阅读理解 Questions 10-19 The strangest-looking fish in the Everglades wetland region of southern Florida is the Florida gar, whose unusual appearance includes sharp needlelike teeth that ftil along snout. Young gars have numerous dark spots and patches on an olive to yellow,long, slender body. Gars darken with age so that adults appear mostly dark brown, especially when seen from above. Several types of gar exist in eastern and centralNorth America, some of which are extremely large. The aptly named alligator gar isoccasionally mistaken for an alligator and occurs from the lower Mississippi drainagebasin to the rivers of the western panhandle of Florida. Only the relatively small Floridagar, seldom longer than two feet, lives in the Everglades. (The much larger long-nose garas occasionally been found in the Everglades hut historically occurs only north of theregion.) As with all gars, the Florida gar is predatory and is adept at catching smallerfish from schools by using a fast sideways snap of the jaws. It is also capable of catchingindividual prey, pursuing them along the bottom or in douse tangles of vegetation. Usinga slow, stealthy approach, tins technique is effective on fish and grass shrimp. Florida gars are sometimes seen in huge numbers, which is the result of low water that confines individuals from the expanses of the marshes to limited aquatic habitatswhere they remain during the dry season. At these times, gars become prey for thealligator. The sight of a gar held in an alligator's jaws is a vision of prehistoric imagery.In fact, gars have changed little from their ancestors that dominated Earth's waters whenthe dinosaurs flourished; they even have primitive interlocking scales that differ greatly from those of most fish. They also have the dual ability to breathe air and water and canbe observed regularly rising to the surface of the water to renew the air in their swimbladders. Florida gars are sometimes confused with a similarly shaped but unrelatedneedlefish, which are marine but commonly enter freshwater. Needlefish are greenish,bluish, or silvery and have a translucent appearance, hi marked contrast to the darkerand opaque Florida gars.