Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Sea turtle”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources

Cutaneous hyalohyphomycosis caused by Fusarium solani in a loggerhead sea turtle (Caretta caretta L.).

Fusarium solani was reported as the agent of a cutaneous infection in an injured sea turtle collected in the Mediterranean Sea. The turtle was treated with both a topical 10% solution of iodine in alcohol and ketoconazole. The source of the causal agent was traced to the sand in the tank in which the turtle was maintained. The strain was only sensitive in vitro to amphotericin B and was resistant to 5-fluorocytosine, fluconazole, itraconazole, and ketoconazole.

Administration, Topical↗

Genomic characterization of novel human-associated CTX-M-15-producing Serratia nevei ST625 lineage infecting a vulnerable loggerhead sea turtle.

BACKGROUND: Serratia nevei is a newly classified and opportunistic bacterial species belonging to the Serratia marcescens complex (SMC). Genomic data from this species is highly relevant for public health and epidemiological tracking. OBJECTIVE: To report the first identification and genomic characterization of extended-spectrum β-lactamase (CTX-M-15)-producing S. nevei sequence type (ST) ST625 lineage infecting a vulnerable loggerhead sea turtle. METHODS: Strain BP02 was recovered from the coelomic cavity of a loggerhead sea turtle (Caretta caretta) admitted to a rehabilitation center in southeastern Brazil. MALDI-TOF MS was initially used for species identification and was further confirmed by whole-genome sequencing on the Illumina HiSeq platform, followed by ANI, dDDH, multilocus sequence typing, resistome, plasmidome, virulome, and SNP-based phylogenomic analyses. RESULTS: Strain BP02 exhibited a multidrug-resistant profile, including resistance to third- and fourth-generation cephalosporins. Genomic analyses identified BP02 as S. nevei ST625 carrying blaCTX-M-15 within the ISEcp1-blaCTX-M-15-wbuC-ΔTn2 genetic environment, in addition to multiple AMR determinants and the IncC plasmid replicon. Phylogenomic analysis demonstrated close relatedness between BP02 and human clinical ST625 strains, previously reported in São Paulo, Brazil, including a urine-derived strain isolated in 2019, differing by only 27 SNPs. Notably, all publicly available ST625 genomes were associated with human clinical sources and displayed multidrug resistance genotypes. CONCLUSION: This study expands the current knowledge regarding the ecology and genomic features of S. nevei, demonstrating the emergence of a human multidrug-resistant clone in marine wildlife. Our findings reinforce the importance of monitoring clinically relevant SMC members across distinct ecological niches within a One Health perspective.

ESBL↗

Parasites of Italian sea turtles. II. Loggerhead turtles (Caretta caretta [Linnaeus, 1758]).

Eleven out of fourteen sea turtles (Caretta caretta) stranded along the coast of the Adriatic sea (Mediterranean sea) were found infected with helminths. Seven trematode species (Rhytidodes gelatinosus, Orchidasma amphiorchis, Enodiotrema megachondrus. Pachypsolus irroratus, Pleurogonius trigonocephalus, Calicodes anthos, Plesiochorus cymbiformis) and one nematode (Sulcascaris sulcata) were found. S. sulcata was the most frequent species in the stomach and R. gelatinosus in the intestine. These species were also the most abundant. The redescriptions of C. anthos (Braun, 1899) and P. trigonocephalus (Rudolphi, 1809) Looss, 1901 are included. The accuracy of Braun's original description is questioned because it refers to specimens studied in dorsal view.

Animals↗

Basal and stress-induced corticosterone levels in olive ridley sea turtles (Lepidochelys olivacea) in relation to their mass nesting behavior.

Adrenocortical responsiveness to turning stress was examined in wild, reproductively-active olive ridley sea turtles (Lepidochelys olivacea) in relation to their mass nesting (arribada) behavior. We hypothesized that the high sensitivity threshold (HST) observed in ovipositing sea turtles is associated with a diminished sensitivity of the hypothalamo-pituitary-adrenal (HPA) axis to stressful stimuli in arribada females. We tested this hypothesis by determining whether arribada females exhibited an increased activation threshold of the HPA axis to an imposed stressor (turning stress). Mean basal corticosterone (B) and glucose levels were below 1.0 ng/ml and 60 mg/dl, respectively. Basal B remained unchanged throughout a 24-hr period in basking females. Most animals responded to turning stress with elevated mean B levels (up to 6.5 ng/ml after 6 hr) and no increase in circulating glucose. Nearly 50% of females (and none of the males) were refractory to the stimulation. Males exhibited the most rapid response, with B levels significantly elevated by 20 min over basal levels. Among females, arribada and solitary nesters exhibited a slower rate of response than basking, non-nesting animals. These results demonstrate that olive ridleys exhibit stress-induced changes in circulating B which are slower than those observed in most reptilian and in mammalian, avian, and piscine species. Furthermore, the presence of refractory females and the relatively slower increase in B in arribada and solitary nesters indicate a hyporesponsiveness of the HPA axis to turning stress in nesting olive ridleys. The hyporesponsiveness may be part of a mechanism to facilitate arribada nesting. J. Exp. Zool. 284:652-662, 1999.

Animals↗

Serum gonadotropins and gonadal steroids associated with ovulation and egg production in sea turtles.

Changes in serum concentrations of gonadotropins and gonadal steroids during the periovulatory period were monitored in green, Chelonia mydas, and loggerhead, Caretta caretta, sea turtles. Turtles were from natural populations that nest on a coral island on the Great Barrier Reef. After nesting, each turtle was transferred to a holding tank and held for a maximum of 8 days. A time series of blood samples was obtained from each of five sea turtles (three C. mydas and two C. caretta) starting immediately after nesting and then at approximately 12-hr intervals until the time of release. Prior to release back into the ocean, each turtle was examined by laparoscopy to verify that ovulation had occurred. Serum concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH), progesterone (PRO), and testosterone (T) in both species exhibited significant changes during this period. Surges of FSH, LH, and PRO were evident within approximately 20 to 50 hr after each turtle had nested. The significant change in FSH concentration during the periovulatory period is the first such report for a reptile. Coincident with maximal concentrations of FSH, LH, and PRO was a decline in T concentrations in both species. Estradiol-17 beta concentrations were near or below assay sensitivity in the C. mydas, whereas those in the C. caretta were detectable but exhibited no significant changes. The dynamic changes in FSH, LH, PRO, and T concentrations are consistent with the hypothesis that these hormones facilitate specific physiological events during ovulation and egg production.

Animals↗

Behaviour of leatherback sea turtles, Dermochelys coriacea, during the migratory cycle.

Leatherback sea turtles, Dermochelys coriacea, undertake broad oceanic movements. While satellite telemetry has been used to investigate the post-nesting behaviour of female turtles tagged on tropical nesting beaches, long-term behavioural patterns of turtles of different sexes and sizes have not been described. Here we investigate behaviour for 25 subadult and adult male and female turtles satellite-tagged in temperate waters off Nova Scotia, Canada. Although sex and reproductive condition contributed to variation in migratory patterns, the migratory cycle of all turtles included movement between temperate and tropical waters. Marked changes in rates of travel, and diving and surfacing behaviour, accompanied southward movement away from northern foraging areas. As turtles approached higher latitudes the following spring and summer, they assumed behaviours consistent with regular foraging activity and eventually settled in coastal areas off Canada and the northeastern USA. Behavioural patterns corresponding to various phases of the migratory cycle were consistent across multiple animals and were repeated within individuals that completed return movements to northern waters. We consider the potential biological significance of these patterns, including how turtle behaviour relates to predator avoidance, thermoregulation and prey distribution.

Animal Migration↗

Residues of petroleum hydrocarbons in tissues of sea turtles exposed to the Ixtoc I oil spill.

Sea turtles found dead when the Ixtoc I oil spill reached Texas waters were necropsied and tissues were analyzed for residues of petroleum hydrocarbons. Two of three turtles were in poor flesh, but had no apparent oil-caused lesions. There was evidence of oil in all tissues examined and indications that the exposure had been chronic. Comparisons with results of studies done on birds indicate consumption of 50,000 ppm or more of oil in the diet. Some possible mechanisms of mortality are suggested.

Animals↗

A herpesvirus-type agent associated with skin lesions of green sea turtles in aquaculture.

Nine successive groups of green sea turtles (Chelonia mydas) were observed in aquaculture during the posthatchling period. During the first 6 months of growth, each group underwent an epizootic of skin lesions, named gray-patch disease. Two types of skin lesions are associated with gray-patch disease: papules and, more characteristically, spreading gray patches which appear 7 to 8 weeks after hatching. In both types of lesions, intranuclear inclusions are found in keratinocytes in the malpighian layer of the epidermis. Electron microscopic examination of scrapings from lesions and biopsies revealed many viral particles, with features characteristic of the herpesvirus group. Transmission of gray-patch disease is possible with bacteria-free preparations of viral particles.

Animals↗

Sectional anatomic and magnetic resonance imaging features of coelomic structures of loggerhead sea turtles.

OBJECTIVE: To compare cross-sectional anatomic specimens with images obtained via magnetic resonance imaging (MRI) of the coelomic structures of loggerhead sea turtles (Caretta caretta). ANIMALS: 5 clinically normal live turtles and 5 dead turtles. PROCEDURES: MRI was used to produce T1- and T2- weighted images of the turtles, which were compared with gross anatomic sections of 3 of the 5 dead turtles. The other 2 dead turtles received injection with latex and were dissected to provide additional cardiovascular anatomic data. RESULTS: The general view on the 3 oriented planes provided good understanding of cross-sectional anatomic features. Likewise, major anatomic structures such as the esophagus, stomach, lungs, intestine (duodenum and colon), liver, gallbladder, spleen, kidneys, urinary bladder, heart, bronchi, and vessels could be clearly imaged. It was not possible to recognize the ureters or reproductive tract. CONCLUSIONS AND CLINICAL RELEVANCE: By providing reference information for clinical use, MRI may be valuable for detailed assessment of the internal anatomic structures of loggerhead sea turtles. Drawbacks exist in association with anesthesia and the cost and availability of MRI, but the technique does provide excellent images of most internal organs. Information concerning structures such as the pancreas, ureters, intestinal segments (jejunum and ileum), and the reproductive tract is limited because of inconsistent visualization.

Abdomen↗

Diving behaviour and haemoglobin function: the primary structure of the alpha- and beta-chains of the sea turtle (Caretta caretta) and its functional implications.

The amino acid sequence of the alpha- and beta-chains of haemoglobin (Hb) from the loggerhead sea turtle (Caretta caretta) has been determined. Comparison with that of human Hb shows differences in several residues involved in both alpha 1 beta 1 and alpha 1 beta 2 packing contacts. On the whole, in spite of the mutations, the essential characteristics of both interfaces seem to be maintained. The functional properties of the sea turtle Hb have been investigated at different temperatures and as a function of proton, chloride and organic phosphate concentrations. In addition to overall similarities shared with most of the vertebrate Hbs previously described, this molecule shows significant differences which could be related to the life behaviour of the turtle. In fact, while the shape of the Bohr-effect curve is well adapted for gas exchange during prolonged dives, the very small enthalpy change for O2 binding ensures that O2 delivery becomes essentially insensitive to the temperature changes of the environment. Moreover, and similarly to the case of emperor penguin Hb, the small alkaline Bohr effect appears to be only choride-linked, since the pH dependence of the O2 affinity is abolished in the absence of this ion. These functional characteristics are discussed on the basis of the primary structure of alpha- and beta-chains.

Adaptation, Physiological↗

Computed tomography of the vertebral column and coelomic structures in the normal loggerhead sea turtle (Caretta caretta).

The aim of this study was to determine the normal computed tomography (CT) appearance of the vertebral column and coelomic structures of the loggerhead sea turtle (Caretta caretta) and to use three-dimensional (3D) and multiplanar reconstructions to indicate the position of each organ in relation to the vertebrae and carapace. Transverse sections of 1mm thickness were performed in seven clinically healthy and in five dead loggerhead sea turtles using multi-detector CT equipment. A computer workstation was used for multiplanar and 3D reconstructions. Dead turtles were frozen and sectioned in the transverse, dorsal and sagittal planes to compare the anatomical structures' appearance with CT images. Clinically relevant organs including the oesophagus, stomach, trachea, bronchi, lungs, liver, gallbladder, heart, spleen, kidneys and vertebral canal were identified in CT images. Computed tomography provides detailed information on the respiratory system and skeleton; the location of the coelomic structures with respect to the carapace and the vertebrae that is provided in this work will facilitate the use of other ancillary diagnostic techniques such as ultrasound, radiography and biopsy, thereby improving safety of access in surgical procedures.

Abdomen↗

Heart rates and diving behavior of leatherback sea turtles in the eastern pacific ocean

Heart rates and diving behavior of leatherback sea turtles (Dermochelys coriacea) were monitored at sea during the internesting interval. Instruments that recorded the electrocardiogram and the depth and duration of dives were deployed on six female leatherback turtles as they laid eggs at Playa Grande, Costa Rica. Turtles dived continually for the majority of the internesting interval and spent 57-68 % of the time at sea submerged. Mean dive depth was 19+/-1 m (mean +/- s.d.) and the mean dive duration was 7.4+/-0.6 min. Heart rate declined immediately upon submergence and continued to fall during descent. All turtles showed an increase in heart rate before surfacing. The mean heart rate during dives of 17.4+/-0.9 beats min-1 (mean +/- s.d.) was significantly lower than the mean heart rate at the surface of 24.9+/-1.3 beats min-1 (P<0.05). Instantaneous heart rates as low as 1.05 beats min-1 were recorded during a 34 min dive. The mean heart rate over the entire dive cycle (dive + succeeding surface interval; 19.4+/-1.3 beats min-1) was more similar to the heart rate during diving than to the heart rate at the surface. Although dive and surface heart rates were significantly different from each other, heart rates during diving were 70 % of heart rates at the surface, showing that leatherback turtles do not experience a dramatic bradycardia during routine diving.

Journal Article↗

Mitogen-induced lymphocyte proliferation in loggerhead sea turtles: comparison of methods and effects of gender, plasma testosterone concentration, and body condition on immunity.

A fully functioning immune system is vital to the survival of threatened and endangered sea turtles. Immunological protection against diseases in any organism can be reduced by a number of natural and anthropogenic factors, such as seasonal changes, malnutrition, disease states, and contaminant exposure. These factors are even more critical when they occur in endangered species or populations. To identify alterations in the immunological health of loggerhead sea turtles (Caretta caretta), the mitogen-induced lymphocyte proliferation (LP) assay was developed using peripheral blood leukocytes (PBLs). Collection and culture conditions were optimized for this assay using non-lethal blood samples collected from free-ranging turtles along the southeastern US coast. During the collection, two anticoagulants (sodium heparin and lithium heparin) were compared to determine effects of different ions on assay results. Optimal culture conditions were established for loggerhead PBLs while two different methods of measuring LP were compared: (1) the traditional radioactive (3)H-thymidine assay and (2) a non-radioactive, colorimetric method utilizing 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium (MTT). The results indicate that the (3)H-thymidine and the non-radioactive MTT methods did not correlate with each other and that the use of heparin type did not influence the results of the LP assay. Lastly, using these optimized methods, we investigated the effect of gender, plasma testosterone concentration, and body condition on LP in loggerhead turtles and found that none of the parameters largely influenced LP.

Animals↗

Visual acuity thresholds of juvenile loggerhead sea turtles (Caretta caretta): an electrophysiological approach.

Visual evoked potentials measure dynamic properties of the visual system by recording transient electric responses of neural tissue identified to correspond to a specific visual stimulus, such as light or a striped grid. In this study, visual evoked potentials were used to test the visual acuity of juvenile loggerhead sea turtles (Caretta caretta) in water. Subject animals were fitted with a Plexiglas goggle filled with filtered seawater. Stimuli of black and white striped gratings were presented to the turtles using a slide projector directing an image onto a screen via a rotatable mirror that shifted the striped pattern laterally one-half cycle. Bioelectric activity was collected using a digital averaging computer and subdermal platinum electrodes, implanted under the head scutes directly above the optic nerve and the contralateral optic tectum. To isolate the response signal from the noise, signal averaging techniques were used when collecting visual evoked potentials. The resulting response waveforms included a robust positive-negative compound that was used to track the turtle's response to visual stimulation. Acuity thresholds for these sea turtles, which were derived from linear regressions analysis of the positive-negative compound amplitudes versus stripe size, ranged from 0.130 to 0.215. This acuity level is comparable to other inshore, shallow water marine species.

Age Factors↗

Phacoemulsification of bilateral cataracts in a loggerhead sea turtle (Caretta caretta).

An immature free-living loggerhead sea turtle (Caretta caretta) of unknown sex was found moribund off the coast of Wise Point, Virginia. It was suffering from cachexia and had bilateral hypermature cataracts which were treated by phacoemulsification under general anaesthesia. The surgery restored the turtle's vision and it was returned to the wild.

Anesthesia, General↗

Cutting the longline to extinction: new sea turtle campaign takes aim at industrial longline fishing and mercury-poisoned seafood.

Chanting "Get on the right track . . . stop killing the leatherback!," a festive protest of people of many ages dressed in colorful turtle costumes wound its way along the busy streets of San Francisco's Fishermen's Wharf. The action last October marked the launching of the Bay Area-based Sea Turtle Restoration Project's Save the Leatherback (www.savetheleatherback.com) campaign for a moratorium on longline fishing in the Pacific Ocean. Longline fishing in the Pacific kills tens of thousands of sea turtles annually to serve up swordfish, shark, and tuna poisoned with high levels of methylmercury for lucrative seafood markets in Japan, the United States, and Europe.

Journal Article↗

Influence of diminished respiratory surface area on survival of sea turtle embryos.

It has been suggested that fungal presence on sea turtle eggs may impede gas exchange. To investigate the influence of diminished gas exchange surface upon embryo survivorship, flatback (Natator depressus) and green (Chelonia mydas) eggs were painted with petroleum jelly. Variable proportions of the egg surface were covered, including both respiratory and nonrespiratory domains. Embryo survival varied with site inhibited, proportion of eggshell affected, and species of turtle. If fungi on the exterior of the eggshell are able to impede respiratory gas exchange, their presence on the upper hemisphere (primary gas exchange area in early incubation) will result in the highest embryo mortality. Large eggs are likely to demonstrate a higher survivorship than small eggs, due to their larger available respiratory area and/or to variation in weight or stage-specific embryonic metabolic demands. Interspecific differences in egg size may therefore be a contributory factor to observed mortality rate differences in the natural presence of fungi.

Animals↗

Cervical and coelomic radiologic features of the loggerhead sea turtle, Caretta caretta.

Many investigators have undertaken radiologic studies in chelonians. However, descriptive papers focusing on the radiographic anatomy are limited to only a few species. The purpose of this article is to provide the normal cervical and coelomic radiographic appearance of the loggerhead sea turtle (Caretta caretta), in the dorsoventral view, and to indicate useful landmarks to identify internal anatomic structures. Dorsoventral radiographs were taken of the neck and body of 30 loggerhead sea turtles by means of analog and digital radiography. At various points, distortion or superimposition of images due to the natural curvature of the shell hindered the accuracy of interpretation. The pectoral and pelvic girdles were easily recognized. Important external landmarks included the vertebral and lateral scutes, and important internal landmarks included the bronchi, coracoid bones, the caudal border of the pulmonary fields, and the acetabulum.

Abdomen↗