Georgia Aquarium Research Center

Athens, GA, United States

Georgia Aquarium Research Center

Athens, GA, United States
SEARCH FILTERS
Time filter
Source Type

de la Parra Venegas R.,Proyecto Domino | Hueter R.,Center for Shark Research | Cano J.G.,Proyecto Domino | Tyminski J.,Center for Shark Research | And 6 more authors.
PLoS ONE | Year: 2011

Whale sharks, Rhincodon typus, are often perceived as solitary behemoths that live and feed in the open ocean. To the contrary, evidence is accumulating that they are gregarious and form seasonal aggregations in some coastal waters. One such aggregation occurs annually north of Cabo Catoche, off Isla Holbox on the Yucatán Peninsula of Mexico. Here we report a second, much denser aggregation of whale sharks (dubbed "the Afuera") that occurs east of the tip of the Yucatán Peninsula in the Caribbean Sea. The 2009 Afuera event comprised the largest aggregation of whale sharks ever reported, with up to 420 whale sharks observed in a single aerial survey, all gathered in an elliptical patch of ocean approximately 18 km2. Plankton studies indicated that the sharks were feeding on dense homogenous patches of fish eggs, which DNA barcoding analysis identified as belonging to little tunny, Euthynnus alletteratus. This contrasts with the annual Cabo Catoche aggregation nearby, where prey consists mostly of copepods and sergestid shrimp. Increased sightings at the Afuera coincide with decreased sightings at Cabo Catoche, and both groups have the same sex ratio, implying that the same animals are likely involved in both aggregations; tagging data support this idea. With two whale shark aggregation areas, high coastal productivity and a previously-unknown scombrid spawning ground, the northeastern Yucatán marine region is a critical habitat that deserves more concerted conservation efforts. © 2011 de la Parra Venegas et al.


Haman K.H.,University of Georgia | Haman K.H.,Tufts University | Norton T.M.,Georgia Sea Turtle Center | Norton T.M.,St Catherines Island Foundation | And 3 more authors.
Journal of Wildlife Diseases | Year: 2012

Sharks are of commercial, research, conservation, and exhibition importance but we know little regarding health parameters and population status for many species. Here we present health indicators and species comparisons for adults of three common wild-caught species: 30 Atlantic sharpnose sharks (Rhizoprionodon terraenovae) and 31 bonnethead sharks (Sphyrna tiburo) from the western Atlantic, and 30 spiny dogfish sharks (Squalus acanthias) from the eastern Pacific. All animals were captured during June-July 2009 and 2010. Median values and preliminary reference intervals were calculated for hematology, plasma biochemistry, trace nutrients, and vitamin A, E, and D concentrations. Significant differences, attributable to physiologic differences among the species, were found in the basic hematologic and plasma biochemistry variables. Significant species differences in arsenic and selenium plasma concentrations were found and appear to coincide with diet and habitat variability among these three species. Vitamin E was significantly higher in the bonnethead shark, again related to the foraging ecology and ingestion of plant material by this species. The Atlantic sharpnose had significantly higher vitamin A concentrations, supported by the higher proportion of teleosts in the diet. Vitamin D was below the limit of quantification in all three species. These preliminary reference intervals for health variables can be used to assess and monitor the population health and serve as indicators of nutritional status in these populations of wild elasmobranchs. © Wildlife Disease Association 2012.


Fair P.A.,National Oceanic and Atmospheric Administration | Schaefer A.M.,Florida Atlantic University | Bossart G.D.,Florida Atlantic University | Bossart G.D.,Georgia Aquarium Research Center | And 2 more authors.
General and Comparative Endocrinology | Year: 2014

There is a growing concern about the impacts of stress in marine mammals as they face a greater array of threats. The stress response of free-ranging dolphins (Tursiops truncatus) was examined by measuring their physiologic response to capture and handling. Samples were collected from 168 dolphins during capture-release health assessments 2003-2007 at two study sites: Charleston, SC (CHS) and the Indian River Lagoon, FL (IRL). Adrenocorticotropic hormone (ACTH), cortisol, aldosterone (ALD) and catecholamines (epinephrine (EPI), norepinephrine (NOR), dopamine (DA)), were measured in blood and cortisol in urine. Mean time to collect pre-examination samples after netting the animals was 22. min; post-examination samples were taken prior to release (mean 1. h 37. min). EPI and DA concentrations decreased significantly with increased time to blood sampling. ACTH and cortisol levels increased from the initial capture event to the post-examination sample. EPI concentrations increased significantly with increasing time to the pre-examination sample and decreased significantly with time between the pre- and post-examination sample. Cortisol concentrations increased between the pre- and post-examination in CHS dolphins. Age- and sex-adjusted mean pre-examination values of catecholamines were significantly higher in CHS dolphins; ALD was higher in IRL dolphins. Significant differences related to age or sex included higher NOR concentrations in males; higher ALD and urine cortisol levels in juveniles than adults. Wild dolphins exhibited a typical mammalian response to acute stress of capture and restraint. Further studies that relate hormone levels to biological and health endpoints are warranted. © 2014.


Bell S.L.,State University of New York at Stony Brook | Allam B.,State University of New York at Stony Brook | McElroy A.,State University of New York at Stony Brook | Dove A.,Georgia Aquarium Research Center | Taylor G.T.,State University of New York at Stony Brook
Journal of Shellfish Research | Year: 2012

Epizootic shell disease (ESD) is a degradative process of the carapace in the American lobster, (Homarus americanus), putatively caused by bacterial infection, and potentially responsible for serious economic losses to the lobster fishery. In Long Island Sound (LIS), ESD is prevalent in lobsters from eastern LIS (ELIS), but almost absent in western LIS (WLIS), presenting a unique opportunity to examine the influence of microbial communities on the disease process among these subpopulations. Bacterial community compositions in diseased shell, healthy shell subsamples from lobsters exhibiting signs of disease, and carapace subsamples of healthy lobsters from ELIS, WLIS, and a coastal Maine reference site were profiled using terminal restriction fragment length polymorphism (TRFLP). Although overall bacterial community membership in diseased shell was not significantly different from healthy shell and healthy lobsters, prevalence of some individual terminal restriction fragments (TRFs) varied among disease state. Several TRFs were more abundant within lesions, whereas representation of other members appeared to be diminished, particularly members of the - and -proteobacteria. One TRF linked to anaerobic bacteria was enriched in lesions, suggesting anoxic microenvironments within diseased tissues. Activities of 4 ectohydrolases among communities were also measured in replicate excised shell samples. Chitinase potentials were high in all samples, and were indistinguishable among sample types. In contrast, proteinase and cellulase potentials were significantly higher in diseased shell than healthy shell and healthy lobster. Lipase potentials in LIS samples were significantly higher than those from Maine, but similar among disease states. The absence of site-specific differences in microbial communities suggests that biogeographic variation in colonizing microbes is not a factor in disease susceptibility. Lesion development appears to induce compositional shifts in normal carapace microflora, with displacement of some community members as others become more prevalent. Protein and cellulose appear to be more important targets than chitin for bacterial degradation within lesions. Furthermore, lipase activity, degrading the epicuticle lipid layer, may play a key role in regions with high disease prevalence.


Dove A.D.M.,Georgia Aquarium Research Center | Leisen J.,Georgia Institute of Technology | Zhou M.,Georgia Institute of Technology | Byrne J.J.,University of Birmingham | And 6 more authors.
PLoS ONE | Year: 2012

In a search for biomarkers of health in whale sharks and as exploration of metabolomics as a modern tool for understanding animal physiology, the metabolite composition of serum in six whale sharks (Rhincodon typus) from an aquarium collection was explored using 1H nuclear magnetic resonance (NMR) spectroscopy and direct analysis in real time (DART) mass spectrometry (MS). Principal components analysis (PCA) of spectral data showed that individual animals could be resolved based on the metabolite composition of their serum and that two unhealthy individuals could be discriminated from the remaining healthy animals. The major difference between healthy and unhealthy individuals was the concentration of homarine, here reported for the first time in an elasmobranch, which was present at substantially lower concentrations in unhealthy whale sharks, suggesting that this metabolite may be a useful biomarker of health status in this species. The function(s) of homarine in sharks remain uncertain but it likely plays a significant role as an osmolyte. The presence of trimethylamine oxide (TMAO), another well-known protective osmolyte of elasmobranchs, at 0.1-0.3 mol L-1 was also confirmed using both NMR and MS. Twenty-three additional potential biomarkers were identified based on significant differences in the frequency of their occurrence between samples from healthy and unhealthy animals, as detected by DART MS. Overall, NMR and MS provided complementary data that showed that metabolomics is a useful approach for biomarker prospecting in poorly studied species like elasmobranchs. © 2012 Dove et al.


Dove A.D.M.,Georgia Aquarium Research Center
Zoo Biology | Year: 2013

This essay explores the potential of metabolomics for exotic animal research in a zoological setting. Metabolomics is a suite of analytical tools aimed at gaining a holistic understanding of animal metabolism without prior knowledge of the compounds to be measured. These metabolic fingerprints can be used to define normal metabolism for an unstudied species, to characterize the metabolic deviation of diseased animals from the normal state over time, to identify biomarker compounds that best capture such deviations, and to measure the metabolic impact of clinical and nutritional interventions. Two approaches, nuclear magnetic resonance (NMR) and mass spectrometry (MS) provide large amounts of complimentary pure and applied biological data. Metabolomic methods hold great potential for researchers, clinicians, and nutritionists studying exotic and aquatic animals because they can produce a huge data return on research effort, and because they do not require much a priori knowledge of the animals' metabolism, which is so often then case in zoological settings. © 2012 Wiley Periodicals, Inc.


Alam M.T.,Emory University | Petit R.A.,Emory University | Read T.D.,Emory University | Dove A.D.M.,Georgia Aquarium Research Center
Gene | Year: 2014

The whale shark (Rhincodon typus) is the largest extant species of fish, belonging to the order Orectolobiformes. It is listed as a "vulnerable" species on the International Union for Conservation of Nature (IUCN)'s Red List of Threatened Species, which makes it an important species for conservation efforts. We report here the first complete sequence of the mitochondrial genome (mitogenome) of the whale shark obtained by next-generation sequencing methods. The assembled mitogenome is a 16,875. bp circle, comprising of 13 protein-coding genes, two rRNA genes, 22 tRNA genes and a control region. We also performed comparative analysis of the whale shark mitogenome to the available mitogenome sequences of 17 other shark species, four from the order Orectolobiformes, five from Lamniformes and eight from Carcharhiniformes. The nucleotide composition, number and arrangement of the genes in whale shark mitogenome are the same as found in the mitogenomes of the other members of the order Orectolobiformes and its closest orders Lamniformes and Carcharhiniformes, although the whale shark mitogenome had a slightly longer control region. The availability of mitogenome sequence of whale shark will aid studies of molecular systematics, biogeography, genetic differentiation, and conservation genetics in this species. © 2014 Elsevier B.V.


PubMed | Georgia Aquarium Research Center
Type: Journal Article | Journal: Zoo biology | Year: 2013

This essay explores the potential of metabolomics for exotic animal research in a zoological setting. Metabolomics is a suite of analytical tools aimed at gaining a holistic understanding of animal metabolism without prior knowledge of the compounds to be measured. These metabolic fingerprints can be used to define normal metabolism for an unstudied species, to characterize the metabolic deviation of diseased animals from the normal state over time, to identify biomarker compounds that best capture such deviations, and to measure the metabolic impact of clinical and nutritional interventions. Two approaches, nuclear magnetic resonance (NMR) and mass spectrometry (MS) provide large amounts of complimentary pure and applied biological data. Metabolomic methods hold great potential for researchers, clinicians, and nutritionists studying exotic and aquatic animals because they can produce a huge data return on research effort, and because they do not require much a priori knowledge of the animals metabolism, which is so often then case in zoological settings.


PubMed | Georgia Aquarium Research Center and Emory University
Type: Comparative Study | Journal: Gene | Year: 2014

The whale shark (Rhincodon typus) is the largest extant species of fish, belonging to the order Orectolobiformes. It is listed as a vulnerable species on the International Union for Conservation of Nature (IUCN)s Red List of Threatened Species, which makes it an important species for conservation efforts. We report here the first complete sequence of the mitochondrial genome (mitogenome) of the whale shark obtained by next-generation sequencing methods. The assembled mitogenome is a 16,875 bp circle, comprising of 13 protein-coding genes, two rRNA genes, 22 tRNA genes and a control region. We also performed comparative analysis of the whale shark mitogenome to the available mitogenome sequences of 17 other shark species, four from the order Orectolobiformes, five from Lamniformes and eight from Carcharhiniformes. The nucleotide composition, number and arrangement of the genes in whale shark mitogenome are the same as found in the mitogenomes of the other members of the order Orectolobiformes and its closest orders Lamniformes and Carcharhiniformes, although the whale shark mitogenome had a slightly longer control region. The availability of mitogenome sequence of whale shark will aid studies of molecular systematics, biogeography, genetic differentiation, and conservation genetics in this species.


PubMed | Georgia Institute of Technology, U.S. Geological Survey and Georgia Aquarium Research Center
Type: | Journal: Comparative biochemistry and physiology. Part D, Genomics & proteomics | Year: 2015

Atlantic salmon Salmo salar undergo months-long inappetence during spawning, but it is not known whether this inappetence is a pathological state or one for which the fish are adapted. Recent work has shown that inappetent whale sharks can exhibit circulating metabolite profiles similar to ketosis known to occur in humans during starvation. In this work, metabolite profiling was used to explore differences in analyte profiles between a cohort of inappetent spawning run Atlantic salmon and captively reared animals that were fed up to and through the time of sampling. The two classes of animals were easily distinguished by their metabolite profiles. The sea-run fish had elevated -9 fatty acids relative to the domestic feeding animals, while other fatty acid concentrations were reduced. Sugar alcohols were generally elevated in inappetent animals, suggesting potentially novel metabolic responses or pathways in fish that feature these compounds. Compounds expected to indicate a pathological catabolic state were not more abundant in the sea-run fish, suggesting that the animals, while inappetent, were not stressed in an unnatural way. These findings demonstrate the power of discovery-based metabolomics for exploring biochemistry in poorly understood animal models.

Loading Georgia Aquarium Research Center collaborators
Loading Georgia Aquarium Research Center collaborators