Egg viability of green turtles nesting on Raine Island, the world’s largest nesting aggregation of green turtles

The viability of Parascaris equorum eggs was studied in two experimental pilot-scale high-rate algal ponds (HRAPs) working in parallel with 4 and 10 days hydraulic retention time respectively. Semi-permeable bags of cellulose (15000 daltons pore size) were used to study the effect of physico-chemical conditions on the survival of these helminth eggs. Three thousand eggs were used in each bag. Replicates of these bags were submerged for 4 and 10 days in the HRAPs and egg viability was compared with that in control bags submerged in sterile water. After 4 days exposure, 60% reduction in viability was achieved, reaching 90% after 10 days, much higher than the 16% and 25% found in the control bags for 4 and 10 days respectively. Ionic conditions of the HRAP may have been responsible for up to 50–60% of the egg mortality, suggesting that mortality due to the ionic environment could be more important than physical retention and other potential removal factors.

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Effects of El Niño Southern Oscillation and local ocean temperature on the reproductive output of green turtles (Chelonia mydas) nesting at Tortuguero, Costa Rica

Marine Biology ◽

10.1007/s00227-020-03749-z ◽

2020 ◽

Vol 167 (9) ◽

Author(s):

Renato Saragoça Bruno ◽

Jaime Alberto Restrepo ◽

Roldán Arturo Valverde

Keyword(s):

Costa Rica ◽

El Niño ◽

Reproductive Output ◽

El Nino ◽

Southern Oscillation ◽

Chelonia Mydas ◽

El Niño Southern Oscillation ◽

El Nino Southern Oscillation ◽

Ocean Temperature ◽

Green Turtles

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Plasma proteomics of green turtles (Chelonia mydas) reveals pathway shifts and potential biomarker candidates associated with health and disease

Conservation Physiology ◽

10.1093/conphys/coab018 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

David P Marancik ◽

Justin R Perrault ◽

Lisa M Komoroske ◽

Jamie A Stoll ◽

Kristina N Kelley ◽

...

Keyword(s):

Chelonia Mydas ◽

Sea Turtle ◽

Protein Abundance ◽

Plasma Samples ◽

Important Species ◽

Green Turtles ◽

Rehabilitation Programs ◽

Potential Biomarker ◽

Health And Disease

Abstract Evaluating sea turtle health can be challenging due to an incomplete understanding of pathophysiologic responses in these species. Proteome characterization of clinical plasma samples can provide insights into disease progression and prospective biomarker targets. A TMT-10-plex-LC–MS/MS platform was used to characterize the plasma proteome of five, juvenile, green turtles (Chelonia mydas) and compare qualitative and quantitative protein changes during moribund and recovered states. The 10 plasma samples yielded a total of 670 unique proteins. Using ≥1.2-fold change in protein abundance as a benchmark for physiologic upregulation or downregulation, 233 (34.8%) were differentially regulated in at least one turtle between moribund and recovered states. Forty-six proteins (6.9%) were differentially regulated in all five turtles with two proteins (0.3%) demonstrating a statistically significant change. A principle component analysis showed protein abundance loosely clustered between moribund samples or recovered samples and for turtles that presented with trauma (n = 3) or as intestinal floaters (n = 2). Gene Ontology terms demonstrated that moribund samples were represented by a higher number of proteins associated with blood coagulation, adaptive immune responses and acute phase response, while recovered turtle samples included a relatively higher number of proteins associated with metabolic processes and response to nutrients. Abundance levels of 48 proteins (7.2%) in moribund samples significantly correlated with total protein, albumin and/or globulin levels quantified by biochemical analysis. Differentially regulated proteins identified with immunologic and physiologic functions are discussed for their possible role in the green turtle pathophysiologic response and for their potential use as diagnostic biomarkers. These findings enhance our ability to interpret sea turtle health and further progress conservation, research and rehabilitation programs for these ecologically important species.

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Oocyte Ageing in Zebrafish Danio rerio (Hamilton, 1822) and Its Consequence on the Viability and Ploidy Anomalies in the Progeny

Animals ◽

10.3390/ani11030912 ◽

2021 ◽

Vol 11 (3) ◽

pp. 912

Author(s):

Swapnil Gorakh Waghmare ◽

Azadeh Mohagheghi Samarin ◽

Roman Franěk ◽

Martin Pšenička ◽

Tomáš Policar ◽

...

Keyword(s):

Danio Rerio ◽

Egg Quality ◽

Complete Loss ◽

Egg Viability ◽

Embryo Survival ◽

Hatching Rates

Fish egg quality can be markedly influenced by the oocyte age after ovulation. In this study, we examined the duration of oocyte ageing in the zebrafish (Danio rerio) and whether prolonged ageing is associated with the incidence of ploidy anomalies in the resulting embryos. Oocytes were incubated in vitro for 6 h post-stripping (HPS) at 26 °C and fertilized at 2-h intervals. Meanwhile, for eggs fertilized immediately after stripping, the fertilization, embryo survival, and hatching rates started at ~80%; these rates decreased to 39%, 24%, and 16%, respectively, for oocytes that had been stored for 4 h (p ˂ 0.05), and there was an almost complete loss of egg viability at 6 HPS. Furthermore, almost 90% of the embryos derived from 6-h aged oocytes died prior to hatching, and all larvae originating from 4- and 6-h aged oocytes showed malformations. The proportion of ploidy abnormal embryos was significantly greater at 4 HPS (18.5%) than at either 0 or 2 HPS (4.7% and 8.8%, respectively). The results revealed that zebrafish oocytes retained their fertilization potential for up to 2 h after stripping at 26 °C and indicated the contribution of post-ovulatory oocyte ageing in the occurrence of ploidy anomalies in the resulting embryos.

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Nest microclimate and limits to egg viability explain avian life‐history variation across latitudinal gradients

Ecology ◽

10.1002/ecy.3338 ◽

2021 ◽

Author(s):

Carl G. Lundblad ◽

Courtney J. Conway

Keyword(s):

Life History ◽

Latitudinal Gradients ◽

Egg Viability ◽

Life History Variation ◽

Nest Microclimate

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Dietary analysis of two sympatric marine turtle species in the eastern Mediterranean

Marine Biology ◽

10.1007/s00227-021-03895-y ◽

2021 ◽

Vol 168 (6) ◽

Author(s):

Josie L. Palmer ◽

Damla Beton ◽

Burak A. Çiçek ◽

Sophie Davey ◽

Emily M. Duncan ◽

...

Keyword(s):

Green Turtle ◽

Eastern Mediterranean ◽

Chelonia Mydas ◽

Marine Turtle ◽

Dietary Analysis ◽

Low Frequencies ◽

Turtle Species ◽

Dietary Shift ◽

Green Turtles ◽

Loggerhead Turtles

AbstractDietary studies provide key insights into threats and changes within ecosystems and subsequent impacts on focal species. Diet is particularly challenging to study within marine environments and therefore is often poorly understood. Here, we examined the diet of stranded and bycaught loggerhead (Caretta caretta) and green turtles (Chelonia mydas) in North Cyprus (35.33° N, 33.47° E) between 2011 and 2019. A total of 129 taxa were recorded in the diet of loggerhead turtles (n = 45), which were predominantly carnivorous (on average 72.1% of dietary biomass), foraging on a large variety of invertebrates, macroalgae, seagrasses and bony fish in low frequencies. Despite this opportunistic foraging strategy, one species was particularly dominant, the sponge Chondrosia reniformis (21.5%). Consumption of this sponge decreased with increasing turtle size. A greater degree of herbivory was found in green turtles (n = 40) which predominantly consumed seagrasses and macroalgae (88.8%) with a total of 101 taxa recorded. The most dominant species was a Lessepsian invasive seagrass, Halophila stipulacea (31.1%). This is the highest percentage recorded for this species in green turtle diet in the Mediterranean thus far. With increasing turtle size, the percentage of seagrass consumed increased with a concomitant decrease in macroalgae. Seagrass was consumed year-round. Omnivory occurred in all green turtle size classes but reduced in larger turtles (> 75 cm CCL) suggesting a slow ontogenetic dietary shift. Macroplastic ingestion was more common in green (31.6% of individuals) than loggerhead turtles (5.7%). This study provides the most complete dietary list for marine turtles in the eastern Mediterranean.

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