Ocular dimensions and schematic eyes of freshwater and sea turtles

1991 ◽  
Vol 7 (6) ◽  
pp. 627-635 ◽  
Author(s):  
D. P. M. Northmore ◽  
A. M. Granda
Keyword(s):  
Refractive Error ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Freshwater Turtle ◽  
Eretmochelys Imbricata ◽  
Marine Turtles ◽  
Pseudemys Scripta

AbstractMeasurements were made of the ocular dimensions from living and frozen eyes of one species of freshwater turtle, Pseudemys scripta elegans, and of three species of marine turtles, Chelonia mydas, Dermochelys cariacea, and Eretmochelys imbricata. Estimates of refractive error by retinoscopy were also obtained with eyes in air and under water. The results suggest that unaccommodated eyes of all four species are approximately emmetropic in air but strongly hyperopic in water. Schematic eyes were calculated for each species in both air and water.

Paramphistomes (Digenea; Paramphistomidae) Parasitic in Marine Turtles (Reptilia: Chelonia).

1983 ◽  
Vol 31 (5) ◽  
pp. 851 ◽  
Author(s):  
D Blair
Keyword(s):  
Green Turtle ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Original Material ◽  
Eretmochelys Imbricata ◽  
Marine Turtles ◽  
Australian Region ◽  
Species Inquirenda ◽  
Australian Specimen

Schizamphistomum scleroporum (Creplin, 1844) Groschaft, Otero & Tenora, 1977 nec Looss, 1912, and S. erratum, sp. nov. [=S. scleroporum sensu Looss, 1912 (nec Creplin, 1844)], are described from the green turtle, Chelonia mydas (L.), from Australia. One specimen of the former species was also recovered from an Australian specimen of the hawksbill turtle, Eretmochelys imbricata (L.). Paramphistomum papillostomum MacCallum, 1916 and Schizamphistomoides chelonei Gupta, 1961, are regarded as synonyms of Schizamphistomum scleroporum (Creplin). S. taiwanense Fischthal & Kunz, 1975 is regarded as a species inquirenda. The remaining species known from sea turtles, Schizamphistomoides spinulosum (Looss, 1901) Stunkard, 1925, is redescribed, mostly from original material collected by Looss. This species has not yet been found in the Australian region. The relationships between Schizamphistomum scleroporum, S. erratum and Schizamphntomoides spinulosum are discussed.

Wavelength-dependent temporal properties of retinal horizontal cells in turtles

1990 ◽  
Vol 4 (05) ◽  
pp. 427-435 ◽  
Author(s):  
C.A. Dvorak ◽  
A.M. Granda
Keyword(s):  
Temporal Integration ◽  
Monochromatic Light ◽  
Maximum Amplitude ◽  
Light Response ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Horizontal Cells ◽  
Freshwater Turtle ◽  
L Cells ◽  
Pseudemys Scripta

AbstractElectrical reponses of luminosity horizontal cells (L cells) to monochromatic stimuli were analyzed by intracellular recordings in the retinas of the freshwater turtle (Pseudemys scripta elegans) and of the sea turtle (Chelonia mydas mydas). Light intensity, duration, and wavelength were varied to assess temporal effects. For a given intensity of monochromatic light, response amplitude increased with stimulus duration until maximum amplitude occurred at a specific duration. This suprathreshold metric of temporal integration is calledhere summation time, and it is wavelength-dependent.L cells always had some level of red-sensitive cone input, although in some cells inputs from green- and blue-sensitive cones were also observed. For these latter cells, summation times were shorter for 640-nm than for 540-nm or 450-nm lights. These results were most evident in cells that received dominant inputs from blue- or green-sensitive cones.Responses of some other L cells were almost completely dominated by inputs from red-sensitive cones. Summation times of these cells were not wavelength-dependent. But when these inputs also included green-sensitive cones, shorter summation times were obtained to 640-nm light than to 540-nm light, even though dominant inputs were still from red-sensitive cones. These results, obtained from both retinal and 3,4-dehydroretinal photopigment systems, are consistent with reported observations inPseudemys scripta elegansthat show linear responses of red-sensitive cones to have shorterintegration times and times-to-peakthan green-sensitive cones.Responses from horizontal cells dominated by blue-sensitive cone inputs were the most sensitive of all; they also had the longest summation times. These results support the hypothesis that a gain in sensitivity occurs from the integration of absorbed photons over longer periods of time.These intracellular responses are of particular importance because behavioral critical durations in turtle, as defined by Bloch&'s law, are similarly wavelength-dependent.

scholarly journals STUDIES ON DIGESTIVE ORGANS OF TWO SEA TURTLES, Chelonia mydas L. and Eretmochelys imbricata L.

2017 ◽  
Vol 11 (1) ◽  
pp. 47
Author(s):  
I Nyoman S. Nuitja ◽  
Silvia Wijaya
Keyword(s):  
Digestive Tract ◽  
Carapace Length ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Eretmochelys Imbricata ◽  
Digestive Organs

The digestive organs of two sea turdes, Chelonia mydas L. and Eretmochelys imbicata L. with purpose to analyse the digestive tract and other organs, also to preform their weight were carapace length relation skimp. The specimens of the two species were obtained from slaughtered houses in Benoa Bay, South Bali.

Serum Antileptospiral Agglutinins in Sea Turtles (Eretmochelys imbricata and Chelonia mydas) from the Gulf of Mexico

2021 ◽  
Vol 30 (4) ◽  
Author(s):  
Jonathan Pérez-Flores ◽  
Octavio López-Fernández ◽  
Daniel Atilano ◽  
Gabriela García-Besné ◽  
Pierre Charruau
Keyword(s):  
Gulf Of Mexico ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Eretmochelys Imbricata

scholarly journals Histologie comparée des fosses nasales de quelques Tortues marines (Dermochelys coriacea et Chelonia mydas) et d’eaux douces (Emys orbicularis et Pseudemys scripta) (Reptilia, Dermochelyidae, Cheloniidae, Emydidae)

1991 ◽  
Vol 61 (1) ◽  
pp. 51-61
Author(s):  
H. Saint-Girons
Keyword(s):  
Nasal Cavity ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Dermochelys Coriacea ◽  
Aquatic Life ◽  
Emys Orbicularis ◽  
Histological Studies ◽  
Long Time ◽  
Pseudemys Scripta

Comparative histological studies carried out on the nasal cavity of four species of turtles showed that the sea turtles have a more or less regressed olfactive epithelium compared to that of the Emydidae but that their vomeronasal epithelium is more developed. The location of the vomeronasal epithelium in the cavum also differs. The data suggest that the Dermochelyidae were adapted to a strict aquatic life a long time before the Cheloniidae.

scholarly journals Two hundred years after a commercial marine turtle fishery: the current status of marine turtles nesting in the Cayman Islands

Oryx ◽  
2001 ◽  
Vol 35 (2) ◽  
pp. 145-151 ◽  
Author(s):  
Jonathan J. Aiken ◽  
Brendan J. Godley ◽  
Annette C. Broderick ◽  
Timothy Austin ◽  
Gina Ebanks-Petrie ◽  
...  
Keyword(s):  
Chelonia Mydas ◽  
Marine Turtle ◽  
Current Status ◽  
Cayman Islands ◽  
Eretmochelys Imbricata ◽  
Marine Turtles ◽  
Mature Adults ◽  
Large Populations ◽  
Sexually Mature ◽  
Insight Into

AbstractLarge populations of marine turtles breeding in the Cayman Islands were drastically reduced in the early 1800s. However, marine turtle nesting still occurs in the islands. The present-day status of this nesting population provides insight into the conservation of marine turtles, a long-lived species. In 1998 and 1999, the first systematic survey of marine turtle nesting in the Cayman Islands found 38 nests on 22 beaches scattered through the three islands. Three species were found: the green Chelonia mydas, hawksbill Eretmochelys imbricata and loggerhead Caretta caretta turtles. Comparison with other rookeries suggests that the small number of sexually mature adults surviving Cayman's huge perturbations may be impeding population recovery. This shows the need to implement conservation measures prior to massive reductions in population size.

scholarly journals Lipid profiling suggests species specificity and minimal seasonal variation in Pacific Green and Hawksbill Turtle plasma

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253916
Author(s):  
Chelsea E. Clyde-Brockway ◽  
Christina R. Ferreira ◽  
Elizabeth A. Flaherty ◽  
Frank V. Paladino
Keyword(s):  
Sea Turtles ◽  
Multiple Reaction Monitoring ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Lipid Classes ◽  
Plasma Samples ◽  
Lipid Profiling ◽  
Eretmochelys Imbricata ◽  
Species Specific ◽  
Hawksbill Turtles

In this study, we applied multiple reaction monitoring (MRM)-profiling to explore the relative ion intensity of lipid classes in plasma samples from sea turtles in order to profile lipids relevant to sea turtle physiology and investigate how dynamic ocean environments affect these profiles. We collected plasma samples from foraging green (Chelonia mydas, n = 28) and hawksbill (Eretmochelys imbricata, n = 16) turtles live captured in North Pacific Costa Rica in 2017. From these samples, we identified 623 MRMs belonging to 10 lipid classes (sphingomyelin, phosphatidylcholine, free fatty acid, cholesteryl ester, phosphatidylserine, phosphatidylinositol, phosphatidylglycerol, phosphatidylethanolamine, ceramide, and triacylglyceride) and one metabolite group (acyl-carnitine) present in sea turtle plasma. The relative ion intensities of most lipids (80%) were consistent between species, across seasons, and were not correlated to body size or estimated sex. Of the differences we observed, the most pronounced was the differences in relative ion intensity between species. We identified 123 lipids that had species-specific relative ion intensities. While some of this variability is likely due to green and hawksbill turtles consuming different food items, we found indications of a phylogenetic component as well. Of these, we identified 47 lipids that varied by season, most belonging to the structural phospholipid classes. Overall, more lipids (n = 39) had higher relative ion intensity in the upwelling (colder) season compared to the non-upwelling season (n = 8). Further, we found more variability in hawksbill turtles than green turtles. Here, we provide the framework in which to apply future lipid profiling in the assessment of health, physiology, and behavior in endangered sea turtles.

scholarly journals Effectiveness of monitoring techniques employed to determine reproductive success of marine turtles in Cuba

2017 ◽  
Vol 43 (3) ◽  
pp. 548-556
Author(s):  
Julia Azanza-Ricardo ◽  
José Luis Gerhartz-Muro ◽  
Yanet Forneiro Martín-Viaña ◽  
Félix Moncada-Gavilán
Keyword(s):  
Cost Benefit ◽  
Chelonia Mydas ◽  
Eretmochelys Imbricata ◽  
Marine Turtles ◽  
Systematic Monitoring ◽  
Monitoring Frequency ◽  
Monitoring Strategies ◽  
Monitoring Effort ◽  
The Right ◽  
Nesting Beaches

Monitoring of nesting has been used globally to estimate the population size of marine turtles. Nevertheless, monitoring effort varies widely, for instance in Cuba, four different approaches are applied: nighttime systematic monitoring, daytime systematic monitoring, sporadic monitoring with nest verification, and sporadic monitoring with no verification. These variations imply that the amount and accuracy of data gathered and the quality of derived information, differ amongst the approaches. This paper assesses the effectiveness of the different methodologies used for determining the reproduction success of marine turtles in Cuba. Nighttime systematic monitoring is only carried out in one area, while sporadic monitoring with nest verification is the most used approach along the country. The proportion of the nesting season covered with monitoring personnel is low in most of the beaches and for all the three species (Chelonia mydas, Caretta caretta and Eretmochelys imbricata), although the species in the most critical situation is hawksbill. Significant differences were found between systematic and sporadic monitoring, which has important implications for the understanding of the nesting behavior, as the capacity to detect false and true crawls essentially depends on the monitoring frequency, according to our findings. Low detection capacity in sporadic monitoring hampered the development of efficiency assessments in all the nesting beaches. In summary, despite the effort carried out nationwide to monitor nesting populations that has even increased in the last three years, important gaps exists and new monitoring strategies are needed to guarantee the right information for the species is gathered, while adequate cost-benefit balance is achieved.

scholarly journals Chelonid Alphaherpesvirus 5 Prevalence and First Confirmed Case of Sea Turtle Fibropapillomatosis in Grenada, West Indies

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1490
Author(s):  
Amanda James ◽  
Annie Page-Karjian ◽  
Kate E. Charles ◽  
Jonnel Edwards ◽  
Christopher R. Gregory ◽  
...  
Keyword(s):  
West Indies ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Dermochelys Coriacea ◽  
Neoplastic Disease ◽  
Extrinsic Factors ◽  
Eretmochelys Imbricata ◽  
Specific Pcr ◽  
The Impact

Chelonid alphaherpesvirus 5 (ChHV5) is strongly associated with fibropapillomatosis, a neoplastic disease of sea turtles that can result in debilitation and mortality. The objectives of this study were to examine green (Chelonia mydas), hawksbill (Eretmochelys imbricata), and leatherback (Dermochelys coriacea) sea turtles in Grenada, West Indies, for fibropapillomatosis and to utilize ChHV5-specific PCR, degenerate herpesvirus PCR, and serology to non-invasively evaluate the prevalence of ChHV5 infection and exposure. One-hundred and sixty-seven turtles examined from 2017 to 2019 demonstrated no external fibropapilloma-like lesions and no amplification of ChHV5 DNA from whole blood or skin biopsies. An ELISA performed on serum detected ChHV5-specific IgY in 18/52 (34.6%) of green turtles tested. In 2020, an adult, female green turtle presented for necropsy from the inshore waters of Grenada with severe emaciation and cutaneous fibropapillomas. Multiple tumors tested positive for ChHV5 by qPCR, providing the first confirmed case of ChHV5-associated fibropapillomatosis in Grenada. These results indicate that active ChHV5 infection is rare, although viral exposure in green sea turtles is relatively high. The impact of fibropapillomatosis in Grenada is suggested to be low at the present time and further studies comparing host genetics and immunologic factors, as well as examination into extrinsic factors that may influence disease, are warranted.

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