Image of the Day: Fish that Eat Fish

Researchers categorize the different jaws of piscivorous fishes.

Emily Makowski
Sep 13, 2019
The different jaws of piscivorous fish: Taenianotus triacanthus (a) is an edentulate, Epinephelus polyphekadion has villiform teeth (b), Plectropomus leopardus is a back-fanged macrodont (c), and Oxycheilinus digramma is a front-fanged macrodont (d).

Researchers can uncover a lot of information about an animal from studying its teeth, such as what it eats, how it eats, and what role it plays in its ecosystem. But most tooth studies are done on mammals, according to Michalis Mihalitsis and David Bellwood at James Cook University, who published a study in Royal Society Open Science on September 11 on the jaws of piscivorous fishes such as coral trout, grouper, and lionfish. 

They categorized the species into three groups based on tooth and jaw traits: edentulate (few or no teeth), villiform (many long, thin teeth), and macrodont (large teeth either in the front or back of the jaw). The location of the teeth has implications for the animals’ feeding behavior. The researchers found that edentulate and villiform fishes tend to ambush and engulf their prey, while macrodont fishes are better at grabbing prey with their teeth after lunging or pursuing over long distances.

M. Mihalitsis, D. Bellwood, “Functional implications of dentition-based morphotypes in piscivorous fishes,” doi/10.1098/rsos.190040, Royal Soc Open Sci, 2019.

Emily Makowski is an intern at The Scientist. Email her at