title: Temporal fluctuation and reproduction of Thermocyclops decipiens (Copepoda, Cyclopoida) in an eutrophic lake of central Brazil.
abstract: Lake Paranoá is an eutrophic reservoir situated in the urban region of Brasília. This study was carried out in a fixed collection station located in the Riacho Fundo branch of the reservoir. Zooplankton samples were collected at intervals of 3-5 d at 9:00 a.m. during two months in the dry and rainy seasons for two years (dry-1996, rainy-1997, dry-1997 and rainy-1998), using a 64 microns-mesh plankton net. The most predominant species was Thermocyclops decipiens (about 50% of the total zooplankton community), which during the whole period had a high reproductive rate. The highest densities were found in the dry-1996 season (1700 ind/l for nauplii), and also fluctuated widely overtime. Nauplii stages dominated during the four periods, comprising 50-75% of the total population density. Ovigerous females peaked in the dry-1996 and rainy-1997 seasons, with 20-30% of the total females. The largest peak in egg production occurred during the dry-1996 season, and the total egg production was 2.0 x 10(3) eggs/l. Mesocyclops longisetus is a first record for Lake Paranoá. The ecological factors that determine the success of T. decipiens in eutrophic systems are related to omnivorous feeding habits and prey-predator interactions.
authors.affiliation: Departamento de Ecologia, Instituto de Biologia, Universidade de Brasília, 70910-900, Brasília-DF, Brazil. padovesi@unb.br
authors.forename: Claudia
authors.initials: C
authors.lastname: Padovesi-Fonseca
authors.forename: Luciana
authors.initials: L
authors.lastname: de Mendonça-Galvão
authors.forename: Diogo Libânio Pereira
authors.initials: DL
authors.lastname: Rocha
mesh_terms: D000818:Animals; D001938:Brazil; D033342:Copepoda / Q000502:physiology*; D005260:Female; D008297:Male; D012098:Reproduction / Q000502:physiology; D012621:Seasons; D015048:Zooplankton / Q000502:physiology*