A sand eel is not related to an actual eel. It is a type of small, silvery fish most commonly used as bait for game fish like bluefish or striped bass. The sand eel's scientific name is Ammodytes americanus. Ammodytes is a Greek compound word for sand burrower--the eel burrows to rest or hide from predators.
Also known as the sand lance, the sand eel is typically slender with a narrow snout. Its coloring ranges from metallic blue to dark bronze with a lighter underside. The eels' prismatic scales allow them to blend into their surroundings by changing colors. For example, a sand eel in the clear waters of Cape Cod, Massachusetts in the United States is generally paler than a sand eel found in the European North Sea's darker waters.
They usually grow up to 6 inches (15.24 cm) and are often found in shallow riverbeds with sandy bottoms. The sand eel has no teeth, but uses its protruding lower jaw to scoop up plankton and fish eggs, including its own offspring. Sand eels travel together in large schools of thousands. When in deeper waters, they are often prey to larger fish such as porpoises, which drive them to the surface where commercial fishermen can catch the sand eels with nets.
Many fly fishermen, who use sand eels as live bait, catch them with a sabiki rig, a fishing device with many small hooks. The rig passes over the bottom of a shallow riverbed and hooks the sand eels that are hiding in the sandy bottom. The sand eels are then kept alive in a small tank until used.
The spawning season for a North American sand eel is in the late fall to early winter. Female sand eels can lay up to 30,000 eggs that are often no bigger than the sand grains in their surroundings. There is not much known about the rate of growth for sand eels, but they are thought to be able to live up to four years.
Sand eels are not commonly served as food in North America, but in Spain, fried sand eels topped with fried eggs are served as one of many traditional bar snacks commonly called tapas. They are also caught in large numbers and processed for pet food and fertilizer. Such demand for sand eels is thought to affect other wildlife populations, such as sea birds like puffins, that eat sand eels as a main part of their diet.