Mimic surgeonfish (juvenile). Photo by J.E. Randall, FishBase
The world’s waterbodies are filled with predatory fish feeding on other animals from zooplankton to squid and other fish, while “vegetarian” or herbivore fish are rare, new research has found.
By developing a framework to better understand aquatic biodiversity, an international team of researchers has analyzed the key traits – size, productivity and trophic level – of over 31,000 fish species recorded in FishBase, the online encyclopedia of fishes.
Among other findings, they document that most fish species are low in the food chain and feed on tiny animals that are carried along by ocean currents – zooplankton –, whereas only 1,200 species are herbivores, and less than 1,000 species are large-fish-eating top predators.
They also noticed that herbivores are slightly larger than omnivores and low-level predators, while mid-level and top predators tend to be the largest of them all.
“Faced with the amazing diversity of over 30,000 species of fish, the goal of the study was to find and understand overarching patterns in functional traits,” said Rainer Froese, lead author of the Cybium paper that presents these findings and senior researcher at the Helmholtz Centre for Ocean Research GEOMAR. “Also, we wanted to create a tool that allows scientists to visualize and compare the roles fishes play within their ecosystems based on those traits and taking into account each area’s environmental conditions and their ongoing change.”
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The study “A simple framework for the exploration of functional biodiversity” was published in Cybium https://doi.org/10.26028/cybium/2023-003.
Read the full article from the Sea Around Us website.
