Walleye (Sander vitreus) are highly sought-after freshwater game fish, prized across North America for their delicate, flaky fillets. Walleye are equipped with a formidable array of dentition, which is a defining feature that enables their predatory lifestyle in lakes and rivers. They feature multiple types of teeth designed specifically for catching and securing prey.
Structure of Walleye Dentition
The walleye’s mouth contains two primary types of teeth, each serving a distinct purpose in capturing food. The most noticeable are the canines, which are sharp, conical, and needle-like structures, often likened to fangs. These canines are especially prominent along the lower jaw, designed for piercing and initially grasping prey. Their curved shape helps secure a hold on slippery targets, preventing escape.
The second type, known as cardiform teeth, forms dense, bristle-like patches lining the jaws and the roof of the mouth. These teeth are numerous, short, fine, and closely packed, providing a sandpaper-like grip that complements the canines. Walleye also feature teeth on the vomer and palatine bones, which are located on the roof and sides of the upper jaw. This extensive dental coverage ensures that prey is firmly held and directed toward the throat for consumption.
Unlike humans, walleye continuously replace their teeth throughout their entire lives. This constant replacement ensures the fish always maintains a set of sharp, functional teeth, regardless of wear or damage. As a tooth wears down or is lost, a new one grows in to take its place over a period of days to a couple of weeks. This ongoing cycle is a biological mechanism that supports the walleye’s predatory needs year-round.
Predatory Role of Walleye Teeth
The complex dental structure of the walleye is perfectly adapted to its role as a nocturnal or low-light predator in freshwater environments. The primary function of the teeth is to seize and hold fast-moving, live prey, which typically includes smaller fish like minnows and perch, as well as small crustaceans. The initial strike is delivered by the prominent canine teeth, which stab and puncture the prey, immediately immobilizing it.
Once the prey is pierced, the numerous smaller cardiform teeth come into play to prevent any movement or escape. These teeth are often slanted backward, creating a one-way path toward the gullet. This backward orientation acts like a ratchet, ensuring that struggling prey is continually pushed deeper into the mouth. This combination of piercing canines and gripping cardiform teeth allows the walleye to effectively manipulate and process its food before swallowing.
The physical structure of the mouth and teeth allows the walleye to be a “strike” feeder, relying on a quick lunge to capture its meal. The teeth are designed not for cutting or slicing, but for a firm, non-slip grip until the prey can be swallowed whole. This specialized dentition supports the walleye’s effective predatory strategy in its native habitat.
Safety and Handling for Anglers
Anglers handling walleye must exercise caution due to the sharpness of the canine teeth and other defensive features. They also possess sharp spines on their dorsal fins and rough gill plates that can cause injury. Puncture wounds from the teeth are possible if fingers are placed carelessly near the jaws.
To ensure both angler safety and the fish’s health, specialized tools should be used for hook removal. Long-nosed pliers or hemostats are recommended, as they provide the necessary reach to dislodge a hook without placing fingers in harm’s way. Minimizing handling time and keeping the fish horizontal is beneficial for the survival of released fish.
Supporting the fish’s weight under the belly while holding the wrist of the tail is a safe method that reduces stress on the fish’s internal organs. Anglers may wear specialized, wet gloves, such as cotton or fleece, for protection against the teeth and sharp spines while maintaining a firm grip. A specialized lip-gripping tool can also help control the fish without direct hand contact. For deeply hooked fish, cutting the line near the hook is often the best practice, as attempting to forcibly pull the hook out can cause extensive, fatal damage to the fish’s mouth and throat.