Dispersal of palm seeds (Bactris Glaucescens Drude) by the fish <em>Piaractus Mesopotamicus</em> in the brazilian pantanal

The flowering and fruiting phenology of Bactris glaucescens (tucum), its fruit consumption by Piaractus mesopotamicus (pacu), and the possible dispersal of its diaspores were observed in riparian forests and nearby areas of a secondary channel of the Rio Paraguai. Between February and October 1998, 136 individuals of P. mesopotamicus were collected, and their gut contents were analyzed to verify the presence of B. glaucescens diaspores. The seeds found were tested in tetrazolium solution to verify their viability. The feeding indices of the diet components were calculated. Phenological observations were made for 40 palm trees. A total of 127 diaspores of B. glaucescens were found in the guts of the fish. Eighty of the diaspores were tested, and 67.5% of those were viable seeds. The feeding index of B. glaucescens varied through the year, reaching more elevated values at the time of the fruiting phenology peak, which occurs at the same time that the water level increases. P mesopotamicus can be considered a potential dispersal agent of B. glaucescens.