Macrozooplâncton da Zona Econômica Exclusiva do Nordeste do Brasil (segunda expedição oceanográfica - REVIZEE/NE II) com ênfase em Copepoda (Crustacea)

Abstract

. ustacea). ustacea). ustacea). ustacea). The present study was performed with the objective to characterise the density, relative abundance, frequency of occurrence, specific diversity and species associations of the oceanic macrozooplankton of the "Exclusive Economic Zone". The area under investigation is located between 7º28'56"S -34º32'45"W and 3º21'08"S -38º40'29"W, sampled during the second oceanographic expedition REVIZEE/NE on board OV Antares of the Brazilian Navy. Twenty-one samples were taken with bongo type plankton net with 300µm mesh size between 0 and 200 m depth. 63 (sixty and three) taxa were identified. Total density varied from 2,31 to 6,06 ind.m -3 (station 55 and 56) for the whole community and from 0,99 to 4,75 ind.m -3 (station 48 and 57) for Copepoda. Regarding frequency of occurrence, Crustacea and Chaetognatha were very frequent, Cnidaria and Teleostei were frequent, Mollusca, Annelida, and Chordata were less frequent, and Protozoa occurred rarely. Specific diversity varied from 0,648 to 4,037 bits.ind -1 , and the equitability from 0,279 to 1,0. Diversity and equitability were low due to the dominance of Undinula vulgaris (Dana, 1849) e Calanopia americana F. Dahl, 1894. Cophenetic analysis revealed a r < 0,8, showing that there were no distinct groups of copepods in the region. The dominant copepod species was Undinula vulgaris, occurring at all stations. The meroplankton was represented mainly by decapod crustacean larvae and fish eggs and larvae, but was less important than the holoplankton community. KEY WORDS. Biodiversity, oceanic Copepoda.RESUMO. Objetivando-se caracterizar a densidade, abundância relativa, freqüência de ocorrência, diversidade específica e associação de espécies do macrozooplâncton oceânico da "Zona Econômica Exclusiva" foi realizado o presente estudo. A região prospectada encontra-se localizada entre os paralelos 7º28'56"S -34º32'45"W, referente a segunda expedição oceanográfica do Programa REVIZEE/NE, realizada pelo Noc. Antares da DHN/ Marinha do Brasil. As amostras foram coletadas com rede de plâncton tipo bongo com malha de 300 e 500µm, no período de 31/01 a 07/02/97 em 21 estações, totalizando 42 amostras. Foram identificados 78 taxa. A densidade total dos organismos (exceto Copepoda) variou de 2,31 a 6,06 org.m -3 (estações 55 e 56) e, para os Copepoda de 0,99 a 4,75 org.m -3 (estações 48 e 57). Em termos de freqüência de ocorrência Crustacea e Chaetognatha foram muito freqüentes; Cnidaria e Teleostei (ovos e larvas) freqüentes; Mollusca, Annelida e Chordata pouco freqüentes e Protozoa raros. A diversidade específica variou de 0,648 a 4,037 ind.bits -1 . A equitabilidade variou de 0,279 a 1,0. Os baixos valores de diversidade e equitabilidade ocorreram devido à dominância de Undinula vulgaris (Dana, 1849) e Calanopia americana F. Dahl, 1894. A análise cofenética revelou um r < 0,8, demonstrando não haver grupos diferentes de Copepoda na região. A espécie de Copepoda dominante foi Undinula vulgaris, ocorrendo em todas as estações independente da malha col...

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