Characterization of oral and cloacal microbial communities of wild and rehabilitated loggerhead sea turtles (Caretta caretta)

Abstract Background Microbial communities of wild animals are being increasingly investigated to provide information about the hosts’ biology and promote conservation. Loggerhead sea turtles (Caretta caretta) are a keystone species in marine ecosystems and are considered vulnerable in the IUCN Red List, which led to growing efforts in sea turtle conservation by rescue centers around the world. Understanding the microbial communities of sea turtles in the wild and how affected they are by captivity, is one of the stepping stones in improving the conservation efforts. Describing oral and cloacal microbiota of wild animals could shed light on the previously unknown aspects of sea turtle holobiont biology, ecology, and contribute to best practices for husbandry conditions. Results We describe the oral and cloacal microbiota of Mediterranean loggerhead sea turtles by 16S rRNA gene sequencing to compare the microbial communities of wild versus turtles in, or after, rehabilitation at the Adriatic Sea rescue centers and clinics. Our results show that the oral microbiota is more sensitive to environmental shifts than the cloacal microbiota, and that it does retain a portion of microbial taxa regardless of the shift from the wild and into rehabilitation. Additionally, Proteobacteria and Bacteroidetes dominated oral and cloacal microbiota, while Kiritimatiellaeota were abundant in cloacal samples. Unclassified reads were abundant in the aforementioned groups, which indicates high incidence of yet undiscovered bacteria of the marine reptile microbial communities. Conclusions We provide the first insights into the oral microbial communities of wild and rehabilitated loggerhead sea turtles, and establish a framework for quick and non-invasive sampling of oral and cloacal microbial communities, useful for the expansion of the sample collection in wild loggerhead sea turtles. Finally, our investigation of effects of captivity on the gut-associated microbial community provides a baseline for studying the impact of husbandry conditions on turtles’ health and survival upon their return to the wild.

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Intraerythrocytic inclusion bodies in the loggerhead sea turtle Caretta caretta from Madeira

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400003015 ◽

2000 ◽

Vol 80 (5) ◽

pp. 957-958 ◽

Cited By ~ 3

Author(s):

J.C. Eiras ◽

T. Dellinger ◽

A.J. Davies ◽

G. Costa ◽

A.P. Alves de Matos

Keyword(s):

Red Blood Cells ◽

Blood Cells ◽

Inclusion Bodies ◽

Sea Turtles ◽

Caretta Caretta ◽

Sea Turtle ◽

Loggerhead Sea Turtles ◽

Loggerhead Sea Turtle ◽

Intracytoplasmic Inclusion ◽

Intracytoplasmic Inclusion Bodies

Intracytoplasmic inclusion bodies were detected in the mature red blood cells of twenty juvenile loggerhead sea turtles, Caretta caretta, captured in Madeira. The bodies were mostly single, round to oval, frequently irregular in outline, and their diameter varied from 0.5 to 2.0 μm. Most bodies were associated with small granular areas, often in the form of a tail or projection. In some cells, only granular areas were apparent. The nuclei of most erythrocytes were irregular in outline but degeneration of red blood cells was not observed. The identity of these intraerythrocytic structures is not clear but they may be viral or rickettsial in nature.

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First record of loggerhead sea turtles Caretta caretta in Sebastián Vizcaíno Bay, Baja California Peninsula, Mexico

Latin American Journal of Aquatic Research ◽

10.3856/vol48-issue1-fulltext-2328 ◽

2020 ◽

Vol 48 (1) ◽

pp. 146-149

Author(s):

Helena Fernández-Sanz ◽

Fabián Castillo Romero ◽

Joaquín Rivera Rodríguez ◽

Noé López Paz ◽

Gabriel Arturo Zaragoza Aguilar ◽

...

Keyword(s):

Baja California ◽

Sea Turtles ◽

Chelonia Mydas ◽

Caretta Caretta ◽

First Record ◽

Sea Turtle ◽

Baja California Peninsula ◽

Loggerhead Sea Turtles ◽

Biometric Data ◽

Loggerhead Sea Turtle

The loggerhead sea turtle (Caretta caretta) is an endangered species which distributes around the west coast of the Baja California Peninsula. In Baja California Sur, the conservation efforts for this species were focused in the Gulf of Ulloa; however, within the Pacific coast of the Baja California Peninsula, Sebastián Vizcaíno Bay (SVB) biological active center suit the optimal conditions for the presence of loggerheads. This study aimed to investigate SVB as a potential foraging area for loggerheads. Between July and August 2018, three prospective surveys were conducted, in search of marine turtles in SVB. A total of three loggerhead turtles and one eastern Pacific green turtle (Chelonia mydas) were captured; biometric data were recorded, and organisms were classified as juveniles. This is the first report of the loggerhead sea turtles in the SVB and given the oceanographic characteristics of the bay, it is a potential foraging and development area for the species.

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Barnacles (Cirripedia, Thoracica) and associated epibionts from sea turtles in the central Mediterranean

Crustaceana ◽

10.1163/156854012x634393 ◽

2012 ◽

Vol 85 (4-5) ◽

pp. 533-549 ◽

Cited By ~ 10

Author(s):

P. Casale ◽

M. D’Addario ◽

D. Freggi ◽

R. Argano

Keyword(s):

Sea Turtles ◽

Caretta Caretta ◽

Sea Turtle ◽

Pioneer Species ◽

Body Parts ◽

Central Mediterranean ◽

Benthic Habitats ◽

Loggerhead Sea Turtles ◽

Juvenile Mortality ◽

Host Habitat

The association patterns and ecology of sea turtle epibionts, and especially obligate epibionts, are still poorly known. Epibiont communities were investigated in the central Mediterranean Sea in relation to the host habitat and seven species of barnacles, three amphipods, one crab, and one tanaid were found on 117 loggerhead sea turtles, Caretta caretta. Particular attention was given to barnacles, some of them being obligate turtle epibionts, with a total of 3330 individuals examined, among which high intraspecific aggregation was observed. Results indicate that (i) the species composition of barnacles varies among turtles frequenting not only different geographic areas but also different habitats in the same area, (ii) different species have marked preferences for hosts frequenting pelagic vs. benthic habitats, and also (iii) for body parts of the host representing microhabitats with different features and trophic opportunities, (iv) settlement is favoured by the presence of conspecific individuals and possibly also (v) by individuals of related species, notably Chelonibia testudinaria that may act as a pioneer species, and finally (vi) barnacles show rapid turnover on turtles, with relatively short lives, rapid growth, and high juvenile mortality.

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Helminth Infection of the Loggerhead Sea Turtle Caretta caretta along the Coasts of Sicily and the North West Adriatic Sea

Animals ◽

10.3390/ani11051408 ◽

2021 ◽

Vol 11 (5) ◽

pp. 1408

Author(s):

Antonino Gentile ◽

Tullia Amato ◽

Andrea Gustinelli ◽

Maria Letizia Fioravanti ◽

Delia Gambino ◽

...

Keyword(s):

Adriatic Sea ◽

Sea Turtles ◽

Single Species ◽

Caretta Caretta ◽

Sea Turtle ◽

Helminth Parasites ◽

Loggerhead Sea Turtles ◽

Loggerhead Sea Turtle ◽

North West ◽

The North

We provide new data on the presence of helminth parasites in 64 individual loggerhead sea turtles Caretta caretta stranded along the coasts of Sicily and the northwest Adriatic Sea between June 2014 and August 2016. The necropsy examination revealed 31 individuals (48.4%) positive for endoparasites, showing a greater prevalence of trematodes than nematodes. In particular, seven species and a single genus of Trematoda (Hapalotrema) and a single species and genus of Nematoda (Kathlania) were identified. Among the Digenea flukes the species with the highest prevalence of infection were Rhytidodes gelatinosus (34.6%) and Hapalotrema sp. (33.3%), while among the Nematoda they were Kathlania sp. (33.3%) and Sulcascaris sulcata (33.3%). Analysis of variance (ANOVA) was applied among the recovery sites of the stranded loggerhead sea turtles and prevalence of endoparasites was used to highlight any relationship between the parasites and the origin of the hosts. ANOVA showed significant differences (p < 0.001) among the data used.

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The widely occurring brittlestar Ophiactis savignyi (Amphilepidida: Ophiactidae) as an epibiont on loggerhead sea turtle, Caretta caretta

Zootaxa ◽

10.11646/zootaxa.4695.5.7 ◽

2019 ◽

Vol 4695 (5) ◽

pp. 497-500

Author(s):

RYOTA HAYASHI ◽

MASANORI OKANISHI

Keyword(s):

New Species ◽

Sea Turtles ◽

Caretta Caretta ◽

Sea Turtle ◽

The Novel ◽

Loggerhead Sea Turtles ◽

Loggerhead Sea Turtle ◽

First Occurrence

We describe the first occurrence of the widely occurring brittlestar Ophiactis savignyi (Müller & Troschel, 1842) as epibionts on Caretta caretta (Linnaeus, 1758), the loggerhead sea turtles. On the sea turtle epibionts, the coronulid barnacles were well studied as listed in Hayashi (2013), and recently some crustaceans were collected from loggerhead sea turtles and described as new species (Tanabe et al. 2017; Tanaka and Hayashi 2019). In contrast, echinoderm epibionts listed from sea turtles are poorly understood (Table 1) and this study represents the novel discovery of an ophiuroid, which was not previously known to occur on the surface of this species.

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Record of the Loggerhead Sea Turtle, Caretta caretta (Testudines, Cheloniidae), in the Black Sea with the Review of the Species Occurrence in the Region

Zoodiversity ◽

10.15407/zoo2021.02.127 ◽

2021 ◽

Vol 55 (2) ◽

pp. 127-132

Author(s):

O. Zinenko ◽

K. A. Vishnyakova ◽

L. Stoyanov ◽

P. E. Gol’din

Keyword(s):

Black Sea ◽

Sea Turtles ◽

Caretta Caretta ◽

First Record ◽

Sea Turtle ◽

The Black Sea ◽

Loggerhead Sea Turtles ◽

Loggerhead Sea Turtle ◽

The North ◽

North Western

A rare live record of the loggerhead sea turtle Caretta caretta (Linnaeus, 1758) is reported from the Dzharylgach Gulf in the north-western Black Sea. This is the first record from Ukrainian waters since 1962 and the northernmost record of the species in the Black Sea. The loggerhead sea turtles of the east Mediterranean origin are increasingly often seen in the Marmara and the Black Sea during the latest decade, which is an evidence for potential expansion of this species range, at least partly due to climate changes. Key words: sea turtles, Caretta caretta, Black Sea, Ukraine, range expansion.

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Smaller longer, larger shorter: energy budget calculations explain intrapopulation variation in remigration intervals for loggerhead sea turtles (Caretta caretta)

Canadian Journal of Zoology ◽

10.1139/z08-035 ◽

2008 ◽

Vol 86 (7) ◽

pp. 595-600 ◽

Cited By ~ 34

Author(s):

Hideo Hatase ◽

Katsumi Tsukamoto

Keyword(s):

Feeding Habits ◽

Sea Turtles ◽

Caretta Caretta ◽

Sea Turtle ◽

Energy Budgets ◽

Loggerhead Sea Turtles ◽

Intrapopulation Variation ◽

Turtle Population ◽

The Difference ◽

And Migration

Adult female loggerhead sea turtles ( Caretta caretta (L., 1758)) show a size-related behavioural and trophic dichotomy within several populations: oceanic planktivory by small females and neritic benthivory by large females. Within a Japanese population, smaller females have longer remigration intervals (the intervals between successive nesting years) than larger females. We hypothesized that this is attributed to the size-related foraging dichotomy, and calculated energy budgets and food requirements for the small and large females. Total reproductive energy costs for the small and large females were 1003 and 434 MJ, equivalent to 4043 kg of planktonic items and 275 kg of benthic items, respectively. The minimum durations necessary for accumulating the total reproductive energy for the small and large females were 430 and 26 days, equivalent to remigration intervals of 2 years and 1 year taking into account the nesting and migration durations and seasonal reproduction. Therefore, it was theoretically demonstrated that the intrapopulation variation in remigration intervals for Japanese loggerheads could be caused by the difference in their feeding habits, implying that remigration dynamics in a sea turtle population that shows a foraging dichotomy is regulated by feeding conditions not in a single habitat but in multiple habitats.

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Foraging and overwintering behavior of loggerhead sea turtles Caretta caretta in the western North Atlantic

Marine Ecology Progress Series ◽

10.3354/meps13296 ◽

2020 ◽

Vol 641 ◽

pp. 209-225 ◽

Cited By ~ 1

Author(s):

J Braun McNeill ◽

L Avens ◽

A Goodman Hall ◽

I Fujisaki ◽

AR Iverson

Keyword(s):

North Carolina ◽

North Atlantic ◽

Spatial Ecology ◽

Net Primary Production ◽

Sea Turtles ◽

Satellite Telemetry ◽

Caretta Caretta ◽

Sea Turtle ◽

Foraging Habitat ◽

Loggerhead Sea Turtles

Discerning the foraging habitat requirements of wildlife is key to providing for their conservation and management, especially with rare species. Sea turtles are slow-growing, late-maturing species that undertake wide-ranging migrations, making them especially susceptible to changes and disruptions in their environment. To protect and successfully manage these imperiled populations, an understanding of their spatial ecology is required; thus, characterizing critical habitats, identifying high-density areas, and identifying foraging regions is essential. We captured 30 loggerhead sea turtles Caretta caretta (male and female; juvenile and adult) in the estuarine waters of North Carolina (USA) and tracked them in western North Atlantic neritic (nearshore and offshore) waters. Using a combination of satellite telemetry and spatial modeling techniques, we characterized their movements and identified foraging and overwintering sites. Average core-use areas in the north had greater net primary production (NPP) and were smaller than those in the south, indicating more abundant marine resources in northern foraging regions. In summer, loggerheads migrated to both northern and southern foraging grounds, but most (53%) resided within North Carolina neritic waters. Likewise, the majority of loggerheads (67%) we tracked in winter remained in North Carolina neritic waters, underscoring the importance of this area as year-round foraging habitat, and lending to its consideration as potential critical habitat for both juvenile and adult loggerheads. The change to foraging behavior mode was significantly influenced by day of the year, geographic location, and NPP; however, individual-specific factors influenced switching probabilities relative to other covariates. Data highlighting ‘hotspots’ or densely used areas by foraging sea turtles can thus be used by conservation managers to make informed decisions concerning sea turtle conservation measures.

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Gastrointestinal investigation of parasites and Enterobacteriaceae in loggerhead sea turtles from Italian coasts

BMC Veterinary Research ◽

10.1186/s12917-019-2113-4 ◽

2019 ◽

Vol 15 (1) ◽

Cited By ~ 4

Author(s):

Antonino Pace ◽

Laura Rinaldi ◽

Davide Ianniello ◽

Luca Borrelli ◽

Giuseppe Cringoli ◽

...

Keyword(s):

Health Status ◽

Sea Turtles ◽

Caretta Caretta ◽

Sea Turtle ◽

Research Centre ◽

Free Living ◽

Loggerhead Sea Turtles ◽

Pathogenic Potential ◽

Starting Point ◽

Faecal Samples

Abstract Background Caretta caretta is the most abundant sea turtle species in the Mediterranean, and studies on this species have vastly expanded during recent years, including those investigating gut bacterial and parasitic communities. Members of these communities have been reported with variable prevalence and pathogenicity, mainly depending on their host and environment (e.g. lifespan, distribution, habitat, diet, health status and stressors). Indeed, many species commonly inhabiting the sea turtle gastrointestinal tract exhibit an opportunistic behaviour. This study aimed to provide baseline data on enterobacterial and parasitic composition, through bacteriological culture-based methods and the FLOTAC parasitological technique, in cloacal and faecal samples of 30 live Caretta caretta, examined upon their arrival at the Marine Turtle Research Centre (Portici, Italy). Results Enterobacteriaceae were isolated in 18/23 cloacal samples (78.3%), with Citrobacter and Morganella as the most common genera, followed by Proteus, Enterobacter, Providencia, and Hafnia. Parasitic elements were detected in 11/30 faecal samples (36.7%), with Enodiotrema, Rhytidodes, and Eimeria as most common genera, followed by Pachypsolus and Cymatocarpus. Additionally, Angiodyctium is reported for the first time in this host. The majority (47.8%) of sea turtles hosted exclusively Enterobacteriaceae, whereas 30.4% hosted both parasites and Enterobacteriaceae; the remaining 21.8% hosted neither of the agents. Conclusions Bacteria and parasites evaluated in the present study are common in Mediterranean loggerhead sea turtles, with slight differences between the western and eastern basin. Although naturally present in the gastrointestinal system of free-living sea turtles, their relationship with these hosts might range from mutualism to parasitism. Indeed, members of the gut community might express their pathogenic potential in immune-compromised animals, such as those in rehabilitation facilities. Therefore, it is advisable to include in the standard work-up of rescued sea turtles a screening procedure for such opportunistic agents, in order to better evaluate the animal’s health status and achieve timely intervention with appropriate treatment, thus improving rehabilitation. Furthermore, data collected from free-living sea turtles represent a starting point for investigating wild populations. However, further studies are needed to clarify the differences between sea turtle’s normal gut microbiome and pathobiome.

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Biodiversity of carapace epibiont diatoms in loggerhead sea turtles (Caretta caretta Linnaeus 1758) in the Aegean Sea Turkish coast

PeerJ ◽

10.7717/peerj.9406 ◽

2020 ◽

Vol 8 ◽

pp. e9406 ◽

Cited By ~ 3

Author(s):

Aydın Kaleli ◽

Ana Car ◽

Andrzej Witkowski ◽

Marta Krzywda ◽

Catherine Riaux-Gobin ◽

...

Keyword(s):

Relative Abundance ◽

Sea Turtles ◽

Aegean Sea ◽

Caretta Caretta ◽

Sea Turtle ◽

Solid Substrate ◽

Loggerhead Sea Turtles ◽

Time Period ◽

Long Time ◽

First Time

Background The Aegean Sea coast of Turkey hosts one of the most important nesting grounds for loggerhead sea turtles (Caretta caretta) in the Mediterranean Sea. Previous studies have revealed that the sea turtle carapace provides favourable conditions for various epibiontic organisms. Epibionts occurring on the carapace have been examined from different locations in the oceans. Methods This is the first time such a high number (39) of samples collected from nesting turtles during such a long time period (extending from 2011 to 2018) has been used for the study of the diatom component of the microbiome on the turtle carapaces. A total of 33 samples were investigated in terms of light microscopy (LM) and scanning electron microscopy (SEM). Six unprocessed biofilm fragments were subject to SEM observations. Results A total of 457 epizoic diatom taxa belonging to 86 genera were identified. Epizoic forms, e.g., Achnanthes spp., Chelonicola spp. or Tripterion spp. (also identified by SEM observations of the undisturbed pieces of the microbiome) dominated in terms of relative abundance, but the highest numbers of taxa were ubiquitously represented by Navicula (79), Nitzschia (45), Amphora (40), Cocconeis (32), Diploneis (25) and Mastogloia (23). Navicula perminuta and Delphineis australis were the most frequent taxa, present in 65% of the samples, both with an average relative abundance of 10%. The results of our study revealed that diatoms are an essential component of the loggerhead sea turtles’ microbiome, in terms of high biodiversity and abundance. Although strict epibionts provide a signature of the turtle microbiome, the carapace as a solid substrate attracts numerous benthic diatom species which are considered opportunistic forms and can be found in the surrounding benthic habitats of the vast ocean littoral space.

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