Viability of seeds consumed by fishes in a lowland forest in the Brazilian Central Amazon

Abstract

Várzeas are forest areas seasonally flooded by white-water rivers and have a variety of tree species, which bear fruit during the filling or flood and in the beginning of low water periods. During those periods of inundation, fruits and seeds are important resources for different fish species. In this study, the viability of whole seeds removed from the stomach and intestine of fishes was analyzed. Fishes were collected with gillnets installed during 24-hr cycles along the flooded forest, during the filling, flood, and in the beginning of low water periods of the Year 2014 in the Catalão lake, Brazilian Central Amazon. In total, 1,915 specimens of fish were captured, and 148 specimens (8% from the total) contained seeds in their digestive tracts. Some fishes that consumed seeds are species commercially important and have migratory habits. Fishes consumed 3,092 seeds. All whole seeds removed from the digestive tracts of fishes were seeded in várzea soil and maintained in a greenhouse. Seeds of 16 plant species (89%) germinated. Our conclusion is that fish species can play an important role in the ecology of várzea forests by dispersing seeds, contributing to the colonization of new areas, and allowing genetic flow between subpopulations distributed along the rivers.