To save confusion in this blog post, I shall be using the word ‘Turtle’ to mean turtle, tortoise and terrapin. There is a confusion in some countries (like the UK) where each of the names of turtle, tortoise and terrapin have different meanings. This confusion does not happen all the time. For example, in the US turtle is interchangeably between what us Brits would call turtles and tortoises. In Spain ‘Tortuga’ (think Breaking Bad) means all 3 types of animal. If you do need to distinguish between the 3 different types of animals, you can add ‘Marina’ (sea-dwelling), de Rio (freshwater) or terreste (for tortoise).
Turtles are members of the Chelonian order and so perhaps it will be easier to refer to them as such. The word Chelonia comes from the Greek word Kelone meaning ‘armour’ or ‘inter-locking shields’. This is why the famous Roman defensive battle position is called a ‘turtle’.
The most obvious feature of the turtles is that they have a shell. The upper part of the shell is known as the carapace with the lower part being named the as being the plastron. The inner part of the turtle’s shell is made up of around 60 bones – including some of its backbone and ribs. This means a turtle, despite what numerous cartoons would tell you, cannot crawl out of their shell. If it was possible, they would immediately die because their organs would become detached from their body! The rigid shell also means that turtles must breath in a completely different way to other reptiles. The traditional method of breathing for land animals would be to expand and contract the space in the chest cavity by the movement of their ribs. Turtles cannot do this because their ribs are fused into their shell and therefore cannot move them up or down. To get around this breathing problem, turtles have developed a buccal pump. This pump allows the turtle to draw air in through its mouth and push it into their lungs. This is also aided by abdominal muscles which contract to cover the back end of the shell, allowing a greater volume to be maintained within the shell. These techniques help to draw air into the lungs in a similar way to the diaphragm in mammals.
The shape of turtle’s shell varies from species to species. Many of the slower moving land turtles have large, round shells. This allows them to be protected by predators who are unable to fit their jaw around the shell. The turtles who spend a lot of their time in water, have much smaller and thinner shells that are used to keep streamline in the water. Colour can also vary amongst turtles. Shells are mostly black, brown, dark green. Other more colourful species, have shells that can be red, orange, yellow, spotty, or stripy. One of the most colorful turtles is the eastern painted turtle that has a yellow underside and a black shell with red markings around the rim.
Turtles are known for living an extremely long time. The land variety have been known to live over 150 years old. There is a somewhat ‘heated’ debate over which turtle has the record for the oldest turtle of all time. The current Guinness World Record holder had lived to the age of 189 and died in 1965. This individual would have lived through two world wars and ten different monarchs! Today, there is a number of different reports of turtles who have lived older. One of the most famous is ‘Jonathan’. In 2008 a British newspaper reported that Jonathan was older than any other turtle in history and apparently had photographic evidence. A photo of Jonathan from 1900 was reportedly taken when he was 70 years old. If true, then Jonathan would be 184 years old and could soon be the oldest living reptile ever. One other Chelonian who has a claim to be the oldest is Adwaita who died in 2006. It was reported that at the time of her death, that she was 255 years old! Maybe it has yet to be confirmed because Adwaita didn’t want people to know her true age!
Turtles are often eaten by humans. The flesh, known as Calipee, is a delicacy that is eaten all over the world. In the England and America, turtle soup is often seen as a highly prized dish. In the Grand Cayman island, turtles are thought to be so delicious that Turtle farms have been set up. The local people had favoured them so much that they had almost ate them to extinction. To stop this, they set up farms which allow the turtles to reproduce before they are eaten. This isn’t the first time tortoise have almost been eaten to extinction. In the 16th century when explorers came across the delicious treat, they could not believe their taste buds. It seemed that every part of the turtle was delicious. The tortoise fat could be used as an extremely nutritious oil which could help fight symptoms of cold and flu. The liver was particular tender and highly revered. Their bones were full of rich marrow which kept sailors healthy. Equally important was that turtles were able to store a month’s supply of water in their specially adapted bladders. All of these wonderful traits, plus the fact that they were extremely slow, meant that turtle’s became rich pickings for many British sailors in the 16th and 17th century.
Today, turtles are kept as pets. In the US it is illegal to sell turtles that under 4 inches in length because of the ease that they can spread salmonellosis to humans. Nonetheless turtles are often sold as ‘educational tools’ to customers and therefore people can get around this ruling. In the UK turtles are often kept as pets either in large tanks or in garden runs. In fact, my younger brother really wants a pet turtle but I must warn him that if I suddenly become hungry one day then I may just have to investigate for myself why sailors when completely mad for them!