Consumo e dispersão de sementes por peixes em floresta de igapó da Reserva de Desenvolvimento Sustentável Do Tupé, Manaus, Amazonas - Brasil

Abstract

In the neotropical region and the Amazon Basin, there is a strong interaction between flooded forests and the ictica community called ichthyochory, which is the dispersion of fruits and seeds carried out by fish. In temporarily flooded environments, many plant species provide an area of refuge, shelter and food for the ichthyofauna, several species of fish can ingest and disperse seeds through this mechanism, contributing to the maintenance of riparian forests and temporarily flooded forests in the floodplains, as well as in floodplain areas. The objective of this work was to identify the presence of fruits and seeds consumed by fish assemblages in the igapó area of Lake Tupé, to determine the trophic structure of fish assemblages in the igapó area of Lake Tupé, to analyze the germination potential of seeds taken from fish stomachs and intestines. The standardized collections were carried out in the igapó forest of Lake Tupé in the months of April, May, June (flood/flood seasons) and August 2022 (low water). For the collection of ichthyofauna, sets of seven gill nets with mesh sizes from 30 to 100 mm between opposite nodes were used. Each net was 10 m long and 1.5 m high. The nets were set up close to the trees that were in the period of fruiting and fruit drop. At each sampling point, the nets remained exposed for a period of 48 h, with harvesting every 6 h. Germination percentage, germination speed index and mean germination time were calculated using an Anova One-way, t test and Wilcoxon test. A total of 1196 fish were collected, distributed in 5 orders, 21 families, 54 genera and 77 species, of which only three species contained intact and crushed fruits, seeds and seeds belonging to nine plant species within the digestive tract, in this sense the species of fish which stood out the most in numbers of seeds conducive to germination was Auchenipterichthys longimanus, this proves to be of crucial importance for ecological actions within the Igapó forest of Lago Tupé in the RDS-TUPÉ because, through the dispersion of seeds, they favor the perpetuation and maintenance of the igapó forest as well as variability of plant species through gene flow promoted through the ichthyochory mechanism.