The tambaqui Colossoma macropomum (Cuvier, 1818) (Characiformes: Characidae) ia a native fish of the Amazon Basin. It is a rheophilic species, and in captivity the reproduction occurs only through hormonal induction. Larvae of native species require more attention in the first stages, so the first feeding has great importance for the fry production and survival. Throughout the development, the larvae of tambaqui undergo morphological and physiological changes and eating habits. The objective of this study was to evaluate the use of different diets on the first feeding tambaqui larvae. Tambaqui larvae were grown during 20 days under the following dietary treatments: plankton; plankton + ration; selected plankton; selected plankton + ration; and ration. The feed was given twice daily, "ad libitum". The physic-chemical variables of water remained in limits accepted for the species. Treatments where it was used live food resulted in better growth performance of tambaqui larvae. The addition of ration associated with the live food to feed the tambaqui larvae also improved performance, although ration is not recommended as the sole food source, in the first days of life. Therefore, the use of live food plus ration, from the third day of exogenous feeding, improves a better growth performance and survival of tambaqui larvae.
first feeding; fry production; zooplancton