Made available in DSpace on 2014-06-11T19:35:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-01-06Bitstream added on 2014-06-13T19:05:57Z : No. of bitstreams: 1 garla_rc_dr_rcla.pdf: 1566045 bytes, checksum: 33a6e91849d61d578c9d020171e589af (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente trabalho visa gerar informações básicas sobre a ecologia e a situação populacional do tubarão-cabeça-de-cesto Carcharhinus perezi, lambarú Ginglymostoma cirratum e tubarão-limão Negaprion brevirostris no Arquipélago de Fernando de Noronha, com ênfase na primeira, por ser numericamente dominante. Utilizou-se a combinação de técnicas de marcação e recaptura e de telemetria ultra-sônica para fornecer informações sobre: estrutura populacional, distribuição espacial dos tubarões e de suas áreas de berçário, época de parto, padrões de movimentação e de utilização do hábitat. Amostras de sangue foram analisadas para caracterização sorológica das espécies. Foi implantado um programa de conscientização e educação sobre a necessidade de conservação dos tubarões, e realizou-se um curso de capacitação em Educação Ambiental para os professores do ensino médio e fundamental. A plataforma insular do arquipélago é utilizada como área de parto e de crescimento de jovens pelas três espécies de tubarões. Carcharhinus perezi apresenta maior segregação espacial por tamanho. Não ocorre segregação espacial em Ginglymostoma cirratum e Negaprion brevirostris pois foram observados indivíduos neonatos, jovens e adultos freqüentando a região próxima à linha costeira do arquipélago. Os tubarões utilizam com menor freqüência o trecho da Área de Proteção Ambiental (APA) do arquipélago, o que possivelmente está relacionado à intensificação da utilização humana e a indícios de empobrecimento biológico da região nos últimos anos. O monitoramento por telemetria mostra que: os tubarões jovens são residentes em trechos específicos do arquipélago; eles podem ser ativos a qualquer horário do dia, mas os maiores espaços de atividade e deslocamentos ocorrem à noite; aparentemente não existem variações sazonais... / The aim of the present study is to provide basic data on the ecology and population status of the reef-shark Carcharhinus perezi, nurse-shark Ginglymostoma cirratum and lemon-shark Negaprion brevirostris at Fernando de Noronha archipelago, with special reference to Carcharhinus perezi, due to its numerical dominance. A combination of mark and recapture and ultrasonic telemetry methods were used to gather data on: the population structure, spatial distribution of the sharks, location of the nursery grounds, parturition time, patterns of movement and habitat use. Blood samples were analyzed for a serological characterization of the species. An educational program was established to increase the community awareness about shark conservation, and a capacitating course on Environmental Education was offered to teachers of the local school. The archipelago s insular shelf is used as a parturition and growing ground for young sharks of the three species. Carcharhinus perezi shows size segregation. Size segregation was not observed in Ginglymostoma cirratum and Negaprion brevirostris, and neonate, young and adult sharks of these species were observed to frequent shallow waters of the archipelago. Sharks rarely frequent the archipelago s Environmental Protection Area (EPA), which is probably related to an intensification of human use and evidences of biological impoverishment of this site in recent years. The telemetry monitoring shows that: the young sharks are resident and present site fidelity to specific portions of the archipelago; they may be active at any time of the day, but the larger activity spaces and excursions occur at night; apparently there is no seasonal variation in activity spaces and habitat use; and larger sharks have more extensive activity spaces. The main problems for the management and conservation of the sharks are:... (Complete abstract click electronic access below)

The nurse shark, Ginglymostoma cirratum, is a sedentary shark species that inhabits coral reefs in the tropical and subtropical Atlantic Ocean and along the western coast of the Americas in the Pacific Ocean. Nurse shark tissue samples were collected from the Bahamas, Belize, Brazil, and Dry Tortugas National Park in Florida. 186 individuals were genotyped at 11 microsatellite loci, the control region of the mitochondrial genome was sequenced in 190 individuals, and 89 individuals from the Bahamas, Belize, and Dry Tortugas were genotyped at the major histocompatibility complex (MHC) class IIα locus. An analysis of molecular variance (AMOVA) for the microsatellite loci indicated significant subdivision only between the Bahamas and Dry Tortugas populations. An AMOVA for the mitochondrial control region sequences indicated significant subdivision between all population pairs. The AMOVA for MHC class IIα locus indicated significant subdivision between two population pairs: the Bahamas population and the Dry Tortugas population and the Belize population and the Dry Tortugas population. The nurse shark has the lowest mitochondrial DNA nucleotide diversity (π=0.0125%) and haplotype diversity (h=0.2402) of any shark species to date. There were 14 MHC alleles from 39 polymorphic sites; ten were the same as published alleles (Kasahara et al. 1993; Ohta et al. 2000). This study was the first study to use MHC class IIα genes as a marker for population genetics in sharks. Our results showed that MHC class IIα locus behaves as a diploid locus and is a powerful tool for determining population genetic structure between populations.

The ability of an organism to modulate its feeding behavior is an important focus of feeding ecology studies. Modulation is the ability to distinctly and consistently alter a behavior to accommodate different stimuli. The goal of this study was to examine the ability of the nurse shark Ginglymostoma cirratum to modulate its food capture behavior with different sizes and types of food items. This was carried out through kinematic and electromyographic analysis. Eight sub-adult specimens of G. cirratum were filmed feeding on two different food types (squid and fish) and sizes (gape size and larger than gape size). Filming consisted of high-speed videography utilizing a low-light digital video system. Kinematic variables related to lower jaw movement, mouth width, and head angle were measured from video footage. Up to twelve muscles in each of six specimens were implanted with bipolar electrodes to measure the onset and duration of motor activity. There were no significant differences between food sizes and any of the kinematic variables. Only two muscles showed significant differences in onset time based on food size. In regards to food types, squid bites were significantly faster than fish bites, but when examined proportionately to bite duration only the time to jaw closure remained significantly different. The motor pattern of G. cirratum demonstrates an anterior to posterior sequence, which corresponds to the anterior to posterior kinematic sequence. Little cranial elevation is present during feeding sequences and is not thought to contribute significantly to feeding. Ginglymostoma cirratum is a stereotyped, inertial suction feeder. There is little evidence that there is modulation in feeding behavior based on food size or food type. If modulation does exist in the feeding behavior, it is more likely to occur after prey capture while the prey is being processed and manipulated prior to transport. Initial observations suggested that a novel behavior termed 'spit-suck manipulation' is utilized for larger prey items.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2017-11-06T14:15:59Z No. of bitstreams: 1 Emmanuelly Creio Ferreira.pdf: 1229374 bytes, checksum: dc3465d26e2a298bd119bc96c5a085b6 (MD5) / Made available in DSpace on 2017-11-06T14:15:59Z (GMT). No. of bitstreams: 1 Emmanuelly Creio Ferreira.pdf: 1229374 bytes, checksum: dc3465d26e2a298bd119bc96c5a085b6 (MD5) Previous issue date: 2015-08-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The Nurse sharks, Ginglymostoma cirratum, is a coastal species, found on continental shelves and islands in tropical and subtropical waters of the Atlantic Ocean and eastern Pacific Ocean. Despite the relatively high abundance of the nurse shark in coastal waters, their behavior and ecology are poorly studied. Due to their markedly coastal and territorial behavior and habit, one of the techniques most recently used in the study of their movements has been the acoustic telemetry. In this study, the acoustic telemetry was used to evaluate the movements and habitat use by the species in the coast of Recife, in the section between the beaches of Pina and Paiva, area where the sharks are monitored. To this end, 29 acoustic receivers were installed along the shoreline, both within the existing channel parallel to the coastline and outside of it, and four close to shipwrecks positioned to the east and to the north of the coast network of receivers. The catch of animals for labeling was performed using two bottom longlines, 4 km long each, released near the channel in front of the beaches, 6 days a week. The nurse sharks caught were shipped to the sexing procedure, biometrics and marking with surgery, and later released. The number of acoustic detections for each shark in each station was used to investigate site fidelity and the minimum area of dispersion. During 4 consecutive years, 18 nurse sharks were tagged, of which 13 were detected totaling, 9.232 detections. Of the 13 detected sharks, 7 were males, with total length from 118 to 244 cm and 6 were females measuring 147-289 cm. Most detections occurred during the night (5.610 detections; 60%), suggesting that the area of study is a possible feeding ground. The use of active acoustic telemetry, however, is necessary to obtain a better understanding of habitat use and movements of nurse sharks at the study site. / O tubarão-lixa, Ginglymostoma cirratum, é uma espécie de hábitos costeiros, encontrada em plataformas continentais e insulares, em águas tropicais e subtropicais do Oceano Atlântico e no leste do oceano Pacífico. Apesar da abundância relativamente elevada do tubarão lixa em águas costeiras, o seu comportamento e ecologia ainda são pouco estudados. Em razão do seu comportamento marcadamente costeiro e hábito territorialista, uma das técnicas mais utilizadas recentemente no estudo do padrão de movimentação da espécie tem sido a telemetria acústica, tecnologia já empregada no monitoramento de várias espécies de elasmobrânquios. No presente estudo, a telemetria acústica foi utilizada para avaliar os movimentos e uso do habitat pela espécie na costa de Recife, no trecho compreendido entre as praias do Pina e do Paiva, área de monitoramento dos tubarões envolvidos no problema dos ataques no Estado. Com esse fim, 29 receptores acústicos foram instalados ao longo da linha de costa, tanto dentro do canal existente paralelo a linha de costa como por fora do mesmo, além de quatro naufrágios posicionados ao leste e ao norte da rede de receptores da costa. A captura dos animais para marcação foi realizada com a utilização de dois espinhéis de fundo, com 4 km de comprimento cada, lançado próximo ao canal em frente às praias, 6 dias por semana. Os tubarões-lixa capturados foram embarcados para o procedimento de sexagem, biometria e marcação com intervenção cirúrgica, sendo posteriormente liberados. O número de detecções acústicas para cada tubarão e para cada estação monitorada foi usado para definição da fidelidade local e da medida da área mínima de dispersão. Durante 4 anos consecutivos foram marcados 18 tubarões-lixa, dos quais 13 foram detectados totalizando 9.232 detecções. Dos 13 tubarões detectados, 7 eram machos com comprimento total variando de 118 a 244 cm e 6 eram fêmeas medindo de 147 a 289 cm. A maioria das detecções ocorreu durante o período noturno 5.610 detecções (60%), o que sugere que a área de estudo seja um possível espaço de alimentação. O emprego da telemetria acústica ativa se faz, contudo, necessário para se obter uma melhor compreensão acerca do uso do habitat e sobre a movimentação do tubarão-lixa no local de estudo.

Molecular tools, such as sequencing of the mitochondrial DNA Control Region (CR) and genotyping of highly variable nuclear microsatellites were applied to survey the genetic diversity, population structure and phylogeography of three shark species: the whale shark, Rhincodon typus; the bull shark, Carcharhinus leucas; and the nurse shark, Ginglymostoma cirratum. The highly migratory and pelagic whale shark exhibited the largest length variation yet reported for an elasmobranch CR (1143–1332 bp), and high haplotype (h = 0.974 ± 0.008) and nucleotide diversities(π = 0.011 ± 0.006). No geographical clustering of lineages was observed and the most common haplotype was distributed globally. The haplotype frequency, however, differed between the Atlantic and Indo-Pacific populations(AMOVA, ΦST = 0.107, P < 0.001). For the bull shark, both mtDNA CR and five microsatellite loci were surveyed for animals from the Gulf of Mexico, the East coast of Florida and the Brazilian coast. Strong genetic structure was observed between theBrazilian and all northern populations for the CR (ΦST > 0.8, P < 0.001), but not for the nuclear microsatellite. The results here presented are congruent with restricted maternal gene flow between populations as a consequence of female nursery site fidelity. The philopatric tendencies as well as the relatively low levels of genetic diversity raises concerns about the conservation of this species. Finally, for the western Atlantic nurse sharks the genetic diversity estimated in a 1,166 bp fragment of the mtDNA comprising partial cytochrome b, tRNAPro, tRNAThr, and partial CR was the second smallest ever recorded for sharks (h = 0.45 ± 0.04; π = 0.0004 ± 0.0004). The data indicated moderate but significant genetic structure with the mtDNA marker (ΦST = 0.22, P<0.05) and no substantial structure in eight microsatellite loci analyzed. A population bottleneck as recent as the lower Pleistocene might have eroded the nurse shark genetic diversity and also contributed to its relatively lower population structure. The data also indicated that dispersal rather than vicariance better explains the Atlantic distribution of nurse shark, and that the Pacific nurse shark might be a cryptic sister species to Ginglymostoma cirratum.