Lo Zooplancton

Abstract

En
The micro-zooplankton of the Acquatina lake has been studied for the first time from October 2006 to March 2007. Tintinnids were the most representative components of the community, which as a whole counted 64 taxa. The three different sites studied of the lake were not significantly different as regarding the period and the community considered. As regarding the copepod presence, a study has been carried out on the abundance of the diapause eggs in the clutch of each female from August 2007 to March 2008 in the species Paracartia latisetosa (Calanoida). The study ascertained that the production of diapause, overwintering, eggs was not typical of single females, and it was not related with the incoming of the Autumn. Diapause eggs were produced together with subitaneous ones also by the same female, and in the same day. A cycle has been individuated in the relative abundance of resting eggs (% of resting eggs / total eggs produced) in clutches produced from September to December, which did not correspond to the reducing photoperiod, temperature, or the varying salinity. A hypothesis has been proposed which links the diapause egg production to the female age.