Turtles, tortoises, and terrapins all belong to a group of four-legged reptiles that have hard outer shells, scaly skins, and horny beaks. Most people use the three words—turtle, tortoise, and terrapin—interchangeably. Scientists, however, sometimes make this distinction: a turtle is a sea reptile; a tortoise is a land reptile; and a terrapin is a fresh-water reptile.

It is correct to call all three turtles. They all breathe air through lungs and have shells that are made up of a “bony box” covered with horny plates or with soft skin. These shells are divided into two parts. One part covers the back; the other covers the underpart of the turtle’s body. Through the openings between the two parts, the turtle can thrust out its head, neck, tail, and legs.

Turtles have well-developed senses of sight, taste, and touch, but their hearing is quite poor. Most turtles eat all kinds of food. Female turtles are able to make a hissing sound, while the male turtle is able to give a kind of “grunt.” Some of the giant land turtles are even able to bellow!

The largest of living turtles is the leatherback, which is a sea turtle. It usually weighs about 450 kilograms, and the biggest specimen on record is over 2 meters long and weighs 680 kilograms.

Turtle soup is made from the flesh of the green turtle, which is also a sea turtle. It is usually found in tropical seas, and may weigh as much as 225 kilograms. Tortoise shell is quite expensive and is obtained from the hawksbill turtle. It is the smallest of the sea turtles and is rarely more than 1 meter long. Its horny shell consists of separate, clear, horny shields of dark brown, richly marbled with yellow.

The biggest North American turtle is the alligator snapping turtle. It can weigh 70 kilograms and lives in the Mississippi region. Snappers, which are fresh-water turtles, have long, large tails and very strong, sharp jaws.

The most common North American land turtle is the wood, which has brick-red skin. It can become quite a friendly pet and will learn to take food from one’s fingers. Turtles hibernate during the winter months, hiding either in the bottom of ponds or in holes in the ground. Turtles sometimes live for 200 years or more!