Trout have many characteristics, including their habitat, diet, and appearance. 

Habitat 

Trout live in cool, clean water in a variety of habitats, from streams to lakes

They are often the first species to disappear from polluted water

 Diet 

Young trout eat plankton, crustaceans, and insects

Older trout eat snails, salamanders, frogs, snakes, small mammals, and fish

 Appearance 

Trout have soft-rayed fins, small scales, and elliptical eyes

They have a small adipose fin behind the dorsal fin

Their pelvic fins are set back on the body

They have teeth on the roof of their mouth called vomerine teeth

Trout scales have growth rings that can be read like tree rings

Trout have fins entirely without spines, and all of them have a small adipose fin along the back, near the tail. The pelvic fins sit well back on the body, on each side of the anus. The swim bladder is connected to the esophagus, allowing for gulping or rapid expulsion of air, a condition known as physostome.

 Behavior

Trout have body language, including gaping and flaring their gills when competing for food 

They select mates to prevent in-breeding and to give offspring desirable traits 

They move daily to feeding and resting habitats

 Feeding

Trout eat a wide variety of organisms. Young trout eat small items, such as plankton, crustaceans and insects. Older trout eat snails, salamanders, frogs, snakes, small mammals and fish, as well as smaller food items.

Although trout will not grow to record size in waters where larger prey is not available, they still survive and grow quite well. The ability to live on smaller prey allows them to provide fishing in some waters too small to support other game fish.

Spawning

Rainbow trout spawn or reproduce in the spring, while New York's other trout spawn in the fall. Like salmon, most trout species build nests, called redds. Using their tails to fan the bottom, female trout create a depression in clean gravel or cobble sites in streams and, occasionally, in seepage areas in ponds. The males remain nearby and drive off rivals. When the nest is ready, the eggs are deposited, quickly fertilized, and covered under a layer of gravel. Both adults then move on, leaving the eggs and young to develop on their own.