gasterosteiform summary

gasterosteiform, Any member of the order Gasterosteiformes, a group of about 350 species of fishes characterized generally by tubular mouths, soft fin rays, pelvic fins located on the abdomen, an air bladder without a duct to the gut, and a primitive kidney. Most species have bony rings around the body or ganoid (thick, bony, enameled, and diamond-shaped) plates rather than scales. The adults of some of the smallest species, such as Satomi’s pygmy seahorse (Hippocampus satomiae) and Denise’s pygmy seahorse (H. denise), are less than 2 cm (0.8 in.) long. The largest species, the red cornetfish (Fistularia petimba), can grow up to about 200 cm (about 80 in.) in length. Most species are of limited economic importance; however, many forms are used in traditional medicines, as aquarium fishes, and as curios. The order is made up of 11 families, which include sticklebacks, pipefishes, seahorses, sea dragons, and pipehorses. Gasterosteiforms are found in salt water, brackish water, and fresh water in many areas of the world.