Occurrences of whale shark (Rhincodon typus Smith, 1828) in the Saint Peter and Saint Paul archipelago, Brazil

Hazin, Fábio Hissa Vieira; Júnior, Teodoro Vaske; Oliveira, Paulo; Macena, Bruno C. L.; Carvalho, Felipe Eduardo Araújo de

doi:10.1590/s1519-69842008000200021

Cited by 31 publications

(31 citation statements)

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“…Since previous research [25] and records from fishermen had already indicated that whale shark FO% in the area was much higher during the first six months of the year, from 2009 on the major part of the research effort was carried out during this period to facilitate the deployment of satellite tags and the collection of tissue samples.…”

Section: Discussionmentioning

confidence: 99%

“…Whale sharks are widely distributed in the Atlantic Ocean, occurring in Central America (Caribbean Sea and Gulf of Mexico (GOM) [56]), Northwest Atlantic [57]; Northeast Atlantic [12], Equatorial Atlantic [25], Southeast Atlantic [58] and Southwest Atlantic ([22]; BCLM, unpub. data).…”

Section: Discussionmentioning

confidence: 99%

“…Additionally, anecdotal sighting records were compiled (COMP) through interviews with local fishermen and other researchers, and collated with sightings from the literature [25] from February 2000 to May 2014. Sightings data included: date, time, location, number of individuals, estimated size and photographs, if available.…”

Section: Methodsmentioning

confidence: 99%

“…Adult whale sharks are infrequently observed, and the majority of sightings have been recorded at oceanic locations, such as the Galapagos Islands [36], Baja California Sur [18,37], the Azores [12], St. Helena Island [38] and ASPSP ([25]; present study). However, complete information on the distribution of mature whale sharks, and on the location of mating and nursery grounds, if any, remains lacking, despite being crucial for the conservation of the species.…”

Section: Introductionmentioning

confidence: 99%

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Whale Shark (Rhincodon typus) Seasonal Occurrence, Abundance and Demographic Structure in the Mid-Equatorial Atlantic Ocean

Macena

Hazin

2016

PLoS ONE

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Whale sharks are generally associated with environmental factors that drive their movements to specific locations where food availability is high. Consequently, foraging is believed to be the main reason for the formation of whale shark aggregations. Feeding aggregations occur mainly in nearshore areas and are composed primarily of immature individuals. Conversely, aggregations of mature adults are rarely observed, and their occurrence is correlated with oceanic environments. Despite an increase in the number of whale shark studies, information on mating and parturition grounds is still lacking. In the present work, we assessed the ecological and behavioural aspects of the whale sharks that visit the archipelago of São Pedro and São Paulo (ASPSP), located ~1,000 km off the coast of Brazil in the equatorial Atlantic Ocean. Forty-nine whale sharks were recorded from February 2005 to May 2014. The estimated mean ± SD size was 8.27 ± 2.52 m (range: 2.5–14.0 m) with no significant differences in size across the year. The maturational stages were classified by size as immature (<8.0 m; 32.56%) and mature (>9.0 m; 46.51%); with almost half of the observed animals being mature specimens. The majority of sightings occurred between February and June. During this period, the ocean current weakens and the waters are enriched by eggs and larvae of fishes and invertebrates that attract marine life to forage. At the same time, evidence of reproductive activity in adult females (i.e. swollen abdomen and bite marks on the pectoral fins), and the potential mating behaviour exhibited by one male, suggest that the ASPSP area might also have a role in whale shark reproduction. Irrespective of its use for feeding or reproduction, this insular habitat serves as a meeting point for both juvenile and adult whale sharks, and may play an important ecological role for the species.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Whale Shark (Rhincodon typus) Seasonal Occurrence, Abundance and Demographic Structure in the Mid-Equatorial Atlantic Ocean

Macena

Hazin

2016

PLoS ONE

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“…The boats operate in the region around São Pedro e São Paulo Archipelago (Fig. 1), located in the North Atlantic Ocean near the Equator (00°55'N 29°21'W), at a distance of approximately 1,100 km from the Brazilian coast (Hazin et al, 2008). Between January 2006 and May 2008, the ovaries of 294 black triggerfish females, caught by a scoop net.…”

Section: Methodsmentioning

confidence: 99%

Oocyte development and ovarian maturation of the black triggerfish, Melichthys niger(Actinopterygii: Balistidae) in São Pedro e São Paulo Archipelago, Brazil

et al. 2013

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The oogenesis is a key stage in the reproductive development of an organism, which can be best understood from histological analysis of ovaries in different maturity stages. In order to provide information on the reproductive biology of the black triggerfish, M. niger, in particular on its oogenesis process, this study aimed at identifying and characterizing the oocyte development stages and its organization within the different stages of ovarian maturation based on specimens from São Pedro e São Paulo Archipelago. In this present report, a number of 294 ovaries were histologically analyzed. It was verified that they are composed of ovigerous lamellae containing oocytes at different development stages. Five different stages of oogenesis were identified: young cells, with an average size of 12.9 ìm; previtellogenic oocytes (perinucleolar), with an average size of 53.5 ìm; cortical-alveoli oocytes with an average size of 83.1 ìm; vitellogenic oocytes, with an average size of 160.4 ìm and mature oocytes, with an average size of 289.8 ìm. In addition to the germ cells, some somatic structures were also identified, such as: ovarian wall, follicular cells and blood vessels. Based on the type and number of oocytes observed, four stages of ovarian maturation were identified: early maturation, represented by only 2.2% of the sample; middle maturation, represented by 9.9%; mature, represented by 44.2% and resting, represented by 43.9%. The identification of five oocyte development stages in the ovarians from M. niger, suggested that the specie follows a pattern similar to that described for other marine fish.A oogênese é um estágio chave no desenvolvimento reprodutivo de um organismo, o qual pode ser melhor compreendido a partir de análises histológicas dos ovários em diferentes estágios de maturidade. A fim de fornecer informações sobre a biologia reprodutiva do cangulo-preto, M. niger, em especial sobre o seu processo de oogênese, este estudo teve como objetivo identificar e caracterizar as fases do desenvolvimento ovocitário e sua organização dentro dos diferentes estágios de maturação ovariana, baseado em espécimes do Arquipélago de São Pedro e São Paulo. No presente estudo, um número de 294 ovários foram analisados histologicamente. Foi verificado que eles são constituídos por lamelas ovígeras contendo ovócitos em diferentes estágios de desenvolvimento. Foram identificados cinco diferentes estágios da oogênese: células jovens, com tamanho médio de 12,9 ìm; ovócitos pré-vitelogênicos (perinucleolares), com tamanho médio de 53,5 ìm; ovócitos alvéolo-corticais, com tamanho médio de 83,1 ìm; ovócitos vitelogênicos, com tamanho médio de 160,4 ìm e ovócitos maduros, com tamanho médio de 289,8 ìm. Além das células germinativas, algumas estruturas somáticas também foram identificadas, tais como: parede do ovário, células foliculares e vasos sanguíneos. Baseado no tipo e número de ovócitos observados, quatro estágios de maturação ovariana foram identificados: início de maturação, representado por apenas 2,2% da amostra; média...

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Occurrence and population structure of sharks in two ecologically or biologically significant marine areas off north‐eastern Brazil

Barcellos

Barreto²,

Lessa

2022

Aquatic Conservation

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1. Ecologically or Biologically Significant Marine Areas (EBSAs) are rare, and highly important sites to the life history of a number of declining shark species are endangered by fishing.2. The high diversity of sharks caught by fisheries is difficult to monitor due to the scarcity of information on species-specific biological aspects (growth, maturity and fertility rate). 3. There are two EBSAs off north-eastern Brazil, where key species are caught, more specifically the oceanic whitetip (Carcharhinus longimanus), mako (Isurus oxyrinchus), blue (Prionace glauca) and silky (Carcharhinus falciformis) sharks. Another 23 species displaying low frequency in catches have also been recorded, many of them considered threatened according to the IUCN Red List and the Brazilian Ministry of Environment. 4. The main purpose of this study was to generate information about shark diversity and demonstrate the role of the two EBSAs in their conservation. After analysing fishing data collected from 2000 to 2011, maps were built to categorize shark species by phases of their ontogenetic development (neonate, young and adult) based on samples of C. falciformis (n = 330), C. longimanus (n = 440), I. oxyrinchus (n = 452) and P. glauca (n = 8,176).5. Shark stocks comprised mainly juveniles, which raises concerns since they are considered a crucial life stage for the sustainability of shark populations. Catch monitoring also highlighted that several of the species caught are threatened and their catch is either prohibited or limited according to the Brazilian laws and international rules in place.6. Action plans and enforcement of laws and rules are needed to deliver the protective measures needed for shark species in these EBSAs.

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Occurrences of whale shark (Rhincodon typus Smith, 1828) in the Saint Peter and Saint Paul archipelago, Brazil

Cited by 31 publications

References 5 publications

Whale Shark (Rhincodon typus) Seasonal Occurrence, Abundance and Demographic Structure in the Mid-Equatorial Atlantic Ocean

Whale Shark (Rhincodon typus) Seasonal Occurrence, Abundance and Demographic Structure in the Mid-Equatorial Atlantic Ocean

Oocyte development and ovarian maturation of the black triggerfish, Melichthys niger(Actinopterygii: Balistidae) in São Pedro e São Paulo Archipelago, Brazil

Occurrence and population structure of sharks in two ecologically or biologically significant marine areas off north‐eastern Brazil

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