Neotropical fish–fruit interactions: eco‐evolutionary dynamics and conservation

Abstract

Frugivorous fish play a prominent role in seed dispersal and reproductive dynamics of plant communities in riparian and floodplain habitats of tropical regions worldwide. In Neotropical wetlands, many plant species have fleshy fruits and synchronize their fruiting with the flood season, when fruit-eating fish forage in forest and savannahs for periods of up to 7 months. We conducted a comprehensive analysis to examine the evolutionary origin of fish-fruit interactions, describe fruit traits associated with seed dispersal and seed predation, and assess the influence of fish size on the effectiveness of seed dispersal by fish (ichthyochory). To date, 62 studies have documented 566 species of fruits and seeds from 82 plant families in the diets of 69 Neotropical fish species. Fish interactions with flowering plants are likely to be as old as 70 million years in the Neotropics, pre-dating most modern bird-fruit and mammal-fruit interactions, and contributing to long-distance seed dispersal and possibly the radiation of early angiosperms. Ichthyochory occurs across the angiosperm phylogeny, and is more frequent among advanced eudicots. Numerous fish species are capable of dispersing small seeds, but only a limited number of species can disperse large seeds. The size of dispersed seeds and the probability of seed dispersal both increase with fish size. Large-bodied species are the most effective seed dispersal agents and remain the primary target of fishing activities in the Neotropics. Thus, conservation efforts should focus on these species to ensure continuity of plant recruitment dynamics and maintenance of plant diversity in riparian and floodplain ecosystems.

The role of Lithodoras dorsalis (Siluriformes: Doradidae) as seed disperser in Eastern Amazon

“…Besides increasing germination performance, disperser's body zise, regardless of the species, can also influence the seed dispersal effectiveness (Schupp et al, 2010;Wotton, Kelly, 2012;Correa et al, 2015b;Li et al, 2016). Individuals of different sizes can generally differ in their diets due to morphological limitations during periods of development (Abelha et al, 2001;Dala Corte et al, 2016).…”

“…Due to this possible interdependence relationship, seed dispersal is an important process for dispersers and plants, where both sides are favored: the disperser, for having a high-energy food source, e.g. açaí with 247 kcal in 100 g of dry fruit (Lorenzi et al, 2006), and the plant, for having the opportunity to perpetuate its species and colonize new environments (Beckman, Rogers, 2013;Correa et al, 2015b). The dispersion sets the initial spatial distribution of plants, determines the group of interacting species and contributes to the community structure and the maintenance of species diversity (Seidler, Plotkin, 2006;Anderson et al, 2009).…”

“…Thus, plant seed dispersal mechanisms are probably the result of natural selection that increases the chances of spreading their seeds (Fenner, 1985;Ferreira et al, 2010). Until a few years ago, fishes had little relevance in studies about frugivory and dispersion, being this process classically linked to birds and mammals (Correa et al, 2007;Correa et al, 2015b). However, fishes were probably the first vertebrate dispersers, playing an important role on the dispersal of the first angiosperms, approximately 70 million years ago in South America (Correa et al, 2015a).…”

“…In tropical ecosystems, ichthyochory contributes to the maintenance of high diversity of plant species in flooded forests and wetlands (Gottsberger, 1978;Goulding, 1980;Horn, 1997;Pilati et al, 1999;Correa et al, 2007;Anderson et al, 2009). Many plant species in these habitats fruit during the flood season and they are adaptated to hydrochory or ichthyochory (Goulding, 1980;Correa, Winemiller, 2014;Correa et al, 2015b). Thus, in such environments, understanding the relationship between the fish fauna and riparian forests can serve as a basis to understand the ecological role played by fishes (Godinho, Godinho, 2003).…”

“…They represent more than 60% of all frugivorous fishes in the world (Horn et al, 2011). These fishes have some adaptations that facilitate their activity as frugivores and seed dispersers, such molar like-teeth, long intestines and enzymes associated with carbohydrates digestion (Goulding, 1980;Drewe et al, 2004;Correa et al, 2007Correa et al, , 2015b. In addition to the adaptations cited above, some studies showed that ichthyochory effectiveness increases with the size of the fish, because of the high consumption of fruits, including the big ones, their extensive movement patterns and the long seed-retention time of large individuals (Galetti et al, 2008;Anderson et al, 2011;Correa et al, 2015a).…”