Fishing profile and commercial landings of shark and batoids in a global elasmobranchs conservation hotspot.

This paper describes the fishing profile and the temporal variation in the commercial landings of elasmobranchs in a global hotspot for their conservation and investigates the variables that influenced the landings. Census data on commercial catches were obtained between April 2008 and October 2010 from nine landing sites in Bragança (Pará, northern Brazil). Five vessel types, four fishing gears, and eight fishing techniques engaged with elasmobranch capture were identified. A total of 2,357 landings were recorded, with a total production of 354 t. The highest yields were recorded in 2009, with sharks being harvested mostly by small and medium-sized vessels, and batoids, by small vessels and canoes. Drifting nets and longlines played a prominent role in elasmobranch fisheries. The results show that the landings were influenced by days at sea, which is common in tropical fisheries. The elasmobranch data series is discontinuous as statistics are absent for most fishing sites albeit imperative for proper management, as well as relevant for decision-makers focusing on their conservation.

Expanding records of occurrence of the whale shark (Rhincodon typus) in The Bahamas and a call for sustainable tourism practices.

This report updates our understanding of whale shark occurrences in The Bahamas by drawing upon a variety of data sources. Our findings reveal previously unreported sighting locations, often associated with tourism activities, underscoring the pivotal role played by nontraditional data sources in addressing knowledge gaps. These revelations emphasize the ongoing necessity for monitoring efforts. Additionally, we have found cases that raise concerns related to unregulated human-shark interactions in the region, highlighting the pressing need for sustainable tourism practices within Bahamian waters.

Ecotoxicology applied to conservation: Potential negative metal and metalloid contamination effects on the homeostatic balance of the critically endangered Brazilian guitarfish, Pseudobatos horkelii (Elasmobranchii: Rhinobatidae).

Metal contamination poses a significant threat to elasmobranchs, underscoring the need for targeted conservation approaches. The critically endangered Brazilian guitarfish, Pseudobatos horkelii, confronts an array of challenges, notably overexploitation, putting its survival at risk. Our study investigated the potential toxicity arising from arsenic (As), cadmium (Cd), mercury (Hg), and lead (Pb) contamination across various adult guitarfish tissues from southeastern Brazil. Serological stress indicators, nutritional metabolites, and creatinine, an organ function marker, were also assessed, and Selenium (Se) levels were also investigated for possible protective effects. Our investigation unveiled significant correlations between metal concentrations and the determined physiological markers, shedding light on potential adverse effects. Remarkably, six correlations were indicative of how Hg and Pb negatively impact hepatic metabolite assimilation, while As was shown to influence renal phosphorus dynamics, Cd to affect rectal gland phosphorus regulation, and Pb to influence creatinine production in muscle tissue. Furthermore, Se demonstrated protective properties against Cd, Hg, and Pb, suggesting a role in alleviating the toxicity of these elements. Despite probable protective Se influences, the detected elemental interactions still suggest potential for organ impairment. These findings gain heightened significance within the context of the cumulative stressors faced by the Brazilian guitarfish, with metal contamination exhibiting the capacity to erode this species resilience against both anthropogenic and environmental pressures, thereby disrupting systemic equilibrium and jeopardizing wild populations. By investigating the intricate balance between metal accumulation and physiological consequences, our study contributes with crucial insights into potential conservation strategy formulations towards pollution for this critically endangered elasmobranch species.

First report on the serum chemistry and haematology of free-ranging dusky (Carcharhinus obscurus) and sandbar (Carcharhinus plumbeus) sharks in the eastern Mediterranean Sea.

Shark assessments in the Mediterranean Sea are still scarce, and serum chemistry and haematological data have yet to be reported for wild dusky (Carcharhinus obscurus) or sandbar (Carcharhinus plumbeus) shark populations in the Mediterranean Sea. Herein, blood samples were obtained from adult dusky (n = 23) and sandbar (n = 14) sharks from an aggregation site near the Hadera power and desalination plants in Israel in the winters of 2016-20. Several serum chemistry analytes were characterized with relation to stress, body size and environmental conditions. Glucose concentrations were higher, while total cholesterol concentrations were lower in dusky sharks than in sandbar sharks, potentially due to distinct metabolic pathways utilized during the capture-related activity by both species. However, differences in sex and size are noted and should be considered. The blood cell morphology of both species was consistent with previous findings for sandbar sharks. Atypical monocytes were noted in one dusky shark. Preliminary and exploratory reference intervals for female dusky sharks were calculated for glucose, triglycerides, total cholesterol, total protein and creatine kinase. These data must be viewed with caution due to the potential influence of capture-related stress on analyte concentrations and activities and the fact that only females were employed in the calculations. Moreover, the sampling site is adjacent to coastal power and desalination plants, which may significantly affect shark physiology. Although limited, this novel database on dusky and sandbar shark serum chemistry and haematology aspects is essential as a first attempt to obtain data on these species in the eastern Mediterranean Sea and for future conservation and long-term biomonitoring efforts.

First description of a Gammaherpesvirus in a common dolphin (Delphinus delphis) from the Eastern Mediterranean Sea.

In September 2020, a male common dolphin (Delphinus delphis) was found dead on a beach near Bat-Yam, Israel. A small, raised, well circumscribed penile lesion (i.e., mass) was identified and removed for histology and molecular characterizations. By histology, the penile mass presented focal keratinization of the squamous epithelium and a mild ballooning of acanthocytes in lower epithelium levels, as well as features compatible with viral plaques, and tested positive for a gammaherpesvirus through molecular characterization analyses. Tissue samples from the lungs, liver, and spleen, however, tested negative for herpesvirus infection. The gammaherpesvirus detected herein is similar to other isolates found in several areas worldwide in different cetacean species. This is the first reported case of gammaherpesvirus infection in dolphins from the eastern Mediterranean Sea, indicative of the need for long-term assessments to create viral infections databases in cetaceans, especially in a climate change context, which is likely to intensify infectious disease outbreaks in marine mammals in the future.

Carbonic anhydrase in elasmobranchs and current climate change scenario implications.

The enzyme carbonic anhydrase (CA) has well-known functions in acid-base balance, respiratory gas exchange, and osmoregulation in teleost fishes. However, studies concerning the role of CA in elasmobranchs are still scarce. Therefore, the aim of this study is to present the current status of CA studies in sharks and rays, as well as to identify gaps and emerging needs, in order to guide future studies. This review is organized according to the main roles of CA, with further considerations on climate change and CA effects indicated as paramount, as strategies in the face of climate change can be crucial for species response. The literature review revealed a reduction in publications on CA over the years. In addition, a historical research differentiation is noted, where the first assessments on the subject addressed investigations on basic CA functions, while the most recent studies present a comparative approach among species as well as interdisciplinary discussions, such as ecology and phylogeny. Considering that several elasmobranchs are threatened, future studies should prioritize non-lethal methodologies, in addition to expanding studies to climate change effects on CA.

Almost nothing is known about the tiger shark in South Atlantic waters.

The tiger shark (Galeocerdo cuvier) has been relatively well assessed concerning biology and ecology aspects in both Atlantic and Pacific North America and in Caribbean waters. The amount of data in these regions has led to the species protection under capture quotas and with the creation of sanctuaries. The reality in developing countries, however, is the exact opposite, with scarce information on the species in the southern hemisphere, namely South American and African waters. In these regions, protection measures are insufficient, and studies on tiger shark biology and ecology are scarce, significantly hindering conservation and management efforts. Thus, the aim of this study was to compile scientific literature on the tiger shark in the South Atlantic and discuss the impact of these data (or lack thereof) distributed within a total of ten research categories for guiding management plans. In total, 41 scientific publications on different G. cuvier biology and ecology aspects were obtained. The most studied topics were Feeding Ecology (n = 12), followed by Human Interactions (n = 8), and Movements and Migration (n = 7). Northeastern Brazil (Southwest Atlantic) was the most researched area, probably due to the higher coastal abundance of tiger sharks in this area, alongside a high number of recorded attacks, justifying funding for studies in the region. No studies carried out in other South American or African countries were found. It is important to mention that even though some research topics are relatively well covered, a severe knowledge gap is noted for risk assessments and fisheries management, with a proposition for the implementation of sanctuaries noted. This is, however, particularly worrisome, as the South Atlantic is mostly unexplored in this regard for tiger sharks. It is also important to note how different the attention given to this species is in the North Atlantic when compared to the South region. Lastly, we highlight that the existence of sub-populations, the lack of migratory corridors geographically connecting distinct areas used by the species, and the lack of fisheries statistics on tiger shark landings, all increase the vulnerability of this species in the South Atlantic.

Photobacterium damselae subspecies damselae Pneumonia in Dead, Stranded Bottlenose Dolphin, Eastern Mediterranean Sea.

Photobacterium damselae subspecies damselae, an abundant, generalist marine pathogen, has been reported in various cetaceans worldwide. We report a bottlenose dolphin in the eastern Mediterranean Sea that was found stranded and dead. The dolphin had a severe case of chronic suppurative pneumonia and splenic lymphoid depletion caused by this pathogen.

Elasmobranch-associated microbiota: a scientometric literature review.

Elasmobranchs provide greatly relevant ecosystem services for the balance of the environments in which they are inserted. In recent decades, sharp population declines have been reported for many species in different regions worldwide, making this taxonomic group currently one of the most threatened with extinction. This scenario is almost entirely due to excessive fishing pressure, but any contributing factor that may cause additional mortality to populations must be mapped and monitored. In a fast-changing world, emerging marine pollution associated with climate change display the potential to increase the spread of infectious agents. These can, in turn, lead to mortality events, both directly and indirectly, by reducing immune responses and the physical and nutritional condition of affected individuals. In this context, the present study aimed to analyze data concerning elasmobranch-associated microbiota, identifying study trends and knowledge gaps in order to direct future studies on this topic of growing relevance for the health of wild populations, as well as individuals maintained in captivity, considering the zoonotic potential of these microorganisms.

Unraveling Metabolite Provisioning to Offspring Through Parental Fluids: A Case Study of the Brazilian Guitarfish, Pseudobatos horkelii.

Elasmobranchs have a very distinct metabolism, and many aspects related to the energetic dynamics of these animals remain poorly investigated. The reproductive period is particularly vulnerable for viviparous species, as part of the energy reserves of the parental biomass is reallocated for gamete production and embryo development. In this context, this study aimed to characterize parental metabolite provisioning to the offspring (both sperm and developing embryos) of the Brazilian Guitarfish, Pseudobatos horkelii, through glucose, ß-hydroxybutyrate, triglycerides, and total cholesterol determinations in the uterine liquid (UL) and serum of pregnant females and in the seminal fluid (SF) and serum of males during the copulation period. No significant difference was observed for the analyzed markers between the UL and SF. Except for triglycerides, higher in female serum samples, all other energy markers were present at similar concentrations in the serum of both females and males. When comparing female UL and serum, significant differences were observed for triglycerides and total cholesterol. No differences were observed between SF and serum in males. The results indicate that all markers are being made available to offspring, possibly complementary to the yolk in the case of maternal liquid, and as an additional source for sperm mobilization required during egg fertilization in the case of the paternal fluid. Correlations between the markers in the parental matrices were also noted, compatible with the metabolic pathways activated during energy mobilization in vertebrates. Moreover, distinct marker predominance patterns were also noted for both UL and SF. Energy mobilization characterization directed to offspring through parental fluids aids in unraveling metabolic dynamics during the reproduction stage while also providing support for stress physiology studies to evaluate the indirect effects of parental allostatic overload in both sperm and developing embryos. Finally, energy mobilization assessments of parental fluids may also help elucidate how internal fertilization and viviparity evolved in this very distinct taxonomic group.

First report on metal and metalloid contamination of Ampullae of Lorenzini in sharks: A case study employing the Brazilian sharpnose shark Rhizoprionodon lalandii from Southeastern Brazil as an ecotoxicological model.

Metal contamination has never been assessed in Ampullae of Lorenzini. This study employed Rhizoprionodon lalandii, as an ecotoxicological model to investigate potential metal accumulation in Ampullae of Lorenzini jelly. No differences between sexes were observed regarding jelly metal concentrations at Rio das Ostras (RJ) or Santos (SP). Statistically significant correlations were noted between total lengths (TL) and condition factors and several metals at both sampling sites, demonstrating the potential for Chondrichthyan sensory capacity disruption and possible effects on foraging success. Maternal metal transfer to Ampullae jelly was confirmed. Rhizoprionodon lalandii is thus, a good model to assess Ampullae of Lorenzini contamination, as this electrosensory organ seems to be highly vulnerable to metal contamination.

Nurse sharks, space rockets and cargo ships: Metals and oxidative stress in a benthic, resident and large-sized mesopredator, Ginglymostoma cirratum.

It is widely recognized that apex predators, such as large sharks with highly migratory behavior, are particularly vulnerable to pollution, mainly due to biomagnification processes. However, in highly impacted areas, mesopredator sharks with resident behavior can be as vulnerable as apex sharks. In this context, this study evaluated cadmium (Cd), mercury (Hg), lead (Pb), and rubidium (Rb) concentrations, as well as the potentially protective effects of selenium (Se) and the behavior of two non-enzymatic biomarkers, metallothionein (MT) and reduced glutathione (GSH), employing the Atlantic nurse shark Ginglymostoma cirratum as a study model and compared the results with other resident benthic sharks, as well as highly mobile apex sharks. Muscle tissue samples from 28 nurse sharks opportunistically sampled from the Brazilian Amazon Coast were analyzed. Lower metal concentrations were observed for Pb, Rb and Se in the rainy season, while statistically significant correlations between metals were observed only between Hg and Cd and Pb and Se. Molar ratio calculations indicate potential protective Se effects against Pb, but not against Cd and Hg. No associations between MT and the determined metals were observed, indicating a lack of detoxification processes via the MT detoxification route. The same was noted for GSH, indicating no induction of this primary cellular antioxidant defense. Our results indicate that benthic/mesopredator sharks with resident behavior are, in fact, as impacted as highly mobile apex predators, with the traditional detoxification pathways seemingly inefficient for the investigated species. Moreover, considering the studied population and other literature data, pollution should be listed as a threat to the species in future risk assessments.

Evaluating conservation status and governmental efforts towards regional flagship species in Brazil.

Several strategies have been adopted to optimize biodiversity conservation. The use of fauna and flora species as flagships can help increase public commitment and raise funds for their conservation. However, species choices must be well balanced, considering not only intrinsic aspects (e.g., risk of extinction and ecological role), but also social, cultural, and economic aspects of the region where the flagship will be adopted. Brazil is one of the countries with the greatest diversity on the planet. Nevertheless, there are several challenges associated with natural resources conservation. Flagships have been adopted informally for decades throughout the country but there are no efforts to evaluate these strategies results for the preservation of the selected species. The aim of this study was to carry out an extensive survey on regional flagship species, their conservation status, level of endemism, and domestic legislation currently in force for their protection or human use. A total of 62 flagships were identified, with at least one species of flora and one of fauna for each of the 27 Brazilian Federative Units. The animals most commonly used as regional symbols are birds, followed by mammals. Flora species used as regional symbols are quite diverse. However, they are all somehow used by humans. As for legal protection, there are government measures for endangered species. Nevertheless, most species used as regional symbols are not at risk of extinction and, for this reason, do not receive any legal protection. Moreover, while some flagships are endemic, others are alien species, indicating that this criterion is not considered when choosing regional symbols. In the overall analysis it was noted that species choice could be optimized to highlight the national biodiversity. Despite efforts to establish legal measures for their preservation, few effective results have been observed. Therefore, improved effective measures for their conservation should be adopted to guarantee the effectiveness of flagship species for biodiversity conservation.

Negative metal bioaccumulation impacts on systemic shark health and homeostatic balance.

Contamination by metals is among the most pervasive anthropogenic threats to the environment. Despite the ecological importance of marine apex predators, the potential negative impacts of metal bioaccumulation and biomagnification on the health of higher trophic level species remains unclear. To date, most toxicology studies in sharks have focused on measuring metal concentrations in muscle tissues associating human consumption and food safety, without further investigating potential impacts on shark health. To help address this knowledge gap, the present study evaluated metal concentrations in the gills, muscle, liver and rectal gland of coastal sharks opportunistically sampled from Brazilian waters and tested for potential relationships between metal bioaccumulation and general shark health and homeostatic balance metrics. Results revealed high metal concentrations in all four tissue types, with levels varying in relation to size, sex, and life-stage. Metal concentrations were also associated with serum biomarkers (urea, lactate, ALT, triglycerides, alkaline phosphatase, and phosphorus) and body condition, suggesting potential negative impacts on organismal health.

Current status and potential contributions of fisheries statistics from artisanal fisheries for managing juvenile istiophorid billfishes in Southern Brazil.

Billfishes are considered important fishery resources and the identification of aggregation sites is imperative for proper management. Here we present evidence of a seasonal aggregation site for juvenile istiophorid billfishes in southern Brazil. We discuss the results as they relate with the need for management at a local scale and participatory monitoring with artisanal fishing communities as a way to ensure access to data on the occurrence and population status in the long term.

Research trends on elasmobranchs from the Brazilian Amazon Coast: a four-decade review / Tendências de pesquisa sobre elasmobrânquios na Costa Amazônica Brasileira: uma revisão de quatro décadas

Abstract: Elasmobranchs exhibit the biggest population declines among vertebrates, being considered one of the groups with the highest risk of extinction. The Brazilian Amazon Coast (BAC) is considered a priority area for elasmobranch conservation, as many species are endemic to the region, and most of them are threatened with extinction. The present study made a scientometric analysis using the IRAMUTEQ method (Interface de R pour les Analyses Multidimensionnelles de Textes et de Questionnaires) to evaluate the trends of research with elasmobranchs in BAC in the last four decades. Ten research trends were identified, highlighting "Biodiversity", "Reproduction", "Trophic Ecology" and "Conservation". However, most of the publications found are aimed at understanding the diversity and abundance of species in the region, with the number of studies focused on reproduction, feeding and other aspects of the biology and ecology of elasmobranchs in the BAC being less expressive. Although the research area "Conservation" stood out in the search, the amount of relevant information so that management and conservation measures can be implemented is still low. Lastly, despite following the global trend of studies with elasmobranchs between 2000 and 2010, investigations into the BAC need to advance, especially considering the poor level of basic information on most species (Biology and population dynamics) and the incomplete knowledge of specific composition of elasmobranch species in the entire area, aspects relevant to conservation and more applied studies that rely on more recent methodologies and technologies.

Resumo: Elasmobrânquios apresentam os maiores declínios populacionais entre os vertebrados, sendo considerado um dos grupos com maior risco de extinção. O Litoral Amazônico Brasileiro (BAC) é considerado uma área prioritária para conservação de elasmobrânquios, pois várias espécies são endêmicas da região, e a maioria delas estão ameaçadas de extinção. O presente estudo fez uma análise cientométrica aplicando o método IRAMUTEQ (Interface de R pour les Analyses Multidimensionnelles de Textes et de Questionnaires) para avaliar as tendências de pesquisas com elasmobrânquios no BAC nas últimas quatro décadas. Dez tendências de pesquisa foram identificadas, destacando-se "Biodiversidade", "Reprodução", "Ecologia trófica" e "Conservação". Entretanto, a maioria das publicações encontradas é voltada para o conhecimento da diversidade e abundância das espécies na região, sendo o número de estudos voltados para a reprodução, alimentação e outros aspectos da biologia e ecologia de elasmobrânquios do BAC menos expressivo. Apesar da área de investigação "Conservação" ter se destacado na busca, a quantidade de informações relevantes para que medidas de manejo e conservação possam ser implementadas ainda é baixa. Por fim, apesar de seguir a tendência mundial de estudos com elasmobrânquios entre 2000 a 2010, as investigações sobre o BAC precisam avançar, especialmente considerando o baixo nível de informações básicas sobre a maioria das espécies (biologia e dinâmica populacional) e o conhecimento incompleto da composição específica das espécies de elasmobrânquios em toda a área, aspectos relevantes para a conservação e estudos mais aplicados e que contem com metodologias e tecnologias mais recentes.

Lesão com infecção secundária e sequelas graves causadas por um peixe-robalo (Centropomus spp.) em um pescador / Injury with secondary infection and severe sequelae caused by a snook fish (Centropomus spp.) to a fisherman

Resumo Introdução: ferimentos causados por peixes são comuns entre pescadores e, se não forem adequadamente assistidos, podem levar a complicações significativas. Objetivo: reportar o caso de um pescador que se acidentou com um camurim/robalo (Centropomus spp.) e apresentou infecção secundária com sequelas graves. Métodos: as informações foram obtidas por meio de revisão de prontuários, entrevista com o paciente e registro fotográfico. Resultados: um pescador de 48 anos se acidentou, com a espícula da base da nadadeira do peixe, na falange do quinto quirodáctilo da mão esquerda, apresentando sinais flogísticos em todo o membro. O serviço de saúde não dispunha de condições para identificar o agente da infecção e diferentes antibióticos foram administrados. Sem resultados expressivos, a terapia antibiótica foi suspensa e foi adotado tratamento sintomático. Após 32 dias de hospitalização, o paciente teve alta. No entanto, dois meses após o acidente, a vítima desenvolveu abscesso do membro com limitação de movimentos dos quirodáctilos, necessitando de procedimento cirúrgico. Após o controle da infecção, apresentou sequelas como atrofia muscular, perda parcial de movimento, redução da capacidade motora, sensibilidade local e aparência da mão em garra. Conclusão: lesões causadas por peixes em pescadores podem resultar em consequências graves e irreversíveis e mais atenção deve ser dada ao tema.

Abstract Introduction: fish injuries are common among fishers and, if not properly assisted, can lead to major complications. Objective: to report the case of a fisherman who had an accident with a snook fish (Centropomus spp.) and presented secondary infection with severe sequelae. Methods: the information was obtained by reviewing medical records, interviewing the patient, and photographic record. Results: a 48-year-old fisherman was injured by the spike on the base of the fish fin. It affected the phalanx of his left hand fifth finger, showing signs of inflammation throughout the limb. The health service was unable to identify the infectious agent and prescribed several antibiotics. Without substancial results, the doctors discontinued the antibiotic therapy and adopted a symptomatic treatment. After 32 days in hospital, the patient was discharged. However, two months after the accident, he presented an abscess in the limb, which limited the fingers movement and required a surgical procedure. After the infection was controlled, he presented some sequelae such as muscle atrophy, partial loss of movement, reduced motor capacity, local sensitivity, and clawed-shaped hand. Conclusion: injuries caused by fish can result in serious and irreversible consequences, and more attention should be paid to the subject-matter.

Physiological Impairment as a Result of Bile Accumulation in an Apex Predator, the Tiger Shark (Galeocerdo cuvier Péron & Lesueur, 1822).

Physiological adaptations have evolved to help sharks face rapid periods of feast. Tiger sharks are generalist apex predators that rely on a high-lipid/protein diet. To achieve a satisfactory nutritional condition, proper lipid absorption and hepatic storage are needed. Bile secretion in sharks is low and sporadic but increases during short periods of fasting. The present study describes a physiological impairment caused by bile accumulation in juvenile tiger sharks, possibly due to prolonged fasting. These evidences suggest that, even though sharks have adaptations that prevent them from dying from starvation, alarming physiological alterations might occur. Future studies are needed to assess how such a condition can affect wild populations, as well as possible sublethal consequences that could impact their long-term survival.

Fatal Infection in a Wild Sandbar Shark (Carcharhinus plumbeus), Caused by Streptococcus agalactiae, Type Ia-ST7.

Streptococcus agalactiae is one of the most important fish pathogenic bacteria as it is responsible for epizootic mortalities in both wild and farmed species. S. agalactiae is also known as a zoonotic agent. In July 2018, a stranded wild sandbar shark (Carcharhinus plumbeus), one of the most common shark species in the Mediterranean Sea, was found moribund on the seashore next to Netanya, Israel, and died a few hours later. A post-mortem examination, histopathology, classical bacteriology and advanced molecular techniques revealed a bacterial infection caused by S. agalactiae, type Ia-ST7. Available sequences publicly accessible databases and phylogenetic analysis suggest that the S. agalactiae isolated in this case is closely related to fish and human isolates. To the best of our knowledge, this is the first description of a fatal streptococcosis in sandbar sharks.

Thermal Imaging Reveals Changes in Body Surface Temperatures of Blacktip Sharks (Carcharhinus limbatus) during Air Exposure.

Fish physiology is significantly affected by temperature variability. During fisheries interactions, fish are often exposed to air and subjected to rapid temperature changes. Fish thermal dynamics during such exposure, and the possible outcomes to their physiology, depend on how heat is distributed across their bodies, the speed at which their body temperatures change, and the size of the individual. Nevertheless, such thermal patterns remain unknown for sharks. This study employed a novel application of thermal imaging to evaluate external body temperature profiles of blacktip sharks (Carcharhinus limbatus) above-water exposure after capture. We found that above-water exposure duration, shark total length, and air temperature on the day of capture significantly influenced body surface temperatures of the analyzed sharks ([Formula: see text]). Body surface temperature significantly increased with increasing exposure; however, thermal profiles of immature sharks (<140 cm) were significantly warmer than those of mature sharks. Moreover, blacktip surface body temperatures were significantly higher during days when air temperatures were at least 2.5°C warmer than water temperatures. We discuss these results as they relate to the ecology of blacktip sharks and their potential vulnerability to fisheries capture due to such changes in peripheral body temperature.