Which aggressive shark lives in warm, shallow brackish and freshwater systems, including the lower reaches of rivers?

How is it possible to determine the sex of a parakeet?

These animals reach lengths of up to 7 feet, have about 100 teeth, emit sounds when moving to help them navigate, and reach travelling speeds of about 35 miles per hour. What kind of animals are they?

What are two common names for jumping, tailless amphibia?

The largest type of living bird can be 9 feet in height and weigh 350 lbs (160 kgs). What kind of bird is it?

What's the difference between a turtle and a tortoise?

By what name do we identify those certain kinds of weasels whose coats change color in the winter?