The herring group includes herrings, menhadens (men-HAY-dens), pilchards (PILL-churds), sardines, shads, sprats, and anchovies. Herrings are small and have streamlined bodies that aid them in swimming fast in open water. The smallest herring is the Sanaga pygmy herring, with a length of only about three-fourths inch (2.1 centimeters). Male wolf herrings are the largest herring, with an average length of 39 inches (100 centimeters). Herrings have dark shading on the back and bright silvery sides. Except for the head, the body is completely covered in large scales. Only one type of herring has a lateral (LAT-uhr-uhl) line, the series of pores and tiny tubes along each side of a fish's body used for sensing vibrations. Many herrings have a row of spiny, ridged scales along the midline of the belly.
Herrings live all over the world.
Nearly all herrings live in open water. Four-fifths of all species live in saltwater habitats ranging from near-shore zones to nearly 100 miles (161 kilometers) offshore. Many herrings swim near the surface at night but move to deeper waters during the day. Some herrings live in inland waters or move inland to spawn, or release eggs. These species live in bays; estuaries (EHS-chew-air-eez), which is where a river meets the sea; marshes; rivers; and freshwater streams. Landlocked populations have formed as the fishes have moved into lakes or rivers and become trapped between dams.
Most herrings eat plankton, or microscopic (MY-kro-SKA-pihk) plants and animals drifting in the water that are too small to be seen with the eye. Herrings prefer plankton that consists of crustaceans (krus-TAY-shuns), or water-dwelling animals that have jointed legs and a hard shell but no backbone, and the larvae (LAR-vee) of larger crustaceans and fishes. Larvae are the early stage of an animal that must change form before becoming an adult. Some herrings visually locate and target food particles.
BEHAVIOR AND REPRODUCTION
Herrings are best known for forming large schools. Being in large groups helps the fish swim efficiently and discourages predators (PREH-duh-terz) or other fish that may hunt them for food. Herrings also form smaller, less-organized groups called shoals, particularly during spawning season. Some herrings migrate, or travel, from the ocean to streams and rivers for spawning. Many herrings make daily migrations in the water, staying deep during the day and moving to shallows at night.
Herrings produce large numbers of offspring. Some species spawn once a year, and others spawn several times a year. Most herrings spawn in shoals by releasing large numbers of small eggs that float near the surface. After fertilization (FUR-teh-lih-zay-shun), or being united with a male's sperm, the eggs and larvae drift in the current as they develop. Some herrings produce eggs that sink to the bottom, where they stick to rocks, gravel, or sand until they hatch. After hatching, larvae move to open water.
Herring scales are used to give pearly lipstick and nail polish their shimmer. Researchers have not been able to make a synthetic substance that gives the same effect.
That's a Lot of Fish!
In the ocean, schools of herring can extend for miles (kilometers) and contain four billion fish.
HERRINGS AND PEOPLE
Herrings are some of the most economically important fishes in the world's oceans. They have been used throughout human history, primarily for food but also as a source of oil, plant fertilizer, and animal feed. Herring fishing was one of the earliest occupations of coastal peoples.
The World Conservation Union (IUCN) lists two herrings as Endangered, or facing very high risk of extinction in the wild in the near future, and two as Vulnerable, or facing high risk of extinction in the wild.
Physical characteristics: Bay anchovies are typically 3 to 4 inches (7.6 to 10.2 centimeters) in total length. They are nearly transparent and greenish and have a silvery band along the sides of the body. The snout overhangs the mouth, and the lower jawbone extends well beyond the eye.
Habitat: Bay anchovies live along the coast in estuaries, bays, and marshes and near sandy beaches. They usually live over muddy bottoms or among plants. Bay anchovies can handle a wide range of saltiness but are often found in water that is slightly less salty than seawater.
Diet: Bay anchovies usually eat plankton, mostly crustaceans, but sometimes they eat small fishes, snails and slugs, and crustaceans called isopods (EYE-suh-pods).
Behavior and reproduction: Bay anchovies swim in schools. They spend the winter in deep waters and migrate to shallow shores and wetlands for spawning in late spring to early summer. Spawning takes place during the evening hours. Females release the eggs into the water, where they are fertilized by males. The eggs float near the surface for approximately twenty-four hours after fertilization and then hatch. Bay anchovies mature to adults in two and one-half months.
Bay anchovies and people: Bay anchovies are used as bait and for making anchovy paste. They are important in the diet of fishes caught by commercial fishermen.
Conservation status: Bay anchovies are not threatened or endangered. ∎
FOR MORE INFORMATION
Berra, Tim M. Freshwater Fish Distribution. San Diego, CA: Academic Press, 2001.
Niesen, Thomas M. The Marine Biology Coloring Book. 2nd ed. New York: HarperResource, 2000.
Ricciuti, Edward R. Fish. Woodbridge, CT: Blackbirch, 1993.
Schultz, Ken. Ken Schultz's Field Guide to Freshwater Fish. New York: Wiley, 2004.
Schultz, Ken. Ken Schultz's Field Guide to Saltwater Fish. New York: Wiley, 2004.
"Category: Anchovies and Herrings." All Science Fair Projects. http://www.all-science-fair-projects.com/science_fair_projects_encyclopedia/Category:Anchovies_and_herrings (accessed on September 23, 2004).
"FishFAQ." Northeast Fisheries Science Center. http://www.nefsc.noaa.gov/faq (accessed on September 23, 2004).