EFFECTS OF ALGAL DIET ON THE ENERGY AVAILABLE FOR GROWTH OF JUVENILE SEA-URCHINS LOXECHINUS-ALBUS (MOLINA, 1782)

The type of algal food affected both the energy balance and the quantity of energy available for growth of young sea urchins (Loxechinus albus). The Rhodophyte alga Gracilaria sp. resulted in the greatest quantity of energy available for growth because the energy lost due to respiration was minimal. On the other hand, feeding the Chlorophyte alga Ulva sp. resulted in a negative sign of the energy balance equation. The energy content of the alp fed did not account for the different results obtained. The fact that the energy balance varied with the different type of algal species offered as food indicates that it is possible to optimize the growth rate of young sea urchins. This is of great significance for the future cultivation of this highly profitable species.