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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

Dieta do ouri?o-branco, Tripneustes ventricosus (Lamarck, 1816), no Arquip?lago de Fernando de Noronha, PE

Cavalcanti, Augusto Muniz 07 December 2007 (has links)
Made available in DSpace on 2014-12-17T14:01:57Z (GMT). No. of bitstreams: 1 AugustoMC.pdf: 592613 bytes, checksum: 225d64aaa5fdd2313487f3c6c109454b (MD5) Previous issue date: 2007-12-07 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Sea urchins are benthic macroinvertebrates that inhabit shallow coastal waters in tropical and temperate zones. Urchins are usually classified as generalists or omnivores as they can adjust their diet according to the food resources available in the environment. Due to the strong grazing pressure they may exert, urchins have an important role in marine ecosystems, occupying different trophic levels and stimulating the intensification of the dynamics of communities where they occur. In 2004, a monitoring program focused on the population dynamics of the white sea urchin, Tripneustes ventricosus, has been initiated in the Fernando de Noronha Archipelago. At the same time, a surprisingly lack of information on the species biology has been noted, despite their wide geographical distribution and economic importance in many parts of its range. Hence, this work was developed to provide information on the feeding habits of T. ventricosus in the archipelago. Ten specimens were collected between December 2006 and July 2007 at two sites of the archipelago, Air France and Sueste Bay for biometrics and analysis of gut contents. Test diameters ranged from 9.19 cm (? 1.1) to 10.08 cm (? 0.58). Calculated stomach repletion index (IRE) was higher (p <0.05) in the Air France site and also during January and July. The IRE was not correlated to the gonad index. Fifteen different species of algae were detected in a total of 120 stomachs examined: 4 Chlorophytas, 4 Phaeophytas and 6 Rhodophytas. Food diversity (p <0.05) was higher in December 2006 and January 2007. Although several items had a high frequency of occurrence, they were low represented in terms of weight, and consequently, had a low level of relative importance. The brown algae Dictyopteris spp and Dictyota spp, followed by the green algae Caulerpa verticillata accounted for the greatest importance in T. ventricosus diet, comprising about 90% of the consumed items / Os ouri?os-do-mar s?o macroinvertebrados bent?nicos que habitam ?guas rasas costeiras em zonas tropicais e temperadas. Os ouri?os s?o geralmente classificados como generalistas ou on?voros por adaptarem sua dieta de acordo com a disponibilidade dos recursos alimentares dispon?veis no ambiente. Devido ? forte press?o de pastagem que exercem, os ouri?os possuem importante papel em ecossistemas marinhos ocupando diversos n?veis tr?ficos e estimulando a intensifica??o da din?mica das comunidades onde ocorrem. Em 2004 foi dado in?cio a um programa de monitoramento das popula??es do ouri?o-branco, Tripneustes ventricosus, quando se percebeu a car?ncia de informa??es sobre a esp?cie, apesar de sua ampla distribui??o e import?ncia econ?mica. Dessa forma, o presente trabalho visou obter informa??es referentes aos h?bitos alimentares de T. ventricosus no arquip?lago de Fernando de Noronha. Durante os meses de dezembro de 2006, janeiro, fevereiro, abril, maio e julho de 2007 foram amostrados 10 indiv?duos de T. ventricosus nas regi?es do Air France e na ba?a do Sueste. Foram realizadas biometrias e an?lises dos itens presentes no conte?do estomacal dos organismos. O di?metro m?dio de carapa?a dos ouri?os amostrados variou entre 9,19 cm (? 1,1) e 10,08 cm (? 0,58). Os ?ndices de reple??o dos conte?dos estomacais (IRE) foram mais elevados (p<0,05) na regi?o do Air France e durante os meses de janeiro e julho de 2007. Foi verificado que o IRE variou independentemente do ?ndice gonadal. Quinze diferentes esp?cies de algas foram encontradas nos 120 conte?dos estomacais analisados: 4 Chlorophytas, 4 Phaeophytas e 6 Rhodophytas, sendo que a maior (p<0,05) diversidade alimentar foi observada nos meses de dezembro de 2006 e janeiro de 2007. Apesar da freq??ncia de ocorr?ncia de alguns dos itens ser alta, suas representatividades em peso foram bastante baixas o que lhes confere um baixo ?ndice de import?ncia relativa. As algas pardas dos g?neros Dictyopteris e Dictyota, seguidas da alga verde Caulerpa verticillata representaram a maior import?ncia na dieta de T. ventricosus nas ?reas amostradas, compondo aproximadamente 90% da dieta da esp?cie no local

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