analysis.…”

Phenotypic variation in American bullfrogs (Lithobates catesbeianus) bred under intensive systems in Mexico: A preliminary report

“…In terms of geometric morphometrics, the variability of the skull shape in bullfrogs was similar to that found for different morphotypes of the neotropical frog, Proceratophrys cristiceps. 15 Therefore, our data suggests the existence of different morphotypes of bullfrogs. However, further studies are needed to clarify whether these groups derive from different genotypes and/or develop as an ontogenetic response to diverse environmental conditions found in bullfrog farms.…”

“…genetic correlation estimates) and heritability analyses are needed to implement successful breeding programs aimed at enhancing frog leg yield and growth rate of animals. 15 Genetic parameters are also needed to design adequate national breeding programs. The effect of factors such as temperature (both in water and air), food quality, population density and diseases on overall body and hind leg growth rates, needs also to be examined.…”

“…Geometric morphometry analyses have been previously used to document the existence of phenotypic variability within the same amphibian species. 15 First, hot water pre-treated male and female skulls from juvenile frogs were cleaned with a 5.4% sodium hypochlorite solution and then manually dissected. Ventral photographs of clean dissected skulls were subsequently taken, and ten anatomical landmarks established in each frame with the aid of the TpsUtil and Tps2 software (James Rohlf, Stony Brook University 16 ) ( Fig.…”