First report of Rhytidodes gelatinosus (Rudolphi, 1819) Looss, 1901 (Digenea: Rhytidodidae) in an olive-ridley Turtle Lepidochelys olivacea (Eschscholtz, 1829) from Brazil.

This article reports the first occurrence of Rhytidodes gelatinosus (Rudolphi, 1819) Looss, 1901 (Digenea: Rhytidodidae) in the olive-ridley turtle Lepidochelys olivacea (Testudines: Chelonidae), in an individual found in the State of Sergipe, Brazil. Although R. gelatinosus has already been described in other species of sea turtles in the world, this is the first report of this parasite in L. olivacea. We also present a list of hosts and locations where this helminth has already been identified.

Suitable habitat of Lepidochelys olivacea and the changes under climate change.

As a vulnerable species identified by the International Union for Conservation of Nature (IUCN), Lepidochelys olivacea has attracted extensive attention in recent years. To examine its current distribution and that under future climate change scenarios, we compiled the occurrence data of L. olivacea. With eight predictor variables, including depth, offshore distance, mean primary productivity, minimum primary productivity, mean sea surface temperature, minimum sea surface temperature, mean sea surface salinity, and minimum sea surface salinity, we predicted its distribution in an ensemble species distribution model. The accuracy of the model was evaluated with the parameters of areas under curves (AUC) and true skill statistics (TSS). The results showed that the AUC and TSS values were 0.96 and 0.81, respectively, indicating a good predictive performance of the ensemble model. Sea surface temperature and salinity were the two most important variables determining the distribution of L. olivacea, with the suitable temperature ranging from 23 to 29 ℃ and salinity below 34. The current distribution range of L. olivacea was between 30° N-25° S. Under future climate scenarios, its distribution range would decrease, especially under the RCP85 scenario in the 2100s (with a 28% reduction in the suitable survival range). The results of model validation showed that it had high accuracy and could make accurate predictions of the distribution. This study would provide references for the development of more rational conservation measures and management strategies.

New Delhi metallo-ß-lactamase-1-producing Citrobacter portucalensis belonging to the novel ST264 causing fatal sepsis in a vulnerable migratory sea turtle.

Olive ridley (Lepidochelys olivacea) turtles migrate across tropical regions of the Atlantic, Pacific, and Indian Oceans. Worryingly, olive ridley populations have been declining substantially and is now considered a threatened species. In this regard, habitat degradation, anthropogenic pollution, and infectious diseases have been the most notorious threats for this species. We isolated a metallo-ß-lactamase (NDM-1)-producing Citrobacter portucalensis from the blood sample of an infected migratory olive ridley turtle found stranded sick in the coast of Brazil. Genomic analysis of C. portucalensis confirmed a novel sequence type (ST), named ST264, and a wide resistome to broad-spectrum antibiotics. The production of NDM-1 by the strain contributed to treatment failure and death of the animal. Phylogenomic relationship with environmental and human strains from African, European and Asian countries confirmed that critical priority clones of C. portucalensis are spreading beyond hospital settings, representing an emerging ecological threat to marine ecosystems.

Corozalito: a nascent arribada nesting beach in Costa Rica.

Costa Rica hosts two renowned olive ridley (Lepidochelys olivacea) arribada beaches: Nancite and Ostional. In addition, the country hosts a third nascent arribada beach in Corozalito. We documented the frequency of arribada events in Corozalito (9°50'55.40″ N; 85°22' 47.67″ W) from 2008 to 2021 and the abundance of egg-laying females during 12 arribadas. Moreover, we report on tag recaptures at Corozalito that were initially deployed at other nesting beaches in Costa Rica. Finally, we estimated incubation temperature, and performed quadrat and nest excavations to estimate hatching rates. We registered 29 arribadas at Corozalito since 2008, all between August and January. We estimated more than 150,000 olive ridleys nested during 12 arribadas from 2019 to 2021. Mean hatching success was 65% in quadrats and 59% for in situ marked nests. The mean incubation temperature was 32.3 °C. We found turtles tagged at other locations on the Pacific coast of Costa Rica nesting at Corozalito, providing evidence of philopatric plasticity. We suggest nascent arribada rookeries form rapidly via recruitment from regional turtle aggregations. Our findings show that hatching success is far higher at Corozalito than Ostional or Nancite. Continued monitoring of nesting dynamics at this site may shed light upon the mechanisms that rule how arribada beaches are born and evolve. Corozalito offers a unique opportunity to study and understand the arribada phenomenon and warrants official protection under official National Wildlife Refuge status.

Evaluation of nest management phases for Lepidochelys olivacea at two beaches in Northwest Mexico.

The olive ridley turtle, Lepidochelys olivacea, is a vulnerable and endangered species according to the IUCN and Mexican Official Standard NOM-059, respectively. On most solitary nesting beaches of olive ridley turtles, the eggs are removed from the in situ nest to hatcheries due to the high incidence of predation, human poaching, and beach erosion; therefore, it is necessary to collect and analyze information on the protection activities conducted for this species from egg laying to hatchling release. In general, protection activities during nest management can be divided into 5 phases: nest logging (F1), egg collection (F2), egg transfer (F3), egg incubation and hatching (F4), and hatchling release (F5). This work was carried out on two Pacific beaches in northwestern Mexico, Ceuta Beach Sanctuary (CBS) during 2013-2019 and Caimanero Beach (CB) during the 2013-2018 nesting seasons, with the objective of quantitatively evaluating the management phases of the protection program for olive ridley turtles by assessing the nest, egg, and hatchling losses in each of the phases using the model of Godínez-Domínguez et al. (1991). The results of the statistical analyses indicate that the greatest losses occurred during the incubation phase (F4) at both beaches, with a 41.99% loss at CBS and a 33.09% loss at CB, followed by the F2 (with 15.56 and 27.27% losses, respectively) and F1 (21.28 and 25.56% losses, respectively) phases. Significant differences between the beaches were observed in F4, F5 and F3, with greater losses at CBS than at CB, indicating that the success of the management phases may vary among beaches. The results obtained show that it is necessary to focus on strategies for improving the success of mainly phase F4 and phases F1 and F2 at both beaches.

Hatching Success Rather Than Temperature-Dependent Sex Determination as the Main Driver of Olive Ridley (Lepidochelys olivacea) Nesting Activity in the Pacific Coast of Central America.

In marine turtles, sex is determined during a precise period during incubation: males are produced at lower temperatures and females at higher temperatures, a phenomenon called temperature-dependent sex determination. Nest temperature depends on many factors, including solar radiation. Albedo is the measure of the proportion of reflected solar radiation, and in terms of sand color, black sand absorbs the most energy, while white sand reflects more solar radiation. Based on this observation, darker sand beaches with higher temperatures should produce more females. As marine turtles show a high degree of philopatry, including natal homing, dark beaches should also produce more female hatchlings that return to nest when mature. When sand color is heterogeneous in a region, we hypothesize that darker beaches would have the most nests. Nevertheless, the high incubation temperature on beaches with a low albedo may result in low hatching success. Using Google Earth images and the SWOT database of nesting olive ridleys (Lepidochelys olivacea) in the Pacific coast of Mexico and Central America, we modeled sand color and nesting activity to test the hypothesis that darker beaches host larger concentrations of females because of feminization on darker beaches and female philopatry. We found the opposite result: the lower hatching success at beaches with a lower albedo could be the main driver of nesting activity heterogeneity for olive ridleys in Central America.

Diversity of Epibionts Associated with Lepidochelys olivacea (Eschscholtz 1829) Sea Turtles Nesting in the Mexican South Pacific.

The present study contributes to the knowledge of epibionts recorded on sea turtles that nested on a beach in the South Pacific of Mexico. A total of 125 Lepidochelys olivacea turtles nested on Llano Real beach, Guerrero, Mexico, were examined. We collected 450 conspicuous organisms from 8 species from 43 turtles. The corresponding data analysis was carried out to obtain the relative abundance, the relationship between turtle sizes and the presence of organisms, the similarity of species between the sampling months, and the interspecific relationships between the epibionts and the turtles observed. Chelonibia testudinaria was the most abundant species, while Remora remora was the least abundant species. The turtles were divided into six body sections, with the greatest abundance of these organisms located in the head-neck section of turtles, and there was a significant difference in the size of the turtles that presented epibionts and those that did not. C. testudinaria showed greater similarity between sampling months, and the interspecific relationships recorded were commensalism, parasitism, amensalism, and protocooperation. This research contributes the first record of epibionts in L. olivacea nesting in Guerrero, Mexico.

Plesiochorus Cymbiformis (Rudolphi, 1819) Looss, 1901 (Digenea: Gorgoderidae) in Olive Ridley Sea Turtles Lepidochelys Olivacea (Eschscholtz, 1829) (Testudines: Chelonidae) from The Brazilian Coast: New Geographic Occurrence and Associated Injuries.

The present study reports the first occurrence of Plesiochorus cymbiformis (Digenea: Gorgoderidae), in two Olive Ridley Sea turtles Lepidochelys olivacea (Testudines: Chelonidae), from the states of São Paulo and Sergipe in Brazilian coast. Concerning the Neotropical region, P. cymbiformis has been previously reported in green sea turtles (Chelonia mydas) from Panama and Brazil, in loggerhead sea turtles (Caretta caretta) from Brazil, in hawksbill sea turtles (Eretmochelys imbricata) from Puerto Rico, and in Olive Ridley Sea turtles only in Costa Rica. Lesions resulting from the presence of parasites in the hosts' urinary bladders are also presented. This is the second report on endoparasites in Olive Ridley sea turtles from Brazil.

Long-term monitoring of marine turtle nests in northeastern Brazil / Monitoramento de longo prazo de ninhos de tartarugas marinhas no nordeste do Brasil

Abstract: This study monitored marine turtle nests in a region known as the Potiguar Basin, which stretches from the northern region of Rio Grande do Norte State (5°4'1.15" S, 36°4'36.41" W) to eastern Ceará State (4°38'48.28" S, 37°32'52.08" W) in Brazil. We collected data from January 2011 to December 2019 to identify species of sea turtles that spawn in the basin, to analyze the nesting spatial-temporal pattern and nests characteristics, and to record effects of environmental and anthropic factors on nests. A field team examined sea turtle tracks and nests signs. Turtle clutches were monitored daily until hatchings emerged from the nests. We monitored nests of hawksbill (Eretmochelys imbricata; n = 238) and olive Ridley turtles (Lepidochelys olivacea; n = 103). The nesting season for E. imbricata occurred between December and May and for L. olivacea from March to August. Hawksbills had clutch size, incubation time, number of unhatched eggs, and dead hatchlings higher than olive Ridley turtles; nevertheless, they presented lower hatching success. Precipitation between 0 and 22 mm and relative humidity (RH) higher than 69% increased the hatching success rate for E. imbricata; however, rainfall above 11 mm and RH 64% had the same effect for L. olivacea. Signs of egg theft and human presence (e.g. vehicle traffic and plastic residues on the beach) were recorded and are considered threats to nests. The results of our long-term monitoring study in the Potiguar Basin provide basis for the implementation of mitigation measures and adoption of management policies at nesting beaches in this Brazilian region.

Resumo: Este estudo permitiu o monitoramento de ninhos de tartarugas marinhas em uma região conhecida como Bacia Potiguar, que se estende da região norte do Estado do Rio Grande do Norte (5 ° 4'1,15 "S, 36 ° 4'36,41" W) até o leste do Estado do Ceará (4 ° 38'48,28 "S, 37 ° 32'52,08" W), no Brasil. Coletamos dados de janeiro de 2011 a dezembro de 2019 com o objetivo de identificar as espécies de tartarugas marinhas que desovam na bacia, analisar o padrão espaço-temporal de nidificação, as características dos ninhos, e registrar os efeitos de fatores ambientais e antrópicos. Uma equipe de campo examinou rastros de tartarugas marinhas e sinais de ninhos. As ninhadas das tartarugas foram monitoradas diariamente até que os filhotes emergissem dos ninhos. Monitoramos ninhos de tartarugas-de-pente (Eretmochelys imbricata; n = 238) e tartarugas-oliva (Lepidochelys olivacea; n = 103). A época de nidificação para E. imbricata ocorreu entre dezembro e maio e para L. olivacea de março a agosto. Tartarugas-de-pente apresentaram maior tamanho das ninhadas, tempo de incubação, número de ovos não eclodidos e número de filhotes mortos quando comparado com tartarugas-oliva; no entanto, apresentaram menor sucesso de eclosão. Precipitação entre 0 e 22 mm e umidade relativa (UR) maior que 69% aumentaram a taxa de sucesso de eclosão para E. imbricata; entretanto, chuvas acima de 11 mm e UR 64% tiveram o mesmo efeito para L. olivacea. Sinais de roubo de ovos e presença humana (por exemplo, tráfego de veículos e resíduos de plástico na praia) foram registrados e são considerados ameaças aos ninhos. Os resultados do nosso estudo de monitoramento de longo prazo na Bacia Potiguar fornecem base para a implementação de medidas de mitigação e adoção de políticas públicas em praias de desova nesta região brasileira.

Relación entre el tamaño de la tortuga anidadora y el número de huevos puestos por nido por parlama (Lepidochelys olivacea, Eschscholtz, 1829) en el Área de Usos Múltiples Hawaii, Santa Rosa, Guatemala / Relationship between the size of the nesting turtle and the number of eggs laid per nest per parlama (Lepidochelys olivacea, Eschscholtz, 1829) in the multi-use area Hawaii, Santa Rosa

Las tortugas marinas pasan toda su vida en el océano, regresando a las playas únicamente en el momento en el que anidan. La parlama (Lepidochelys olivacea) es una de las especies que anida frecuentemente en el Pacífico de Guatemala. Sin embargo, hace falta información tanto de generalidades de los nidos de parlama como de la biología de anidación de las mismas en el país. Es por eso que se buscó: 1) determinar si existe una relación entre el tamaño de la parlama (ancho curvo del caparazón) y el número de huevos puestos en cada nido; y 2) de explorar el tipo de relación existente entre el tamaño de la parlama (ancho curvo de caparazón) y el número de huevos con el momento (día dentro de la temporada) donde los huevos fueron puestos. Este estudio fue de orden descriptivo y exploratorio, en donde se midió a 74 hembras que anidaron de junio a octubre del 2017 en el Área Protegida de Usos Múltiples Hawaii, Departamento de Santa Rosa. Cabe resaltar que en Guatemala no hay datos cualitativos ni cuantitativos sobre tortugas anidadoras, por lo que es el primer estudio de esta naturaleza. Se obtuvo un tamaño promedio (desviación estándar) del ancho curvo del caparazón de 70.7cm (Desviación estándar: 2.60), IC 95 % [63 a 77cm] y un promedio de 92 huevos (D.E: 15.67), IC 95 % [59 a 120 huevos] puestos por nido. Se desarrolló un modelo lineal generalizado (3.715e+00x + 1.670e-04 -4.932e-06; p= 1.12e-3; AICc=617.14), demostrando que el ancho curvo del caparazón de la tortuga anidadora y la fecha en la que los huevos fueron puestos tienen una relación directa con el número de huevos puestos por cada tortuga anidadora. El ancho curvo del caparazón presenta una relación directa con el número de huevos. Mientras que el momento de anidación (día) presenta un efecto polinomial de segundo orden, lo cual lleva a un incremento en el número de huevos conforme avanza la temporada de anidación, y resulta en un pico a la mitad de la temporada de anidación con un patrón de descenso hacia el final de la misma.

Sea turtles spend their entire lives in the ocean, returning to the beaches only at the time they nest. The olive ridley (Lepidochelys olivacea) is one of the species that frequently nest in the Pacific of Guatemala. However, information is needed on both the generalities of sea turtle nesting behavior and the nesting biology of the turtles in the country, so it was sought to 1) determine the relationship between the size of the turtle and the number of eggs in each nest; and 2) explore what type of relationship exists between the size of the turtle and the number of eggs, with the moment (day during the nesting season) when the eggs were layed. This first descriptive and exploratory study measured 74 females that nested between the months of June to October in 2017 in the Multiple Use Area Hawaii, Santa Rosa, Guatemala. An average carapace width of 70.7cm (Standar deviation: 2.60; 95% CI of [63 to 77cm]) was obtained and an average of 92 eggs (SD: 15.67; 95% CI of [59 to 120]) per nest. A Generalized Linear Model was made and demonstrated that the width of the carapace of the nesting female and the date on which the eggs were laid have a direct relationship with the number of eggs laid by each nesting turtle (3.715e+00x + 1.670e-04 -4.932e-06; p= 1.12e-3 ; AICc=617.14). The width of the carapace has a direct relationship with the number of eggs, while the moment (day during nesting season) has a second-order polynomial effect, which leads to an increase in the number of eggs as the nesting season progresses, and results in a peak half of the nesting season with a pattern of decline towards the end of it.

Ocular ultrasonography of sea turtles.

BACKGROUND: Environmental changes contribute to the development of ophthalmic diseases in sea turtles, but information on their eye biometrics is scarce. The aim of this study was to describe ophthalmic ultrasonographic features of four different sea turtle species; Caretta caretta (Loggerhead turtle; n = 10), Chelonia mydas (Green turtle; n = 8), Eretmochelys imbricata (Hawksbill turtle; n = 8) and Lepidochelys olivacea (Olive ridley; n = 6) under human care. Corneal thickness, scleral ossicle width and thickness, anterior chamber depth, axial length of the lens, vitreous chamber depth and axial globe length were measured by B-mode sonography with a linear transducer. Carapace size and animal weight were recorded. A sonographic description of the eye structures was established. RESULTS: The four species presented an ovate eyeball, a relatively thin cornea, and a small-sized lens positioned rostrally in the eye bulb, near the cornea, resulting in a shallow anterior chamber. The scleral ossicles did not prevent the evaluation of intraocular structures, even with a rotated eye or closed eyelids; image formation beyond the ossicles and measurements of all proposed structures were possible. B-mode sonography was easily performed in all animals studied. The sonographic characteristics of the eye were similar among the four species. Since there was a correlation between the size of the eye structures and the size of the individual, especially its carapace size, the differences found between E. imbricata and Caretta caretta are believed to be due to their overall difference in size. CONCLUSIONS: Sonography is a valuable tool in ophthalmic evaluation of these species. Only minor differences were found between the species in this study, reinforcing their phylogenetic proximity and their similar functions and habitats.

Optimized technique to extract and fix Olive ridley turtle hatchling retina for histological study.

The efficient extraction and fixation of a tissue allows in preserving the cytoarchitecture, chemical composition and tissue organization, which is key in physiological and histopathological studies. The main goal of this study was to establish a microsurgery technique to obtain ocular tissue and provide an optimized immersion fixation protocol based on the 10 % formalin-intraocular injection on Olive ridley sea turtle hatchlings (Lepidochelys olivacea). To evaluate this optimized technique, a histological comparison between traditional immersion and intraocular/immersion protocols was done. The eyeball were processed into five protocols: Frozen eyes (Group 1), frozen eyes immersed in 10 % formalin (Group 2), fresh eyes immersed in 10 % formalin (Group 3), fresh eyes intraocularly injected with 0.1 M phosphate buffer solution (PBS) and then immersed in 10 % formalin (Group 4), and fresh eyes fixed by 10 % formalin-intraocular followed by 10 % formalin-immersion (Group 5). In comparison with all groups evaluated, the intraocular/immersion fixation protocol lead the conservation of eyeball shape, cell integrity and maintenance of the organization of the retina layers of sea turtle hatchlings. If this method will be the key in studying sea turtle, we suppose that this procedure, with minimal adjustments, could be useful in animals with similar eye anatomy.

Recent advances on the estimation of the thermal reaction norm for sex ratios.

Temperature-dependent sex determination, or TSD, is a widespread phenomenon in reptiles. The shape of the relationship between constant incubation temperature and sex ratio defines the TSD pattern. The TSD pattern is considered a life-history parameter important for conservation because the wider the range of temperatures producing both sexes, the more resilient the species is to climate change impacts. We review the different published equations and methodologies that have been used to model TSD patterns. We describe a new flexible model that allows for an asymmetrical pattern around the pivotal temperature, which is the constant temperature producing both sexes in equal proportions. We show that Metropolis-Hastings with Markov chain produced by a Monte Carlo process has many advantages compared to maximum likelihood and is preferred. Finally, we apply the models to results from incubation experiments using eggs from the marine turtle Lepidochelys olivacea originating in Northeast Indian, East Pacific, and West Atlantic Regional Management Units (RMUs) and find large differences in pivotal temperatures but not in transitional ranges of temperatures.

First report of fibropapillomatosis in an olive ridley turtle Lepidochelys olivacea from the southeastern Pacific.

An adult olive ridley turtle Lepidochelys olivacea with lesions suggestive of fibropapillomatosis was rescued on the coast of San Antonio, central Chile. Histopathologic analysis showed an exophytic and pedunculated mass formed by epidermal papillary projections supported by fibrovascular cores, epidermal hyperplasia and marked orthokeratotic hyperkeratosis. ChHV5 unique long genes UL27, UL28 and UL30 were amplified from tumor lesions and sequenced for phylogeny. Phylogenetic reconstruction showed the Chilean sequences clustering with the Eastern Pacific group. This is the first case of fibropapillomatosis in an olive ridley turtle diagnosed in Chile and in the southeastern Pacific region. Our results suggest a regional grouping of ChHV5 variants independent of the marine turtle's species.

Supernumerary scutes verify a segment-dependent model of the horny shell development in turtles.

Turtle horny shell has a scute pattern, which is conservative through evolution and across species. The discovery of epidermal placodes as the scute primordia and their strict topographical association to the somites of the turtle embryo suggested a new interpretation of the developmental mechanism of the scute pattern. Here, we tested the hypothesis that horny scutes develop from a mosaic of placodes corresponding exactly to the paths of myoseptae, with vertebral and pleural scutes developing staggered in adjacent segments, and marginal scutes developing in every segment. This scheme predicts little variation in marginals and suggests intercalary supernumerary scutes as potential variations for the vertebral and pleural rows. We examined spatial and numerical variations of the horny shell in 655 newly hatched olive ridley sea turtle, Lepidochelys olivacea, which is known to have a highly variable horny shell. In total, 120 patterns of carapacial scutes and 10 patterns of scutes on plastron, differing in the number and position of scutes were found. The number of vertebral scutes varied from 4 to 10. Variations with five, six and seven vertebrals occurred with the greatest and nearly equally frequency (31.5% on average). Pleural scutes were from 5 to 10 at one or both sides, and the typical symmetric pattern for sea turtles with five pairs of pleurals was only seen in ca. 12% of specimens. In contrast, the majority of the specimens (92.7%) had just 13 pairs of marginals, showing a stable normal pattern. Similarly, on plastron the horny scutes were conservative, too; about 85% of specimens standardly had six pairs of plastral scutes and all specimens had four pairs of inframarginals. Despite a high level of variation of vertebral and pleural scutes in olive ridley turtle, all patterns fall into the theoretical spectrum of possible variants predicted by the segment-dependent model of development of the turtle horny shell. Therefore, the results of our analysis support the existence of direct morphogenetic correlation between the number and distribution of normal and supernumerary scutes and metamere organization of the turtle embryo.

Presence of chelonid herpesvirus 5 (ChHV5) in sea turtles in northern Sinaloa, 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.

Spatiotemporal Expression of Foxl2 and Dmrt1 before, during, and after Sex Determination in the Sea Turtle Lepidochelys olivacea.

The sex of sea turtles is determined by temperature during egg incubation. Thus, climate change affects the sex ratio, exacerbating their vulnerability to extinction. Understanding spatiotemporal effects of temperature on sex determination at the gonadal level may facilitate the design of strategies to mitigate the effects of global warming. Here, we used qRT-PCR and immunofluorescence to analyze the spatiotemporal expression of Dmrt1 and Foxl2 in developing gonads of Lepidochelys olivacea incubated at male-producing temperature (MPT, 26°C) or female-producing temperature (FPT, 33°C). Although both transcription factors are expressed in bipotential gonads up to stage 25, the timing of their sexually dimorphic regulation differs. Whereas the dimorphic expression of Dmrt1 protein initiates at stage 24, Foxl2 protein was expressed specifically in females at stage 25. Interestingly, whereas Dmrt1 colocalizes with Sox9 in cell nuclei of primary medullary cords to form the testis cords, Foxl2 protein is first detected in Sox9-negative cells of primary medullary cords, prior to its substantial expression in the ovarian cortex. Thus, results suggest that the temperature-dependent regulation of sexual pathways is stochastic among the cells of primary medullary cords in undifferentiated bipotential gonads of the olive ridley.

Conjunctival bacterial flora and antimicrobial susceptibility of captive and free-living sea turtles in Brazil.

PURPOSE: To describe the aerobic conjunctival bacterial flora of 3 especies of free-living and under human care sea turtles and determine its antimicrobial susceptibility in vitro. METHOD: Thirty-six sea turtles (72 eyes), juveniles and adults, 7 free-living Chelonia mydas and 8 Chelonia mydas, 4 Caretta caretta, 11 Eretmochelys imbricata, and 6 Lepidochelys olivacea under human care, were evaluated. Conjunctival cultures were collected for identification of aerobic bacteria and antimicrobial susceptibility testing for ciprofloxacin, chloramphenicol, gentamicin, neomycin, oxacillin, polymyxin B, tetracycline, and tobramycin using antibiotic disks. Bacterial strains showing no sensitivity to 4 or more antimicrobials were considered multiresistant to this panel. RESULTS: Bacterial growth was observed in 12/14 (85.71%) samples in the free-living sea turtles, and there was growth in 100% (58/58) of the samples from captive animals. There were 94 strains isolated and 15 species identified. There was a predominance of Gram-positive bacteria in free-living Chelonia mydas, most of which were Bacillus and Staphylococcus. The most commonly isolated Gram-negative species were enterobacteria for free-living and under human care animals. The strains were predominantly sensitive to ciprofloxacin and tobramycin, and less sensitive to oxacillin or polymyxin B. Ten multiresistant strains were isolated. Yeast were identified in 13.89% (10/72) of the samples. CONCLUSIONS: These results, showing differences in the conjunctival bacterial flora of free-living and captive animals, may be helpful for diagnosis and treatment of ocular disorders in sea turtles.

Monitoring data of marine turtles on the Togolese coast during 2012-2013.

This dataset contains information on the presence and distribution of sea turtles in Togo. Observations were carried out through a network of ten ecoguards (local guides), facilitated by five fishermen, and coordinated by a field technician, all under the supervision of a scientific coordinator. Data on the occurrence or direct observation of sea turtles on the Togolese coast from September 2012 to August 2013 is presented based on 740 occurrences.

Schistosomus Reflexus Syndrome in Olive Ridley Sea Turtles ( Lepidochelys olivacea).

The olive ridley sea turtle ( Lepidochelys olivacea), considered the most abundant sea turtle species, is listed as vulnerable on the International Union for Conservation of Nature Red List. The most important nesting areas are located in the Eastern Pacific, and congenital malformations have been previously reported in this species. The present study was conducted in a single population at El Verde beach, one of the most important nesting beaches for the species in the northwestern Mexican Pacific. The study was based on embryos that had been incubated in a controlled environment. Schistosomus reflexus syndrome (SRS) was observed in 124 of 20 257 olive ridley embryos (0.6%), comprising 124 of 400 (31%) cases of congenital malformations over a 7-month period. Affected embryos had malformations of the carapace, bridge, or plastron, resulting in exposure of the abdominal or thoracic viscera, as well as spinal malformation and abnormal positioning of limbs adjacent to the head with subsequent ankylosis. SRS phenotypes (although lethal) varied from mild to severe, although most cases were severe. SRS was mostly associated with congenital malformations in the neck (short neck, 80%), tail (anury, 38%), and flippers (different types of dysmelias, 53%). In most cases of severe SRS, ankyloses were present. Documenting these findings could be important to identify the cause of the developmental defects, and identification of the cause of the defects may be of significance to the population and to our efforts to manage this and other populations at risk.