Garden eels (Ruth Hartnup / CC BY)
Garden eels (Heterocongrinae) have slender bodies and small mouths with jutting lower jaws. Pectoral fins are either absent or reduced. Garden eels typically form colonies on sandy bottoms. Their front bodies can often be observed hovering above the bottom, whereas their tails are anchored in the sand. When an animal is disturbed, it retracts its body rapidly into the burrow. Garden eel species usually range from 40 centimeters (16 inches) to 70 centimeters (27.5 inches) in length. They feed on plankton.