The objective of this work was to evaluate the effect of florfenicol doses on the incubation of "pacamã" (Lophiosilurus alexandri) eggs. In the first phase, eggs were subjected to florfenicol doses between 0 and 500 mg L-1, for 24 hours. In the second phase, larvae were observed until the seventh day after hatching. In the third phase, larvae were fed for ten days. Weight and length showed responses that varied according to the development stage and to florfenicol doses. Doses lower than 309 mg L-1 florfenicol can be used without affecting larvae in later stages.
Lophiosilurus alexandri; early development; preventive treatment
