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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.
11

Ecologia reprodutiva do peixe-donzela, Stegastes fuscus cuvier, 1830 (osteichthyes: pomacentridae) em arrecifes rochosos da praia de B?zios, Rio Grande do Norte, Brasil

Souza, Liliane de Lima Gurgel 10 July 2006 (has links)
Made available in DSpace on 2014-12-17T14:02:02Z (GMT). No. of bitstreams: 1 LilianeLGS.pdf: 3221431 bytes, checksum: 94de7bf42be19a1c9a513aa1e36efe19 (MD5) Previous issue date: 2006-07-10 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The reproductive ecology of fish plays a key role both for rational exploitation methods and for protective measures of natural stocks. The purpose of this study was to analyze the reproductive aspects of the damsel-fish, Stegastes fuscus, during October 2004 to September 2005, in the coastal rocky reefs of B?zios Beach, N?sia Floresta, RN. Fish were captured using hooks and hand nets, during low tide. Reproduction was determined using sexual ratio, mean length of first maturation (L50), absolute fecundity and macroscopic characteristics of gonads. The following parameters were related to gonadosomatic index (GSI): condition factor (CF), hepatosomatic index (HSI), rain fall and temperature. In relation to sex distribution, it was observed that 78% were females and 22% were males. The L50 was 6.2 cm for females and 7.0 for males. Average fecundity was 6832 oocytes. Results showed that S. fuscus had better body condition in the months prior to spawning, particularly during initial and intermediate stages of maturation. Five stages of gonadal maturation were identified through macroscopic analysis: immature, in maturation, mature, spent and resting. The HSI was inversely related to the GSI. This was possibly due to the reproductive cycle of this species which was associated to the dry period of this region. During this period, low rain fall and high temperatures provide an propitious reproductive condition for the study species / A ecologia reprodutiva dos peixes ? fundamental na racionaliza??o dos m?todos de explora??o e na prote??o dos estoques naturais. O presente estudo analisou aspectos relacionados ? reprodu??o do peixe-donzela, Stegastes fuscus, durante o per?odo de outubro de 2004 a setembro de 2005, nos arrecifes rochosos da praia de B?zios, N?sia Floresta, RN. Os peixes foram capturados durante a mar? baixa utilizando anz?is e rede de m?o. A reprodu??o foi verificada mediante a propor??o sexual, o comprimento m?dio da primeira matura??o, a fecundidade absoluta e os caracteres macrosc?picos gonadais. Os seguintes par?metros foram relacionados ao ?ndice gonadossom?tico (IGS): fator de condi??o (FC), ?ndice hepatossom?tico (IHS), pluviosidade e temperatura. Em rela??o ? distribui??o por sexo de S. fuscus, 78% foram f?meas e 22% foram machos. O L50 foi 6,2 cm para as f?meas e 7,0 cm para os machos. A m?dia da fecundidade absoluta foi 6832 ov?citos. S. fuscus apresentou melhores condi??es corporais nos meses que antecederam a desova, principalmente nos est?dios inicial e intermedi?rio de matura??o gonadal. A partir de an?lises macrosc?picas das g?nadas, foram identificados cinco est?dios de matura??o gonadal: imaturo, em matura??o, matura??o, esgotado e repouso. O IHS demonstrou tend?ncia inversa ao IGS. Este fato pode estar relacionado ao ciclo reprodutivo da esp?cie, que foi relacionado ao per?odo de seca na regi?o. Neste per?odo, as menores precipita??es e as temperaturas elevadas conferem condi??es reprodutivas favor?veis para a esp?cie em estudo
12

Structure génétique des populations de trois espèces de poissons de récifs cubains : stegastes partitus, haemulon flavolineatum et acanthurus tractus / Population genetics of three coral reef fishes of Cuba : stegastes partitus, Haemulon flavolineatum and Acanthurus tractus

Castellanos gell, Jessy 01 June 2012 (has links)
La dispersion des poissons des récifs coralliens dépend, pour une large part, de l’existence de larves pélagiques qui peuvent être transportées au sein des courants marins loin de la population source. De l’efficacité de ce transport dépendra l’existence de populations formant un continuum, plus ou moins connectées, tout le long des zones de récifs. Toutefois, ce phénomène de dispersion est complexe et il implique aussi d’autres facteurs, physiques et biologiques, qui influent sur la dispersion de ces organismes.L’objectif de cette thèse a été d’étudier les effets des caractéristiques géographiques de l’archipel cubain et de la biologie des espèces sur la structure génétique et la connectivité des populations de poissons de récifs en utilisant comme modèle trois espèces présentant des traits d’histoire de vie différents : Stegastes partitus, Haemulon flavolineatum et Acanthurus tractus.Nous avons échantillonné des individus adultes dans cinq localités situées autour de l´archipel cubain pendant la période 2005-2010. Le polymorphisme de marqueurs microsatellites a été étudié chez S. partitus et H. flavolineatum, celui de la région non codante de l’ADNmt chez les trois espèces et celui du gène cytb chez A. tractus.L’analyse de la diversité génétique des locus microsatellites révèle des taux d’hétérozygotie observés (Ho) et attendus (He) élevés à chaque locus et pour les deux espèces, mais elles présentent différents patrons d’organisation de la diversité génétique. Chez S. partitus, la comparaison des localités prises deux à deux nous montre une différentiation exprimée par des valeurs de FST très faibles mais significatives, alors que chez H. flavolineatum aucune structuration géographique n’est observée. Ces résultats sont confirmés au niveau de l’ADN mitochondrial, lequel indique aussi une absence de différentiation d’A. tractus pour l’ensemble des localités étudiées. Les différences de structuration génétique des espèces étudiées pourraient être le résultat des effets des courants marins autour de l’ile qui agissent de façon différente sur la dispersion des espèces en fonction de leur comportement reproducteur (e.g. sites de fraie, œufs pélagiques ou benthiques et capacité des larves de rester prêt des récifs natals ou d’être transportés au loin).Pour les marqueurs mitochondriaux, nous avons obtenu des valeurs élevées de diversité haplotypique pour les trois espèces, mais la diversité nucléotidique est très différente selon les espèces, faible chez S. partitus, grande chez H. flavolineatum, et très grande chez A. tractus. La distribution du nombre de différences entre les séquences suggère que ces populations sont passées par des périodes d’expansion démographique. Ceci est confirmé par les estimations des paramètres de tests de neutralité. Les paramètres caractérisant la croissance des populations qui ont été obtenus pour les trois espèces ne sont pas semblables, ce qui suggère que le temps et l’ampleur des événements d’expansion ont été différents pour les trois espèces.L’analyse du gène cytb nous a permis d’identifier des haplotypes chez A. tractus qui n’avaient été observés préalablement que chez A. bahianus. L’aire de répartition de cette dernière espèce a été récemment restreinte à l’Atlantique Sud sur la base de la divergence génétique avec A. tractus et de la séparation géographique qui est maintenu par la barrière que constitue l’embouchure des rivières Orénoque et Amazone. La présence d’haplotypes du sud à Cuba suggère que des individus du sud ont été capables de traverser cette barrière. / Dispersal of marine fishes mainly depends on passive transport of planktonic larvae driven by ocean currents. It allows populations to be connected through thousands of kilometers but also make them sensitive to factors limiting larval dispersion. In this regard it is known that there are several physical and biological factors that determine the distribution of marine species larvae and therefore population connectivity.The present work aims to study the effects of geographic traits of Cuban archipelago and biological characteristics of reef fishes inhabiting it on the genetic structure of their populations. Three different species with distinct biological characteristics and broadly distributed within the Caribbean were selected: Stegastes partitus, Haemulon flavolineatum and Acanthurus tractus. Individuals were sampled from five localities distributed around Cuba during the time period from 2005 to 2010. We analyzed mitochondrial DNA (mtDNA) polymorphism: a fragment of the non coding region (NCR) for the three species and cytb for A. tractus. The polymorphism of nuclear microsatellite loci was studied for S. partitus and H. flavolineatum.Genetic diversity, assessed by means of Ho and He have high values when analysing microsatellite loci. These molecular markers revealed the presence of contrasting geographic structure patterns for the two species. Low but significant pairwise FST estimates were obtained for S. partitus while H. flavolineatum was genetically homogenous. These results were supported by mtDNA analyses. Likewise, A. tractus showed no evidence of significant genetic differentiation at the level of the NCR and cytb gene. Differences in population genetic structure of surveyed species could be the result of extant marine currents acting distinctly on species dispersion according to their reproductive behaviour (i.e. spawning sites, benthonic or pelagic eggs and capacity of larvae to staying close to the natal reef or being driven away from it). Mitochondrial markers showed high levels of haplotypic diversity for the three species and contrasted nucleotide diversity, low for S. partitus, intermediate for H. flavolineatum and high for A. tractus. According to these observations and results of neutrality tests and mismatch distribution analyses, it is suggested that recent population expansion occurred in these species. However differences in population parameter estimations suggest that the time and the rate of population expansion were different for the different species.The analysis of A. tractus cytb haplotype relationships grouped some Cuban individuals with two haplotypes previously described as A. bahianus. This latter species has been recently proposed as restrict to South Atlantic and separated from A. tractus by the Amazon-Orinoco outflow barrier. The presence of mtDNA haplotypes from the southern region in Cuba suggests that A. bahianus may be able to overcome this barrier.
13

Din?mica populacional e alimentar de Stegastes fuscus, (Osteichthyes:pomacentridae) em arrecifes da praia de B?zius, no Rio Grande do Norte

Canan, Bhaskara 14 December 2007 (has links)
Made available in DSpace on 2014-12-17T15:36:31Z (GMT). No. of bitstreams: 1 BhaskaraC.pdf: 2061435 bytes, checksum: 1ff82521fda22176fb2e79fff7117ece (MD5) Previous issue date: 2007-12-14 / The damselfish, Stegastes fuscus Cuvier, 1830 (Osteichthyes: Perciformes: Pomacentridae), is abundant in the coastal reefs of B?zios Beach, Rio Grande do Norte, Brazil and they play an important role in the reef community ecology. The present study investigated the feeding strategy of this species considering the food habits and morfo-histology of the digestive tract. Influence of the environmental correlates such as temperature, rainfall and luminosity in the tidal rock pools were studied. The fish were captured on a monthly basis from September 2004 to August 2005, during which period 842 individuals of S. fuscus were captured, 125 males, 437 females and 280 individuals without sex identification. The sex ratio observed was 1 M : 3,5 F. The total body length of males varied from 3.6 to 11.3 cm, with a mean of 7.77 cm; that of females varied from 2.9 to 11.4 cm, with a mean of 7.85 cm, and that of sex grouped individuals varied from 2.9 to 11.4 cm, with a mean of 7.83. However, there was no difference between males and females in total body length. This species presented a positive alometric growth and the equations obtained for the relation between body mass and total body length were: Wt =0,0174Lt 3,1123 for males; Wt =0,0137Lt 3,2294 for females and Wt = 0,0148Lt 3.1928 for sex grouped individuals. The relation between total body length and standard length was L t = 1 ,3223Ls + 0,1527 for sex grouped individual s. February to August was associated to a long period of gonadal resting. The fish spawned during January and in September -October. The frequency of fish with empty stomachs occurred during August to December, whereas frequency of fish with food contents i n stomachs occurred during January to July. This species is considered as a preferential herbivore based on the volume of macroalgae in its diet composition. The morfo -histological aspects of S. fuscus confirm herbivory. Among the environmental factors con sidered only rainfall showed a correlation with the feeding habits of this species / O peixe-donzela, Stegastes fuscus Cuvier, 1830 (Osteichthyes: Perciformes: Pomacentridae), ? abundante nos arrecifes costeiros da praia de B?zios, Rio Grande do Norte e desempenha um important e papel ecol?gico em comunidades recifais. O presente estudo investigou a din?mica populacional e alimentar desta esp?cie levando em considera??o o regime alimentar e a morfo -histologia do trato digest?rio. Avaliou - se a influ?ncia das vari?veis ambientais, tais como, temperatura, pluviosidade e luminosidade em po?as de mar?. Foram realizadas coletas mensais no per?odo de setembro de 2004 a agosto de 2005, durante as quais foram capturados 842 indiv?duos de S. fuscus, sendo 125 machos, 437 f?meas al?m de 280 indiv?duos com sexo n?o identificado. A propor??o sexual observada foi de 1 M : 3,5 F. Em rela??o ao comprimento total os valores para machos machos variaram de 3,6 a 11,3 cm, com m?dia de 7,77 cm; para as f?meas de 2,9 a 11,4 cm, com m?dia de 7,85 cm e p ara os sexos agrupados de 2,9 a 11,4 cm, com m?dia de 7,83 cm, n?o havendo diferen?as entre os sexos quanto ao comprimento total. A esp?cie estudada apresentou um crescimento do tipo alom?trico positivo e as equa??es obtidas para a rela??o entre peso total e comprimento total foram: Wt = 0,0174Lt 3,1123 para machos; Wt =0,0137Lt 3,2294 para f?meas e Wt = 0,0148Lt 3,1928 para os sexos agrupados. A rela??o entre o comprimento total e o comprimento padr?o foi L t = 1,3223Ls + 0,1527 para os sexos agrupados. Nesses peixes foi observado um per?odo de repouso gonadal que se prolongou de fevereiro a agosto com a desova sendo realizada em janeiro e em setembro e outubro. Em rela??o ao regime alimentar, as maiores freq??ncias de est?magos sem alimento ocorreram entre os meses de agosto a dezembro enquanto que as maiores freq??ncias de est?magos com alimento ocorreram nos meses de janeiro a julho. Em fun??o do volume de macroalgas em sua composi??o de dieta, a esp?cie Stegastes fuscus ? considerada como preferencialmente herb?vora e os aspectos morfo-histol?gicos confirmam essa prefer?ncia. Dentre os fatores abi?ticos considerados por ocasi?o do estudo utilizando Stegastes fuscus, apenas a pluviosidade influenciou significativamente no regime alimentar desta esp?cie
14

Ictiofauna em cristas recifais no litoral de Pernambuco: Relação entre a cobertura algal e complexidade estrutural dos habitats

OLIVEIRA, Walter Dennis Menezes de 31 May 2016 (has links)
Submitted by Rafael Santana (rafael.silvasantana@ufpe.br) on 2017-07-14T18:46:22Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação_Walter DM Oliveira_ Oceanografia_UFPE.pdf: 1745886 bytes, checksum: 62870c6bfbb9848afc84e4fb94eff45e (MD5) / Made available in DSpace on 2017-07-14T18:46:22Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação_Walter DM Oliveira_ Oceanografia_UFPE.pdf: 1745886 bytes, checksum: 62870c6bfbb9848afc84e4fb94eff45e (MD5) Previous issue date: 2016-05-31 / Os recifes costeiros são comumente afetados por ações antrópicas que vão desde o turismo contemplativo a poluição por efluentes domésticos. Essas formações recifais abrigam muitas espécies de peixe que em busca de abrigo para diferentes fazes do ciclo de vida e alimento. Nesses sentido as cristas recifais formam um importante papel para o desenvolvimento desses organismos, sem comumente um local de berçário natural. A cobertura de substrato é um outro fator importante para essas espécies pois pode gerar proteção, alimentação direta a indireta com invertebrados epifíticos. As cristas recifais do litoral sul de Pernambuco são dominadas por cobertura algal. Os recifes locais são importantes como fonte de renda para as comunidades locais e para conservação dos ambientes marinhos costeiros. Foram analisadas as relações entre a ictiofauna e a categorias de algas nas cristas recifais de Porto de Galinhas, Serrambi e São José da Coroa Grande, tendo sido amostrados três piscinas em cada praia. Para isso foram feitas amostragens com transecto de faixa de 20x2 m² em cada piscina, com registros fotográficos da cobertura de substrato, essas fotos foram posteriormente analisadas para estimar o percentual de cada categoria representada na cobertura do substrato da crista recifal. Os dados mostraram que Stegastes fuscus, Abudefduf saxatilis, Sparisoma axillare, Halichoeres poeyi e Ophioblennius trinitatis foram as espécies mais representativas nas cristas recifais analisadas. As algas calcárias articuladas e turf foram as algas mais abundantes nessas formações. As algas folhosas foram pouco abundantes, sendo mais representadas em São José da Coroa Grande. A maioria da abundância de peixes representou a categoria trófica de herbívoros errante e a mais rica foi comedores de invertebrados móveis. St. fuscus e O. trinitatis foram registrados em todas as classes de tamanho, enquanto A. saxatilis, Sp. axillare,e H. poeyi foram observados em fases juvenis. A relação verificada entre a comunidade de peixes, a cobertura de substrato e as características estruturais foi baixa visto que a distribuição de peixes foi homogênea e houve pouca variação nas categorias de algas. / The reef crests form an important habitat for fish of different habits and life stages. Coastal reefs are commonly affected by human activities ranging from the contemplative tourism to the pollution from domestic sewage. The substrate coverage can indicate the distribution of fish species that use this place to establish throughout the life cycle or in transitional phases. The reef crests of the southern coast of Pernambuco are dominated by algal cover. Local reefs are important as source of income for local communities and for conservation of coastal marine environments. The relationship between fish community and categories of algae on the reef crests of Porto de Galinhas, Serrambi and São José da Coroa Grande were analyzed. Three points were sampled at each beach. For the sampling of fish were made four transects of 20x2 m in each pool. At the same time were made photos of substrate coverage, these photos were then analyzed to estimate the percentage of each category. The data showed that Stegastes fuscus, Abudefduf saxatilis, Sparisoma axillare, Halichoeres poeyi and Ophioblennius trinitatis were the most significant species in the reef crests analyzed. The jointed calcareous macroalgae and turf were the most abundant in these formations. The sheet-like algaes were less abundant and more represented in São José da Coroa Grande. Most of the abundance of fish represented the trophic category herbivores and the richest was eaters of mobile invertebrates. St. fuscus and O. trinitatis were recorded in all size classes, while A. saxatilis, Sp. Axillare, and H. poeyi were observed in juvenile stages. The relationship between the fish community and substrate coverage and structural characteristics was low as the fish distribution is homogeneous and there was little variation in types of substrate coverage.
15

The acoustic signals associated with territorial behaviors in Stegastes lividus (Pomacentridae)

Chen, Nien-wen 26 July 2005 (has links)
Acoustic signals are widely used by fish such as pomacentrids, to communicate during courtship and agonistic activities. Adult Stegastes lividus holds a permanent territory in a coral reef environment. Previous studies suggested that S. lividus seems to produce clicking sounds when intruders close to its territory. This study aimed to describe (1) the sounds produced by this species; (2) the behavioral pattern associated with these acoustic signals; (3) vocal activity of diurnal variation. The study site was near the water inlet of the Third Nuclear Power Plant in southern Taiwan (120¡C45¡¬E , 21¡C57¡¬N). 24-hour recordings at the habitat of S. lividus at 5-6 m and at 2-3 m were made in February, March and April, 2005. The synchronous video-audio recordings were also made at the colonies of S. lividus at 2-3 m. The observations showed that S. lividus produced clicking sounds for territorial defense (e.g. aggressive behavior). These sounds were composed of a variable number of pulses that had a dominant frequency at 200 to 400 Hz. Stegastes lividus produced different sound types to defend against conspecifics or heterospecifics. Although the acoustic signals were emitted throughout all day, more sounds were recorded during the noon, fewer sounds at night, and a small peak presented at sunset. Therefore, I suggested the acoustic signals of S. lividus may be also serves as species recognition. The fish may be a diurnal fish, and its social interaction peaks at noon.
16

Structure génétique des populations de trois espèces de poissons de récifs cubains : Stegastes partitus, haemulon flavolineatum et acanthurus tractus

Castellanos gell, Jessy 01 June 2012 (has links) (PDF)
La dispersion des poissons des récifs coralliens dépend, pour une large part, de l'existence de larves pélagiques qui peuvent être transportées au sein des courants marins loin de la population source. De l'efficacité de ce transport dépendra l'existence de populations formant un continuum, plus ou moins connectées, tout le long des zones de récifs. Toutefois, ce phénomène de dispersion est complexe et il implique aussi d'autres facteurs, physiques et biologiques, qui influent sur la dispersion de ces organismes.L'objectif de cette thèse a été d'étudier les effets des caractéristiques géographiques de l'archipel cubain et de la biologie des espèces sur la structure génétique et la connectivité des populations de poissons de récifs en utilisant comme modèle trois espèces présentant des traits d'histoire de vie différents : Stegastes partitus, Haemulon flavolineatum et Acanthurus tractus.Nous avons échantillonné des individus adultes dans cinq localités situées autour de l'archipel cubain pendant la période 2005-2010. Le polymorphisme de marqueurs microsatellites a été étudié chez S. partitus et H. flavolineatum, celui de la région non codante de l'ADNmt chez les trois espèces et celui du gène cytb chez A. tractus.L'analyse de la diversité génétique des locus microsatellites révèle des taux d'hétérozygotie observés (Ho) et attendus (He) élevés à chaque locus et pour les deux espèces, mais elles présentent différents patrons d'organisation de la diversité génétique. Chez S. partitus, la comparaison des localités prises deux à deux nous montre une différentiation exprimée par des valeurs de FST très faibles mais significatives, alors que chez H. flavolineatum aucune structuration géographique n'est observée. Ces résultats sont confirmés au niveau de l'ADN mitochondrial, lequel indique aussi une absence de différentiation d'A. tractus pour l'ensemble des localités étudiées. Les différences de structuration génétique des espèces étudiées pourraient être le résultat des effets des courants marins autour de l'ile qui agissent de façon différente sur la dispersion des espèces en fonction de leur comportement reproducteur (e.g. sites de fraie, œufs pélagiques ou benthiques et capacité des larves de rester prêt des récifs natals ou d'être transportés au loin).Pour les marqueurs mitochondriaux, nous avons obtenu des valeurs élevées de diversité haplotypique pour les trois espèces, mais la diversité nucléotidique est très différente selon les espèces, faible chez S. partitus, grande chez H. flavolineatum, et très grande chez A. tractus. La distribution du nombre de différences entre les séquences suggère que ces populations sont passées par des périodes d'expansion démographique. Ceci est confirmé par les estimations des paramètres de tests de neutralité. Les paramètres caractérisant la croissance des populations qui ont été obtenus pour les trois espèces ne sont pas semblables, ce qui suggère que le temps et l'ampleur des événements d'expansion ont été différents pour les trois espèces.L'analyse du gène cytb nous a permis d'identifier des haplotypes chez A. tractus qui n'avaient été observés préalablement que chez A. bahianus. L'aire de répartition de cette dernière espèce a été récemment restreinte à l'Atlantique Sud sur la base de la divergence génétique avec A. tractus et de la séparation géographique qui est maintenu par la barrière que constitue l'embouchure des rivières Orénoque et Amazone. La présence d'haplotypes du sud à Cuba suggère que des individus du sud ont été capables de traverser cette barrière.

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