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.
Environmental contaminants endanger human health and non-target organisms such as crocodiles (Crocodylus acutus) that live in aquatic bodies surrounding agricultural areas. Due to their intrinsic ...characteristics, these organisms could be bioaccumulating and transmitting organochlorine pesticides (OCs) to their eggs. The objectives of this study were to determine the OCs in infertile eggs of C. acutus from Sinaloa and their correlation with the morphometric characteristics (MC), and to perform a preliminary estimate of the ecological risk due to the presence of pesticides using the PERPEST model. In June 2022, 76 infertile eggs (Ie) were collected: 57 from wild areas (Wa) and 19 from a crocodile farm (CSMf). Determination of OC in Ie was performed according to the USEPA method 8081b, modified. The observed percentages of Ie in Wa were 31.48% and 21.33% in CSMf. Twenty OCs were detected in the Ie, where dieldrin recorded the highest average concentration in Wa (6542.6 ng/g), and endosulfan-II in the CSMf (2172.8 ng/g). Bad negative and positive correlations were observed between OCs and MC, standing out the correlations between endosulfan-II and %Ie (-0.688) in the Wa, Cedritos drain, and between endrin and the weight of Ie (0.786) of the CSMf. The evaluation of the ecological risks of the aquatic environment due to the presence of OCs follow the sequence cyclodienes > aromatic > alicyclic hydrocarbons. A potential risk to the endocrine health of the species C. acutus was observed. Crocodiles are excellent biological models for monitoring the effects of OCs.
This study investigated selected trace elements toxicity in sea turtles
Caretta caretta
population from Baja California Sur (BCS), Mexico, by analyzing associations among Zn, Se, Cu, As, Cd, Ni, Mn, ...Pb, and Hg with various biochemical parameters (packed cell volume, leukocytes, and selected blood parameters), and whether their concentrations could have an impact on the health status of sea turtles. Blood samples from 22 loggerhead (
C. caretta
) sea turtles from BCS, Mexico, were collected for trace elements on biochemistry parameter analyses. Significant associations among trace element levels and the biochemistry parameters were found: Cd vs ALP (
R
2
= 0.874,
p
˂ 0.001), As vs ALP (
R
2
= 0.656,
p
˂ 0.001), Mn vs ALP (
R
2
= 0.834,
p
˂ 0.001), and Ni vs LDH (
R
2
= 0.587,
p
˂ 0.001). This study is the first report of the biochemical parameters of the North Pacific loggerhead sea turtle (
C. caretta
) from Baja California Sur, Mexico, and it is the first to observe several associations with toxic and essential trace elements. Our study reinforces the usefulness of blood for the monitoring of the levels of contaminating elements and the results suggest that, based on the associations with health clinical parameters, high levels of Cd and As could be representing a risk to the North Pacific loggerhead population health.
Trace metals have been found in sea turtle blood and tissues and may represent a threat to these endangered species. Essential trace metal (Cu, Zn Cd, Pb, As, and Hg) concentrations were determined ...in blood of adult female, post-nesting olive ridley turtles
Lepidochelys olivacea
(
n
= 35) on Ceuta beach, Sinaloa, Mexico. Essential metals (Zn and Cu) analyzed were found in higher concentrations than toxic metals (Cd and Pb), while As and Hg concentrations were below the limits of detection (0.01 μg g
-1
). Low Pb concentrations (0.09 μg g
-1
) were previously observed in sea turtles in the Gulf of California. There were no significant correlations found between curved carapace length (61.00–71.00 ± 2.29) vs metal concentrations (
p > 0.05
). Cd levels were relatively high when compared to other species and populations of sea turtles worldwide and Cd may represent the greatest risk for sea turtles in the Mexican Pacific. Such concentrations of Cd may pose a further risk to sea turtles through bioaccumulation from the nesting female to offspring which may affect embryo development.
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.
Olive ridleys (
Lepidochelys olivacea
) are the most common sea turtle found in the Gulf of California. Unfortunately, the bacterial flora of nesting olive ridley turtles is still unknown. We ...conducted a study to identify, characterize, serotype, and determine the antibiotic resistance of potentially pathogenic bacteria isolated from olive ridley turtles nesting in northwestern Mexico. Bacteria were isolated and identified from the oral cavity and cloaca of 47 postnesting turtles.
Escherichia coli
and
Vibrio parahaemolyticus
were characterized, and antibiotic resistance testing was performed. One hundred bacteria belonging to 21 species were isolated, 53 from the oral cavity and 47 from the cloaca, the most prevalent being
Pseudomonas aeruginosa
, followed by
Aeromonas hydrophila
,
Vibrio alginolyticus
,
Vibrio
parahaemolyticus
,
Klebsiella pneumoniae
, and
E. coli
, among others. Moreover, two to three different bacterial species were found co-colonizing both anatomical sites in some turtles.
E. coli
phylogroups B1, A, F, and unknown were identified as diarrheagenic
E. coli
(enteroaggregative and enteropathogenic
E. coli
). O1, O4, K8, K12, OUT, and KUT of
V. parahaemolyticus
serogroups were identified, also comprising pathogenic and nonpathogenic strains. Finally, 100% of the bacterial species tested were antibiotic resistant, and both MDR and XDR strains were found. In conclusion, olive ridley turtles are colonized by a diversity of bacterial species with a high rate of antibiotic resistance, some with pathogenic potential to turtles, representing a health risk factor for the species.
