Passage through the digestive tract of frugivorous vertebrates likely influences seed dormancy, time to germination, and/or future seedling growth. Effects of gut passage on seed germination have been extensively investigated among frugivorous birds and mammals, however, few studies have focused on frugivorous fish. Here we present the results of a feeding experiment focusing on a broadly distributed Amazonian frugivorous fish, Brycon falcatus, and a fig tree, Ficus gomelleira. We investigated the effects of gut passage and ontogeny on seed germination probability and speed. The probability of seed germination and germination speed increased for seeds defecated by fish relative to control seeds. We also detected a negative effect of intestine length, where germination probability and speed decreased when seeds passed through larger fish with greater intestine to body length ratio. Such effects are probably the result of ontogenetic diet shifts, in which young fish transition from carnivory to frugivory as adults; a process only revealed by the inclusion of both small juvenile and large adult individuals in our study. As such, we advance knowledge of the mechanisms involved in frugivory as a feeding habit among fishes and on animal-fruit mutualisms.

穿过食肉性脊椎动物的消化道可能会影响种子的休眠，发芽时间和/或将来的幼苗生长。在食肉类鸟类和哺乳动物中，广泛研究了肠道通行对种子发芽的影响，但是，很少有研究针对食肉类鱼类。在这里，我们介绍了一项饲喂实验的结果，该实验的重点是分布广泛的亚马逊食肉鱼Brycon falcatus和无花果树Ficus gomelleira。我们调查了肠道传代和个体发育对种子发芽概率和速度的影响。相对于对照种子，被鱼排便的种子的种子发芽和发芽速度增加。我们还检测到肠长的负面影响，当种子通过较大的肠长与体长之比的较大的鱼时，发芽的可能性和速度降低。这种影响可能是个体遗传饮食转变的结果，在这种转变中，成年幼鱼从食肉动物过渡到食肉动物；这个过程仅在我们的研究中同时包括了少年和大成年人。因此，我们提高了关于节食作为鱼类之间的喂养习惯以及动物与水果之间的相互关系的机制的知识。