Bonefishes and Relatives: Albuliformes
BONEFISHES AND RELATIVES: Albuliformes
The feature shared by bonefishes and their relatives, the halosaurs (HAH-leh-sawrs) and the spiny eels, is an open canal, or a tube-shaped passage, in the lower jaw that is an extension of the series of pores and tiny tubes along each side of a fish's body used for sensing vibrations (vie-BRAY-shuns). Bonefishes have a long, thin body that tapers, or gets thinner, at each end. The relatives are eel shaped with a very long anal (AY-nuhl) fin, the fin that runs along the bottom of the body, and no tail fin. Most bonefishes and their relatives are 3.3 feet (1 meter) long or shorter.
Bonefishes and their relatives live all over the world.
Bonefishes live in shallow tropical waters, or waters with an average annual temperature more than 68°F (20°C). Halosaurs and spiny eels live at the bottom of the ocean in water that is 3,281–9843 feet (1,000–3,000 meters) deep.
Bonefishes eat fishes and small invertebrates (in-VER-teh-brehts), or animals without backbones. Halosaurs and spiny eels eat bottom-dwelling animals, including worms; mollusks (MAH-lusks), or soft-bodied, usually hard-shelled animals such as clams; and crustaceans (krus-TAY-shuns), or water-dwelling animals without a backbone and that have jointed legs. Larger bonefishes also eat fish.
BEHAVIOR AND REPRODUCTION
Bonefishes live in small schools in sometimes extremely shallow water. They are ready to reproduce when they are about three and a half to four years old. The spawning areas of bonefishes, or the areas where they produce and release their eggs, are unknown. Bonefishes live for at least nineteen years. Spiny eel larvae (LAR-vee), or spiny eels in the early stage of development before becoming adults, can reach a length of 3.3 to 6.6 feet (1 to 2 meters).
BONEFISHES AND THEIR RELATIVES AND PEOPLE
Bonefishes are popular sport fishes. Bonefishes are not considered a food fish in Florida, and most are released when caught. Halosaurs and spiny eels are of no commercial value.
Bonefishes and their relatives are not threatened or endangered.
Physical characteristics: Bonefishes have a blue-green back with narrow, dark, horizontal lines. The sides are silver. The tail is deeply forked. The average weight of a bonefish is 2 to 5 pounds (0.9 to 2.3 kilograms), and its average length is 12 to 30 inches (30 to 76 centimeters), but these fishes can weigh as much as 10 pounds (4.5 kilograms) and be 41 inches (104 centimeters) long. The upper jaw juts out beyond the lower jaw and does not have teeth.
Geographic range: Bonefishes live all over the world.
Habitat: Bonefishes live in tropical shallow-water areas. They are most abundant at depths of less than 115 feet (35 meters) and often feed in water less than 3.3 feet (1 meter) deep. Bonefishes also can be found in shallow grass flats and sandy areas.
Diet: Bonefishes feed on a variety of small bottom-dwelling invertebrates and fishes. Feeding often takes place in shallow water, where bonefishes can be seen with their fins sticking out of the water as they seek food. As they forage (FOR-ihj), or search for food, bonefish schools frequently dig in the bottom and disturb the mud and sand.
Behavior and reproduction: Bonefishes are remarkable because they commonly go into water that is extremely shallow for the size of the fishes. They can use their swim bladder, an internal sac usually used to control position in the water, for breathing. These fishes usually swim in small schools of five to twenty, although they sometimes swim in large schools of one hundred or more. People fishing for bonefishes often find them by spotting their tails sticking out of the water as the fishes dig in the bottom for food.
Male bonefishes are ready to reproduce when they are about 15 inches (38 centimeters) long and about three and a half years old. Females are ready at a length of about 19 inches (48 centimeters) and about four years of age. Spawning, or the production and release of eggs, peaks from November to May. Females contain about 0.4 million to 1.7 million eggs, and the number of eggs increases with the weight of the fish. Spawning areas are not known. The long, clear larvae reach a length of about 3 inches (8 centimeters). The fishes shrink during metamorphosis (meh-tuh-MOR-pho-sus), or the changes in form that some animals make to become adults, and the fins appear during the shrinking. In about ten to twelve days, the fishes look like miniature adults. Bonefishes grow rapidly until the age of about six years, and then growth slows. Bonefishes live for at least nineteen years.
Bonefishes and people: In many areas bonefishes are important business for people who make their living running fishing trips, especially in the Florida Keys. Fishermen like to try for bonefishes because the fish are difficult to sneak up on and fight hard when they are hooked. People who fish for bonefishes in most areas need special boats that can enter shallow water with little or no noise. Bonefishes are not considered a food fish in Florida, and most bonefishes are released when caught. In some areas of the world, however, people do eat bonefish.
Conservation status: Bonefishes are not threatened or endangered. ∎
FOR MORE INFORMATION
Nelson, Joseph S. Fishes of the World. New York: Wiley, 1994.
Ricciuti, Edward R. Fish. Woodbridge, CT: Blackbirch, 1993.
Schultz, Ken. Ken Schultz's Field Guide to Saltwater Fish. New York: Wiley, 2004.
Morey, Sean. "Biological Profiles: Bonefish." Ichthyology at the Florida Museum of Natural History. http://www.flmnh.ufl.edu/fish/Gallery/Descript/bonefish/bonefish.html (accessed on September 13, 2004).