Composição química e reprodução do mapará (Hypophthalmus edentatus Spix, 1829) do lago do Castanho, Amazonas. (Siluriformes, Hypophthalmidae) ()

Abstract

The following paper discusses the reproduction and the percent composition of water, fat, protein and mineral salts in the fish as well as the filet of Hypophthalmus edentatus. The high proportion of fat found is thought to be a possible ecological adaptation in virtue of the fact that this pelagic species has an extremely reduced air bladder. In both the filet and the whole fish the proportion of water varies inversely with fat and it was observed that the proportion of fat diminishes as the ovaries mature. Proteins and mineral salts showed little seasonal variation. In november the ovaries began to develop, coincinding with the period when the water level began to rise. Spawning ocurred during the period of February through April before the water reached their peak lavels. Fecundity was found to be more closely related to ovary weight and the total fish length. The average total fecundity was 96,923 eggs.