Life history and emergence patterns of stonefly species in mountain streams of the Futaleufú basin, Patagonia (Argentina)

HOLLMANN EUGENIA MARIA TERESA; MISERENDINO, M. L

ANNALES DE LIMNOLOGIE-INTERNATIONAL JOURNAL OF LIMNOLOGY

INTERNATIONAL JOURNAL OF LIMNOLOGY

Lugar: Tolousse; Año: 2008 p. 1 - 10

0003-4088

The temporal dynamics in density, life cycles, and emergence patterns were determined for the first time for five Plecoptera species in tributaries of the FutaleufúRiver in Patagonia, Argentina. Benthic samples and adult collections were made in five low order Nothofagus forested streams. Four species of grypopterigids (Aubertoperla illiesi, Notoperlopsis femina, Antarctoperla michaleseni and Senzilloides panguipulli) had simple, highly synchronized univoltine life cycles. The austroperlid Klapopteryx kuscheli had a semivoltine life cycle and our results suggest that it takes more than two years for the species to develop. Emergence periods in most of the species were concentrated in late spring and summer (October to February), which suggests seasonal and synchronized life cycles. Most of N. femina adult specimens were collected in mid spring indicating this specie emerged the first, whereas S. panguipulli was the last one, and emerged from January to April. A. illiesi showed a slightly delayed emergence in the high elevation site (La Hoya Stream) when compared to a piedmont stream, suggesting that temperature was an important control. Although we were unable to describe life cycle of Limnoperla jaffueli (Gripopterygidae) the adult emergence period was observed from November to January. Life histories of Plecoptera species in the studied streams seem to have a high degree of seasonality at least in this latitude, which is possibly determined by predictable temperature patterns and discharge regimes. This first contribution about life histories of Plecoptera species is significant to better understand the dynamics and functioning of pristine but fragile aquatic environments in Patagonia.