The use of net cages allows the exploration of some water bodies, without usual aquacultural
techniques for earthen ponds. Several advantages are proposed for the use of cages, however some
disadvantages, as the higher possibility of stress and diseases are known. Growth parameters,
survival rate and stress response of hatchery-bred Jundia´ (Rhamdia quelen, Quoy & Gaimard) fry
reared at different cage types and densities in net cages suspended in pond were evaluated. The first
experiment compared fry reared at the circular and cubic-shaped cages at a density of 100 fry/m3.
Fish held in cubic cages were heavier than the fish held in circular cages, presented higher weight
gain and daily weight gain and a better food conversion. The survival rates were similar between
fish raised in both types of cages. In the second experiment, cubic cages were stocked with 100, 200
and 300 fry/m3. Fish held in cages with lower density were heavier than the ones held at higher
densities, presented higher weight gain and daily weight gain. Food conversion and survival rates