scholarly journals Congenital Malformations in Sea Turtles: Puzzling Interplay between Genes and Environment

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 444
Author(s):  
Rodolfo Martín-del-Campo ◽  
María Fernanda Calderón-Campuzano ◽  
Isaías Rojas-Lleonart ◽  
Raquel Briseño-Dueñas ◽  
Alejandra García-Gasca
Keyword(s):  
Congenital Malformations ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
The Body ◽  
Embryonic Mortality ◽  
Olive Ridley ◽  
Mexican Pacific ◽  
Regulatory Pathways ◽  
Genes And Environment

The completion of embryonic development depends, in part, on the interplay between genetic factors and environmental conditions, and any alteration during development may affect embryonic genetic and epigenetic regulatory pathways leading to congenital malformations, which are mostly incompatible with life. Oviparous reptiles, such as sea turtles, that produce numerous eggs in a clutch that is buried on the beach provide an opportunity to study embryonic mortality associated with malformations that occur at different times during development, or that prevent the hatchling from emerging from the nest. In sea turtles, the presence of congenital malformations frequently leads to mortality. A few years ago, a detailed study was performed on external congenital malformations in three species of sea turtles from the Mexican Pacific and Caribbean coasts, the hawksbill turtle, Eretmochelys imbricata (n = 23,559 eggs), the green turtle, Chelonia mydas (n = 17,690 eggs), and the olive ridley, Lepidochelys olivacea (n = 20,257 eggs), finding 63 types of congenital malformations, of which 38 were new reports. Of the three species, the olive ridley showed a higher incidence of severe anomalies in the craniofacial region (49%), indicating alterations of early developmental pathways; however, several malformations were also observed in the body, including defects in the carapace (45%) and limbs (33%), as well as pigmentation disorders (20%), indicating that deviations occurred during the middle and later stages of development. Although intrinsic factors (i.e., genetic mutations or epigenetic modifications) are difficult to monitor in the field, some environmental factors (such as the incubation temperature, humidity, and probably the status of feeding areas) are, to some extent, less difficult to monitor and/or control. In this review, we describe the aetiology of different malformations observed in sea turtle embryos, and provide some actions that can reduce embryonic mortality.

scholarly journals Incidental capture of sea turtles by industrial bottom trawl fishery in the Tropical South-western Atlantic

2017 ◽  
Vol 98 (6) ◽  
pp. 1525-1531 ◽  
Author(s):  
Suzana Machado Guimarães ◽  
Davi Castro Tavares ◽  
Cassiano Monteiro-Neto
Keyword(s):  
Sea Turtles ◽  
Action Plan ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Bottom Trawl ◽  
Conservation Strategies ◽  
Future Research ◽  
Olive Ridley ◽  
Western Atlantic ◽  
Turtle Species

The five sea turtle species occurring in Brazilian waters are susceptible to threats, including incidental catches by fisheries. Studies on incidental captures in fishing gears are the main focus of several conservation actions due to high sea turtle fishery mortality worldwide. This study provides the first evaluation of incidental sea turtle catches by industrial bottom trawl fisheries operating in Brazilian waters. Four twin-trawler vessels were monitored between July 2010 and December 2011 by captains who voluntarily completed logbooks. Forty-four turtles were captured during the 1996 tows (8313 fishing hours), resulting in a catch of 5.3 ± 0.8 turtles per 1000 h per unit effort. Captured species included the loggerhead turtle (Caretta caretta, 22 individuals), olive ridley turtles (Lepidochelys olivacea, 21 individuals) and one green turtle (Chelonia mydas). Water depth was the only variable that significantly affected sea turtle captures according to Generalized Linear Models. The capture rates reported in this study ranked sixth in relation to other published studies of similar fisheries occurring worldwide. Considering the importance of this region for sea turtles, the increasing evidence of sea turtle mortality and the goals of the National Action Plan for Conservation of Sea Turtles in Brazil, it is essential to identify the main threats towards these animals and propose mitigating solutions to reduce sea turtle mortality induced by fishing activities. This study provides results that may guide future research and goals in meeting sea turtle conservation strategies.

scholarly journals First field observation of the predation by Jaguar (Panthera onca) on Olive Ridley sea turtle (Lepidochelys olivacea) at Nancite Beach, Santa Rosa National Park, Costa Rica

2016 ◽  
Vol 3 (1) ◽  
pp. 20-23
Author(s):  
Sergio Escobar-Lasso ◽  
Luis Fonseca ◽  
Wilbert N. Villachica ◽  
Hansel Herrera ◽  
Roldán A. Valverde ◽  
...  
Keyword(s):  
Costa Rica ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Dermochelys Coriacea ◽  
Olive Ridley ◽  
Eretmochelys Imbricata ◽  
Lepidochelys Olivacea ◽  
Santa Rosa National Park ◽  
Key Resources

Jaguars have been recorded preying on adult female sea turtles on their nesting beaches in Costa Rica, Guyana, Mexico and Suriname (Fretey 1977, Autar 1994, Cuevas et al. 2014, Guildera et al. 2015). Jaguars prey on Green (Chelonia mydas), Olive Ridley (Lepidochelys olivacea), Hawksbill (Eretmochelys imbricata), and Leatherback (Dermochelys coriacea) sea turtles (see Fretey 1977, Autar 1994, Carrillo et al. 1994, Chinchilla 1997, Tröeng 2000, Heithaus et al. 2008, Veríssimo et al. 2012, Arroyo-Arce et al. 2014, Cuevas et al. 2014, Arroyo-Arce & Salom-Pérez 2015, Guildera et al. 2015). The capture effort and risk of injury associated with the predation of nesting sea turtles is expected to be lower relative to other prey species in the jaguar’s diet (Cavalcanti & Gese 2010). Additionally, they can be key resources when other pr ey availability is low (Veríssimo et al. 2012).

scholarly journals Ocular ultrasonography of sea turtles

2020 ◽  
Vol 62 (1) ◽  
Author(s):  
Caterina Muramoto ◽  
Vinícius Cardoso-Brito ◽  
Ana Cláudia Raposo ◽  
Thais Torres Pires ◽  
Arianne Pontes Oriá
Keyword(s):  
Anterior Chamber ◽  
Environmental Changes ◽  
Sea Turtles ◽  
Corneal Thickness ◽  
Anterior Chamber Depth ◽  
Chelonia Mydas ◽  
Caretta Caretta ◽  
Sea Turtle ◽  
Olive Ridley ◽  
Turtle Species

Abstract 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.

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

2016 ◽  
Vol 54 (1) ◽  
pp. 171-177 ◽  
Author(s):  
A. Bárcenas-Ibarra ◽  
I. Rojas-Lleonart ◽  
R. I. Lozano-Guzmán ◽  
A. García-Gasca
Keyword(s):  
Congenital Malformations ◽  
Sea Turtle ◽  
Olive Ridley ◽  
Developmental Defects ◽  
Mexican Pacific ◽  
Turtle Species ◽  
Lepidochelys Olivacea ◽  
Populations At Risk ◽  
Different Types ◽  
Nesting Beaches

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.

scholarly journals Spatial distribution of epibionts on olive ridley sea turtles at Playa Ostional, Costa Rica

2019 ◽  
Author(s):  
Nathan J. Robinson ◽  
Emily Lazo-Wasem ◽  
Brett O. Butler ◽  
Eric A. Lazo-Wasem ◽  
John D. Zardus ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Sea Turtles ◽  
Sea Turtle ◽  
The Body ◽  
Olive Ridley ◽  
Quantitative Characterization ◽  
Lepidochelys Olivacea ◽  
Almost All ◽  
Full Body

ABSTRACTThere is a wealth of published information on the epibiont communities of sea turtles, yet many of these studies have exclusively sampled epibionts found only on the carapace. Considering that epibionts may be found on almost all body-surfaces and that it is highly plausible to expect different regions of the body to host distinct epibiont taxa, there is a need for quantitative comparative studies to investigate spatial variation in the epibiont communities of turtles. To achieve this, we measured how total epibiont abundance and biomass on olive ridley turtles Lepidochelys olivacea varies among four body-areas of the hosts (n = 30). We show that epibiont loads on olive ridleys are higher, both in terms of number and biomass, on the skin than they are on the carapace or plastron. This contrasts with previous findings for other hard-shelled sea turtles, where epibionts are usually more abundant on the carapace. Moreover, the arguably most ubiquitous epibiont taxon for other hard-shelled sea turtles, the barnacle Chelonibia spp., only occurs in relatively low numbers on olive ridleys, while the barnacles Stomatolepas elegans and Platylepas hexastylos are far more abundant. We postulate that these differences between the epibiont communities of different sea turtle taxa could indicate that the carapaces of olive ridley turtles provide a more challenging substratum for epibionts than do the hard shells of other sea turtles. In addition, we conclude that it is important to conduct full body surveys when attempting to produce a holistic qualitative or quantitative characterization of the epibiont communities of sea turtles.

Monitoring green sea turtles in Brazilian feeding areas: relating body condition index to fibropapillomatosis prevalence

2019 ◽  
Vol 99 (8) ◽  
pp. 1879-1887 ◽  
Author(s):  
Silmara Rossi ◽  
Angélica María Sánchez-Sarmiento ◽  
Robson Guimarães dos Santos ◽  
Roberta Ramblas Zamana ◽  
Fabiola Eloisa Setim Prioste ◽  
...  
Keyword(s):  
Body Mass ◽  
Body Condition ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Condition Index ◽  
Sea Turtle ◽  
The Body ◽  
Body Condition Index ◽  
Green Sea Turtles ◽  
Green Turtles

AbstractFibropapillomatosis (FP) can be an important conservation threat to green sea turtles (Chelonia mydas) due to its widespread distribution and complex aetiology. Thus, understanding the impacts of FP in sea turtle populations is a research priority towards conservation efforts. The body condition index (BCI), based on straight carapace length (SCL) and body mass (BM), is an accurate indicator of body-nutritional condition that can be used in routine green turtle health evaluations. This study aimed to compare BCI in FP-free (N = 369) and FP-affected (N = 518) green turtles from Brazilian feeding areas. Body condition indices were evaluated in terms of the South-west Atlantic Fibropapillomatosis Score – FPSSWA (mild, moderate and severe), study sites (five Brazilian states), origin (intentional capture, fishery, stranding and afloat) and sex (when known). Curved and straight carapace lengths, and body mass were recorded in order to calculate BCI. Statistical analysis revealed significant differences in BCI among green turtles from different study areas (P = 0.02), and lower BCI values in FP-free than in FP-positive individuals (P < 0.0001). With regards to origin, the highest BCI was found in the intentional capture group (N = 245; 1.47 ± 0.16), followed by fishery (N = 180; 1.46 ± 0.20). Analysis according to sex revealed a higher mean BCI among females than males (P < 0.017). This study provides relevant data on the health and nutritional status of green turtles along the Brazilian coast, in important feeding areas for this species.

scholarly journals Rediscovering Kemp’s Ridley Sea Turtle (Lepidochelys kempii): Molecular Analysis and Threats

2021 ◽  
Author(s):  
Miguel Angel Reyes-López ◽  
Fátima Yedith Camacho-Sánchez ◽  
Catherine E. Hart ◽  
Valeria Leal-Sepúlveda ◽  
Kevin Alan Zavala-Félix ◽  
...  
Keyword(s):  
Anthropogenic Activities ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Olive Ridley ◽  
Lepidochelys Kempii ◽  
Eretmochelys Imbricata ◽  
Sources Of Pollution ◽  
Padre Island ◽  
Kemp's Ridley

Sea turtles are reptiles that have inhabited the earth for 100 million years. These are divided into 2 families (Cheloniidae and Dermochelyidae) and 7 species of sea turtles in the world: the leatherback turtle (Dermochelys coriacea); hawksbill turtle (Eretmochelys imbricata); Kemp’s ridley (Lepidochelys kempii); olive ridley (L. olivacea); Loggerhead turtle (Caretta caretta); flatback sea turtle (Natator depressus) and green turtle (Chelonia mydas). In particular, Kemp’s ridley is included in the red list of IUCN categorized as “critically endangered”. The most important site around the Word is in Rancho Nuevo, Tamaulipas, Mexico. Where 80–95% of the world’s nesting is concentrated. Other nesting areas are Tepeguajes and Barra del Tordo, in Tamaulipas, and with less intensity in Veracruz (Lechuguillas and El Raudal beaches) and South Padre Island, Texas, USA. They deposit an average of about 90 eggs and hatching takes 40 to 60 days. Therefore, they are vulnerable to different anthropogenic activities and sources of pollution, such as heavy metals, which can cause toxic effects that are harmful to the turtles, damage their physiology and health. To understand the real situation about health and genetic parameters it is necessary to analyze biochemical and molecular factors in this species.

scholarly journals Chelonicola and Poulinea, two new gomphonemoid diatom genera (Bacillariophyta) living on marine turtles from Costa Rica

Phytotaxa ◽  
2015 ◽  
Vol 233 (3) ◽  
pp. 236 ◽  
Author(s):  
Roksana Majewska ◽  
J. P. Kociolek ◽  
Evan W. Thomas ◽  
Mario De Stefano ◽  
Mario Santoro ◽  
...  
Keyword(s):  
Costa Rica ◽  
Marine Mammals ◽  
Sea Turtles ◽  
Sea Turtle ◽  
New Genera ◽  
Olive Ridley ◽  
Lepidochelys Olivacea ◽  
Marine Turtles ◽  
The Family ◽  
Long Time

Marine mammals such as whales and dolphins have been known for a long time to host a very specific epizoic community on their skin. Less known however is the presence of a similar community on the carapaces of sea turtles. The present study is the first describing new taxa inhabiting sea turtle carapaces. Samples, collected from nesting olive ridley sea turtles (Lepidochelys olivacea) on Ostional Beach (Costa Rica), were studied using light and scanning electron microscopy. Two unknown small-celled gomphonemoid taxa were analysed in more detail and are described as two new genera, closely related to other gomphonemoid genera with septate girdle bands, such as Tripterion, Cuneolus and Gomphoseptatum. Chelonicola Majewska, De Stefano & Van de Vijver gen. nov. has a flat valve face, uniseriate striae composed of more than three areolae, simple external raphe endings, internally a siliceous flap over the proximal raphe endings and lives on mucilaginous stalks. Poulinea Majewska, De Stefano & Van de Vijver gen. nov. has at least one concave valve, uniseriate striae composed of only two elongated areolae, external distal raphe endings covered by thickened siliceous flaps and lives attached to the substrate by a mucilaginous pad. Chelonicola costaricensis Majewska, De Stefano & Van de Vijver sp. nov. and Poulinea lepidochelicola Majewska, De Stefano & Van de Vijver sp. nov. can be separated based on stria structure, girdle structure composed of more than 10 copulae, raphe structure and general valve outline. A cladistics analysis of putative members of the Rhoicospheniaceae indicates that the family is polyphyletic. Chelonicola and Poulinea are sister taxa, and form a monophyletic group with Cuneolus and Tripterion, but are not closely related to Rhoicosphenia, or other genera previously assigned to this family. Features used to help diagnose the family such as symmetry and presence of septa and pseudosepta are homoplastic across the raphid diatom tree of life.

scholarly journals Study on the etiology of fibropapillomatosis of olive ridley sea turtles (Lepidochelys olivacea) nesting in the National Wildlife Refuge at Ostional, Guanacaste, Costa Rica

2013 ◽  
Vol 5 ◽  
pp. 119 ◽  
Author(s):  
Laura Brenes Chaves ◽  
Alexis Berrocal ◽  
Ana I. Meneses ◽  
Carlos Jiménez Sánchez ◽  
Carlos M. Orrego Vásquez
Keyword(s):  
Sea Turtles ◽  
Cytoplasmic Inclusion ◽  
Blood Chemistry ◽  
Sea Turtle ◽  
Olive Ridley ◽  
Blood Samples ◽  
Lepidochelys Olivacea ◽  
Wildlife Refuge ◽  
Para Determinar ◽  
Olive Ridley Sea Turtles

Sea turtle fibropapillomatosis is an emerging disease characterized by a proliferation of cutaneous papillomas, fibromas, and fibropapillomas and occasional visceral fibromas. This paper aims to contribute tothe etiology of fibropapillomatosis in olive ridley sea turtles (Lepidochelys olivacea) nesting in OstionalNational Wildlife Refuge. Twenty six olive ridley turtles with cutaneous fibropapilloma were sampled and24 healthy olive ridley turtles served as controls. Biopsies were taken of the cutaneous tumors in sick seaturtles, as well as skin biopsies from control subjects, and blood samples were collected from all turtles.Tumorous samples and skin samples were microscopically analyzed in order to differentiate the histologicalfactors resulting from the disease pathogenesis, where the main histological findings were papillaryepidermal hyperplasia, orthokeratotic hyperkeratosis, spirorchid-like eggs in the dermis, and eosinophilic cytoplasmic inclusion. Hematology and blood chemistry studies were conducted on blood samples, andMCHC, heterophils, lymphocytes, monocytes, AST, total protein, albumin and globulin values were significantlydifferent between healthy turtles and turtles with tumors. A PCR test was also conducted in thesamples to determine the presence of herpesvirus and papillomavirus as possible etiologic agents, wherethe papilomavirus was absent in all the samples, while the herpesvirus was present in 69.23% of the tumors,this being the most probable etiological agent of fibropapillomatosis.La fibropapilomatosis de la tortuga marina es una enfermedad emergente caracterizada por múltiples papilomas, fibromas y fibropapilomas cutáneos, así como ocasionales fibromas viscerales. El presente trabajo tiene como objetivo contribuir a la etiología de la fibropapilomatosis en la tortuga lora (Lepidochelys olivacea) que anida en el Refugio Nacional de Vida Silvestre Ostional. Se muestrearon 26 tortugas lora con fibropapilomas cutáneos y 24 tortugas lora sanas que sirvieron de control. Se tomaron biopsias excisionales de los tumores cutáneos de las tortugas enfermas y biopsias de piel de las tortugas control, además se recolectaron muestras de sangre de todas las tortugas. Las muestras tumorales y de piel se analizaron microscópicamente para diferenciar los factores histológicos que resultan de la patogénesis de la enfermedad, donde los hallazgos histopatológicos principales en los fibropapilomas fueron: crecimiento papiliforme, hiperqueratosis ortoqueratótica, huevos de parásitos similares a espiróquidos en la capa dérmica e inclusión eosinofílica citoplasmática. A las muestras de sangre se les realizó análisis hematológico y de química sanguínea, donde los valores de CHCM, heterófilos, linfocitos, monocitos, AST, proteínas totales, albúmina y globulinas resultaron significativamente diferentes entre las tortugas sanas y las tortugas con tumores. Se realizó PCR a las muestras para determinar la presencia de genoma de herpesvirus y papilomavirus como posibles agentes etiológicos, donde el papilomavirus estuvo ausente en la totalidad de las muestras, mientras el virus Herpes se presentó en el 69.23% de los tumores posicionándose como el posible agente etiológico de la enfermedad.

scholarly journals Red blood cell osmotic fragility in healthy loggerhead and green sea turtles

2020 ◽  
Vol 32 (6) ◽  
pp. 908-911
Author(s):  
Rebecca Radisic ◽  
Sean D. Owens ◽  
Charles A. Manire ◽  
Nicole Montgomery ◽  
Doug Mader ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Sea Turtles ◽  
Osmotic Fragility ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Green Sea Turtles ◽  
Nacl Concentration ◽  
Life Threatening ◽  
Rehabilitation Facilities

Loggerhead ( Caretta caretta; Cc) and green sea ( Chelonia mydas; Cm) turtles admitted to rehabilitation facilities may require blood transfusions for supportive treatment of disorders resulting in life-threatening anemia, but, considering the unique erythrocyte chemistry of sea turtles, standardized donor red blood cell (RBC) storage protocols have not been established. Prolonged cold storage and the effects of various anticoagulant-preservative solutions have been associated with increased RBC osmotic fragility across a broad range of species. Increased RBC fragility in stored RBC products has been associated with acute transfusion reactions. The osmotic fragility test is used to measure erythrocyte resistance to hemolysis while being exposed to a series of dilutions of a saline solution. We obtained baseline measurements for osmotic fragility in healthy Cc and Cm. Osmotic fragility testing was performed on samples from 10 Cc to 10 Cm. Fifty percent (50%) RBC hemolysis was identified at a mean NaCl concentration of 0.38% in both species. Results of our study will help guide future studies evaluating optimal storage solutions for sea turtle blood products.

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