Fernando de Noronha as an insular nursery area for lemon sharks, Negaprion brevirostris, and nurse sharks, Ginglymostoma cirratum, in the equatorial western Atlantic Ocean

Garla, Ricardo C.; García, José Manuel Guerra; Veras, Leonardo B.; Lopes, Norberto P.

doi:10.1017/s1755267209000670

Cited by 31 publications

(41 citation statements)

References 7 publications

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“…During the last thirty years, the lemon shark has been extensively studied within their nurseries in the Bimini Islands, Bahamas (Gruber 1982, Morrissey & Gruber 1993a, Feldheim et al 2002, Jennings et al 2008, Newman et al 2010. Nursery areas for this species have been also characterized at the Atol das Rocas, Brazil (Freitas et al 2006) (Garla et al 2009), andTurks andCaicos Islands, British West Indies (Henderson et al 2010). Although most of the biological knowledge on the lemon shark comes from the Bahamian population, essential habitats of this species, such as nursery grounds, continue to be poorly studied in areas of the southern Caribbean Sea and elsewhere.…”

Section: Introductionmentioning

confidence: 99%

Nursery area and size structure of the lemon shark population, Negaprion brevirostris (Poey, 1868), in Los Roques Archipelago National Park, Venezuela

Tavares

Rodrı́guez

Morales³

2016

Univ. Sci.

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The protection of the habitats used by juvenile sharks is a management strategy that has recently caught the attention of fishery biologists. In the present study, we evaluated the population of the lemon shark (Negaprion brevirostris) from Los Roques Archipelago in order to identify the nursery area, describe the size composition, and examine the variation in nocturnal activity of the juvenile individuals. The data analysed came from three different sources: commercial shark fishery, tagrecapture sampling, and visual records. A total of 375 lemon sharks with total lengths between 55 and 281 cm were recorded during the study period. Overall data showed that the area occupied by juvenile lemon sharks was clearly partitioned into primary and secondary nurseries. Additionally, nighttime activity seemed to change according to the size of sharks in the primary nursery, suggesting a reduction of time activity overlapping among juveniles of distinct size/age. Results suggest that the strategy of utilization of the primary nurseries by the lemon shark may lead to important ecological benefits by reducing the competition, predation and natural mortality.

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Section: Introductionmentioning

confidence: 99%

Nursery area and size structure of the lemon shark population, Negaprion brevirostris (Poey, 1868), in Los Roques Archipelago National Park, Venezuela

Tavares

Rodrı́guez

Morales³

2016

Univ. Sci.

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“…These findings indicate that social preferences might well play an important role in the formation and composition of free-ranging groups of juvenile sharks. Interestingly, lemon sharks from all life stages have been documented to form groups (Gruber et al 1988, Reyier et al 2008, Garla et al 2009). Large numbers of adult lemon sharks come together over the winter months in Florida, USA, resting in close proximity and performing social behaviours, such as 'follow head to tail' (Kessel 2010).…”

Section: Introductionmentioning

confidence: 99%

Assortative interactions and leadership in a free-ranging population of juvenile lemon shark Negaprion brevirostris

Guttridge¹,

Gruber²,

DiBattista³

et al. 2011

Mar. Ecol. Prog. Ser.

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For marine predators there is a paucity of studies on social behaviour, and even fewer studies have quantified interactions between individuals. In the present study, we looked at the social structure and leadership of free-ranging juvenile lemon shark Negaprion brevirostris in a known aggregation site, Bimini, the Bahamas. Observations of these sharks were made from towers placed in a mangrove inlet, where clear, shallow, protected waters made it possible to record group compositions of externally colour-code tagged wild juvenile lemon sharks. Thirty-eight different individual sharks were observed to use the area over a 2 yr period. Results show repeated social interactions suggestive of active partner preference. In addition, we found that group structure was mostly explained by body length, and possibly by preference for relatives but not by sex. Finally, we observed that some sharks led more groups than others and that those lead individuals were usually larger than those following them. This study quantifies the social structure of a free-ranging shark population and provides novel insights into the social behaviour of juvenile sharks.

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“…The collected imagery evidenced that FEN encompasses mating grounds where nurse sharks aggregate for reproducing. Such a function adds on to the nursery role previously suggested by Garla et al (2009) in depicting the significance of FEN's MPA for the life history of this species. Being classified as a highly valued, unique ecosystem by both national and international institutions and enjoying of strict environmental management, FEN may potentially provide an important framework for the successful conservation of marine wildlife in Brazil and elsewhere.…”

Section: Discussionmentioning

confidence: 74%

“…through a longer period of time compared to Florida, where 27-30 cm TL offspring are born mainly during November and early December (Castro, 2000). However, Garla et al (2009) reported neonates visually-estimated at 30 cm TL to occur off FEN considerably earlier, mostly from July to September, which chronologically matches the observation of a 30-cm individual at the nearby Atol das Rocas in August (Castro & Rosa, 2005). The fact that the presence of yolk sac scars was not assessed, though, together with pigmentation distinctive of newborns persisting until ~55 cm TL (Castro, 2000), both bring uncertainty to the actual free-swimming age of these individuals.…”

Section: Discussionmentioning

confidence: 99%

Evasive mating behaviour by female nurse sharks, Ginglymostoma cirratum (Bonnaterre, 1788), in an equatorial insular breeding ground

Afonso

Cantareli²,

Levy

et al. 2016

Neotrop. ichthyol.

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Mating events and aggregations of vulnerable nurse sharks Ginglymostoma cirratum were recorded in the insular protected area of Fernando de Noronha (FEN), Brazil, between April and August 2015. Female sharks were observed clustering in groups of up to 14 individuals in shallow water adjacent to the shore. Several evasive mating behaviours in the presence of males were noticed, including shoreward movement, positioning ventral side up at the sea surface with emerged pectoral and pelvic fins, body rolling and caudal fin thrashing. Fresh bite marks indicative of male courtship and coupling attempts were visible in female's pectoral and caudal fins. Altogether, the observed behaviours match previous reports of noncooperative female nurse sharks during mating opportunities. An extended mating season coupled with a persistent use of inshore habitats result in nurse sharks being particularly vulnerable to human pressure during a most sensitive stage of their life cycle. The effective conservation of nurse shark populations from the western South Atlantic may thus depend on the protection of critical habitats where this species aggregates to reproduce. Explicitly addressing environmental requirements by vulnerable species in local management strategies is indispensable to ensure that human pressure, including ecotourism development, does not collide with stipulated conservation aims.Agregações e eventos reprodutivos do vulnerável tubarão-lixa, Ginglymosytoma cirratum, foram registrados na área insular protegida do Arquipélago de Fernando de Noronha (FEN), Brasil, entre Abril e Agosto de 2015. Grupos constituídos por até 14 fêmeas foram observados em águas rasas adjacentes à linha costeira. Perante a presença de machos, diversos comportamentos evasivos por parte das fêmeas foram identificados, incluíndo movimentação para águas ainda mais rasas, posicionamento na superfície do mar com a face ventral orientada para cima e emersão das nadadeiras peitorais e pélvicas, enrolamento do corpo e batimento da nadadeira caudal na superfície do mar. Foram identificadas marcas recentes de mordida nas nadadeiras peitorais e caudais das fêmeas, sugerindo interações de acasalamento com machos. No geral, os comportamentos observados coincidem com os comportamentos exibidos por fêmeas não aquiescentes à cópula reportados no hemisfério norte. Em FEN, a duração relativamente longa do período de acasalamento, juntamente com a utilização persistente dos habitats mais costeiros, promovem a vulnerabilidade do tubarão lixa às pressões antrópicas durante uma das fases mais sensíveis do seu ciclo de vida. A conservação efetiva das populações de tubarão-lixa do Oceano Atlântico Sul ocidental poderá, assim, depender da proteção dos habitats críticos de agregação onde esta espécie se reproduz. Por conseguinte, a abordagem explícita dos requisitos ambientais associados a espécies vulneráveis no âmbito dos planos de manejo locais deve ser considerada como indispensável para assegurar que as pressões antrópicas, incluíndo o desenvolvimento ecoturístico,...

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Fernando de Noronha as an insular nursery area for lemon sharks, Negaprion brevirostris, and nurse sharks, Ginglymostoma cirratum, in the equatorial western Atlantic Ocean

Cited by 31 publications

References 7 publications

Nursery area and size structure of the lemon shark population, Negaprion brevirostris (Poey, 1868), in Los Roques Archipelago National Park, Venezuela

Nursery area and size structure of the lemon shark population, Negaprion brevirostris (Poey, 1868), in Los Roques Archipelago National Park, Venezuela

Assortative interactions and leadership in a free-ranging population of juvenile lemon shark Negaprion brevirostris

Evasive mating behaviour by female nurse sharks, Ginglymostoma cirratum (Bonnaterre, 1788), in an equatorial insular breeding ground

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