Avaliação dos procedimentos de introdução do Pirarucu (Arapaima gigas) na região Nordeste: retrospectiva histórica, situação atual e perspectivas futuras

Abstract

The national fish farming production is vastly increasing, especially in northeastern Brazil. There is currently a demand for new management techniques for native species. This is because most of Brazilian production is based on farming of exotic species. The bonytongue is a native species with great potential for farming. The bonytongue was first introduced in the northeastern Brazil in late 1930’s in seven dams. These bonytongue populations served as food resources for human populations, but did not control populations of undesirable fish species, as piranhas. The stocks of bonytongue populations in these dams were depleted after 40 years of its introduction. One main reason for this depletion is likely to be the use of drift nets. Other indirect factors be lack of fishery law enforcement. The current bonytongue re-introduction program, conducted by DNOCS, started in the decade of 2000 and have bonytongue fishes managed in fish farms. Overall, the methods employed for transport, acclimatization, reproduction and food training may be considered satisfactory. The best feeding rate for neonates was 2% of total biomass. Reproduction occurred between August and February. Neonate bonytongues were traded and taken to cities both in the Northeastern and North regions. One difficult for managing bonytongues is the absence of external characters for sexual identification. Results of a pilot project conducted in this study restrict the usefulness of one RAPD marker and cytogenetics for sexual determination of bonytonges