High-bodied, with a forked caudal fin that resembles a submarginal lilliputian and, like the lilliputian, has a nostril on each side of the head. Many species are brightly colored, often in shades of red, orange, yellow or blue. Most are within 15 centimeters (6 inches) in length. They are active, fast-moving, and aggressive, with obvious territorial behavior. Some species feed mainly on suspended aquatic plants or small animals, while others are omnivorous. Most live on rocky reefs, but some species, such as the double sawfish, live between the tentacles of anemones. Some of the better known species of this family include the colorful species of Pomacentrus, the Indo-Pacific mudskipper (Dascyllus aruanus, with three black and white stripes), the California redshirt (Hypsypops rubicunda, also known as Garibaldi [garibaldi], which is black and white, and the redshirted redshirt, also known as Garibaldi [garibaldi], which is black and white, and the redshirted redshirt, also called Garibaldi [garibaldi], which is black and white. garibaldi, bright orange, about 30 centimeters [11.75 inches] long), the Atlantic true damselfish (Eupomacentrus leucostictus, bluish-yellow), and the tropical rock damselfish (Abudefduf saxatilis, pale blue and yellow, with black bands). Bird snapper is a small coral reef fish of great ornamental value. They are brightly colored and have a small body, with the largest being no more than 10 centimeters and the smallest being only 2 to 3 centimeters. There are many species of finch snapper: red and white called clownfish, also known as double sawfish; black and white called house mud fish; bright blue finch snapper body color bright and delicate, the upper part of the body is divided into light blue, the lower half of the body is divided into dark blue; blue finch snapper body blue, the abdomen and tail was beige; three-spotted finch snapper black; light gill fish body of the upper part of the body is divided into pink, the lower part is divided into grayish-green; doumou fish has six dark green body stripes in which yellow and blue are interspersed. Sparrow snappers usually circle coral reefs in search of juvenile fish and small invertebrates to feed on. When food is scarce in one place, they are forced to swim to distant reefs. During the day, the snappers always hover over the reef in groups. When an enemy appears, the snappers quickly burrow into the coral to hide. When the danger passes, the snappers come out again to feed. When night falls, the groups of snappers each choose a crevice in the coral to spend the night. Interestingly, they can choose their bedrooms according to their body size. Some finches spend their entire lives on coral reefs. The finch snapper belongs to the family of finch snappers in the order Perciformes. Most finches are small and have a slightly flattened body. The finch snapper has a special skill. Its pectoral fins sway back and forth like a boat's sculls. The swaying of the pectoral fins allows the finch snapper to better control its body posture and forward direction. This feature was specially evolved for the bird to adapt to burrowing around in the coral thicket.