The Red Drum (Sciaenops ocellatus) is a highly sought-after sport fish known for its powerful runs and preference for coastal estuaries. This species possesses a specialized mouth structure that allows it to process a diverse range of food items, distinguishing it from typical predatory fish in these waters.
The Red Drum’s Mouth Structure
The Red Drum’s mouth structure is divided into two sections. In the front of the jaw, the fish possesses small, brush-like teeth used primarily for gripping prey. These teeth are not designed for biting or shearing but function to hold food items before they are swallowed.
The primary dental mechanism is located deeper in the throat, in the pharynx. Here, the Red Drum features specialized bones called pharyngeal teeth or crushing plates. These structures are not visible externally and are positioned near the final gill arch. Unlike the sharp, pointed teeth of many marine predators, the pharyngeal teeth are large, dense, and resemble flattened molars. This unique placement allows the fish to perform a distinct function separate from its initial capture of prey, giving the Red Drum its crushing capability.
The Mechanics of Crushing
The crushing action is driven by a complex musculoskeletal arrangement called a pharyngeal four-bar linkage system. This specialized apparatus translates muscle contraction into immense grinding force deep inside the throat. The upper crushing plates (the third pharyngobranchial) connect to the skull via bones that act as levers.
Power comes from four major muscles, including the levator posterior, which serves as the primary input link. When these muscles contract, they pull the skeletal elements, depressing the toothed plates against the lower pharyngeal jaw. This creates the high compressive force necessary to process hard prey. The linkage system transmits approximately 50% of the total muscle force directly to the bite.
The Red Drum’s mechanism is adapted for shredding and breaking apart moderately hard items, such as crab exoskeletons. This differs from its close relative, the Black Drum, which uses a more vice-like compression to crush the thick shells of mollusks. The Red Drum’s technique involves a combination of crushing and retraction to tear its food apart before ingestion.
Diet and Feeding Strategy
The Red Drum’s powerful pharyngeal jaws dictate its diet and foraging behavior in coastal environments. The ability to crush and shred allows it to consume a wide range of hard-shelled invertebrates that other fish cannot easily access. Primary food sources include small crabs, shrimp, and marine worms, with larger adults occasionally consuming small fish.
The fish’s mouth is positioned slightly downward, a feature known as subterminal, which is perfectly suited for feeding along the bottom substrate. This bottom-dwelling diet influences the Red Drum’s characteristic feeding behavior, often called “tailing.” The fish tips its head down into the mud or sand to vacuum up bottom-dwelling prey, leaving its tail exposed above the surface of the water.
This preference for crustaceans and other benthic organisms means the Red Drum is frequently found near oyster beds, muddy bottoms, and marsh grasses. The unique dental arrangement allows the Red Drum to occupy a distinct ecological niche as an efficient bottom forager.