The Red Drum (Sciaenops ocellatus) is a highly valued coastal sport fish found from the Gulf of Mexico up the Atlantic Coast to Massachusetts. Recognized by the distinctive black spot near its tail, this species is the only member of its genus within the drum family (Sciaenidae). Its life cycle involves migrating from sheltered estuaries to open coastal waters, which dictates a dramatic change in its diet. The Red Drum is an aggressive, opportunistic carnivore whose food choices shift significantly as it grows from juvenile to adult.
The Diet of Juvenile Red Drum (Estuarine Phase)
The early life of a Red Drum is spent in shallow, brackish water nurseries, such as estuaries, tidal creeks, and marsh systems. These juvenile fish, typically under 18 inches, are often referred to as “puppy drum” and focus on the smaller prey available in these sheltered habitats.
Initially, very small juveniles (less than 3 inches) primarily consume planktonic organisms and microscopic crustaceans. As they grow, their diet quickly shifts to small benthic invertebrates. This menu includes small grass shrimp (Palaemonetes spp.), various copepods, tiny amphipods, polychaete worms, and aquatic insect larvae, which they root for in the soft substrate. As the juveniles reach sub-adult size, they begin to incorporate larger macrocrustaceans, like small penaeid shrimp and portunid crabs, marking a transition toward the adult diet.
The Diet of Adult Red Drum (Nearshore and Offshore Phase)
As Red Drum mature, often reaching three to four years of age, they emigrate from protected estuaries into deeper, more open waters, including inlets and nearshore environments. These mature fish, sometimes called “bull reds,” require significantly more energy, prompting a shift to larger, calorie-dense prey. The adult Red Drum is a dietary generalist, aggressively pursuing a wide array of food sources.
Crustaceans remain a staple, but adults target much larger, harder-shelled organisms, such as large blue crabs (Callinectes sapidus) and fiddler crabs. They also consume larger shrimp (Penaeus spp.). The most significant dietary change is the increased consumption of finfish. Adult Red Drum opportunistically prey on various schooling and bottom-dwelling species:
- Menhaden (Brevoortia spp.)
- Mullet
- Spot
- Atlantic croaker
- Pinfish
While primarily bottom-oriented, these large fish will feed throughout the water column when schools of baitfish are available.
Feeding Techniques and Behavior
The Red Drum’s physical anatomy is highly specialized for its bottom-feeding lifestyle, allowing it to efficiently hunt and process a diverse range of prey. The fish possesses a subterminal mouth, meaning its mouth is positioned slightly downward on the head, which is perfectly designed for rooting and vacuuming up food from the substrate. This mouth structure enables the fish to target hidden invertebrates and small fish that live on or in the muddy or sandy bottom.
Once prey is captured, the Red Drum uses specialized pharyngeal teeth, often described as “crushers,” located in the back of its throat. These robust teeth are employed to effectively break apart the hard shells of crabs and other mollusks, allowing the fish to digest the meaty contents.
To locate prey concealed in the sediment, the Red Drum relies heavily on its highly developed lateral line system, which functions as a mechanoreceptor. This system detects the subtle vibrations and pressure changes made by scuttling shrimp or burrowing crabs. Mechanoreception is the primary foraging technique, with vision serving a secondary role.
A distinct and visible feeding behavior is “tailing,” which occurs when the Red Drum tips its body head-down to root in the shallow bottom. During this action, the tail of the fish breaks the water surface, a clear visual sign of an actively foraging fish. The rooting action disturbs the mud and grass to expose hidden crustaceans, which the Red Drum then traps and consumes.