Comparative Cytogenetics of Four Sea Turtle Species (Cheloniidae): G-Banding Pattern and in situ Localization of Repetitive DNA Units

2020 ◽  
Vol 160 (9) ◽  
pp. 531-538
Author(s):  
Caroline R.D. Machado ◽  
Larissa Glugoski ◽  
Camila Domit ◽  
Marcela B. Pucci ◽  
Daphne W. Goldberg ◽  
...  
Keyword(s):  
Ribosomal Dna ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Marine Biodiversity ◽  
Comparative Cytogenetics ◽  
Turtle Species ◽  
Lepidochelys Olivacea ◽  
Karyotypic Formula

Sea turtles are considered flagship species for marine biodiversity conservation and are considered to be at varying risk of extinction globally. Cases of hybridism have been reported in sea turtles, but chromosomal analyses are limited to classical karyotype descriptions and a few molecular cytogenetic studies. In order to compare karyotypes and understand evolutive mechanisms related to chromosome dif­ferentiation in this group, <i>Chelonia mydas</i>, <i>Caretta caretta</i>, <i>Eretmochelys imbricata</i>, and <i>Lepidochelys olivacea</i> were cytogenetically characterized in the present study. When the obtained cytogenetic data were compared with the putative ancestral Cryptodira karyotype, the studied species showed the same diploid number (2n) of 56 chromosomes, with some variations in chromosomal morphology (karyotypic formula) and minor changes in longitudinal band locations. In situ localization using a 18S ribosomal DNA probe indicated a homeologous microchromosome pair bearing a 45S ribosomal DNA locus and size heteromorphism in all 4 species. Interstitial telomeric sites were identified in a microchromosome pair in <i>C. mydas</i> and <i>C. caretta</i>. The data showed that interspecific variations occurred in chromosomal sets among the Cheloniidae species, in addition to other Cryptodira karyotypes. These variations generated lineage-specific karyotypic diversification in sea turtles, which will have considerable implications for hybrid recognition and for the study, the biology, ecology, and evolutionary history of regional and global populations. Furthermore, we demonstrated that some chromosome rearrangements occurred in sea turtle species, which is in conflict with the hypothesis of conserved karyotypes in this group.

Trace metal concentrations in livers and kidneys of sea turtles from south-eastern Queensland, Australia

1998 ◽  
Vol 49 (5) ◽  
pp. 409 ◽  
Author(s):  
A. R. Pople ◽  
A. N. Gordon ◽  
J. Ng
Keyword(s):  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Metal Concentrations ◽  
Eretmochelys Imbricata ◽  
Turtle Species ◽  
Lepidochelys Olivacea ◽  
South Eastern ◽  
Obvious Association ◽  
High Concentrations

The concentrations of some or all of arsenic (As), cadmium (Cd), mercury (Hg), selenium (Se) and zinc (Zn) were determined in the livers and kidneys of 50 stranded sea turtles (38 Chelonia mydas, eight Caretta caretta, three Eretmochelys imbricata, one Lepidochelys olivacea) from the Moreton Bay region of south-eastern Queensland, Australia. Concentrations of Cd, Se and Zn in the kidney tended to decrease with age, whereas concentrations of Zn in the liver tended to increase. Concentrations of Cd in all sea turtle species (1.7–75.9 µg g-1 wet weight) were amongst the highest recorded for marine vertebrates globally. Although there was no obvious association between metal concentrations and particular diseases in C. mydas, the high concentrations of Cd found in edible turtle tissues may pose a threat to the health of indigenous people whose diet includes C. mydas.

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 Occurrence of sea turtles during seismic surveys in Northeastern Brazil

2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Cristiano Leite Parente ◽  
Juliana Doyle Lontra ◽  
Maria Elisabeth de Araújo
Keyword(s):  
Sea Turtles ◽  
Low Frequency ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Reproductive Period ◽  
Northeastern Brazil ◽  
Seismic Survey ◽  
Shallow Waters ◽  
Seismic Surveys ◽  
Lepidochelys Olivacea

There are seven species of sea turtles around the world. Among these, five visit the northeast coast of Brazil to reproduce and feed. These sea turtles are impacted by human activity and need conservation measures. The seismic survey is one of these activities due to its high intensity and low frequency sound emissions in the marine environment. Records of sea turtles during seismic surveys in shallow waters of the northeast of Brazil between 2002 and 2003 are presented in this study with some discussion about the effectiveness of the monitoring procedures. Three species of sea turtle were recorded within the seismic survey areas. The Chelonia mydas species was the most commonly sighted turtle. There was only one record of Caretta caretta and Lepidochelys olivacea. The presence of sea turtles in Sergipe state was linked to the reproductive period while this pattern was not observed in Ceará state. The absence of information about distribution and abundance of sea turtles in the surveyed areas previous to and after the seismic surveys, as well as numerous incomplete data make it hard to identify the effect of seismic surveys on those factors and also sea turtle behaviors.

scholarly journals West Florida Shelf pipeline serves as sea turtle benthic habitat based on in situ towed camera observations

2019 ◽  
Vol 29 ◽  
pp. 17-31 ◽  
Author(s):  
HA Broadbent ◽  
SE Grasty ◽  
RF Hardy ◽  
MM Lamont ◽  
KM Hart ◽  
...  
Keyword(s):  
Habitat Use ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Environmental Data ◽  
Benthic Habitat ◽  
West Florida Shelf ◽  
Benthic Habitats ◽  
Florida Shelf ◽  
Turtle Species

The use of marine offshore benthic habitats by sea turtles is poorly characterized due to the difficulty of obtaining in situ data. Understanding benthic habitat use that is important to the species’ reproduction, foraging, and migrations is critical for guiding management decisions. A towed camera-based assessment survey system (C-BASS) equipped with environmental sensors was used to characterize and assess benthic habitats on the West Florida Shelf (WFS) from 2014 to 2018. During these cruises, sea turtles were opportunistically observed during the surveys, and critical in situ data such as spatiotemporal information, species identification, habitat use, behavior, and environmental data were collected and evaluated. In total, 79 sea turtles were observed during 97 transects of approximately 2700 km of seafloor, which was recorded on 380 h of video. Several sea turtle species were spotted within the WFS, including loggerhead Caretta caretta, Kemp’s ridley Lepidochelys kempii, and green turtles Chelonia mydas. These opportunistic sightings revealed an area of high use on the WFS, an anthropogenic structure known as the Gulfstream natural gas pipeline (GSPL). C-BASS survey results suggest that 2 sea turtle species (C. caretta and L. kempii) utilize this artificial structure primarily as a resting area. We emphasize the importance of combining habitat mapping techniques (towed underwater video and multibeam bathymetry/backscatter) with tracking technology to better understand the fine-scale habitat use of sea turtles.

scholarly journals Quantifying Illegal Extraction of Sea Turtles in Costa Rica

2021 ◽  
Vol 2 ◽  
Author(s):  
Helen Pheasey ◽  
George Glen ◽  
Nicole L. Allison ◽  
Luis G. Fonseca ◽  
Didiher Chacón ◽  
...  
Keyword(s):  
Costa Rica ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Wildlife Trade ◽  
Caribbean Coast ◽  
Turtle Species ◽  
Illegal Wildlife Trade ◽  
The Caribbean ◽  
The Impact

Estimates of illegal wildlife trade vary significantly and are often based on incomplete datasets, inferences from CITES permits or customs seizures. As a result, annual global estimates of illegal wildlife trade can vary by several billions of US dollars. Translating these figures into species extraction rates is equally challenging, and estimating illegal take accurately is not achievable for many species. Due to their nesting strategies that allow for census data collection, sea turtles offer an exception. On the Caribbean coast of Costa Rica, three sea turtle species (leatherback, Dermochelys coriacea; green, Chelonia mydas; and hawksbill, Eretmochelys imbricata) are exploited by poachers. Despite the consumption of turtle eggs and meat being illegal, they are consumed as a cultural food source and seasonal treat. Conservation programmes monitor nesting beaches, collect abundance data and record poaching events. Despite the availability of robust long-term datasets, quantifying the rate of poaching has yet to be undertaken. Using data from the globally important nesting beach, Tortuguero, as well as beaches Playa Norte and Pacuare on the Caribbean coast of Costa Rica, we modelled the spatial and temporal distribution of poaching of the three sea turtle species. Here, we present data from 2006 to 2019 on a stretch of coastline covering c.37 km. We identified poaching hotspots that correlated with populated areas. While the poaching hotspots persisted over time, we found poaching is declining at each of our sites. However, we urge caution when interpreting this result as the impact of poaching varies between species. Given their low abundance on these beaches, the poaching pressure on leatherback and hawksbill turtles is far greater than the impact on the abundant green turtles. We attribute the decline in poaching to supply-side conservation interventions in place at these beaches. Finally, we highlight the value of data sharing and collaborations between conservation NGOs.

scholarly journals Strandings of sea turtles on beaches around the oil capital in Brazil

2021 ◽  
Vol 16 (4) ◽  
pp. 521-538
Author(s):  
Raísa da Silva Costa Rêgo ◽  
Eric Azevedo Cazetta ◽  
Caio Henrique Gonçalves Cutrim ◽  
Amanda Soares Miranda ◽  
Ana Paula Albano Araújo ◽  
...  
Keyword(s):  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
The State ◽  
Dermochelys Coriacea ◽  
Anthropogenic Factors ◽  
Long Beach ◽  
Eretmochelys Imbricata ◽  
Lepidochelys Olivacea ◽  
The North

The south-western region of the Atlantic Ocean has feeding and nesting areas for the five species of sea turtles registered in Brazil, which are in different degrees of extinction threat, mainly due to anthropogenic factors. Fishing and the ingestion of solid waste, were identified as causing stranding and the mortality of sea turtles. In this work, data from the monitoring of beaches in the Municipalities of Macaé and Rio das Ostras, important oil zone in Brazil, in the north-central region of the State of Rio de Janeiro, were used in order to analyse the effects of seasonality on the sea turtle stranding. The monitoring was carried out daily from September 2017 to June 2019, in a study area covering 23.8 km long beach. Stranding data were obtained from active (n = 126) and passive (n = 66) monitoring of beaches and included the records of Chelonia mydas (n = 151), Caretta caretta (n = 23), Lepidochelys olivacea (n = 14), Dermochelys coriacea (n = 2) and Eretmochelys imbricata (n = 1). The largest stranding record occurred in the summer (n = 61) and spring (n = 60), a period compatible with the reproductive season of the species. The results obtained in this study emphasise the importance of the analysis of strandings of sea turtles, which provide relevant data on the biology of the group, the intra and interspecific dynamics and the state of conservation of these animals.

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 Insights Into Sea Turtle Population Composition Obtained With Stereo-Video Cameras in situ Across Nearshore Habitats in the Northeastern Gulf of Mexico

2021 ◽  
Vol 8 ◽  
Author(s):  
Tabitha Siegfried ◽  
Christopher Noren ◽  
Jackson Reimer ◽  
Matthew Ware ◽  
Mariana M. P. B. Fuentes ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Sea Turtles ◽  
Sea Turtle ◽  
Life Stages ◽  
Turtle Species ◽  
Stereo Video ◽  
Population Size Estimates ◽  
Turtle Population ◽  
Northeastern Gulf Of Mexico

Population size estimates are key parameters used in assessments to evaluate and determine a species’ conservation status. Typically, sea turtle population estimates are made from nesting beach surveys which capture only hatchling and adult female life stages and can display trends opposite of the full population. As such, in-water studies are critical to improve our understanding of sea turtle population dynamics as they can target a broader range of life stages – though they are more logistically and financially challenging to execute compared to beach-based surveys. Stereo-video camera systems (SVCS) hold promise for improving in-water assessments by removing the need to physically capture individuals and instead extract 3D measurements from video footage, thereby simplifying monitoring logistics and improving safety for the animals and surveyors. To demonstrate this potential, snorkel surveys were conducted at artificial habitats in the northeastern Gulf of Mexico (neGOM) to collect size and photo-identification data on sea turtles in situ using a SVCS. Over 29.86 survey hours, 35 sea turtles were observed across three species (Caretta caretta, Chelonia mydas, and Lepidochelys kempii) and all neritic life stages (juvenile, sub-adult, and adult) utilizing different habitats, including artificial reefs, jetties, and fishing piers. Greens straight carapace length ranged from 28.55 to 66.96 cm (n = 23, mean 43.07 cm ± 11.26 cm standard deviation; SD) and loggerheads ranged from 59.71 to 91.77 cm (n = 10, mean 74.50 cm ± 11.35 cm SD), and Kemp’s ridleys ranged from 42.23 cm to 44.98 cm (mean 43.61 cm ± 1.94 cm SD). Using a linear mixed model, we found that species and habitat type were the most important predictors of sea turtle body length distribution. Overall, this case study demonstrates the potential of SVCS surveys to enhance our understanding of the population structure of sea turtle species within the neGOM and elsewhere.

scholarly journals Comparative Study of Plasma Parameters in Olive Ridley (Lepidochelys Olivacea) and Hawksbill (Eretmochelys Imbricata) During Nesting

2002 ◽  
Vol 7 (2) ◽  
pp. 231
Author(s):  
A.Y.A. Alkindi ◽  
I.Y. Mahmoud ◽  
J.L. Plude
Keyword(s):  
Plasma Parameter ◽  
Sea Turtles ◽  
Stress Hormones ◽  
Sea Turtle ◽  
Olive Ridley ◽  
Plasma Parameters ◽  
Eretmochelys Imbricata ◽  
Turtle Species ◽  
Lepidochelys Olivacea ◽  
Significant Difference

The aim of this study is to investigate the role of plasma level parameters during nesting activity and provide data potentially useful to future studies on the dynamics of reproductive and stress hormones in the most endangered sea turtle species in the world. Plasma parameters in the sea turtles, olive ridley (Lipodochelys oliveacea) and hawksbill (Eretmochelys imbricata) from Masirah Island, Oman, were analyzed relative to nesting stress. To date, no study has been conducted on plasma parameter levels in sea turtles during nesting. Field observations were conducted under ideal temperature conditions. At the time of sampling, there was no significant difference for cloacal, sand, air or water temperature for the two species. Electrolytes (Cl¯, Ca++, K+, Na+ and Mg++), cholesterol, urea, uric acid and osmolarity were measured during nesting. Both species were observed to spend between 1.5 and 2.00 hours on the nesting grounds. Some had successful oviposition and completed all nesting phases, while others with incomplete nesting phases failed to oviposit their  eggs. Under both conditions, the turtles of both species had an exhaustive and stressful nesting exercise. Plasma parameter values, both intra-specifically and inter-specifically, were not significantly different for oviposited and non-oviposited turtles. This may indicate that both species have the same physiological adjustment relative to plasma parameters whether or not the turtles oviposited their eggs.  

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