Life cycle, feeding and secondary production of Plecoptera community in a constant temperature stream in Central Europe

We studied the nymphal biology (life cycle, secondary production and feeding) of some Plecoptera species in a calcareous spring stream with almost constant temperature through the year (7–8 °C) at Prosiek valley (Chočské Vrchy Mts., West Carpathians, Slovakia). We found complicate life cycle consisting of two cohorts for Leuctra prima with growth rate positively correlated to photoperiod length. Isoperla sudetica showed an univoltine life cycle. The annual secondary production of the stonefly community was reaching 4304 mg DW m−2. It was mainly related to the abundance of three dominant species – I. sudetica, L. prima and Protonemura intricata – and to the permanence of their nymphs in the water through the whole year. We suppose that the stable thermal regime is a factor which could allow high production and biomass values, irrespective of seasons. Nymphs of I. sudetica passed from gatherer-collector to predator and nymphs of L. armata passed from gatherer-collector to shredder during their development.