A sand lance (Ammodytes hexapterus) hides amongst brown Rockweed (Ascophyllum nodosum) and green Sea Lettuce (Ulva) in 25 feet of water off Folly Cove in Rockport, Massachusetts. Although also commonly known as "sand eels", the sand lance is not related to true eels. The family and genus name (Ammodytes) means "sand burrower", a reference to the sand lance's habit of burrowing into sand to avoid tidal currents.
Sand lances are most common in the North Pacific and North Atlantic, but are found in oceans throughout the world. These fish do not have pelvic fins and do not develop swim bladders, being bottom-dwelling as adults. The larval form of the Sand Lance may be the most abundant of all fish larvae in areas such as the northwest Atlantic, serving as a major food for cod, salmon, whales and diving birds such as puffins, auks, terns, and cormorants. Sand lances can control the movement of each eye independently.