Sheepshead fish are a common North American marine species that span from Cape Cod and Massachusetts through to Florida and the Gulf of Mexico to Brazil. Preferring coastal habitats around rock pilings, jetties, mangroves, reefs and piers, they can grow up to around 91 cm in length and weigh up to 9.6 kg. They have five to seven distinctive black, vertical bars running down their silvery bodies, which is why the sheepshead is also called the ᴄᴏɴᴠɪᴄᴛ fish. And true to their name, sheepshead fish are notorious for stealing bait.
Sheepshead has a hard mouth, with several rows of stubby teeth – the frontal ones resembling human teeth. They are remarkably humanlike, with the same shape and color. But that’s where the similarities end.
Sheepshead have extremely powerful jaws and flattened teeth so that they can crush through their prey, which consists of hard-shelled sea life like oysters, clams, crabs and barnacles.
The front teeth grab hold of of their prey and their multiple rows of molars help grind their prey into smaller pieces that they can chew and eat. A fully-grown adult sheepshead will have well-defined incisors sitting at the front of the jaw, and molars set in three rows in the upper jaw and two rows in the lower jaw. It has strong, heavy grinders set in the rear of the jaw too, which are particularly important for crushing the shells of its prey. As with humans, this unique combination of teeth helps the sheepshead process a wide-ranging, omnivorous diet consisting of a variety of vertebrates, invertebrates and some plant material.
When they’re young, sheepshead fish will eat marine worms, bryozoan ‘moss animals’ and pretty much anything soft-bodied they can catch in the seagrasses. Although thick, sharp teeth begin to appear when a sheepshead is just 4.5 mm long, it will have to wait until it’s about 15 mm long before all the incisors have come in and the back teeth begin to develop into adult molars. Once they reach around 50 mm in length, the sheepshead will advance to eating more robust, armoured prey such as echinoderms, barnacles, clams, crabs and oysters, using their highly specialised teeth.
During this stage, its jaw musculature is also developing, and this keeps improving right through to old age. So an old fish living around a good supply of hard-shelled prey will end up having much greater jaw crushing power than a younger fish in a less rich environment.