Fish
River Redhorse
Moxostoma carinatum · also called river redhorses
In a fast-flowing stretch of clean river, a river redhorse crushes an entire mussel shell using specialised teeth hidden in its throat, a feeding trick considerably more powerful than the modest crushing ability of several smaller redhorse relatives sharing the same water.
Overview
The river redhorse, Moxostoma carinatum, is one of the larger members of the redhorse group, native to clean, large rivers with strong current across a broad range of eastern and central North America. Its unusually powerful throat teeth, capable of crushing whole snail and mussel shells, make it one of the more specialised feeders among North American sucker fish.
A crushing tool hidden where you wouldn’t expect it
Rather than relying on jaws for its toughest food, the river redhorse keeps its real crushing power tucked away in its throat, an internal set of molar-like teeth that lets it break into shells most other fish sharing the same river couldn’t begin to open.
Status
Least Concern, though decreasing in parts of its range — present across suitable clean, large river habitat throughout eastern and central North America, affected locally by dam construction.
River Redhorse: common questions
How does the river redhorse crack open snail and mussel shells?
A river redhorse has unusually large, molar-like pharyngeal teeth located in its throat rather than its mouth, a specialised crushing tool capable of breaking open snail and mussel shells whole, a feeding adaptation more powerful than the throat teeth found in most other redhorse species.
Why has the river redhorse declined in some rivers?
A river redhorse has declined in portions of its range due to dam construction and river impoundment, changes that can eliminate both the fast-flowing water the species requires and the native mussel populations it depends on heavily for food.
How big does a river redhorse get?
The river redhorse ranks among the larger species within the redhorse group, growing noticeably bigger than several of its smaller redhorse relatives, a size that pairs well with its powerful shell-crushing throat teeth.
Where does the river redhorse live?
The river redhorse is native to clean, large rivers with strong current across a broad range of eastern and central North America, requiring good water quality and healthy native mussel populations to thrive.