Freshwater Sardines of the Pantanal Delay Seed Germination in a Floodplain Tree Species

Abstract

Most studies involving the consumption of fruit and subsequent secondary dispersal of seeds by vertebrates point to birds and mammals as the main agents of dispersal. However, evidence suggests that fish also perform this important ecological role. After observing the consumption of Banara arguta fruits by fish of the Pantanal floodplain, we decided to investigate the disperser role of the freshwater sardine Triportheus nematurus. Our main goal was to compare the germination of seeds recovered from the intestinal tract of individuals (consumed) with that of seeds collected directly from uneaten ripe fruit (control). While no difference in germination percentage was found between consumed and control seeds, germination speed was higher in control seeds. Delay in germination speed during the flood season is a well-known mechanism adopted by floodplain plants to ensure germination in appropriate conditions. Thus far, few studies have reported on the effect of fish in this process. Furthermore, germination percentage was not affected by the presence of intact seeds in the intestinal tract of T. nematurus, placing this species among potential dispersers of B. arguta fruit.