Species-Specific Characteristics Influence Contaminant Accumulation Trajectories and Signatures Across Ontogeny in Three Pelagic Shark Species

2019 ◽  
Vol 53 (12) ◽  
pp. 6997-7006 ◽  
Author(s):  
Kady Lyons ◽  
Dovi Kacev ◽  
Antonella Preti ◽  
David Gillett ◽  
Heidi Dewar ◽  
...  
2021 ◽  
Author(s):  
Asha Goodman ◽  
Bhavya Papudeshi ◽  
Michael P. Doane ◽  
Colton Johnson ◽  
Maria Mora ◽  
...  

Abstract Background: Characterizations of sharks-microbe systems in wild environments have outlined patterns of species-specific microbiomes; however, whether captivity affects these trends has yet to be determined. We used high-throughput shotgun sequencing to assess the epidermal microbiome belonging to leopard sharks (Triakis semifasciata) in captive (Birch Aquarium, La Jolla California), semi-captive (<1 year in captivity; Scripps Institute of Oceanography, California) and wild environments (Moss Landing and La Jolla, California). Results: Here we report captive environments do not drive microbiome composition of T. semifasciata to significantly diverge from wild counterparts as life-long captive sharks maintain a species-specific epidermal microbiome resembling those associated with semi-captive and wild populations. Major taxonomic composition shifts observed were inverse changes of top taxonomic contributors across captive duration, specifically an increase of Pseudoalteromonadaceae and consequent decrease of Pseudomonadaceae relative abundance as T. semifasciata increased duration in captive conditions. Moreover, we show captivity did not lead to significant losses in microbial α-diversity of shark epidermal communities. Finally, we present a novel association between T. semifasciata and the Muricauda genus as MAGs revealed a consistent relationship across captive, semi-captive, and wild populations. Conclusions: Our report illustrates the importance of conservation programs for coastal fishes as epidermally-associated microbes of near-shore shark species do not suffer detrimental impacts from long or short-term captivity. Our findings also expand on current understanding of shark epidermal microbiomes, explore the effects of ecologically different scenarios on benthic shark microbe associations, and highlight novel microbial associations that are consistent across captive gradients.


2020 ◽  
Vol 84 (4) ◽  
pp. 343-354
Author(s):  
José G. Pérez-Rojas ◽  
Katherine Torres-Palacios ◽  
Amalia Uribe ◽  
Andrés F. Navia ◽  
Paola A. Mejía-Falla

The aim of this study was to assess the suitability of different vertebrae staining techniques for the visualization and counting of growth bands in tropical species of batoids (Narcine leoparda, Urotrygon aspidura, Hypanus longus, Potamotrygon magdalenae) and sharks (Alopias pelagicus, Carcharhinus falciformis, Sphyrna lewini, Sphyrna corona and Mustelus lunulatus). Different cutting thicknesses and staining protocols were tested, analysing the precision and bias of each combination to identify the most accurate technique for estimating age. Vertebral sections of 0.4 mm were more suitable for batoids, except for Narcine leoparda; for this species and for all the shark species assessed, sections of 0.5 mm are recommended. Different combinations of stain and exposure time were required to achieve the best visualizations of vertebral growth band pair for the shark and ray species. Intraspecific variation occurred among vertebrae size of batoids. Our results confirm the importance of defining a suitable species-specific protocol for sectioning and staining hard structures before carrying out an age and growth study to improve the reliability of the age estimates.


2021 ◽  
Vol 8 ◽  
Author(s):  
Mariah C. Livernois ◽  
John A. Mohan ◽  
Thomas C. TinHan ◽  
Travis M. Richards ◽  
Brett J. Falterman ◽  
...  

As predators, coastal and oceanic sharks play critical roles in shaping ecosystem structure and function, but most shark species are highly susceptible to population declines. Effective management of vulnerable shark populations requires knowledge of species-specific movement and habitat use patterns. Since sharks are often highly mobile and long-lived, tracking their habitat use patterns over large spatiotemporal scales is challenging. However, the analysis of elemental tracers in vertebral cartilage can describe a continuous record of the life history of an individual from birth to death. This study examined trace elements (Li, Mg, Mn, Zn, Sr, and Ba) along vertebral transects of five shark species with unique life histories. From most freshwater-associated to most oceanic, these species include Bull Sharks (Carcharhinus leucas), Bonnethead Sharks (Sphyrna tiburo), Blacktip Sharks (Carcharhinus limbatus), Spinner Sharks (Carcharhinus brevipinna), and Shortfin Mako Sharks (Isurus oxyrinchus). Element concentrations were compared across life stages (young-of-the-year, early juvenile, late juvenile, and adult) to infer species-specific ontogenetic patterns of habitat use and movement. Many of the observed elemental patterns could be explained by known life history traits: C. leucas exhibited clear ontogenetic changes in elemental composition matching expected changes in their use of freshwater habitats over time. S. tiburo elemental composition did not differ across ontogeny, suggesting residence in estuarine/coastal regions. The patterns of elemental composition were strikingly similar between C. brevipinna and C. limbatus, suggesting they co-occur in similar habitats across ontogeny. I. oxyrinchus elemental composition was stable over time, but some ontogenetic shifts occurred that may be due to changes in migration patterns with maturation. The results presented in this study enhance our understanding of the habitat use and movement patterns of coastal and oceanic sharks, and highlights the applicability of vertebral chemistry as a tool for characterizing shark life history traits.


1999 ◽  
Vol 82 (5) ◽  
pp. 1163-1170 ◽  
Author(s):  
LaShawn A Weaver ◽  
Ronald C Lundstrom ◽  
A Ann Colbert

Abstract Isoelectric focusing of muscle proteins is a fast and highly reproducible technique that has been used to identify fish species. Application of isoelectric focusing of sarcoplasmic proteins is described for identification of shark species. Sarcoplasmic protein patterns from muscle tissue of single individuals from 26 shark species and multiple individuals from 2 of the 26 shark species are shown on 1 mm thick polyacrylamide gels. Eight of these species showed pattern polymorphisms in major and minor bands; however, no individual within a species displayed the same protein pattern as that in any other species. Protein banding patterns of each species were visually distinguishable, and patterns generated on the basis of defined parameters were analyzed by a computer to obtain isoelectric points of bands, to produce schematic representations of banding patterns, and to distinguish between species-specific patterns. Isoelectric focusing appears to be an excellent method for identifying sharks. Additionally, isoelectric focusing of muscle proteins is readily applicable as a forensic tool to identify the species of shark samples received as evidence for law enforcement actions supporting shark fishery management plans.


2021 ◽  
Vol 12 ◽  
Author(s):  
Rachael Storo ◽  
Cole Easson ◽  
Mahmood Shivji ◽  
Jose V. Lopez

Profiles of symbiotic microbial communities (“microbiomes”) can provide insight into the natural history and ecology of their hosts. Using high throughput DNA sequencing of the 16S rRNA V4 region, microbiomes of five shark species in South Florida (nurse, lemon, sandbar, Caribbean reef, and tiger) have been characterized for the first time. The microbiomes show species specific microbiome composition, distinct from surrounding seawater. Shark anatomical location (gills, teeth, skin, cloaca) affected the diversity of microbiomes. An in-depth analysis of teeth communities revealed species specific microbial communities. For example, the genus Haemophilus, explained 7.0% of the differences of the teeth microbiomes of lemon and Caribbean reef sharks. Lemon shark teeth communities (n = 11) contained a high abundance of both Vibrio (10.8 ± 26.0%) and Corynebacterium (1.6 ± 5.1%), genera that can include human pathogenic taxa. The Vibrio (2.8 ± 6.34%) and Kordia (3.1 ± 6.0%) genera and Salmonella enterica (2.6 ± 6.4%) were the most abundant members of nurse shark teeth microbial communities. The Vibrio genus was highly represented in the sandbar shark (54.0 ± 46.0%) and tiger shark (5.8 ± 12.3%) teeth microbiomes. The prevalence of genera containing potential human pathogens could be informative in shark bite treatment protocols and future research to confirm or deny human pathogenicity. We conclude that South Florida sharks host species specific microbiomes that are distinct from their surrounding environment and vary due to differences in microbial community composition among shark species and diversity and composition among anatomical locations. Additionally, when considering the confounding effects of both species and location, microbial community diversity and composition varies.


Author(s):  
Linda Sicko-Goad

Although the use of electron microscopy and its varied methodologies is not usually associated with ecological studies, the types of species specific information that can be generated by these techniques are often quite useful in predicting long-term ecosystem effects. The utility of these techniques is especially apparent when one considers both the size range of particles found in the aquatic environment and the complexity of the phytoplankton assemblages.The size range and character of organisms found in the aquatic environment are dependent upon a variety of physical parameters that include sampling depth, location, and time of year. In the winter months, all the Laurentian Great Lakes are uniformly mixed and homothermous in the range of 1.1 to 1.7°C. During this time phytoplankton productivity is quite low.


2005 ◽  
Vol 173 (4S) ◽  
pp. 18-18
Author(s):  
Joseph C. Liao ◽  
Mitra Mastali ◽  
David A. Haake ◽  
Bernard M. Churchill

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