The eponymous maw of the largemouth bass — and the fish’s ability to suck prey into that gaping gullet in a rapacious strike — are part of the lore and legend of the bass to the many anglers who pursue it. But they are not the only ones who are fascinated.

The functioning of the large mouth of the largemouth is also of interest to scientists trying to understand how joints and other complicated biological structures work.

The bass’s mouth is full of bones and muscles, but the parts that function in its rapid vacuum-cleaner attack fit a model that engineers call a four-bar linkage — four rigid sections linked by flexible joints.

Aaron M. Olsen of the University of Chicago, with Ariel L. Camp and Elizabeth L. Brainerd of Brown University, used X-ray videos and a kind of motion capture to create the most accurate representations yet of how that mouth works.