Influência de fatores abióticos na eclosão de ovos dormentes do rotífero Brachionus calyciflorus Pallas (Monogononta, Ploima)

Abstract

The factors involved in the induction of resting eggs development and hatching are poorly understood for Brachionus calyciflorus populations of South Hemisphere. The role of some abiotic factors in controlling the hatching rates of B. calyciflorus resting eggs was investigated. Determination of optimum hatching conditions would be important in developing the use of this species as food for fish larvae in aquaculture. Resting eggs were exposed to different treatments in the laboratory, and monitored for hatching over a period of five days. Optimum hatching conditions were: pH 5-9, water ionic concentrations from 220 to 880 mg.l-1 of selected salts, temperature 25 - 30ºC, photoperiod eight or more hours light per day, and light intensity equal to or greater than 850 lux.