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Gayford JH, Godfrey H, Whitehead DA. Ontogenetic morphometry of the brown smoothhound shark Mustelus henlei with implications for ecology and evolution. J Morphol 2023; 284:e21608. [PMID: 37458085 DOI: 10.1002/jmor.21608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/17/2023] [Accepted: 05/29/2023] [Indexed: 07/18/2023]
Abstract
The central tenet of ecomorphology links ecological and morphological variation through the process of selection. Traditionally used to rationalise morphological differences between taxa, an ecomorphological approach is increasingly being utilised to study morphological differences expressed through ontogeny. Elasmobranchii (sharks, rays and skates) is one clade in which such ontogenetic shifts in body form have been reported. Such studies are limited to a relatively small proportion of total elasmobranch ecological and morphological diversity, and questions remain regarding the extent to which ecological selection are driving observed morphometric trends. In this study, we report ontogenetic growth trajectories obtained via traditional linear morphometrics from a large data set of the brown smoothhound shark (Mustelus henlei). We consider various morphological structures including the caudal, dorsal and pectoral fins, as well as several girth measurements. We use an ecomorphological approach to infer the broad ecological characteristics of this population and refine understanding of the selective forces underlying the evolution of specific morphological structures. We suggest that observed scaling trends in M. henlei are inconsistent with migratory behaviour, but do not contradict a putative trophic niche shift. We also highlight the role of predation pressure and sex-based ecological differences in driving observed trends in morphometry, a factor which has previously been neglected when considering the evolution of body form in sharks.
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Affiliation(s)
- Joel H Gayford
- Department of Life Sciences, Imperial College London, Ascot, UK
- Marine Research and Conservation Department, Investigación Tiburones México A.C, La Paz, Mexico
- Shark Measurements, London, UK
| | - Hana Godfrey
- Marine Research and Conservation Department, Investigación Tiburones México A.C, La Paz, Mexico
| | - Darren A Whitehead
- Marine Research and Conservation Department, Investigación Tiburones México A.C, La Paz, Mexico
- Instituto Politécnico Nacional, Centro Interdisciplinario de Ciencias Marinas, La Paz, México
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Rangel BS, Hammerschlag N, Martinelli LA, Moreira RG. Effects of urbanization on the nutritional ecology of a highly active coastal shark: Preliminary insights from trophic markers and body condition. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 826:154082. [PMID: 35218820 DOI: 10.1016/j.scitotenv.2022.154082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 02/18/2022] [Indexed: 06/14/2023]
Abstract
The synergistic effects of coastal urbanization have dramatically impacted biological communities. Yet, few studies have investigated how urbanization can influence the diet quality and trophic ecology of coastal sharks. In a preliminary study, we examined for spatial variation in the nutritional ecology of a highly active marine predator, the blacktip (Carcharhinus limbatus) exposed to regional differences in coastal urbanization in southeast Florida. We used medium-term nutritional indicators (i.e., body condition and whole blood stable isotopes [δ15N and δ13C]) and short-term dietary markers (i.e., plasma fatty acid profiles) to test the hypothesis that blacktip sharks sampled within highly urbanized areas (hereafter, 'urban sharks') would exhibit higher body condition, but lower diet quality, compared to conspecifics sampled in areas exposed to relatively low levels of urbanization (hereafter, 'urban sharks'). Our initial results showed that urban blacktip sharks exhibited relatively higher body condition, blood δ15N levels, and percentages of saturated fatty acids compared to non-urban sharks. Collectively, these results suggest a possible positive alteration in the amount of food consumed by blacktip sharks in the study region and/or in the caloric value of their prey. We also found lower percentages of bacterial markers and higher values of dinoflagellate markers in urban sharks. Accordingly, we did not detect an expected reduction in diet quality (in terms of essential fatty acids) in this highly active species exposed to urbanization, as has been previously reported in a resident shark species (Ginglymostoma cirratum). Therefore, it is possible that lifestyle and feeding behavior influence the quality of food consumed by urban sharks. We suspect that impacts of urbanization are more pronounced in resident, sedentary and benthic species.
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Affiliation(s)
- Bianca S Rangel
- Laboratório de Metabolismo e Reprodução de Organismos Aquáticos, Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo. Rua do Matão, travessa 14, 321, CEP 05508-090, Cidade Universitária, São Paulo, SP, Brazil.
| | - Neil Hammerschlag
- Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, FL 33149, USA; Leonard and Jayne Abess Center for Ecosystem Science and Policy, University of Miami, Coral Gables, FL 33146, USA
| | - Luiz A Martinelli
- Departamento de Ecologia Isotópica, Centro de Energia Nuclear na Agricultura (CENA), Universidade de São Paulo, Piracicaba, São Paulo 13416-000, Brazil
| | - Renata Guimarães Moreira
- Laboratório de Metabolismo e Reprodução de Organismos Aquáticos, Departamento de Fisiologia, Instituto de Biociências, Universidade de São Paulo. Rua do Matão, travessa 14, 321, CEP 05508-090, Cidade Universitária, São Paulo, SP, Brazil
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3
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Pérez-Rojas JG, Mejía-Falla PA, Navia AF, Tarazona AM, Pardo-Carrasco SC. Hematology and blood biochemistry profile of the freshwater stingray Potamotrygon magdalenae as a tool for population assessment in artificial environments. BRAZ J BIOL 2021; 82:e233780. [PMID: 33787714 DOI: 10.1590/1519-6984.233780] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 07/30/2020] [Indexed: 11/21/2022] Open
Abstract
Hematological and blood biochemical reference information is important to establish physiological status of freshwater stingray populations and improve care and management protocols in artificial environments. Here, we used a commercial freshwater stingray with high mortality rates in the market (Potamotrygon magdalenae), as an example to understand how artificial environments and handling protocols influence physiological status of captive freshwater stingrays. To this purpose, blood from five adult males and six adult females was collected to perform complete blood counts and blood chemistry analyses. All sampled animals showed good body condition with no differences between sexes. Differences between sexes were only found for the differential count of lymphocytes. Red blood results were consistent with previously studied potamotrygonids while white blood results showed higher values of leukocytes, thrombocytes, heterophils and lymphocytes in P. magdalenae compared to other Potamotrygonids. All types of leukocytes described for elasmobranchs were found except neutrophils and basophils. Blood metabolites showed an influence of ex situ diet in total protein, triglycerides and cholesterol. Glucose results were consistent while urea showed lower levels than those recorded for other freshwater stingrays. These results highlight the importance of physical, physiological and health analysis in freshwater stingrays as a part of welfare assessment to improve monitoring protocols and survival rates in public or private aquaria.
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Affiliation(s)
- J G Pérez-Rojas
- Fundación Colombiana para la Investigación y Conservación de Tiburones y Rayas - SQUALUS, Cali, Colombia.,Universidad Nacional de Colombia, Facultad de Ciencias Agrarias, Departamento de Producción Animal, Medellín, Colombia
| | - P A Mejía-Falla
- Fundación Colombiana para la Investigación y Conservación de Tiburones y Rayas - SQUALUS, Cali, Colombia.,Wildlife Conservation Society - WCS Colombia, Cali, Colombia
| | - A F Navia
- Fundación Colombiana para la Investigación y Conservación de Tiburones y Rayas - SQUALUS, Cali, Colombia
| | - A M Tarazona
- Universidad Nacional de Colombia, Facultad de Ciencias Agrarias, Departamento de Producción Animal, Medellín, Colombia
| | - S C Pardo-Carrasco
- Universidad Nacional de Colombia, Facultad de Ciencias Agrarias, Departamento de Producción Animal, Medellín, Colombia
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Moorhead SG, Gallagher AJ, Merly L, Hammerschlag N. Variation of body condition and plasma energy substrates with life stage, sex, and season in wild-sampled nurse sharks Ginglymostoma cirratum. JOURNAL OF FISH BIOLOGY 2021; 98:680-693. [PMID: 33161578 DOI: 10.1111/jfb.14612] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/23/2020] [Accepted: 11/07/2020] [Indexed: 06/11/2023]
Abstract
Reported here are the relationships among morphological (i.e., body condition) and biochemical (i.e., plasma concentrations of triglycerides, cholesterol, free fatty acids, and ketone bodies and ketone body ratios) parameters related to energy storage and use, as well as the variation of such parameters, for 107 free-ranging nurse sharks Ginglymostoma cirratum sampled off South Florida. Immature G. cirratum exhibited a higher variance in body condition, plasma free fatty acid concentrations and ketone body ratios compared to adults. Mature female G. cirratum had significantly higher body condition than mature males, driven by a seasonal increase in mature female body condition during the wet season. Mature male G. cirratum showed a decrease in the ketone body β-hydroxybutyric acid during the dry season. Taken together, this study provides a baseline assessment of body condition and internal physiological state for a data-poor marine species and demonstrates significant ontogenetic, sexual and seasonal variation in G. cirratum energetic state. As concluded by other studies of energy metabolism in free-ranging sharks, this research highlights the importance of considering intraspecific patterns and sampling context for inferring the drivers of variation.
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Affiliation(s)
- Shannon G Moorhead
- Department of Marine Ecosystems and Society, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA
| | - Austin J Gallagher
- Beneath the Waves, Herndon, Virginia, USA
- Fish Ecology and Conservation Physiology Laboratory, Carleton University, Ottawa, Ontario, Canada
| | - Liza Merly
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA
| | - Neil Hammerschlag
- Department of Marine Ecosystems and Society, Rosenstiel School of Marine and Atmospheric Science, University of Miami, Miami, Florida, USA
- Leonard and Jayne Abess Center for Ecosystem Science and Policy, University of Miami, Coral Gables, Florida, USA
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Same species, different prerequisites: investigating body condition and foraging success in young reef sharks between an atoll and an island system. Sci Rep 2019; 9:13447. [PMID: 31530846 PMCID: PMC6748967 DOI: 10.1038/s41598-019-49761-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 08/27/2019] [Indexed: 11/08/2022] Open
Abstract
Acquiring and storing energy is vital to sharks of all age-classes. Viviparous shark embryos receive endogenous maternal energy reserves to sustain the first weeks after birth. Then, in order to maintain body condition, sharks must start foraging. Our goal was to understand whether maternal energy investments vary between blacktip reef sharks (Carcharhinus melanopterus) from two populations and to what extent body condition and the initiation of foraging might be affected by presumably variable maternal investments. A total of 546 young sharks were captured at St. Joseph atoll (Seychelles) and Moorea (French Polynesia) between 2014 and 2018, and indices of body condition and percentage of stomachs containing prey were measured. Maternal investment was found to be site-specific, with significantly larger, heavier, and better conditioned individuals in Moorea. Despite these advantages, as time progressed, Moorea sharks exhibited significant decreases in body condition and were slower to initiate foraging. We suggest that the young sharks' foraging success is independent of the quality of maternal energy resources, and that other factors, such as prey availability, prey quality, and/or anthropogenic stressors are likely responsible for the observed differences across sites. Insights into intraspecific variations in early life-stages may further support site-specific management strategies for young sharks from nearshore habitats.
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Merly L, Lange L, Meÿer M, Hewitt AM, Koen P, Fischer C, Muller J, Schilack V, Wentzel M, Hammerschlag N. Blood plasma levels of heavy metals and trace elements in white sharks (Carcharodon carcharias) and potential health consequences. MARINE POLLUTION BULLETIN 2019; 142:85-92. [PMID: 31232352 DOI: 10.1016/j.marpolbul.2019.03.018] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/04/2019] [Accepted: 03/10/2019] [Indexed: 06/09/2023]
Abstract
Heavy metals may adversely affect health in marine organisms. As top predators, sharks may be especially vulnerable to exposure over long lifespans. Here we evaluate plasma levels of 14 heavy metals and 12 trace elements in white sharks, Carcharodon carcharias, in South Africa to determine whether they are related to sex, body size, and/or body condition and other health parameters. High levels of mercury and arsenic were found in shark blood at levels considered toxic in other vertebrates. Heavy metal concentrations were not related to body size or sex. Metal concentrations were not related to body condition with exception of copper, which was positively correlated. Protective effects of elements such as selenium, zinc, and iron were not detected. No negative effects on health parameters, such as total leukocytes or granulocyte to lymphocyte ratios were observed. Results suggest that sharks may have protective mechanisms that mitigate harmful effects of heavy metal exposure, providing new opportunities for future studies.
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Affiliation(s)
- Liza Merly
- Department of Marine Biology and Ecology, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, FL 33149, USA.
| | - Lucia Lange
- PathCare VetLab, PathCare Reference Laboratory, Private Bag X107, N1 City, Goodwood 7460, South Africa
| | - Michael Meÿer
- Branch: Oceans and Coasts, Department of Environmental Affairs, Private Bag X4390, Cape Town 8000, South Africa
| | - Adrian Michael Hewitt
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch, 7701, Cape Town, South Africa
| | - Pieter Koen
- Western Cape Department of Agriculture, Veterinary Services, Private Bag X1, Elsenberg, 7607, South Africa
| | | | - Johann Muller
- PathCare VetLab, PathCare Reference Laboratory, Private Bag X107, N1 City, Goodwood 7460, South Africa
| | - Volker Schilack
- V&M Analytical Toxicology Laboratory Services, Private Bag X6590, George 6530, South Africa
| | - Mauritz Wentzel
- V&M Analytical Toxicology Laboratory Services, Private Bag X6590, George 6530, South Africa
| | - Neil Hammerschlag
- Department of Marine Ecosystems and Society, Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Miami, FL 33149, USA; Leonard and Jayne Abess Center for Ecosystem Science and Policy, University of Miami, Coral Gables, FL 33146, USA
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Corsso JT, Gadig OBF, Barreto RRP, Motta FS. Condition analysis of the Brazilian sharpnose shark Rhizoprionodon lalandii: evidence of maternal investment for initial post-natal life. JOURNAL OF FISH BIOLOGY 2018; 93:1038-1045. [PMID: 30120771 DOI: 10.1111/jfb.13780] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 08/13/2018] [Indexed: 06/08/2023]
Abstract
The present study analysed the condition factor (K) and the hepato-somatic index (I H ) of the Brazilian sharpnose shark Rhizoprionodon lalandii during its entire life cycle. Discontinuity of liver growth was observed after sexual maturity. High condition values were recorded in the length classes of 300-350 mm (neonates), when the livers represented about 8% of total mass, decreasing until the length classes of 400-450 and 450-500 mm in females and males, respectively. Seasonal analysis exhibited low I H values in the summer, while for K, low values were in spring, indicating greater investment for body growth during spring and for gonad maturation in summer. Such findings indicate that this small coastal shark species accumulates reserve substances in the liver that will be used during reproduction. The decline in I H values in juveniles suggests that reserves provisioned by the mother to the neonate liver can be used in the first months of life.
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Affiliation(s)
- Jessica T Corsso
- Laboratório de Ecologia e Conservação Marinha (LABECMAR), Instituto do Mar, Universidade Federal de São Paulo (UNIFESP), Santos, Brazil
| | - Otto B F Gadig
- Laboratório de Pesquisa de Elasmobrânquios, Instituto de Biociências, Universidade, Estadual Paulista - UNESP, Campus do Litoral Paulista, São Vicente, Brazil
| | - Rodrigo R P Barreto
- Centro Nacional de Pesquisa e Conservação da Biodiversidade Marinha do Sudeste e Sul do Brasil (CEPSUL/ICMBio), Itajaí, Brazil
| | - Fabio S Motta
- Laboratório de Ecologia e Conservação Marinha (LABECMAR), Instituto do Mar, Universidade Federal de São Paulo (UNIFESP), Santos, Brazil
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