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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Comparative demography and assemblage structure of serranid fishes : implications for conservation and fisheries management /

Pears, Rachel Jane. January 2005 (has links)
Thesis (Ph.D.) - James Cook University, 2005. / Typescript (photocopy) Bibliography: leaves 158-183.
2

Diversidade genética, conectividade populacional e a conservação do Mero (Epinephelus itajara; Percifomes Epinephelidae) na costa atlântica da América do Sul

BENEVIDES, Emilly Anny 31 January 2011 (has links)
Made available in DSpace on 2014-06-12T15:07:28Z (GMT). No. of bitstreams: 2 arquivo6527_1.pdf: 2175542 bytes, checksum: a264d5b0969311161a1b2144b7246125 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2011 / Petróleo Brasileiro S/A / O Mero, Epinephelus itajara, é umas das espécies de peixes marinhos mais ameaçadas no Brasil e em todo planeta e o seu status de conservação é de "Criticamente em Perigo de Extinção" pela União Internacional para a Conservação da Natureza (IUCN). Neste estudo, objetivou-se avaliar a diversidade genética da espécie, assim como as relações entre as populações do mero de diversas localidades ao longo da sua distribuição. Para tal, foi acessada, por meio de marcadores moleculares nucleares de DNA do tipo ISSRs e de seqüências do genoma mitocondrial (citocromo b), a variação genética da espécies ao longo de 12 localidades do oceano Atlântico (Belize, Estados Unidos, Guiana Francesa, Pará, Piauí, Ceará, Rio Grande do Norte, Pernambuco, Bahia, São Paulo, Paraná e Santa Catarina) Nas análises de ISSR, foram analisados 95 exemplares de 10 localidades (Guina Francesa, Pará, Piauí, Ceará, Rio Grande do Norte, Pernambuco, Bahia, São Paulo, Santa Catarina e Paraná). Oito primers ISSR foram selecionados e amplificaram 94 loci (variando de 250 a 1700bp) sendo 97% polimórficos. A análise de variância molecular (AMOVA) mostrou que 57% da variância total dos dados se encontra dentro das populações e 43% entre as populações. Os indivíduos de Santa Catarina são mais distantes geneticamente das demais localidades. A maior distância genética encontrada foi entre SC e Paraná (0,37) e a menor entre Pará e Guiana Francesa (0,10). A análise de agrupamento Bayesiano revelou um K=2 linhagens genético-evolutivas e as análises de agrupamento por Neighbor-Joinning (NJ) e Máxima Parcimônia (MP) foram similares entre si, confirmando a presença destas duas linhagens de mero ao longo da costa Atlântica da América do Sul. Uma destas linhagens compreende a maior parte da amostragem de SC. A outra é composta pelos exemplares oriundos de todas as outras localidades, incluindo alguns poucos indivíduos de SC. Os resultados obtidos para ISSRs mostram pouca estruturação genético-geográfica para a maioria das localidades amostradas, à exceção do clado monofilético observados com aqueles exemplares de SC. Tal evidência é concordante com os agrupamentos (NJ, MP e agrupamento Bayesiano) e com os valores de distância genética e FST. A alta estruturação genético-evolutiva dos Meros de Santa Catarina (Baía da Babitonga, São Francisco do Sul) pode ser explicada pelo isolamento desta população, possivelmente pela retenção das larvas e/ou fixação reprodutiva de adultos na mesma região, já que parece não existir nenhuma barreira física que pudesse isolá-las geograficamente das outras regiões. Já os dados do genoma mitocondrial, revelam uma forte estruturação genético-evolutiva da população do estuário do rio Potengi (Natal, RN), igualmente sem aparente isolamento geográfico. A união dos dados oriundos das regiões nucleares com aqueles mitocondriais sugere que Epinephelus itajara apresenta um provável comportamento filopátrico em termos reprodutivos nos estuários da baía da Babitonga (SC) e do rio Potengi (RN), dada a estruturação genético-evolutiva observada. Além disso, é possível ainda hipotetizar que na baía da Babitonga (SC) machos e fêmeas são filopátricos, mas que no rio Potengi apenas as fêmeas parecem apresentar tal comportamento demográfico-reprodutivo. Tais hipóteses são sustentadas pelas características dos genomas acessados: ISSRs nucleares de origem biparental e genoma mitocondrial de origem uniparental
3

Primeros registros de helmintos parásitos de Hemanthias signifer y Hemanthias peruanus (Teleostei: Serranidae) “doncella” procedentes de Puerto Pizarro, Tumbes.

Luna Mori, Katherine Rosario January 2016 (has links)
En el presente estudio se describen los helmintos parásitos presentes en Hemanthias signifer y H. peruanus, procedentes de Puerto Pizarro, Tumbes, Perú, así como la prevalencia y diversidad parasitaria en ambos peces. El material ictiológico se obtuvo del Terminal Pesquero de Villa María del Triunfo, el muestreo se realizó desde octubre del 2014 hasta febrero del 2015. Los especímenes fueron colectados en solución salina y luego fijados; los monogeneos, trematodos y cestodos en alcohol al 70 %, para la tinción se usó Carmín de Semichon, Hematoxilina Delafield y Tricromica de Gomori y se montaron con bálsamo de Canadá. Se identificó al monogeneo Hemanthicotyle sanmarquensis n. g., n. sp, los trematodos Lecithochirium magnaporum y Gonocerca crassa y la post larva de cestodo Tentacularia coryphaenae, registrándose una nueva localidad y hospedero para todos los parásitos estudiados. En cuanto a la prevalencia parasitaria, H. signifer se encontró parasitado en 75.75 % (25/33) y H. peruanus en 72.72 % (24/33) con al menos 1 parásito. En relación a la diversidad de parásitos, se encontraron 4 especies: 1 monogeneo, 2 digeneos, 1 post larva de cestodo; en H. signifer se aisló un total de 93 ejemplares de Hemanthicotyle sanmarquensis n. g., n. sp., 12 de Lecithochirium magnaporum, 10 de Gonocerca crassa y 5 post larvas de Tentacularia coryphaenae; en H. peruanus un total de 34 ejemplares de Lecithochirium magnaporum, 25 de Gonocerca crassa y 2 de Tentacularia coryphaenae. Palabras clave: Diclidophoridae, Hemanthicotyle sanmarquensis, helmintos, peces Serranidae, Perú. / --- In the present study helminth parasites are described in Hemanthias signifer and H. peruanus, from Puerto Pizarro, Tumbes, Peru, and the prevalence and diversity of parasites in both fish. The ichthyological material was the Fishing Terminal of Villa Maria del Triunfo, sampling was carried out from October 2014 to February 2015. The specimens were collected in saline solution and then fixed; the monogeneos, trematodos and cestodos in alcohol to 70 %, for the coloring there was used Carmine of Semichon, Hematoxilina Delafield and Tricromica de Gomori and they were mounted by balsam of Canada. . The monogeneo Hemanthicotyle sanmarquensis n. g. n. sp was identified., , the trematodos Lecithochirium magnaporum and Gonocerca crassa and the post larva of cestodo Tentacularia coryphaenae, registering a new locality and host for all the studied parasites. As for the parasitic prevalency, H. signifer parasitized found in 75.75 % (25/33) and H. peruanus in 72.72 % (24/33) with at least 1 parasite. As regards the parasites diversity, 4 species were found: 1 monogeneo, 2 digeneos, 1 post cestodo larva; in H. signifer there isolated himself a whole of 93 specimens of Hemanthicotyle sanmarquensis n. g., n. sp., 12 of Lecithochirium magnaporum, 10 of Gonocerca crassa and 5 post Tentacularia coryphaenae larvae; in H. peruanus a whole of 34 specimens of Lecithochirium magnaporum, 25 of Gonocerca crassa and 2 of Tentacularia coryphaenae. Key words: Diclidophoridae, Hemanthicotyle sanmarquensis, helmintes, fish Serranidae, Perú. / Tesis
4

Juvenile Population Dynamics of Families Lutjanidae and Serranidae in the Gulf of Mexico, with Respect to the Loop Current and other Hydrographic Features

Unknown Date (has links)
The Gulf of Mexico (GoM) contains a variety oceanographic features including; the Loop Current, cyclonic/anticyclonic eddies, common water, and the Mississippi River Plume. The relationship these features have on the community assemblages of Families Lutjanidae and Serranidae has been of great interest from both biological and economic standpoints. These families represent some of the most economically important fisheries in the GoM. Identifying the role these features play in the transportation of larval and juvenile nearshore species to offshore environments is vital to resource managers. Using data collected shortly after the Deepwater Horizon Oil Spill via the NOAA Natural Resource Damage Assessment in 2011 as well as cruises conducted by the Deep Pelagic Nekton Dynamics of the Gulf of Mexico (DEEPEND) Consortium from 2015-2017, the faunal composition and abundance of these families were analyzed with respect to seasonality, oceanographic features, depth distribution, and time. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2018. / FAU Electronic Theses and Dissertations Collection
5

Comparative life histories and stock assessments of rockcods (family Serranidae) from the east coast of South Africa.

Fennessy, Sean Thomas. January 2000 (has links)
The family Serranidae is a diverse group of fishes, of which the genus Epinephelus (rockcods or groupers) is the largest. Serranids are commonly caught in reef fisheries in tropical and warm-temperate latitudes, and are targeted because of their tasty flesh and high value. In South Africa, epinepheline serranids mainly occur in hook and line fisheries in the province of KwaZulu-Natal. Mostserranids are caught by the boat-based (skiboat) fishery, and the commonestspecies are the endemic catface rockcod (Epinephelus andersoni), thehalfmoon rockcod (E. rivulatus), the yellowbelly rockcod (E. marginatus) and the endemic white-edge rockcod (E. albomarginatus). Although serranids contribute about ten percent to catches by the commercial and recreational skiboat sectors in KwaZulu-Natal, representing an estimated total catch of around 200 mt per year, little is known about these fishes in South Africa. From the mid-1980s to the mid-1990s, the mean lengths of E. marginatus and E. albomarginatus in the region declined significantly. Over this period, lengths of E. andersoni remained the same, while those of E. rivulatus increased. Lengths of E. marginatus and E. albomarginatus from Mozambique, where fishing effort was low at the time of sampling, were significantly greater than in KwaZulu-Natal. Monthly biological data were mostly collected from commercial skiboat catches on the northern and southern coast of KwaZulu-Natal. Additional data for E. marginatus and E. albomarginatus were also collected irregularly from commercial catches made in Mozambique. Unless the fish had ripe ovaries, all gonads had to be sectioned to establish sex and stage. Histology revealed that all gonads had a female-like appearance, with lamellae and a central lumen. In E. andersoni, there was a complete overlap of male and female length frequencies, and their meanlengths were not significantly different. Some males and inactive bisexuals were both smaller and younger than the female size and age at first maturity. Together with the occurrence of mature bisexual fish (transitionals), these observations indicate that males are derived from immature or mature females, hence this species is a diandric protogynous hermaphrodite. The other three species exhibit typical signs of monandric protogynous hermaphroditism. Males and females had significantly different mean lengths, and age and length frequencies by sex werebimodal. Transitional individuals were recorded in E. rivulatus. E. andersoni and E. rivulatus matured at small sizes and early ages relative to E. marginatus and E. albomarginatus. Ripe ovaries were much larger than ripe testes in all four species. E. andersoni, E. marginatus and E. albomarginatus spawned in spring and summer, while E. rivulatus spawned in winter and spring. There were no indications of spawning in E. andersoni in the southern sampling region, and few ripe individuals of E. albomarginatus were encountered in KwaZulu-Natal samples. Size at maturity of this species was much smaller in Mozambique samples. Large, reproductively inactive individuals of E. andersoni were frequently observed in the spawning season. The lack of reproductive activity of E. andersoni and E. albomarginatus in KwaZulu-Natal may be because this area represents thesouthernmost limit of the distribution of these species. Ageing of the four species was undertaken using sectioned otoliths. Age validation was undertaken by a combination of tetracycline marking in captive fishes, and analysis of the marginal zone in otoliths. All four species are relatively long-lived, although estimates of maximum age may be under-estimated because of long-term harvesting. In all four species, fish from the southern sampling region were larger than fish from the northern region at the same age. Only in the case of E. rivulatus were these significant enough to warrant the fitting of two growth curves to the northern and southern populations. Males in all four species tended to be larger than females at the same age, suggesting that there may be a growth spurt following sex change, or that faster-growing females changed sex. A logistic growth curve was fitted to the age-length data for E. andersoni, while von Bertalanffy curves produced the best fit for the other species. Based on the rates at which L∞ attained in these four species, E. marginatus and E. albomarginatus are slow-growing species, while E. andersoni and, particularly, E. rivulatus arefaster growing. Rates of total mortality and natural mortality were estimated using length-converted catch curves and the Rikhter and Efanov equation, respectively. Stock assessments undertaken by yield per recruit and spawner biomass per recruit analyses indicate that E. andersoni in KwaZulu-Natal is currently optimally exploited, while E. rivulatus is lightly exploited. Both E. marginatus and E. albomarginatus are over-exploited. The potential problems in applying standard per recruit models to species with complex life histories are discussed. Support for the reduced stock status of the latter two species is provided by the observed changes in lengths of these species over a ten-year period, and their relatively small size in KwaZulu-Natal compared to the lightly-fished Mozambique populations. Local fishers in KwaZulu-Natal have also reported declines in sizes and reduced catches of these two species.The life history styles and other features of the four species are compared and discussed with reference to the resilience of these species to harvesting. Two of the species (E. marginatus and E. albomarginatus) are monandric protogynous hermaphrodites, which grow slowly, mature late and attain large sizes. E.andersoni and E. rivulatus grow faster, mature earlier and are smaller species. The normally deleterious effects of fishing on sex-changing species are not manifested in these two species, possibly because E. rivulatus is so small, that males are not selectively removed. In contrast, E. andersoni is a diandric protogynous hermaphrodite, and hence, does not rely on sex-change as a source of males. The current management methods for serranids in KwaZulu-Natal are presented, and suggestions for future approaches are discussed. / Thesis (Ph.D.)-University of Natal, Durban, 2000.
6

An?lise da estrutura gen?tica populacional da pira?na (cephalopholis fulva: serranidae) ao longo da costa e ilhas oce?nicas brasileiras

Souza, Allyson Santos de 26 April 2011 (has links)
Made available in DSpace on 2015-03-03T14:00:59Z (GMT). No. of bitstreams: 1 AllysonSS_DISSERT.pdf: 3119890 bytes, checksum: 5de05e8e42f3274421226e677a37e4ea (MD5) Previous issue date: 2011-04-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Brazil has about 8,500 km of coastline and on this scale, fishing is a historically important source of animal protein for human consumption. The national fishing background shows a growth of marine fishery production until 1985 and within this period it was recorded a steady decline. From the year 2003 fishing statistics aim to some "recovery" of the total fisheries production, which probably is related to a change in industry practice. The target of commercial fishing became smaller species with low commercial value, but very abundants. The coney, Cephalopholis fulva (Serranidae), is one of these species that have been suffering a greater fishing pressure in recent years. In order to provide data about the current situation of the genetic diversity of these populations, several molecular markers have been being used for this purpose. The prior knowledge of genetic variability is crucial for management and biodiversity conservation. To this end, the control region sequences (dloop) of mtDNA from Cephalopholis fulva (Serranidae) from five geographical points of the coast of Brazil (Cear?, Rio Grande do Norte, Bahia and Esp?rito Santo) and the Archipelago of Fernando de Noronha (FN) were sequenced and their genetic diversity analyzed. The FST values were very low (0.0246 to 0.000), indicating high gene flow between the sampled spots. The indices h and indicate a secondary contact between previously allopatric lineages differentiated or large and stable populations with long evolutionary history. Tests of Tajima and Fu showed expansion for all populations. In contrast, the mismatch distribution and SSD indicated expansion just for coastal populations. Unlike other species of the Atlantic which have been deeply affected by events on later Pleistocene, the population-genetic patterns of C. fulva may be related to recent events occurred approximately 130,000 years ago. Moreover, the data presented by geographical samples of the specie C. fulva showed high genetic diversity, also indicating the absence of deleterious effects of over-exploitation on this specie, as well as evidence of complete panmixia between all sampled populations / Brasil possui cerca de 8.500 km de litoral e diante desta dimens?o, a pesca historicamente constitui uma importante fonte de prote?na animal para consumo humano. O hist?rico nacional na pesca mostra um crescimento da produ??o pesqueira marinha at? 1985 e a partir deste per?odo registrou-se um cont?nuo decr?scimo. A partir do ano de 2003 as estat?sticas pesqueiras apontam para certa ?recupera??o? da produ??o pesqueira total, o que provavelmente esta relacionada a uma mudan?a nas pr?ticas do setor. O alvo da pesca comercial passou a ser esp?cies menores e de baixo valor comercial, por?m muito abundantes. A pira?na, Cephalopholis fulva (Serranidae) ? uma destas esp?cies alvo que vem sofrendo uma maior press?o pesqueira nos ?ltimos anos. A fim de fornecer dados sobre a real situa??o da diversidade gen?tica destas popula??es, diversos marcadores moleculares v?m sendo utilizados para esta finalidade. O pr?vio conhecimento da variabilidade gen?tica ? crucial para o manejo e conserva??o da biodiversidade. Neste intuito, sequ?ncias da regi?o controle (d-loop) do DNAmt de Cephalopholis fulva (Serranidae) de cinco pontos geogr?ficos da costa brasileira (Cear?, Rio Grande do Norte, Bahia e Esp?rito Santo) e o Arquip?lago de Fernando de Noronha (FN) foram sequenciadas e sua diversidade gen?tica analisada. Os valores de FST se revelaram muito baixos (0.0246 a 0.000), indicando intenso fluxo g?nico entre os pontos amostrados. Os ?ndices h e indicam um contato secund?rio entre linhagens alop?tricas previamente diferenciadas ou a grandes e est?veis popula??es com longa hist?ria evolutiva; Os testes de Fu e Tajima indicaram expans?o para todas as popula??es. J? as diferen?as par-a-par e o SSD indicaram expans?o apenas para as popula??es costeiras. Diferentemente de outras esp?cies do Atl?ntico que foram profundamente afetadas por eventos Pleistoc?nicos mais tardios, os padr?es gen?tico-populacionais presentes em C. fulva parecem estar relacionados a eventos mais recentes ocorridos a cerca de 130.000 anos. Al?m disso, os dados apresentados pelas amostras geogr?ficas da esp?cie C. fulva demonstram elevada diversidade gen?tica, indicando ainda a aus?ncia de efeitos delet?rios da sobrepesca da esp?cie, bem como evid?ncias de panmixia plena tanto entre as ?reas continentais, como entre estas e o regi?es insulares
7

Pesca de linha e comunidades de peixes recifais na plataforma externa e talude superior da costa leste do Brasil

SILVA, George Olavo Mattos e 31 January 2010 (has links)
Made available in DSpace on 2014-06-12T23:02:51Z (GMT). No. of bitstreams: 2 arquivo9597_1.pdf: 3782852 bytes, checksum: 06f90dbd6e7ddfaef3f9b588578ea3f2 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2010 / Foram investigados dados primários de cruzeiros de pesca experimental com espinhel de fundo visando caracterizar a diversidade, a estrutura de comunidades e padrões de distribuição batimétrica de peixes demersais ao longo da plataforma continental externa e talude superior ao largo da costa brasileira entre as latitudes 13ºS e 22ºS. Mais de 75% das capturas registradas foram de peixes recifais das famílias Serranidae, Lutjanidae, Malacanthidae, Muraenidae, Sparidae, Balistidae, Carangidae, Haemulidae, Scorpaenidae e Priacanthidae. A ocorrência desta fauna característica de ambientes de substrato consolidado indica a existência e importância de formações recifais na zona de borda da plataforma (40-200m) e também no talude superior, até cerca de 500m de profundidade. Os resultados indicaram uma riqueza de espécies mais elevada na zona de borda da plataforma (40-80m), com índices de diversidade caindo mais acentuadamente nos primeiros 200 metros. Esse padrão de variação batimétrica é acompanhado por mudanças na estrutura das comunidades de peixes demersais. Análises multivariadas permitiram a distinção de três diferentes assembléias de espécies separadas primariamente pela isóbata de 200m. A latitude age também como um fator estruturante secundário sobre as comunidades de peixes recifais da zona de borda da plataforma. Os resultados apresentados confirmam a divisão da ictiofauna brasileira da plataforma externa em uma componente tropical, ao norte de 19ºS (grupo A), e outra componente subtropical ao sul dessa latitude (grupo C). Uma terceira assembléia (grupo B) foi identificada no talude superior ao longo de toda a área de estudo. A profundidade máxima de ocorrência de 20 espécies foi ampliada dos limites batimétricos anteriormente registrados. Os resultados reforçam a hipótese de um corredor de dispersão de espécies associadas a formações recifais profundas ao longo da zona de borda da plataforma e maiores profundidades na margem continental Sul-Americana, conectando a província do Atlântico Sudoeste com a província do Caribe. Os recifes de borda da plataforma sustentam importantes pescarias multiespecíficas e proporcionam habitats críticos para o ciclo de vida de muitas espécies de peixes recifais, inclusive sítios de agregação reprodutiva extremamente vulneráveis às pressões humanas. O estudo revela a importância biológica dos recifes de borda como hotspots ecológicos e áreas prioritárias para a conservação no Atlântico Tropical

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