A spadefish is a type of marine fish found in the western Atlantic Ocean from the US state of Massachusetts to Brazil, including the Gulf of Mexico and the Caribbean. Other common names for this fish include Atlantic Spadefish, Ocean Cobbler, and sometimes Moonfish. First described in 1782 by Auguste-Marie Broussonet, its scientific name is Chaetodipterus faber. It is a member of the family Ephippidae, along with batfish and scats.
Chaetodipterus faber is the only species in the family Ephippidae that is native to the Western Atlantic, but individual batfish, probably released from home aquariums, have been found in schools of spadefish in the Florida Keys. Spadefish are often confused with angelfish because of the shape of their bodies and fins. One way to tell them apart is that angelfish have continuous dorsal fins, while spadefish have separated first and second dorsal fins.
Juveniles usually are black, and they swim in shallow waters where they hide from predators by blending in with dead leaves. Adults are disc-shaped and silvery, with four to six vertical black stripes. They are usually about 1.5 feet (50 cm) long and weigh an average of 6 pounds (about 2.7 kilograms). Their average lifespan is eight to 10 years. They primarily eat invertebrates that live on the sea floor, but they vary their diets with plankton and jellyfish as well.
Scuba divers who visit western Atlantic shipwrecks or the shallow waters off of beaches or mangrove systems often see schools of spadefish circling them as they dive. The schools, which consist of as many as 500 individuals, are popular targets for fishermen. They entice the fish by using cannonball jellyfish as bait. The school nibbles at the bait until one fish grabs the hook, and they are known for putting up a spirited fight against being reeled in.
Some people enjoy the taste of spadefish, but the treat can be dangerous. One of its food sources is a type of microalgae that produces ciguatera toxin. The toxin builds up in the fish’s tissues and can poison humans who dine on them. Ciguatera causes gastrointestinal symptoms and muscle weakness on the extremities that can last for several days.
The investment required to keep spadefish makes it difficult for the keepers of typical home aquariums to accommodate their needs. They thrive in very large tanks with varied food sources and room to school. There are plenty of opportunities to enjoy schools of spadefish circling around shipwrecks or in public aquariums, however.