Longitudinal distribution of Copepoda populations in the transition zone of Paranapanema river and Jurumirim Reservoir (São Paulo, Brazil) and interchange with two lateral lakes

Abstract

Longitudinal changes in composition, abundance, and distribution of copepods were studied at the transition zone of Paranapanema River-Jurumirim Reservoir (SP, Brazil). The interchange of biotic material between marginal lakes and the river system was also examined. Water samples were obtained from 6 stations along a stretch of 13 km of the Paranapanema River, from an upstream reach with high water velocity up to the river mouth into Jurumirim Reservoir. Two other sites in lateral lakes were also sampled. Nine copepod taxa were identified: 3 calanoids (Argyrodiaptomus furcatus Sars, Notodiaptomus iheringi Wright, and N. conifer Sars) and 6 cyclopoids (Eucyclops Claus, Microcyclops Claus, Mesocyclops longisetus Thiébaud, Thermocyclops decipiens Fischer, T. minutus Lowndes, and Paracyclops Claus). Harpacticoids were also collected. Calanoid and cyclopoid nauplii and copepodids, and harpacticoids were the most abundant organisms. In general, there was a longitudinal decrease in copepod abundance, whereas an increase was detected near the lakes. The abundance of most copepods was inversely correlated with current velocity and suspended solids. Higher abundance was observed in the river main course during the rainy season, during which there is a higher connectivity between the lakes and the main river. This promotes exportation of biologic material from marginal lakes to the river system, a biotic exchange reflecting the importance of marginal lakes to the river community structure.Key words: Copepoda, longitudinal distribution, river, lakes, floodplain. RESUMO Distribuição longitudinal de Copepoda na região de transição rio-reservatório (rio Paranapanema-Represa de Jurumirim, SP) e influência de duas lagoas lateraisO presente estudo foi realizado na zona de desembocadura do rio Paranapanema, na Represa de Jurumirim, visando a verificar as mudanças longitudinais na composição, abundância e distribuição dos Copepoda e a analisar a influência de lagoas laterais na exportação de material biótico para o rio. Foram amostrados 6 pontos no rio (trecho de 13 km), desde um local mais a montante, com alta velocidade da correnteza, até um local com características mais lênticas, na desembocadura do rio na represa, além de duas lagoas conectadas ao rio. Foram identificados 9 taxa: 3 Calanoida (Argyrodiaptomus furcatus Sars, Notodiaptomus iheringi Wright e N. conifer Sars) e 6 Cyclopoida (Eucyclops Claus, Microcyclops Claus, Mesocyclops longisetus Thiébaud, Thermocyclops decipiens Fischer, T. minutus Lowndes e Paracyclops Claus), além de representantes da ordem Harpacticoida. Braz. J. Biol., 64(1): 11-26, 2004 12 CASANOVA, S. M. C. and HENRY, R.Os organismos mais abundantes foram as fases de desenvolvimento nauplius e copepoditos, de Calanoida e Cyclopoida e os Harpacticoida. De forma geral, observou-se diminuição na abundância dos Copepoda, do ponto 1 ao ponto 5, aumentando, porém, no ponto 6 e nas lagoas marginais. A maioria dos Copepoda mostrou relação inversa com a velocidade da corrente e o material em suspensão...

Copepod assemblage structure (Crustacea: Copepoda) along a longitudinal environmental gradient in a tropical river-floodplain system, Brazil

“…However, the absence of flood during the studied period leads us to disregard this idea. In this sense, Casanova & Henry (2004) verified that low water levels determined a small contribution of lakes, both in terms of abundance and diversity, to the increment of copepod species in the Paranapanema River.…”

Parasite infracommunities of Leporinus friderici: A comparison of three tributaries of the Jurumirim Reservoir in southeastern Brazil

“…This study highlighted the disappearance of the digenean Prosthenhystera obesa after the establishment of a reservoir. In the studied area, the effects of the Jurumirim Dam have been well documented for phytoplankton (Henry et al 2006), zooplankton (Casanova and Henry 2004), periphyton (Moschini-Carlos et al 2000), benthic macroinvertebrates (Jorcin and Nogueira 2008), aquatic macrophytes (Costa and Henry 2010), and fishes (Carvalho et al 2005, Kurchevski and. However, no data of the effects on the fish parasite community are available for this dam.…”

Aquatic macroinvertebrates associated with Eichhornia azurea (Swartz) Kunth and relationships with abiotic factors in marginal lentic ecosystems (São Paulo, Brazil)

“…The mouth zone is a current reduction site of river water (Casanova and Henry, 2004), and laterally, a great number of marginal aquatic environments with different hydrodynamic characteristics (Carmo, 2007) are observed. In this river -reservoir transition region, extensive permanently inundated ecosystems with different degrees of connection with lotic environment are influenced by the variability of hydrologic pulse (Figure 1).…”