Resumen de Distribución vertical de zooplancton en El Embalse Arenal, Costa Rica

Gerardo Umaña Villalobos, Federico Villalobos, Beatiz Bofll

• The vertical distribution of Bomina, Daphnia, Ceriodaphnia, Diaptomus and cyclopoids was studied Cor a 48 hours period in Arenal Reservoir, Costa Rica. In general the zooplankton decreased during day t across the water column. Daphnia, Diaptomus and the cyclopoids had a constant depth distribution with time, whereas Bosmina, and Cerodhnia showed slight evidénce oC vertical migration. Due to the scarcity of planktivorous fishes in the limnetic zone oC the reservoir, the migration of small-sized cladocerans is puroudtely explained by invertebrate predation pressure (e.g. cyclopoids)