Sex Ratio of Green Turtle (Chelonia mydas) Hatchlings at Sugözü, Turkey: Higher Accuracy with Pivotal Incubation Duration

2016 ◽  
Vol 15 (1) ◽  
pp. 102-108 ◽  
Author(s):  
Onur Candan ◽  
Dürdane Kolankaya
Keyword(s):  
Sex Ratio ◽  
Green Turtle ◽  
Chelonia Mydas ◽  
Incubation Duration

scholarly journals The value of long-term, community-based monitoring of marine turtle nesting: a study in the Lamu archipelago, Kenya

Oryx ◽  
2017 ◽  
Vol 53 (1) ◽  
pp. 71-80 ◽  
Author(s):  
Mike I. Olendo ◽  
Gladys M. Okemwa ◽  
Cosmas N. Munga ◽  
Lilian K. Mulupi ◽  
Lily D. Mwasi ◽  
...  
Keyword(s):  
Green Turtle ◽  
Low Cost ◽  
Western Indian Ocean ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Marine Turtle ◽  
Olive Ridley ◽  
Community Based ◽  
Green Turtles ◽  
Incubation Duration

AbstractMonitoring of nesting beaches is often the only feasible and low-cost approach for assessing sea turtle populations. We investigated spatio-temporal patterns of sea turtle nesting activity monitored over 17 successive years in the Lamu archipelago, Kenya. Community-based patrols were conducted on 26 stretches of beach clustered in five major locations. A total of 2,021 nests were recorded: 1,971 (97.5%) green turtleChelonia mydasnests, 31 (1.5%) hawksbillEretmochelys imbricatanests, 8 (0.4%) olive ridleyLepidochelys olivaceanests and 11 (0.5%) unidentified nests. Nesting occurred year-round, increasing during March–July, when 74% of nests were recorded. A stable trend in mean annual nesting densities was observed in all locations. Mean clutch sizes were 117.7 ± SE 1 eggs (range 20–189) for green turtles, 103±SE 6 eggs (range 37–150) for hawksbill turtles, and 103±SE 6 eggs (range 80–133) for olive ridley turtles. Curved carapace length for green turtles was 65–125 cm, and mean annual incubation duration was 55.5±SE 0.05 days. The mean incubation duration for green turtle nests differed significantly between months and seasons but not locations. The hatching success (pooled data) was 81.3% (n = 1,841) and was higher for in situ nests (81.0±SE 1.5%) compared to relocated nests (77.8±SE 1.4%). The results highlight the important contribution of community-based monitoring in Kenya to sustaining the sea turtle populations of the Western Indian Ocean region.

Natural temperature regimes for loggerhead and green turtle nests in the eastern Mediterranean

1998 ◽  
Vol 76 (4) ◽  
pp. 723-729 ◽  
Author(s):  
Y Kaska ◽  
R Downie ◽  
R Tippett ◽  
R W Furness
Keyword(s):  
Sex Ratio ◽  
Incubation Period ◽  
Green Turtle ◽  
Eastern Mediterranean ◽  
Loggerhead Turtle ◽  
Chelonia Mydas ◽  
Maximum Temperature ◽  
Diel Cycles ◽  
Mean Temperature ◽  
The Mean

Temperatures of green turtle (Chelonia mydas) and loggerhead turtle (Caretta caretta) nests on the beaches of northern Cyprus and Turkey were examined. Electronic continuous-temperature recorders programmed by computer were placed at the top, middle, and bottom of the nests. The sex of 3-7 hatchlings from each level was determined from gonadal histology. The maximum temperature increase during the incubation period was 9.6oC for both species. The mean temperature during the middle third of the incubation period is a good indicator of the sex ratio of the clutch. The percentage of female embryos increased with temperature, 50% being female at 29°C. The mean temperature over the entire incubation period is not a good indicator of sex ratio but can be used to predict the duration of incubation period. The temperature differences within the clutch were larger in loggerhead than in green turtle nests. Eggs at the top of the nest experienced generally warmer (up to 1.4°C) conditions than eggs at the bottom of the same nest, and this caused variation in sex ratio within nests. Over all nests, the sex ratio (percent female) of hatchlings was 91% at the top, 83% at the middle, and 69% at the bottom. There was considerable interbeach thermal variation. Marked diel cycles of up to 1.5°C were detected in loggerhead turtle nests but not in the deeper nests of green turtles.

scholarly journals Hatchling sex ratio, body weight and nest parameters for Chelonia mydas nesting on Sugözü beaches (Turkey)

2014 ◽  
Vol 37 (2) ◽  
pp. 177-182
Author(s):  
Ç Kılıç ◽  
◽  
O. Candan ◽  
Keyword(s):  
Body Weight ◽  
Sex Ratio ◽  
Incubation Period ◽  
Green Turtle ◽  
Chelonia Mydas ◽  
Nest Temperature ◽  
Apparent Relationship ◽  
Embryo Sex ◽  
Female Bias ◽  
The Relationship

We investigated the relationship between nest parameters, hatchling body mass, and sex ratio of green turtle, Chelonia mydas, embryos and hatchlings at the temperate nesting rookery of Sugözü Beach (Adana–Turkey). Mean nest temperature and distance from the sea were correlated, while mean nest temperature and incubation period were inversely related. There was no apparent relationship between incubation period and hatchling mass. Hatchling and embryo sex ratios, determined by histological examination, showed a 70.5% and 93.5% female bias, respectively. There was no correlation between sex and body weight of hatchlings,

CONDITIONS OF HILLING HABITAT OF CHELONIA MYDAS (GREEN TURTLE) IN PANGUMBAHAN BEACH UJUNG GENTENG, SUKABUMI SELATAN

2019 ◽  
Vol 1 (02) ◽  
pp. 64-67
Author(s):  
Meilisha Putri Pertiwi ◽  
Suci Siti Lathifah
Keyword(s):  
Data Collection ◽  
Surface Temperature ◽  
Green Turtle ◽  
Data Retrieval ◽  
Distribution Patterns ◽  
Chelonia Mydas ◽  
Nesting Habitat ◽  
Beach Width ◽  
The Many ◽  
Pandanus Tectorius

Research on the condition of the nesting habitat of Chelonia mydas (green turtle) in Pangumbahan Beach, Ujung Genteng, South Sukabumi has been carried out. Data retrieval is done 6 times for 2 days, 27-28 November 2017 at 3 observation stations. The abiotic parameters measured include surface temperature and depth of 50 cm, surface humidity and depth of 50 cm, beach width, beach slope, and the size of sand grains. While the biotic parameters measured were density, relative density, the frequency of attendance, and distribution patterns of Pandanus tectorius (sea pandanus) vegetation. Based on the results of data processing, the biophysical conditions in Pangumbahan Beach are still suitable for the Chelonia mydas nesting habitat. It also got clear evidence of the many Chelonia mydas landings during the data collection.

Structural description of sea turtle fibropapilloma

2020 ◽  
Vol 13 (3) ◽  
pp. 585-591
Author(s):  
Luana Melo ◽  
Isabel Velasco ◽  
Julia Aquino ◽  
Rosangela Rodrigues ◽  
Edris Lopes ◽  
...  
Keyword(s):  
Green Turtle ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Tumor Formation ◽  
Neoplastic Disease ◽  
Structural Description ◽  
Chemical Carcinogens ◽  
Epidermal Proliferation ◽  
Turtle Population ◽  
Bulky Mass

Fibropapillomatosis is a neoplastic disease that affects sea turtles. It is characterized by multiple papillomas, fibropapillomas and cutaneous and/or visceral fibromas. Although its etiology has not been fully elucidated, it is known that there is a strong involvement of an alpha - herpesvirus, but the influence of other factors such as parasites, genetics, chemical carcinogens, contaminants, immunosuppression and ultraviolet radiation may be important in the disease, being pointed out as one of the main causes of a reduction in the green turtle population. Thus, the objective of this article was to describe the morphology of cutaneous fibropapillomas found in specimens of the green turtle (Chelonia mydas), using light and scanning electron microscopy in order to contribute to the mechanism of tumor formation. Microscopically, it presented hyperplastic stromal proliferation and epidermal proliferation with hyperkeratosis. The bulky mass was coated with keratin, with some keratinocyte invaginations, that allowed the keratin to infiltrate from the epidermis into the dermis, forming large keratinized circular spirals. Another fact that we observed was the influence of the inflammation of the tumors caused by ectoparasites.

Discovery of a Major East Pacific Green Turtle (Chelonia mydas) Nesting Population in Northwest Costa Rica

2018 ◽  
Vol 17 (2) ◽  
pp. 169
Author(s):  
Luis G. Fonseca ◽  
Pilar Santidrián Tomillo ◽  
Wilbert N. Villachica ◽  
Wagner M. Quirós ◽  
Marta Pesquero ◽  
...  
Keyword(s):  
Costa Rica ◽  
Green Turtle ◽  
Chelonia Mydas ◽  
East Pacific

The Effect of Invertebrate Infestation on Green Turtle (Chelonia mydas) Nests on Kazanlı Beach, Mersın, Turkey

2020 ◽  
Vol 27 (5) ◽  
pp. 245-256
Author(s):  
Cemil Aymak ◽  
Aşkın Hasan Uçar ◽  
Yusuf Katılmış ◽  
Eyup Başkale ◽  
Serap Ergene
Keyword(s):  
Green Turtle ◽  
Hatching Success ◽  
Negative Relationship ◽  
Chelonia Mydas ◽  
Sea Turtle ◽  
Faunal Composition ◽  
Independent Variables ◽  
Invertebrate Species ◽  
First Time ◽  
Nesting Season

In this study invertebrate infestation in green turtle (Chelonia mydas) nests were recorded for the first time for Kazanlı beach, Mersin, Turkey. For this aim, in 2006 nesting season, 294 natural intact green turtle nests were sampled to examine their contents and invertebrate infestation was found in 76 (25.85% of the total sampling green turtle nests). These infested nests were examined in terms of the invertebrate faunal composition. The specimens found in the green sea turtle nests were identified to order, family or genus levels and they were represented in 5 orders. These invertebrate groups are Elater sp. larvae (Elateridae; Coleoptera), Pimelia sp. larvae (Tenebrionidae; Coleoptera), Enchytraeidae (Oligochaeta), Cyrptostigmata (Acari), Oniscidae (Isopoda), Formicidae (Hymenoptera). Elater sp. was the most common invertebrate group in the green turtle nests. According to student t test, we found statistically significant differences between 7 independent variables and invertebrate species presence. Furthermore, logistic regression analysis explained that there is a negative relationship between hatching success rate and invertebrate species presence.

Pulmonary Blood Flow at Rest and during Swimming in the Green Turtle, Chelonia mydas

1992 ◽  
Vol 65 (2) ◽  
pp. 287-310 ◽  
Author(s):  
Nigel H. West ◽  
Patrick J. Butler ◽  
Richard M. Bevan
Keyword(s):  
Blood Flow ◽  
Green Turtle ◽  
Pulmonary Blood Flow ◽  
Chelonia Mydas
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