When you think of seed dispersal what do you think of? Monkeys? Birds? Wind?

How about fish? According to a new review article, fruit eating fishes have been found across the globe and hundreds of species snack on those ingenious and tasty seed dispersal mechanisms.

“[N]ew evidence demonstrates that the consumption of fruits by fishes is not a rare process concerning just a few fish and plant species in a particular area,” write Michael Horn, of California State University, Fullerton, and his colleagues. “Rather, fruit consumption by fishes is a widespread phenomenon that has been documented in all biogeographic regions and involves more than 275 fish and numerous plant species.”

Earlier this year, Nature reported on a study showing that huge Amazonian fish called characids were probably carrying seeds they had eaten more than five kilometres across flooded forests. As Horn noted then, seed dispersal by fish had often been neglected in the past (see: Fruit-feasting fish fertilize faraway forests).

Now his team’s new review article shows just how widespread the phenomenon is. But as recognition of the importance of ‘ichthyochory’ (fish seed dispersal) grows, so do threats to it.

Overfishing, damming of rivers, deforestation and logging all affect the relationship, by decreasing fish population sizes, producing smaller fish which swim less far and hindering traditional migration routes. These problems “require immediate attention”, Horn and colleagues write in Acta Oecologica.