Amphibians are probably the most vulnerable group to climate change and climate-change associate diseases. This ongoing biodiversity crisis makes it thus imperative to improve the taxonomy of anurans ...in biodiverse but understudied areas such as Amazonia. In this study, we applied robust integrative taxonomic methods combining genetic (mitochondrial 16S, 12S and COI genes), morphological and environmental data to delimit species of the genus
(Anura: Bufonidae) sampled from throughout their pan-Amazonian distribution. Our study confirms the hypothesis that the species diversity of the genus is grossly underestimated. Our analyses suggest the existence of eighteen linages of which seven are nominal species, three Deep Conspecific Lineages, one Unconfirmed Candidate Species, three Uncategorized Lineages, and four Confirmed Candidate Species and described herein. We also propose a phylogenetic hypothesis for the genus and discuss its implications for historical biogeography of this Amazonian group.
The genus Chelus, commonly known as Matamata is one of the most emblematic and remarkable species among the Neotropical chelids. It is an Amazonian species with an extensive distribution throughout ...Negro/Orinoco and Amazonas River basins. Currently, two species are formally recognized: Chelus orinocensis and Chelus fimbriata and although it is still classified as "Least Concern" in the IUCN, the Matamatas are very appreciated and illegally sold in the international pet trade. Regardless, little is known regarding many aspects of its natural history. Chromosomal features for Chelus, for instance, are meagre and practically restricted to the description of the diploid number (2n = 50) for Chelus fimbriata, and its sex determining strategies are yet to be fully investigated. Here, we examined the karyotype of Chelus fimbriata and the newly described Chelus orinocensis, applying an extensive conventional and molecular cytogenetic approach. This allowed us to identify a genetic sex determining mechanism with a micro XY sex chromosome system in both species, a system that was likely present in their most common recent ancestor Chelus colombiana. Furthermore, the XY system found in Chelus orinocensis and Chelus fimbriata, as seen in other chelid species, recruited several repeat motifs, possibly prior to the split of South America and Australasian lineages, indicating that such system indeed dates back to the earliest lineages of Chelid species.
AIM: We used chelonian distribution data to (1) predict suitable areas of the occurrence for freshwater turtle species using species distribution models and (2) evaluate whether these species are ...protected by the current network of protected areas (PAs). LOCATION: The Brazilian Amazon. METHODS: We generated predictions of suitable areas for chelonian occurrence based on BIOCLIM, SVM, GLM and maximum entropy modelling procedures. We used maximum entropy to run the gap analysis and compared the effectiveness of three kinds of protected areas with different levels of protection: (1) integral protection areas (IPA) only; (2) integral protection areas + sustainable use areas (IPA+SUA); and (3) integral protection areas + sustainable use areas + indigenous lands (IPA + SUA + IL). RESULTS: We identified only one full gap species, Mesoclemmys nasuta, whose distribution is not included in any PAs. Other chelonian species have at least a portion of their distribution included in PAs. Some protected species and partial gap species occur in areas with high rates of deforestation. Considering PAs with the highest level of protection (IPA), only Rhinoclemmys punctularia and Kinosternon scorpioides achieve their conservation targets. In the IPA + SUA scenario, conservation targets of some species with small range sizes are not achieved. When all PA types were considered (IPA + SUA + IL), only two species fail to achieve their conservation targets, Acanthochelys macrocephala and M. nasuta. MAIN CONCLUSIONS: Despite the large number of PAs in the Brazilian Amazon, IPAs alone are not sufficient for capturing suitable areas for freshwater turtles. The inclusion of SUA and IL is crucial for achieving coverage targets for most species. However, chelonians may be overharvested in SUAs and ILs, due to their importance as a food resource. Areas that have high turtle richness next to existing PAs and the needs of traditional cultures should be considered in management planning for freshwater turtles.
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•Another matamata species is described as new to science.•Chelus orinocensis is genetically and morphologically significantly different.•Chelus orinocensis and C. fimbriata diverged ...approximately 13 million years ago.•Chelus orinocensis lives in the Orinoco, Río Negro, and Essequibo drainages.•Chelus fimbriata sensu stricto occurs in the Amazon and Mahury drainages.
The matamata is one of the most charismatic turtles on earth, widely distributed in northern South America. Debates have occurred over whether or not there should be two subspecies or species recognized due to its geographic variation in morphology. Even though the matamata is universally known, its natural history, conservation status and biogeography are largely unexplored. In this study we examined the phylogeographic differentiation of the matamata based on three mitochondrial DNA fragments (2168 bp of the control region, cytochrome oxidase subunit I, and the cytochrome b gene), one nuclear genomic DNA fragment (1068 bp of the R35 intron) and 1661 Single Nucleotide Polymorphisms (SNPs). Our molecular and morphological analyses revealed the existence of two distinct, genetically deeply divergent evolutionary lineages of matamatas that separated in the late Miocene (approximately 12.7 million years ago), corresponding well to the time when the Orinoco Basin was established. As a result of our analyses, we describe the genetically and morphologically highly distinct matamata from the Orinoco and Río Negro Basins and the Essequibo drainage as a species new to science (Chelus orinocensis sp. nov.). Chelus fimbriata sensu stricto is distributed in the Amazon Basin and the Mahury drainage. Additionally, the analyses revealed that each species displays phylogeographic differentiation. For C. orinocensis, there is moderate mitochondrial differentiation between the Orinoco and the Río Negro. For C. fimbriata, there is more pronounced differentiation matching different river systems. One mitochondrial clade was identified from the Amazon, Ucayali, and Mahury Rivers, and another one from the Madeira and Jaci Paraná Rivers. The C. orinocensis in the Essequibo and Branco Rivers have haplotypes that constitute a third clade clustering with C. fimbriata. Phylogenetic analyses of the R35 intron and SNP data link the matamatas from the Essequibo and Branco with the new species, suggesting past gene flow and old mitochondrial introgression. Chelus orinocensis is collected for the pet trade in Colombia and Venezuela. However, neither the extent of the harvest nor its impact are known. Hence, it is crucial to gather more information and to assess its exploitation throughout its distribution range to obtain a better understanding of its conservation status and to design appropriate conservation and management procedures.
La matamata es una de las tortugas más carismáticas del mundo, ampliamente distribuida en el norte de Sudamérica. Debido a su variación morfológica geográfica, se debate sobre el reconocimiento de dos subespecies o especies. A pesar de que la matamata es universalmente conocida, su historia natural, estado de conservación y biogeografía han sido muy poco estudiados. En este estudio examinamos la diferenciación filogeográfica de las matamatas en base a tres fragmentos de ADN mitocondrial (2168 pb de la región de control, la subunidad I del citocromo oxidasa y el gen del citocromo b), un fragmento de ADN genómico nuclear (1068 pb del intrón R35) y 1661 polimorfismos de nucleótido único (SNPs). Nuestros análisis moleculares y morfológicos revelaron la existencia de dos linajes evolutivos distintos de matamatas, genéticamente divergentes que se separaron en el Mioceno tardio (hace aproximadamente 12.7 millones de años), correspondiendo al tiempo en que se estableció la cuenca del Orinoco. Como resultado de nuestros análisis, describimos las genéticamente y morfológicamente distintas matamatas de las cuencas del Orinoco, Río Negro y Essequibo como una especie nueva para la ciencia (Chelus orinocensis sp. nov.). Chelus fimbriata sensu stricto se distribuye en la cuenca del Amazonas y en el drenaje del Mahury. Adicionalmente, los análisis revelaron que cada especie muestra diferenciación filogeográfica. Para C. orinocensis, hay una moderada diferenciación mitocondrial entre el Orinoco y el Río Negro. Para C. fimbriata, hay una diferenciación más pronunciada, concordando con los diferentes sistemas fluviales. Se identificó un clado de los ríos Amazonas, Ucayali y Mahury y otro de los ríos Madeira y Jaci Paraná. Las C. orinocensis de los ríos Essequibo y Branco tienen haplotipos que constituyen un tercer clado que se agrupa con C. fimbriata. Los análisis filogenéticos del intrón R35 y los datos de SNP asocian las matamatas de Essequibo y Branco con la nueva especie, sugiriendo flujo de genes pasado e introgresión mitocondrial antigua. Chelus orinocensis se colecta para el comercio de mascotas en Colombia y Venezuela. Sin embargo, ni se conoce el alcance de las colectas ni su impacto. Por lo tanto, es crucial recopilar más información y evaluar su explotación en todo su rango de distribución, comprender mejor su estado de conservación y para diseñar acciones apropiadas de conservación y manejo.
The turtles of Mexico Legler, John M; Vogt, Richard C
2013., 20130709, 2013, 2013-08-28
eBook
The Turtles of Mexico is the first comprehensive guide to the biology, ecology, evolution, and distribution of more than fifty freshwater and terrestrial turtle taxa found in Mexico. Legler and Vogt ...draw on more than fifty years of fieldwork to elucidate the natural history of these species. The volume includes an extensive introduction to turtle anatomy, taxonomy, phylogeny, biogeography, and physiology. A key to the turtles of Mexico is included along with individual species accounts featuring geographic distribution maps and detailed color illustrations. Specific topics discussed for each species include habitat, diet, feeding behavior, reproduction, predators, parasites, growth and ontogeny, sexual dimorphism, growth rings, economic use, conservation, legal protection, and taxonomic studies. This book is a complete reference for scientists, conservationists, and professional and amateur enthusiasts who wish to study Mexican turtles.
•Keratin is a better predictor of exposure to Hg than muscle and bone.•Keratin layer only should be used to study Hg in epidermis of reptiles.•Disagreement between previous studies is attributed to ...inconsistency in methods.•Carapace growth rings are useful for estimating Hg bioaccumulation over time.
Reptiles are ideal organisms for the non-invasive monitoring of mercury (Hg) contamination. We have investigated Hg bioaccumulation in tissue layers of reptile dermis as a basis for establishing a standardized collection method for Hg analysis. Tissue samples from freshwater turtle species Podocnemis unifilis and Podocnemis expansa and caiman species Melanosuchus niger and Caiman crocodilus, all from the Amazonian region, were analysed in this study. We first tested the relationships between Hg concentrations in keratin and bone to Hg concentrations in muscle to determine the best predictor of Hg concentration in muscle tissue. We then investigated the potential for measuring Hg concentrations across turtle carapace growth rings as an indicator of longer term changes in Hg concentration in the environment. Hg concentrations were significantly lower in bone (120ngg−1 caimans and 1ngg−1 turtles) than keratin (3600ngg−1 caimans and 2200ngg−1 turtles). Keratin was found to be a better predictor of exposure to Hg than muscle and bone tissues for both turtles and caimans and also to be a reliable non-invasive tissue for Hg analysis in turtles. Measurement of Hg in carapace growth rings has significant potential for estimating Hg bioaccumulation by turtles over time, but full quantification awaits development and use of a matrix-matched reference material for laser ablation ICPMS analysis of Hg concentrations in keratin. Realising this potential would make a valuable advance to the study of the history of contamination in mining and industrial sites, which have until now relied on the analysis of Hg concentrations in sediments.
Until recently, freshwater turtles were thought to be silent reptiles, neither vocalizing nor hearing very well. We recorded individuals in nature, captivity, and during interactions between adults ...and hatchlings and show that hatchlings and adult turtles, Podocnemis expansa, produce sounds in and out of the water. Sounds were emitted by hatchlings inside the egg, in open nests, in the river, and in captive conditions. Adult females were recorded producing sounds in the river, while basking, while nesting, and in captivity. Females were recorded in the river approaching and responding to hatchling sounds. We detected 2,122 sounds, classified in 11 different types. These data suggest that there is sound communication between adults and hatchings and that these sounds may be used to congregate hatchlings with adults for mass migration. Hatchlings and females with transmitters were found migrating together. We consider these findings as the first evidence of acoustic communication mediating posthatching parental care in chelonians. We anticipate that our findings will influence the way turtle behavior is studied and interpreted, and add communication and sound pollution to turtle conservation concerns.
Models of sustainable tourism consider not only the aspects of the physical environment but also the dimensions of the social and cultural environment of destinations. During the past two decades a ...number of researchers have made the case that local residents must be involved in tourism development decisions if support for, and thereby sustainability of, the industry is to be maintained. Minority ethnic and racial groups, however, are often differentially influenced by tourism within a community. This study investigates the differences between Hispanic and Anglo residents with respect to their perceptions of tourism and quality of life framed with the context of ethnicity marginality theory.
Due to their natural history and ecological attributes, turtles are excellent organisms for studies of heavy metal contamination. Turtles have a large geographical distribution, occupy different ...aquatic habitats, and occupy various trophic levels. The present study investigated mercury bioaccumulation in the carnivorous chelonian
Chelus fimbriata
(Matamata turtle) and Hg biomagnification in relation to its aquatic food chain in the middle Rio Negro, AM-Brazil. Tissue samples of muscle, carapace and claws were collected from 26
C. fimbriata
individuals, as well as collections of autotrophic energy sources found in the turtle’s aquatic habitat area. The samples were collected in February-March/2014 and analyzed for THg concentrations and carbon (δ
13
C) and nitrogen (δ
15
N) stable isotopes. The highest THg levels were found in claws (3780 ng.g
−1
), carapace (3622 ng.g
−1
) and muscle (403 ng.g
−1
), which were found to be significantly different F(2.73) = 49.02
p
< 0.01. However, THg concentrations in muscle tissue were below the consumption threshold indicated by the WHO and Brazilian Health Ministry. The average δ
13
C and δ
15
N values in Matamata samples were −31.7‰ and 11.9‰, respectively. The principal energy source sustaining the food chain of
C. fimbriata
was found to be terrestrial shrubs, with smaller contributions from emergent aquatic herbaceous plants and algae, while δ
15
N values showed its trophic position to be two levels above the autotrophic energy sources. There was a positive correlation between THg and turtle size, while a significant relationship was found between THg and δ
15
N, showing strong biomagnification in the food chain of
C. fimbriata
: y = 0.21x + 0.46;
r
2
= 0.45;
p
< 0.001, for which the slope presented a value of 0.21.
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