The concentrations of trace elements including As, Zn, Cu, Se, Pb, Hg and Cd, were determined in the blood of nesting Kemp’s ridley turtles (
Lepidochelys kempii
) at Rancho Nuevo sanctuary, ...Tamaulipas, Mexico during 2018–2020. The sequential concentrations analyzed were Zn> Se> Cu> As> Pb; while Cd and Hg concentrations were below the limits of detection (0.01 μg g
-1
). No significant differences were observed between the concentrations of trace elements (
p> 0
.
05
) by year, except Se levels, possibly resulting from recorded seasonal differences in turtle size. No relationships among turtle size
vs
elements concentration were observed. In conclusion, essential and toxic trace elements concentrations in the blood of nesting Kemp’s ridley turtles may be a reflex of the ecosystem in which the turtles develop, that is, with low bioavailability of elements observed in the trophic webs in the Gulf of Mexico.
Few hematologic profiles for free-ranging amphibians are available. Hematologic evaluation is a useful tool for determining the health of amphibian populations and providing further knowledge for ...conservation actions.
Hematologic variables and the presence and effect of hemoparasites in anuran species were evaluated in Northern Sinaloa, Mexico.
Blood samples were collected from wild anurans of eight species to perform blood cell counts, leukocyte differential counts, and serum protein concentrations using manual methods and refractometry. In addition, morphologic identification and quantification of the hemoparasites were performed on blood smears.
Differences were observed by sex, age, and season for the hematologic values of Incilius alvarius (n = 23), Incilius mazatlanensis (n = 46), Rhinella horribilis (n = 64), Leptodactylus melanonotus (n = 46), Lithobates forreri (n = 135), Lithobates catesbeianus (n = 20), Smilisca fodiens (n = 42), and Scaphiopus couchii (n = 7). Intra- and extra-erythrocytic hemoparasites were found in 56.2% of amphibian hosts; the hemoparasite infection of R. horribilis and L. melanonotus was higher in the dry season, showing increases in erythroplastids and monocytes. For L. forreri, males were more infected than females, and increases in leukocytes were associated with infections of different types of hemoparasites species.
Hematologic values, hemoparasite prevalence, and the response to hemoparasite infection vary among amphibian species, sex, and age, as well as on season and hemoparasite type. This highlights the importance of hematologic evaluations in wild amphibian populations to determine the subclinical effects of hemoparasite infections.
Aim
Understanding the spatial ecology of animal movements is a critical element in conserving long‐lived, highly mobile marine species. Analyzing networks developed from movements of six sea turtle ...species reveals marine connectivity and can help prioritize conservation efforts.
Location
Global.
Methods
We collated telemetry data from 1235 individuals and reviewed the literature to determine our dataset's representativeness. We used the telemetry data to develop spatial networks at different scales to examine areas, connections, and their geographic arrangement. We used graph theory metrics to compare networks across regions and species and to identify the role of important areas and connections.
Results
Relevant literature and citations for data used in this study had very little overlap. Network analysis showed that sampling effort influenced network structure, and the arrangement of areas and connections for most networks was complex. However, important areas and connections identified by graph theory metrics can be different than areas of high data density. For the global network, marine regions in the Mediterranean had high closeness, while links with high betweenness among marine regions in the South Atlantic were critical for maintaining connectivity. Comparisons among species‐specific networks showed that functional connectivity was related to movement ecology, resulting in networks composed of different areas and links.
Main conclusions
Network analysis identified the structure and functional connectivity of the sea turtles in our sample at multiple scales. These network characteristics could help guide the coordination of management strategies for wide‐ranging animals throughout their geographic extent. Most networks had complex structures that can contribute to greater robustness but may be more difficult to manage changes when compared to simpler forms. Area‐based conservation measures would benefit sea turtle populations when directed toward areas with high closeness dominating network function. Promoting seascape connectivity of links with high betweenness would decrease network vulnerability.
West Nile Virus Prevalence in Wild Birds from Mexico Barbachano-Guerrero, Arturo; Vásquez-Aguilar, Antonio Acini; Aguirre, A Alonso ...
Journal of wildlife diseases,
04/2019, Letnik:
55, Številka:
2
Journal Article
Recenzirano
West Nile virus (WNV) emerged in the Americas with its introduction in 1999 and now is considered endemic across the continent. In 2002, WNV was detected in Mexico, where its occurrence and mortality ...are considerably lower compared with the US. However, continuous national surveillance programs in Mexico are nonexistent. Birds are considered the primary hosts and primary geographic dispersers of this pathogen. A total of 200 cloacal and tracheal samples from wild migratory or resident birds were retrospectively analyzed using reverse transcription PCR to detect WNV from birds collected in Mexico from 2008 to 2009. The overall prevalence was 8% (16/200), and positive samples were from Oaxaca, Chiapas, and Tamaulipas in Ruby-throated Hummingbird ( Archilochus colubris), Double-crested Cormorant ( Phalacrocorax auritus), Ring-billed Gull ( Larus delawarensis), and Mourning Dove ( Zenaida macroura). Analysis of the partial sequence of the envelope gene from one of the samples from Oaxaca provided evidence that the virus belonged to the WN99 genotype. Taken together, these results demonstrated that WNV circulated in wild birds from northern and southern Mexico during the 2008-09 season, providing further information about the presence of WNV in Mexico.
The presence of fibropapilloma and its associated chelonid herpesvirus 5 (ChHV5) was assessed in 82 wild sea turtles. Olive ridley turtles Lepidochelys olivacea (n = 58) were caught in the pelagic ...Area of Marine Influence (AMI) (off the coast of Guasave, Sinaloa), and black turtles Chelonia mydas agassizii (n = 24) were captured in the Navachiste Lagoon System. The apparent physical condition was evaluated as 'good' or 'poor' by physical examination. The population structure and general health status was determined by condition index, hematocrit and total plasma protein. Detection of ChHV5 from skin samples was done by PCR. The overall physical condition of black turtles was good and all the individuals were tumor-free. Likewise, the physical condition of most olive ridley turtles was good, except for 10 individuals with poor condition. Of these, 4 had fibropapilloma-like tumors. PCR analyses showed that 3 tumors were ChHV5-positive. The DNA sequence showed 96% identity with ChHV5. All other skin samples from black or olive ridley turtles were ChHV5-negative. This is the first report of fibropapillomatosis-ChHV5 in foraging grounds off northern Sinaloa. The virus was present in a small proportion of L. olivacea individuals, a free-ranging species. It is suggested that infected turtles acquired the virus at a different location somewhere during their development before arriving in the AMI zone. This finding makes the case for setting up a health monitoring program for turtle populations in the area, enforcing sanitary measures to reduce the spread of the pathogen.
Abstract Fibropapillomatosis (FP) - tumour-associated chelonid alphaherpesvirus 5 (ChHV5; Scutavirus chelonidalpha5) - is a disease that affect marine turtles around the world, and characterized by ...the formation of cutaneous tumours that can appear anywhere on the body. We carried out a thorough literature search (from 1990 to 2024) in the feeding sites of North-western Mexico, a region that hosts important habitats for feeding, development, and reproduction for five of the seven existing sea turtle species. We found 18 reports recording a total of 32 cases of FP and/or ChHV5/Scutavirus chelonidalpha5 in coastal and insular areas of North-western Mexico. Baja California Sur resulted with the highest number of cases (75%). While the first case of ChHV5/Scutavirus chelonidalpha5 infection was reported in 2004, the presence of FP tumours was reported in 2014 and became more frequent between 2019 and 2024. The affected species were black, Chelonia mydas (50%), olive ridley, Lepidochelys olivacea (46.8%) and loggerhead turtles, Caretta caretta (3.2%). Tumours occurred mainly in anterior flippers (46.1%) and neck (22.5%), and most had a nodular and verrucous appearance with a rough surface. In the study region, there is a potential sign of the emergence of the ChHV5/Scutavirus chelonidalpha5 infections and FP disease during the last 20 years, with a rapid increase during the last 10 years. As long as infections by ChHV5/Scutavirus chelonidalpha5 and the prevalence of the FP disease may be potentially influenced by anthropogenic activities, a One Health approach is needed to understand and improve sea turtles’ health.
The aerobic oral and cloacal bacterial microbiota and their antimicrobial resistance were characterized for 64 apparently healthy sea turtles captured at their foraging grounds in Ojo de Liebre ...Lagoon (OLL), Baja California Sur (BCS), Mexico (Pacific Ocean) and the lagoon system of Navachiste (LSN) and Marine Area of Influence (MAI), Guasave, Sinaloa (Gulf of California). A total of 34 black turtles (Chelonia mydas agassizii) were sampled in OLL and eight black turtles and 22 olive ridley turtles (Lepidochelys olivacea) were sampled in LSN and MAI, respectively from January to December 2012. We isolated 13 different species of Gram-negative bacteria. The most frequently isolated bacteria were Vibrio alginolyticus in 39/64 (60%), V. parahaemolyticus in 17/64 (26%), and V. cholerae in 6/64 (9%). However, V. cholerae was isolated only from turtles captured from the Gulf of California (MAI). Among V. parahaemolyticus strains, six O serogroups and eight serovars were identified from which 5/17 (29.4%) belonged to the pathogenic strains (tdh (+) gene) and 2/17 (11.7%) had the pandemic clone (tdh (+) and toxRS/new (+)). Among V. cholerae strains, all were identified as non-O1/non-O139, and in 4/6 (66%) the accessory cholera enterotoxin gene (ace) was identified but without virulence gene zot, ctxA, and ctxB. Of the isolated V. parahaemolyticus, V. cholerae, and V. alginolyticus strains, 94.1, 33.4, and 100% demonstrated resistance to at least one commonly prescribed antibiotic (primarily to ampicillin), respectively. In conclusion, the presence of several potential (toxigenic) human pathogens in sea turtles may represent transmission of environmental microbes and a high-risk of food-borne disease. Therefore, based on the fact that it is illegal and unhealthy, we discourage the consumption of sea turtle meat or eggs in northwestern Mexico.
During routine monitoring in Ojo de Liebre Lagoon, Mexico, a juvenile black turtle (
) was captured, physically examined, measured, weighed, sampled, and tagged. The turtle showed no clinical signs ...suggestive of disease. Eleven months later, this turtle was recaptured in the same area, during which one lesion suggestive of fibropapilloma on the neck was identified and sampled for histopathology and molecular analysis. Histopathology revealed hyperkeratosis, epidermal hyperplasia, acanthosis, papillary differentiation and ballooning degeneration of epidermal cells, increased fibroblasts in the dermis, and angiogenesis, among other things. Hematological values were similar to those reported for clinically healthy black turtles and did not show notable changes between the first capture and the recapture; likewise, clinicopathological evaluation did not show structural or functional damage in the turtle's systems. The chelonid alphaherpesvirus 5 (ChHV5) UL30 gene was amplified and sequenced for phylogeny; Bayesian reconstruction showed a high alignment with the genus
of the Eastern Pacific group. This is one of the first reports of ChHV5 in a cutaneous fibropapilloma of a black turtle in the Baja California peninsula.
Technological and analytical advances to study evolutionary biology, ecology, and conservation of green turtles (Chelonia mydas) are realized through molecular approaches including DNA barcoding. We ...characterized the usefulness of COI DNA barcodes in green turtles in Mexico to better understand genetic divergence and other genetic parameters of this species. We analyzed 63 sequences, 25 from green turtle field specimens collected from the Gulf of Mexico and from the Mexican Pacific, and 38 already present in the Barcode of Life Data Systems (BOLD). A total of 13 haplotypes were identified with 4 novel haplotypes from the Pacific Ocean and 3 novel haplotypes from the Atlantic Ocean. Intraspecific distance values among COI gene sequences by two different models were 0.01, demonstrating that there is not a subdivision for green turtle species. Otherwise, the interspecific distance interval ranged from 0.07 to 0.13 supporting a clear subdivision among all sea turtle species. Haplotype and total nucleotide diversity values of the COI gene reflect a medium genetic diversity average. Green turtles of the Mexican Pacific showed common haplotypes to some Australian and Chinese turtles, but different from the haplotypes of the Mexican Atlantic. COI analysis revealed new haplotypes and confirmed that DNA barcodes were useful for evaluation of the population diversity of green turtles in Mexico.
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