scholarly journals Survival and breeding interval of an endangered marine vertebrate, the leatherback turtle Dermochelys coriacea, in French Guiana

2020 ◽  
Vol 41 ◽  
pp. 153-165 ◽  
Author(s):  
D Chevallier ◽  
M Girondot ◽  
R Berzins ◽  
J Chevalier ◽  
B de Thoisy ◽  
...  
Keyword(s):  
Life Cycle ◽  
French Guiana ◽  
Sea Turtles ◽  
Monitoring Program ◽  
Biological Information ◽  
Dermochelys Coriacea ◽  
Adult Survival ◽  
Leatherback Turtle ◽  
State Uncertainty ◽  
Intermittent Sampling

In the context of global change, endangered species such as sea turtles undergo strong population dynamics changes. Understanding demographic processes inducing such changes is critical for developing appropriate measures for conservation and management. Nesting females of the French Guiana population of leatherback sea turtles Dermochelys coriacea represented 40% of the world’s total in 2001; today, they represent only 10%. Here, we analyze data from the long-term monitoring program of leatherbacks in French Guiana, based on 28 yr of capture-mark-recapture data from 46051 individuals in northwestern French Guiana. We used multievent models (multistate capture-recapture models with state uncertainty) to represent the main peculiarity of the life cycle, intermittent reproduction, and to take advantage of the use of several different types of marks to account for mark loss and incomplete detection. The average annual adult survival probability (mean ± SE) 0.789 ± 0.009 is low compared to published estimates for this species. By combining the estimates of departure and return probabilities, we provide an estimate of the interval among laying seasons equal to 2.777 ± 0.118 yr, which matches previous findings. Taking survival into account, this interval translates into an average of 1.704 ± 0.034 further reproductive seasons for an adult female having just bred, which is remarkably low compared to other long-lived vertebrates. The representation of the life cycle and mark loss in our models provides a sound structure for broader and richer analyses to extract biological information from marked individuals and offers an invaluable source of demographic information on leatherbacks, a species for which only a small segment of the population is accessible to intermittent sampling.

scholarly journals Checklist of sea turtles endohelminth in Neotropical region

2016 ◽  
Vol 53 (3) ◽  
pp. 211-223 ◽  
Author(s):  
M. R. Werneck ◽  
R. J. Da Silva
Keyword(s):  
Sea Turtles ◽  
Loggerhead Turtle ◽  
Chelonia Mydas ◽  
Neotropical Region ◽  
Dermochelys Coriacea ◽  
Olive Ridley ◽  
Eretmochelys Imbricata ◽  
Leatherback Turtle ◽  
Lepidochelys Olivacea ◽  
The Caribbean

SummaryThis paper presents a list of parasites described in sea turtles from the Neotropical region. Through the review of literature the occurrence of 79 taxa of helminthes parasites were observed, mostly consisting of the Phylum Platyhelminthes with 76 species distributed in 14 families and 2 families of the Phylum Nematoda within 3 species. Regarding the parasite records, the most studied host was the green turtle (Chelonia mydas) followed by the hawksbill turtle (Eretmochelys imbricata), olive ridley turtle (Lepidochelys olivacea), loggerhead turtle (Caretta caretta) and leatherback turtle (Dermochelys coriacea). Overall helminths were reported in 12 countries and in the Caribbean Sea region. This checklist is the largest compilation of data on helminths found in sea turtles in the Neotropical region.

scholarly journals Gross morphology and microstructure of type locality ossicles of Psephophorus polygonus Meyer, 1847 (Testudines, Dermochelyidae)

2013 ◽  
Vol 150 (5) ◽  
pp. 767-782 ◽  
Author(s):  
MASSIMO DELFINO ◽  
TORSTEN M. SCHEYER ◽  
FRANCESCO CHESI ◽  
TAMARA FLETCHER ◽  
RICHARD GEMEL ◽  
...  
Keyword(s):  
Middle Miocene ◽  
Ventral Surface ◽  
Dive Depth ◽  
Type Locality ◽  
Dermochelys Coriacea ◽  
Compact Layer ◽  
Leatherback Turtle ◽  
New Diagnosis ◽  
First Time ◽  
Growth Centres

AbstractPsephophorus polygonus Meyer, 1847, the first fossil leatherback turtle to be named, was described on the basis of shell ossicles from the middle Miocene (MN6–7/8?) of Slovakia. The whereabouts of this material is uncertain but a slab on display at the Naturhistorisches Museum Wien is considered the neotype. We rediscovered further type locality ossicles in four European institutions, re-evaluated their gross morphology and described for the first time their microstructure by comparing them with Dermochelys coriacea, the only living dermochelyid turtle. The gross morphology is congruent with that already described for P. polygonus, but with two significant exceptions: the ridged ossicles of P. polygonus may have a distinctly concave ventral surface as well as a tectiform shape in cross-section. They do not develop the external keel typical of many ossicles of D. coriacea. Both ridged and non-ridged ossicles of P. polygonus are characterized by compact diploe structures with an internal cortex consisting of a coarse fibrous meshwork, whereas the proportionately thinner ossicles of D. coriacea tend to lose the internal cortex, and thus their diploe, during ontogeny. The ossicles of both P. polygonus and D. coriacea differ from those of other lineages of amniotes whose carapace is composed of polygonal ossicles or platelets, in having growth centres situated at the plate centres just interior to the external bone surface and not within the cancellous core or closer to the internal compact layer. The new diagnosis of P. polygonus allows us to preliminarily re-evaluate the taxonomy of some of the Psephophorus-like species. Despite some macro- and micromorphological differences, it seems likely that Psephophorus was as cosmopolitan as extant Dermochelys and had a broadly similar ecology, with a possible difference concerning the dive depth.

Arsenic compounds in tissues of the leatherback turtle, Dermochelys coriacea

1994 ◽  
Vol 74 (2) ◽  
pp. 463-466 ◽  
Author(s):  
J.S. Edmonds ◽  
Y. Shibata ◽  
R.I.T. Prince ◽  
K.A. Francesconi ◽  
M. Morita
Keyword(s):  
Mass Spectrometry ◽  
Inductively Coupled Plasma ◽  
High Performance ◽  
Pectoral Muscle ◽  
Dermochelys Coriacea ◽  
Aqueous Extracts ◽  
Arsenic Compounds ◽  
Leatherback Turtle ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry

Examination of extracts of tissues of a leatherback turtle, Dermochelys coriacea (L.) (Reptilia: Dermochelyidae) by high-performance liquid chromatography inductively coupled plasma-mass spectrometry has demonstrated the presence of arsenobetaine, arsenocholine and inorganic arsenate in heart muscle and liver, and arsenobetaine and inorganic arsenate in pectoral muscle. Although arsenobetaine was the major form in all tissues, inorganic arsenate and arsenocholine accounted for 50% and 15% respectively of arsenic in aqueous extracts of the liver.

scholarly journals Scapteriscus didactylus (Orthoptera, Gryllotalpidae), predator of leatherback turtle eggs in French Guiana

2003 ◽  
Vol 249 ◽  
pp. 289-296 ◽  
Author(s):  
A Maros ◽  
A Louveaux ◽  
MH Godfrey ◽  
M Girondot
Keyword(s):  
French Guiana ◽  
Leatherback Turtle

scholarly journals The Effects of Nest Location and Beach Environment on Hatching Success for Leatherback (Dermochelys Coriacea) and Green (Chelonia Mydas) Sea Turtles on Bioko Island, Equatorial Guinea

2021 ◽  
Author(s):  
Callie A. Veelenturf ◽  
Elizabeth M. Sinclair ◽  
Peter Leopold ◽  
Frank V. Paladino ◽  
Shaya Honarvar
Keyword(s):  
Green Turtle ◽  
Hatching Success ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Dermochelys Coriacea ◽  
Equatorial Guinea ◽  
Leatherback Turtles ◽  
Nest Location ◽  
Bioko Island ◽  
Elevation Range

Abstract Hatching success in sea turtles is hindered by a variety of biotic and abiotic factors. This study of the nesting ecology of leatherback (Dermochelys coriacea) and green (Chelonia mydas) sea turtles, investigated how several environmental factors and beach characteristics on Bioko Island, Equatorial Guinea influence sea turtle reproductive success. Average clutch hatching success was 40.4% for green turtles and 41.73% for leatherback turtles. For leatherback turtles, clutch elevation relative to the high tide line (HTL) was found to be the most influential factor in determining hatching success, highlighting the sensitivity of this species to sea level rise (SLR). Multiple linear regression analysis demonstrated that nest distance to vegetation and sand conductivity also played significant roles in leatherback clutch hatching success. For leatherback clutches, 33% percent of experimental nests were affected by inundation and 17% by predation. An optimum clutch elevation range for leatherback turtles was identified, where a distinct increase in hatching success was observed between -0.286 m to -0.0528 m above the HTL. For green sea turtles, 64% of experimental nests were affected by predation, confounding conclusions about the roles of environmental characteristics in green turtle hatching success. We propose further investigation into influential characteristics in green turtle nests and confirmation of the observed optimum elevation range on Bioko Island and other nesting grounds. Identified sensitivities of each species to SLR and beach characteristics will be used to encourage the government of Equatorial Guinea to consider the vulnerability of their resident turtle populations when planning for future coastal development.

On the orientation circle of the leatherback turtle, Dermochelys coriacea

1975 ◽  
Vol 23 ◽  
pp. 568-591 ◽  
Author(s):  
N. Mrosovsky ◽  
Sara J. Shettleworth
Keyword(s):  
Dermochelys Coriacea ◽  
Leatherback Turtle
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