Change in body mass associated with long-term fasting in a marine reptile: the case of green turtles (Chelonia mydas) at Ascension Island

2002 ◽  
Vol 80 (7) ◽  
pp. 1299-1302 ◽  
Author(s):  
Graeme C Hays ◽  
Annette C Broderick ◽  
Fiona Glen ◽  
Brendan J Godley
Keyword(s):  
Mass Loss ◽  
Body Mass ◽  
Chelonia Mydas ◽  
Green Sea Turtles ◽  
Green Turtles ◽  
Ascension Island ◽  
Pinniped Species ◽  
Marine Reptile ◽  
Nesting Season

Female green sea turtles (Chelonia mydas) nesting at Ascension Island (7°57'S, 14°22'W) in the middle of the Atlantic Ocean had a mean body mass (post oviposition) of 166.3 kg (range 107.5–243.5 kg, n = 119). Individuals lost mass slowly during the nesting season (mean mass loss 0.22 kg·d–1, n = 14 individuals weighed more than once). Gut-content analysis and behavioural observations indicated a lack of feeding. Females of equivalent-sized pinniped species that also do not feed while reproducing (nursing pups) on islands lose mass about 17 times faster. This comparatively low rate of mass loss by green turtles probably reflects their ectothermic nature and, consequently, their low metabolic rate. We estimate that a female turtle would lose only 19% of her body mass during the 143-day, 4400-km round trip from Brazil if she did not eat, laid 3 clutches of eggs, and lost 0.22 kg·d–1.

scholarly journals Foraging Habits of Green Sea Turtles (Chelonia mydas) in the Northwestern Gulf of Mexico

2021 ◽  
Vol 8 ◽  
Author(s):  
Lyndsey N. Howell ◽  
Donna J. Shaver
Keyword(s):  
Gulf Of Mexico ◽  
Green Turtle ◽  
Carapace Length ◽  
Foraging Ecology ◽  
Chelonia Mydas ◽  
Foraging Habitat ◽  
Seagrass Meadows ◽  
Green Sea Turtles ◽  
Green Turtles

Knowledge of green turtle (Chelonia mydas) foraging ecology in the northwestern Gulf of Mexico (GOM) is critical as populations begin to recover from heavy harvesting in prior centuries. We present a comprehensive long-term assessment of green turtle diets from carcasses salvaged from 1987 to 2014 along the Texas coast. Digestive tract contents were examined from 420 green turtles, ranging in size from 7.3 to 86.0 cm in straight carapace length (SCLmax). Green turtles as small as 16.2 cm SCLmax recruit from the oceanic environment to nearshore foraging habitat in the northwestern GOM and consume macroalgae principally. A successive shift in diet and habitat to inshore seagrasses was evident by the seagrass-dominated diet of turtles larger than 30 cm SCLmax. Animal matter remained a frequently ingested diet item suggesting these immature green turtles are better classified as omnivores. The overall evidence indicates that Texas’ recovering green turtle assemblage is exhibiting foraging plasticity within seagrass meadows changing species composition and density.

Monitoring green sea turtles in Brazilian feeding areas: relating body condition index to fibropapillomatosis prevalence

2019 ◽  
Vol 99 (8) ◽  
pp. 1879-1887 ◽  
Author(s):  
Silmara Rossi ◽  
Angélica María Sánchez-Sarmiento ◽  
Robson Guimarães dos Santos ◽  
Roberta Ramblas Zamana ◽  
Fabiola Eloisa Setim Prioste ◽  
...  
Keyword(s):  
Body Mass ◽  
Body Condition ◽  
Sea Turtles ◽  
Chelonia Mydas ◽  
Condition Index ◽  
Sea Turtle ◽  
The Body ◽  
Body Condition Index ◽  
Green Sea Turtles ◽  
Green Turtles

AbstractFibropapillomatosis (FP) can be an important conservation threat to green sea turtles (Chelonia mydas) due to its widespread distribution and complex aetiology. Thus, understanding the impacts of FP in sea turtle populations is a research priority towards conservation efforts. The body condition index (BCI), based on straight carapace length (SCL) and body mass (BM), is an accurate indicator of body-nutritional condition that can be used in routine green turtle health evaluations. This study aimed to compare BCI in FP-free (N = 369) and FP-affected (N = 518) green turtles from Brazilian feeding areas. Body condition indices were evaluated in terms of the South-west Atlantic Fibropapillomatosis Score – FPSSWA (mild, moderate and severe), study sites (five Brazilian states), origin (intentional capture, fishery, stranding and afloat) and sex (when known). Curved and straight carapace lengths, and body mass were recorded in order to calculate BCI. Statistical analysis revealed significant differences in BCI among green turtles from different study areas (P = 0.02), and lower BCI values in FP-free than in FP-positive individuals (P < 0.0001). With regards to origin, the highest BCI was found in the intentional capture group (N = 245; 1.47 ± 0.16), followed by fishery (N = 180; 1.46 ± 0.20). Analysis according to sex revealed a higher mean BCI among females than males (P < 0.017). This study provides relevant data on the health and nutritional status of green turtles along the Brazilian coast, in important feeding areas for this species.

scholarly journals Efficiency of island homing by sea turtles under multimodal navigating strategies

2018 ◽  
Author(s):  
K. J. Painter ◽  
A. Z. Plochocka
Keyword(s):  
Charles Darwin ◽  
Sea Turtles ◽  
Paradigm Case ◽  
Agent Based ◽  
Green Sea Turtles ◽  
Green Turtles ◽  
Guidance Cues ◽  
Animal Navigation ◽  
Ascension Island ◽  
Odour Plumes

AbstractA dot in the vastness of the Atlantic, Ascension Island remains a lifelong goal for the green sea turtles that hatched there, returning as adults every three or four years to nest. This navigating puzzle was brought to the scientific community’s attention by Charles Darwin and remains a topic of considerable speculation. Various cues have been suggested, with orientation to geomagnetic field elements and following odour plumes to their island source among the most compelling. Via a comprehensivein silicoinvestigation we test the hypothesis that multimodal cue following, in which turtles utilise multiple guidance cues, is the most effective strategy. Specifically, we combine agent-based and continuous-level modelling to simulate displaced virtual turtles as they attempt to return to the island. Our analysis shows how population homing efficiency improves as the number of utilised cues is increased, even under “extreme” scenarios where the overall strength of navigating information decreases. Beyond the paradigm case of green turtles returning to Ascension Island, we believe this could commonly apply throughout animal navigation.

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.

Long-term trends in abundance of green sea turtles (Chelonia mydas) assessed by non-lethal capture rates in a coastal fishery

2017 ◽  
Vol 79 ◽  
pp. 254-264 ◽  
Author(s):  
Berenice M.G. Silva ◽  
Leandro Bugoni ◽  
Bruno A.D.L. Almeida ◽  
Bruno B. Giffoni ◽  
Fernando S. Alvarenga ◽  
...  
Keyword(s):  
Sea Turtles ◽  
Chelonia Mydas ◽  
Green Sea Turtles ◽  
Long Term Trends ◽  
Capture Rates

scholarly journals Inter- and Intra-Beach Thermal Variation for Green Turtle Nests on Ascension Island, South Atlantic

1995 ◽  
Vol 75 (2) ◽  
pp. 405-411 ◽  
Author(s):  
Graeme C. Hays ◽  
Colin R. Adams ◽  
Jeanne A. Mortimer ◽  
J.R. Speakman
Keyword(s):  
Green Turtle ◽  
Chelonia Mydas ◽  
South Atlantic ◽  
Nest Temperature ◽  
Long Beach ◽  
Thermal Variation ◽  
Green Turtles ◽  
North East ◽  
Ascension Island ◽  
East Bay

Nest temperatures for green turtles (Chelonia mydas) nesting on Ascension Island, South Atlantic (7°57'S 14°22'W), were examined. Temperature probes were placed into nests on two beaches, Long Beach (26 nests) and North East Bay (8 nests). Within these beaches there was relatively little thermal variation (SD of nest temperature was 0.32°C for Long Beach and 0.30°C for North East Bay). To examine inter-beach thermal variation temperature probes were buried at 55 cm on 12 beaches. Inter-beach thermal variation was large and was related to the beach albedo with the darkest beach (albedo, 016) being 4.2°C warmer than the lightest coloured beach (albedo, 0.73).

Long-term growth and survival dynamics of green turtles (Chelonia mydas) at an isolated tropical archipelago in Brazil

2014 ◽  
Vol 162 (1) ◽  
pp. 111-122 ◽  
Author(s):  
Liliana P. Colman ◽  
Ana Rita C. Patrício ◽  
Andrew McGowan ◽  
Armando J. B. Santos ◽  
Maria Ângela Marcovaldi ◽  
...  
Keyword(s):  
Chelonia Mydas ◽  
Growth And Survival ◽  
Green Turtles

scholarly journals Activation of the central melanocortin system in rats persistently reduces body and fat mass independently of caloric reduction

2018 ◽  
Vol 96 (3) ◽  
pp. 308-312 ◽  
Author(s):  
Isabelle Côté ◽  
Sara M. Green ◽  
Drake Morgan ◽  
Christy S. Carter ◽  
Nihal Tümer ◽  
...  
Keyword(s):  
Food Intake ◽  
Mass Loss ◽  
Body Mass ◽  
Fat Mass ◽  
Control Level ◽  
Mass Ratio ◽  
Melanocortin System ◽  
Body Mass Loss ◽  
Fat Mass Ratio

Recent evidence indicate that melanotan II (MTII) reduces body mass independently of caloric reduction. Because MTII induces a transient hypophagia, caloric reduction is still considered a primary mechanism for MTII-mediated body mass loss. To examine the contribution of caloric reduction to long-term body mass loss in response to MTII, we centrally infused MTII or vehicle in ad libitum fed (MTII and Control) animals in comparison with a group of animals that were pair-fed (PF) to the MTII group. Food intake and body mass were recorded daily, and body composition was assessed biweekly. The present study demonstrates that central MTII-mediated body mass loss is only partially mediated by caloric restriction, and the long-term body mass loss is independent of the initial hypophagia. More importantly, central MTII administration induced a rapid but sustained fat mass loss, independently of caloric reduction. MTII-treated animals preserved their lean/fat mass ratio throughout the study, whereas PF animals underwent a transient reduction of lean/fat mass ratio that was only normalized when food intake returned to Control level. In summary, it can be concluded that activation of the central melanocortin system in rats persistently reduces body and fat mass independently of caloric reduction.

Increase of sea turtles stranding records in Rhodes Island (eastern Mediterranean Sea): update of a long-term survey

2013 ◽  
Vol 93 (7) ◽  
pp. 1991-2002 ◽  
Author(s):  
Maria Corsini-Foka ◽  
Gerasimos Kondylatos ◽  
Elias Santorinios
Keyword(s):  
Eastern Mediterranean ◽  
Sea Turtles ◽  
Loggerhead Turtle ◽  
Aegean Sea ◽  
Chelonia Mydas ◽  
Caretta Caretta ◽  
Fishing Ground ◽  
Green Turtles ◽  
Loggerhead Turtles

A total of 209 strandings of sea turtles (152 loggerhead turtles Caretta caretta, 42 green turtles Chelonia mydas, 15 unidentified) were recorded during the period 1984–2011 along the coasts of Rhodes (Aegean Sea, Greece). The proportion of dead to live individuals was different in the two species. Stranded Caretta caretta were larger than Chelonia mydas. The size range of stranded green turtles, usually juveniles, appeared to increase since 2000, including the largest specimens ever observed in Greek waters. For both species, a tendency to strand more frequently on the west coast of the island, along fishing ground areas, was noted. The higher incidence of loggerhead turtle strandings was observed in summer, while more green turtle strandings were documented in winter. Factors involved in the increased trend of stranding records of both species, along with the acceleration of this phenomenon in the last decade, are discussed. Data from Rhodes provide evidence that human activities detrimentally affect mainly larger-sized loggerhead turtles living in shallow waters.

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