Population structure and allometry of Podocnemis unifilis (Testudines, Podocnemididae) in a protected area upstream Belo Monte dam in Xingu River, Brazil

Miorando, Priscila S.; Giarrizzo, Tommaso; Pezzuti, Juarez Carlos Brito

doi:10.1590/0001-3765201520140321

Cited by 12 publications

(4 citation statements)

References 25 publications

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“…Sexual dimorphism has been reported previously for members of the Podocnemididae family, such as P. erythrocephala and P. unifilis in Brazil ( 23 , 24 ). The morphological parameters assessed here showed statistically significant differences between males and females of both species, where females are bigger.…”

Section: Discussionsupporting

confidence: 55%

Hematological and blood chemistry parameters of a Podocnemis vogli and P. unifilis captive population in Colombia

et al. 2022

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The Podocnemididae family is seriously affected by anthropogenic factors, which is why almost all of their family members are threatened, according to the IUCN red list. The biology and ecology of these species, as well as the hematological and serum chemistry reference intervals that allow clinical action and decision-making conservation programs, are poorly known. Based on this, the objective of this study was to establish the hematological and blood chemistry parameters of the Savannah side-necked turtle (Podocnemis vogli) and Yellow-spotted river turtle (Podocnemis unifilis) maintained in captivity at the Estación de Biología Tropical Roberto Franco (Villavicencio-Colombia). Forty-nine captive turtles of the species P. vogli (n = 28) and P. unifilis (n = 21) were sampled to determine hematological and serum chemistry parameters. Blood samples were taken from the jugular veins of both male and female turtles across both species. Student's t-test and Mann–Whitney–Wilcoxon tests were used to compare values between the parameters evaluated against genders and sizes. Reference intervals were calculated for the hematological and biochemical values of each species. Some assessed parameters demonstrated significant differences between the males and females of both species. Most of the analyzed parameters exhibited similar reference intervals in both species. In this study, we report values and propose the hematological and serum chemistry reference intervals for P. vogli and P. unifilis, which can be used in the clinical diagnosis of these reptiles and in future research.

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Section: Discussionsupporting

confidence: 55%

Hematological and blood chemistry parameters of a Podocnemis vogli and P. unifilis captive population in Colombia

et al. 2022

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“…When the body mass of the individuals was not available from the source but only SVL or CL was given, body mass was estimated from SVL or CL using published allometric equations [15][16][17]. For Podocnemis spp., no corresponding equation was published; therefore, we derived our own BM-CL regression equation based on data from various sources [18][19][20][21][22][23][24].…”

Section: Methodsmentioning

confidence: 99%

Less need for differentiation? Intestinal length of reptiles as compared to mammals

et al. 2021

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Although relationships between intestinal morphology between trophic groups in reptiles are widely assumed and represent a cornerstone of ecomorphological narratives, few comparative approaches actually tested this hypothesis on a larger scale. We collected data on lengths of intestinal sections of 205 reptile species for which either body mass (BM), snout-vent-length (SVL) or carapax length (CL) was recorded, transforming SVL or CL into BM if the latter was not given, and analyzed scaling patterns with BM and SVL, accounting for phylogeny, comparing three trophic guilds (faunivores, omnivores, herbivores), and comparing with a mammal dataset. Length-BM relationships in reptiles were stronger for the small than the large intestine, suggesting that for the latter, additional factors might be relevant. Adding trophic level did not consistently improve model fit; only when controlling for phylogeny, models indicated a longer large intestine in herbivores, due to a corresponding pattern in lizards. Trophic level effects were highly susceptible to sample sizes, and not considered strong. Models that linked BM to intestine length had better support than models using SVL, due to the deviating body shape of snakes. At comparable BM, reptiles had shorter intestines than mammals. While the latter finding corresponds to findings of lower tissue masses for the digestive tract and other organs in reptiles as well as our understanding of differences in energetic requirements between the classes, they raise the hitherto unanswered question what it is that reptiles of similar BM have more than mammals. A lesser effect of trophic level on intestine lengths in reptiles compared to mammals may stem from lesser selective pressures on differentiation between trophic guilds, related to the generally lower food intake and different movement patterns of reptiles, which may not similarly escalate evolutionary arms races tuned to optimal agility as between mammalian predators and prey.

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“…Although these studies are important, there are few studies dealing with Caatinga testudine species (Moura et al, 2014;Moura et al, 2015;Rodrigues & Silva, 2015), unlike chelonian species from other regions of Brazil (Fachín-Terán et al, 2003, 2004Batistella et al, 2008;Brito et al, 2009;Miorando et al, 2015). This biome, which occupies much of northeastern Brazil, is characterized by remarkable seasonality, featuring a prolonged dry season and an extremely irregular rainy season (Moro et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Ecological aspects of a population of Phrynops geoffroanus (Schweigger, 1812) in a semi-arid area of Northeastern Brazil

Abrantes

Pereira

Brasil

et al. 2021

RSD

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Phrynops geoffroanus is a testudine of the family Chelidae that has a wide distribution. However, there are gaps in the knowledge of its biology. This study aimed to characterize demographically and morphometrically a population of Phrynops geoffroanus in an ephemeral water reservoir in a semi-arid area of Paraíba, in the period from April 2016 to March 2017. The individuals were captured manually and by hoop-net trap. Data on size distribution were described by mean and standard deviation. Size and weight were compared between sexes and capture methods using a MANOVA. Sex ratio was compared between capture methods using Pearson's chi-squared test. Population density and biomass were calculated. The number of animals captured was grouped into two shifts and compared. Throughout the year, 113 individuals of P. geoffroanus were captured in the reservoir, with a population of 43.4% males, 47.8% females and 8.8% juveniles, with a density of at least 41.8 individuals / ha and biomass of 33.05kg / ha. There is no significant relationship between the amount of animals captured and the amount of rainfall during the period sampled. Due mainly to the ephemerality of the aquatic environments of the Caatinga and the unpredictability of rainfall in this biome, the populations of aquatic species show large variations in population and in their biological activities. Further studies are needed to fill several gaps in the knowledge of the natural history of Caatinga testudines.

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Population structure and allometry of Podocnemis unifilis (Testudines, Podocnemididae) in a protected area upstream Belo Monte dam in Xingu River, Brazil

Cited by 12 publications

References 25 publications

Hematological and blood chemistry parameters of a Podocnemis vogli and P. unifilis captive population in Colombia

Hematological and blood chemistry parameters of a Podocnemis vogli and P. unifilis captive population in Colombia

Less need for differentiation? Intestinal length of reptiles as compared to mammals

Ecological aspects of a population of Phrynops geoffroanus (Schweigger, 1812) in a semi-arid area of Northeastern Brazil

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