Estudo comparativo dos copépodes Temora stylifera e T. turbinata na plataforma continental sudeste do Brasil no verão e inverno de 2002 / Comparative study of the Temora stylifera and T. turbinata on the southeastern Brazilian continental shelf im summer and winter of 2002

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Marine biological invasions have impacts in several different levels in the recipient ecosystem, including those related to interactions with native species, especially those sharing similar ecological niches. The main goal of the present work was to investigate the distribution, abundance and biomass of Temora stylifera (native species) and T. turbinata (exotic species) on the southeastern Brazilian continental shelf in the summer and winter of 2002, and their relation to physical variables and chlorophyll a concentration. The distribution of T. stylifera was more homogeneous within the entire study area compared to T. turbinata. The former occupied mainly coastal sites while T. stylifera was frequent in oceanic stations where the exotic species did not occur. An upwelling event recorded during summer causing an increase in chlorophyll a concentration was concurrent with abundance peaks of the exotic species, probably indicating a more efficient use of phytoplankton or microzooplankton as food resource. Temperature and salinity were positively related to T. stylifera abundance. Both species peaked in summer, while winter concentrations were low. The higher abundance value found for T. turbinata was 1,334 org.m?³ and 572 org.m?³ for T. stylifera, both at the surface layer (0-20 m) in summer. Neither species contributed with a high percentage of the total zooplankton biomass. The life cycle of both species was not synchronized: young copepodites were more abundant in the case of T. stylifera, while oldest copepodites predominated in the T. turbinata populations. The exotic species had a more variable male/female ratio. The results indicate possible advantages of the introduced species over the native species in relation to food resources utilization and reproductive behavior.

ASSUNTO(S)

bioinvasão estrutura etária temora stylifera bioinvasion distribuição vertical horizontal distribution temora turbinata temora turbinata abundância ressurgência. vertical distribution temora stylifera distribuição horizontal

ACESSO AO ARTIGO

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