Ciclo de vida, produtividade secundária, distribuição, alimentação e crescimento de Massartella brieni (Lestage) (Ephemeroptera: Leptophlebiidae) em riachos do Parque Estadual Intervales, Estado de São Paulo / Life cycle, secondary production, distribution, feeding habits and growth of Massartela brieni from streams of the Parque Estadual Intervales, State of São Paulo

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The present work had as general aim to study the life cycle, secondary production, distribution, feeding habits and growth of Massartela brieni from streams of the Parque Estadual Intervales, State of São Paulo. The analyzed material was collected in six collection stations, one in Roda d´Água stream, one in Mirante stream, one in Bocaina stream, two in Água Comprida stream and one in Lajeado stream. In all stations, rocky substratum was collected with Surber sampler with 0,250 mm of mesh, in each sampling 10 sampling units were taken randomily, totalling 1m2. In the Bocaina stream, litter in riffles and in pools were also sampled with D net (10 litter patches with 0,01 m2 each). The collections were carried out between September/1999 and September/2001. The analysis of size frequency histograms representing the number of individuals in different classes of size was inconclusive in relation to voltinism of the studied species. The annual secondary production of Massartella brieni was 4802,79 mg.m-2yr-1 for a CPI of 120 days, 3842,24 mg.m-2yr-1 for a CPI of 150 days and 3201,86 mg.m-2yr-1 for a CPI of 180 days. The results indicate that M. brieni occurred preferentialy in sites with lesser water speed and with litter accumulations. There was not a negative linear relation between the discharge and the precipitation (previous month) with density of M. brieni in Mirante stream. However, it was possible to observe that months with higher discharge or precipitation (previous month) did not present high densities. For the most part of the months, the periods with low densities had lesser biomass, except for the months from March to May of 2000 (months in which individuals of larger size occurred). During the growth, the most of the structures of the head had negative allometry, whereas of the abdomen and most measurements of the thorax had positive allometry. The change of shape of the maxillae (Relative Warps I) had a slight significant relationship with the growth of M. brieni.

ASSUNTO(S)

recruitment. morfometria insetos aquáticos ambientes lóticos biomassa morfometrics lotic environments aquatic insects biomass recrutamento

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