scholarly journals Influence of incubation temperature on morphology and locomotion performance of Leatherback (Dermochelys coriacea) hatchlings

2010 ◽  
Vol 88 (4) ◽  
pp. 359-368 ◽  
Author(s):  
L. E. Mickelson ◽  
J. R. Downie
Keyword(s):  
Incubation Temperature ◽  
Carapace Width ◽  
Chelonia Mydas ◽  
Dermochelys Coriacea ◽  
Life History Stage ◽  
Terrestrial Locomotion ◽  
Green Turtles ◽  
Locomotion Speed ◽  
Incubation Temperatures ◽  
The Relationship

The journey of Leatherback ( Dermochelys coriacea (Vandelli, 1761)) hatchlings from nest to the sea is a vulnerable life-history stage. Studies have shown that nest incubation temperatures influence hatchling morphology and locomotor performance, which may affect hatchling fitness. We obtained incubation temperature profiles from 16 Leatherback nests in Tobago, West Indies, during the 2008 nesting season (March–June). There was significant variation among mean nest incubation temperatures, which had a significant influence on hatchling morphology. Using principal components analysis, we determined the morphological traits that explained the most variation among hatchlings, which allowed investigation of the relationship between hatchling morphology and terrestrial locomotion speed. Hatchlings with a narrower carapace width and longer flipper reach (produced at lower incubation temperatures) had significantly faster terrestrial speed and total run time than those with opposite characteristics (produced at higher incubation temperatures). Our results demonstrate that lower incubation temperatures produce hatchlings with traits that are significantly advantageous to terrestrial locomotion. These findings suggest that nest incubation temperature is important in determining hatchling fitness, as nest incubation temperature significantly influences hatchling morphology and locomotor capabilities. This study supplements related findings in Green Turtles ( Chelonia mydas (L., 1758)), but also illustrates some unique features in Leatherbacks.

Nest temperature´s influence on morphology of Dermochelys coriacea hatchlings incubated in hatcheries in Oaxaca, Mexico

2021 ◽  
Author(s):  
Jesús García-Grajales ◽  
Juan Francisco Meraz ◽  
José Luis Arcos García ◽  
Eustacio Ramírez Méndez
Keyword(s):  
Incubation Temperature ◽  
Carapace Width ◽  
Principal Component ◽  
Dermochelys Coriacea ◽  
Egg Mass ◽  
Natural Environments ◽  
Data Logger ◽  
Geometric Morphometric ◽  
Low Weight ◽  
Incubation Temperatures

The influence of nest incubation temperatures on the carapace shape and morphological traits of Dermochelys coriacea (Vandelli 1761) hatchlings incubated in two hatcheries of Oaxaca, Mexico was evaluated. This study was carried out from October 2016 through May 2017. On each beach, there are community groups consisting of volunteers without association with universities, that protect and relocate the nests to increase hatching success. In each translocated nest, a data logger was placed in the centre of the egg mass. Hatchlings were collected as they emerged from each nest. The carapaces of the hatchlings were photographed and subjected to geometric morphometric analysis; later, hatchlings were weighed and their bodies were measured. The mean temperature of 12 nests in each hatchery were recorded, with no significant differences between hatcheries. The principal component analysis (PCA) revealed an overlapping of the carapace shape under different duration of temperature. Temperature had a significant influence on hatchling morphology. Higher mean incubation temperatures produced hatchlings with low weight, smaller appendage; narrower carapace width and shorter flippers length. Lower mean incubation temperatures produced hatchlings that had greater weight, greater appendage width, wider carapace width and longer flipper length. Results indicate that the D. coriacea hatchlings incubated in hatcheries demonstrate morphology that varies in relation to nest incubation temperature in a similar way to hatchlings produced in natural environments.

scholarly journals Incubation temperatures, hatching success and congenital anomalies in green turtle nests from Guanahacabibes Peninsula, Cuba

2021 ◽  
Vol 4 (4) ◽  
pp. 321-330
Author(s):  
Randy Calderón Peña ◽  
Julia Azanza Ricardo
Keyword(s):  
Congenital Anomalies ◽  
Green Turtle ◽  
Thermal Tolerance ◽  
Elevated Temperatures ◽  
Hatching Success ◽  
Incubation Temperature ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Green Turtles ◽  
Incubation Temperatures

Elevated incubation temperatures of sea turtle nests decrease hatching success and alter the resulting hatchlings' morphology. There is an absence of studies assessing the relationships between temperature and hatching success in Cuba, even when they could improve understanding the limits of thermal tolerance in these species. This study evaluated the influence of incubation temperature on hatching success and phenotypic malformations in green turtle hatchlings (Chelonia mydas); and analyzed the temporal variation in hatching success on the studied beaches. In 48 green turtles nests distributed along two beaches, incubation temperature and hatching success were recorded between 2014 and 2019. Increasing incubation temperature caused a decrease in the hatching success and an increase in the frequency of supernumerary scutes. Despite the elevated temperatures (average > 30°C), hatching was higher than 80%. Significant differences in hatching success were only observed among seasons for nests in Antonio Beach (lower values in 2016 and 2019 compared to 2014).

scholarly journals Status of Marine Turtles in British Columbia Waters: A Reassessment

2004 ◽  
Vol 118 (1) ◽  
pp. 72 ◽  
Author(s):  
Donald F. McAlpine ◽  
Stan A. Orchard ◽  
Kelly A. Sendall ◽  
Rod Palm
Keyword(s):  
British Columbia ◽  
Marine Environment ◽  
Chelonia Mydas ◽  
Marine Turtle ◽  
Dermochelys Coriacea ◽  
Concerted Effort ◽  
Leatherback Turtles ◽  
Marine Turtles ◽  
Green Turtles

Marine turtles in British Columbia have previously been considered off course stragglers. Here we document 20 new reports for Green Turtles, Chelonia mydas, and Leatherback Turtles, Dermochelys coriacea, for the province. Until recently there had been no concerted effort to acquire data on marine turtle abundance or frequency off British Columbia. Observations presented here allow a reassessment of marine turtle status in British Columbia waters. We suggest Green Turtles and Leatherbacks should be considered rare vagrants and uncommon seasonal residents, respectively, off British Columbia and that they are a natural part of the British Columbia marine environment.

scholarly journals ASPEK MORFOLOGI, REPRODUKSI, DAN PERILAKU PENYU HIJAU (Chelonia mydas) Di PANTAI PANGUMBAHAN, KABUPATEN SUKABUMI, JAWA BARAT

2017 ◽  
Vol 3 (2) ◽  
pp. 93
Author(s):  
Adriani Sri Nastiti Krismono ◽  
Achmad Fitriyanto ◽  
Ngurah Nyoman Wiadnyana
Keyword(s):  
Green Turtle ◽  
Carapace Width ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Stratified Sampling ◽  
Hatching Rate ◽  
Brood Stock ◽  
Green Turtles ◽  
And Behavior ◽  
Nesting Season

Penyu hijau (Chelonia mydas) termasuk dalam phylum Chordata dan famili Cheloniideae. Jumlah penyu hijau yang singgah ke Pantai Pangumbahan untuk bertelur semakin menurun karena tidak terkendalinya masyarakat melakukan penangkapan induk penyu dan pengambilan telurnya. Penelitian tentang morfologi, reproduksi, dan perilaku penyu hijau sebagai salah satu dasar pengelolaan telah dilakukan di Pantai Pangumbahan pada bulan Agustus 2008. Metode penelitian yang digunakan pengambilan contoh berstrata. Penelitian ini dilaksanakan pada bulan Agustus 2008 (pada saat puncak peneluran). Parameter yang diamati antara lain ukuran penyu dari 89 ekor jumlah penyu bersarang, jumlah telur dan tingkat penetasan, serta perilaku pada saat penyu bertelur. Hasil penelitian menunjukan yang diamati diperoleh panjang karapas berkisar antara 97-15 cm dan lebar karapas 83,5-108 cm, jumlah penyu naik ke pantai 89 ekor dan penyu yang bertelur 39 ekor. Jumlah telur penyu hijau berhasil dihitung 80-105 butir per induk penyu. Bulan Agustus 2008 merupakan puncak musim peneluran. Kegiatan peneluran penyu hijau dibagi menjadi enam tahap. Upaya konservasi yang sudah dilakukan adalah penetasan telur penyu semi alami, restocking tukik, dan menjaga keamanan sarang telur penyu. Green turtles (Chelonia mydas), including the phylum Chordata and families Cheloniideae. The number of green turtles come to lay eggs Pangumbahan beach to decline because of increasingly unmanageable public do making arrests turtles brood stock and their eggs. Research on the morphology, reproduction, and behavior of green turtles as one of the basic management has been conducted on the Pangumbahan Beach in August 2008. The method used stratified sampling. The experiment was conducted in August 2008 (at the peak of nesting). Other parameters were observed between the size of the 89 tail number of turtles nesting turtles, the number of eggs and hatching rate and behavior during turtle nesting. Results obtained showed that the observed length ranges from 97- 15 cm carapace and carapace width from 83.5-108 cm, the number went up to the beach 89 sea turtle and sea turtle nesting tail as much as 39 tails. The number of green turtle eggs had counted as many as 80-105 eggs per turtles brood stock. Month August 2008 is the peak nesting season of green turtle nesting activities are divided into six stages. Conservation efforts that have been done is semi natural turtle hatchery, restocking hatchlings, and nest of turtle eggs to maintain security.

Estimating past and present sex ratios of sea turtles in Suriname

1996 ◽  
Vol 74 (2) ◽  
pp. 267-277 ◽  
Author(s):  
Matthew H. Godfrey ◽  
N. Mrosovsky ◽  
R. Barreto
Keyword(s):  
Sea Turtles ◽  
Sex Ratios ◽  
Negative Relationship ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Dermochelys Coriacea ◽  
Green Turtles ◽  
Sand Temperature ◽  
Turtle Conservation ◽  
Sea Turtle Conservation

Leatherback (Dermochelys coriacea) and green (Chelonia mydas) sea turtles in Suriname lay eggs over several months of the year. During this nesting season, changes in rainfall produce changes in sand temperature, which in turn influence the sexual differentiation of incubating sea turtle embryos. The overall sex ratio of leatherback and green sea turtle hatchlings produced at Matapica beach in Suriname was investigated. Estimates of the sex ratios of these turtles in 1993 (green turtles 63.8% female, leatherbacks 69.4% female) were roughly 10% more female-biased than those from an earlier study in 1982. For both species, a significant negative relationship was found between monthly rainfall and monthly sex ratios. Using this relationship and data on rainfall in the past, it was possible to estimate overall sex ratios for an additional 12 years. These estimates varied considerably among different years, ranging from 20 to 90% female in the case of green turtles. Nevertheless, males tended to be produced primarily in April and May, while some females were produced in all months. Such seasonal patterns of production of turtles of different sexes have implications for sea turtle conservation programs that involve manipulating or harvesting eggs.

Reproductive investment by green turtles nesting on Ascension Island

1993 ◽  
Vol 71 (6) ◽  
pp. 1098-1103 ◽  
Author(s):  
Graeme C. Hays ◽  
Colin R. Adams ◽  
John R. Speakman
Keyword(s):  
Egg Size ◽  
Reproductive Investment ◽  
Chelonia Mydas ◽  
The Body ◽  
Adult Size ◽  
Green Turtles ◽  
Female Body Size ◽  
Ascension Island ◽  
Egg Chamber ◽  
The Relationship

Clutch sizes and egg sizes were measured for green turtles (Chelonia mydas) nesting on Ascension Island in the South Atlantic (7°57′S, 14 °22′W) in 1992. The mean number of eggs per clutch was 127.5 (SD = 22.9; n = 46 clutches). The number of eggs per clutch increased in larger turtles and declined as the nesting season progressed. Mean egg size was 45.5 mm (SD = 1.45 mm; n = 47 clutches). Three turtles laid significantly smaller eggs than the rest of the sample. When these three clutches were removed from the analysis, mean egg size increased in larger turtles. When the effect of female body size was removed there was no relationship between the number and size of the eggs in a clutch. The depth from the top to the bottom of the egg chamber, the depth from the top of the egg chamber to the topmost egg, and the depth of the body pit were all independent of adult size. Egg size varied systematically within clutches, the largest eggs being laid first and the smallest eggs last. This intraclutch variation in egg size had important consequences for the calculated gradient of the relationship between egg size and adult size.

scholarly journals Polyandry pays off: The effects of multiple mating and number of fathers on morphological traits and survival in clutches of nesting green turtles at Tortuguero

2014 ◽  
Author(s):  
Alonzo Alfaro-Núñez ◽  
Michael P. Jensen ◽  
F. Alberto Abreu-Grobois
Keyword(s):  
Morphological Traits ◽  
Incubation Temperature ◽  
Multiple Mating ◽  
Chelonia Mydas ◽  
Environmental Variable ◽  
Green Turtles ◽  
Exact Number ◽  
Paternal Contribution ◽  
Emergence Success ◽  
Significant Difference

Despite the long debate of whether or not multiple mating benefits the offspring, studies still show contradicting results. Multiple mating takes time and energy. Thus, if females fertilize their eggs with a single mating, why to mate more than once? We investigated and inferred paternal identity and number of sires in 12 clutches (240 hatchlings) of green turtles (Chelonia mydas) nests at Tortuguero, Costa Rica. Paternal alleles were inferred through comparison of maternal and hatchling genotypes, and indicated multiple paternity in at least 11 of the clutches (92%). The inferred average number of fathers was three (ranging from 1 to 5). This in returns suggests that most females successfully got fecundated by at least three males. Moreover, regression analyses were used to investigate for correlation of inferred clutch paternity with morphological traits of hatchlings fitness (emergence success, length, weight and crawling speed); and size of the mother; and an environmental variable (incubation temperature). We suggest and propose two different comparative approaches for evaluating morphological traits and clutch paternity, in order to infer greater offspring survival. First, clutches coded by the exact number of fathers and second by the exact paternal contribution (fathers who gives greater proportion of the offspring per nest). We found significant differences (P < 0.05) in clutches coded by the exact number of fathers for all morphological traits, where a tendency of higher values in offspring sired by two to three fathers was found. The second approach analysing the paternal contribution showed no significant difference (P > 0.05) for any of the traits. The main conclusion is that multiple mating analysed by the exact number of inferred fathers significantly affects the survival of the offspring regardless of morphological trait measured.

Low male production at the world’s largest green turtle rookery

2020 ◽  
Vol 653 ◽  
pp. 181-190
Author(s):  
DT Booth ◽  
A Dunstan ◽  
I Bell ◽  
R Reina ◽  
J Tedeschi
Keyword(s):  
Green Turtle ◽  
Hatching Success ◽  
Incubation Temperature ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Green Turtles ◽  
Nesting Site ◽  
Almost All ◽  
Monthly Variations ◽  
Nesting Season

Because the sex of all sea turtle hatchlings is determined by incubation temperature, with low temperatures producing mainly males and high temperatures producing mainly females, sea turtle populations worldwide are threatened by feminization of hatchlings due to increases in global temperature. Data obtained by laparoscopic sexing of immature individuals captured from a major feeding ground indicates that over several decades there has been little recruitment of males into the northern Great Barrier Reef (nGBR) green turtle Chelonia mydas population, one of the largest sea turtle populations in the world. Over 2 nesting seasons, we measured nest temperatures at Raine Island, the most important nesting site for this nGBR population, and predicted that almost all nests would have produced all female hatchlings. The few nests that produced some male hatchlings were constructed at the very end of the nesting season, and these nests had the lowest hatching success. Taking into account monthly variations in nest construction, hatching success, and hatchling sex ratio, we estimate that over an entire nesting season only 0.7% of hatchlings produced are male. Hence, we conclude that the nGBR population of green turtles has likely recruited very few males in recent years.

Incubation temperature, energy expenditure and hatchling size in the green turtle (Chelonia mydas), a species with temperature-sensitive sex determination

2001 ◽  
Vol 49 (4) ◽  
pp. 389 ◽  
Author(s):  
David T. Booth ◽  
Katherine Astill
Keyword(s):  
Oxygen Consumption ◽  
Production Cost ◽  
Incubation Temperature ◽  
Chelonia Mydas ◽  
Temperature Sensitive ◽  
Barrier Reef ◽  
Body Dimensions ◽  
Green Turtles ◽  
The Difference ◽  
Hatchling Size

Eggs from the Heron Island, Great Barrier Reef, nesting population of green turtles (Chelonia mydas) were incubated at all-male-determining (26˚C) and all-female-determining (30˚C) temperatures. Oxygen consumption and embryonic growth were monitored throughout incubation, and hatchling masses and body dimensions were measured from both temperatures. Eggs hatched after 79 and 53 days incubation at 26˚C and 30˚C respectively. Oxygen consumption at both temperatures increased to a peak several days before hatching, a pattern typical of turtle embryos, and the rate of oxygen was higher at 30˚C than 26˚C. The total amount of energy consumed during incubation, and hatchling dimensions, were similar at both temperatures, but hatchlings from 26˚C had larger mass, larger yolk-free mass and smaller residual yolks than hatchlings from 30˚C. Because of the difference in mass of hatchlings, hatchlings from 30˚C had a higher production cost.

The Southern Oscillation Regulates the Annual Numbers of Green Turtles (Chelonia-Mydas) Breeding Around Northern Australia

1988 ◽  
Vol 15 (2) ◽  
pp. 157 ◽  
Author(s):  
CJ Limpus ◽  
N Nicholls
Keyword(s):  
Southern Oscillation ◽  
Chelonia Mydas ◽  
Northern Australia ◽  
Biological Impact ◽  
Turtle Species ◽  
Green Turtles ◽  
Interannual Fluctuations ◽  
The Impact ◽  
The Relationship ◽  
The Tropical Pacific

The green turtle (Chelonia mydas) is one of six turtle species which breeds around northern Australia and Indonesia. The number of green turtles observed nesting varies substantially from year to year. The interannual fluctuations in the number of nesting turtles are in phase at widely separated rookeries. They are also correlated with an index of the Southern Oscillation, a coherent pattern of atmospheric pressure, temperature and rainfall fluctuations which dominates the interannual variability of the climate of the tropical Pacific. Major fluctuations in the numbers of turtles breeding occur two years after major fluctuations in the Southern Oscillation. The relationship is strong enough to be useful in predicting, two years in advance, the numbers of green turtles breeding in Great Barrier Reef rookeries. This is the first study to report a biological impact of the Southern Oscillation that allows such a long-range prediction of the impact.

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