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Tortoise

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About Tortoise

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Tortoise are any member of the reptile species of the family Testudinidae which comes under the order of Testudines. Tortoise scientific name is given by writing the genus name and the species name following the rules of binomial nomenclature. Out of the different types of tortoise an example of the types species can be given by Testudo graeca. Formerly, any turtle that lived on land was referred to as Tortoise. This was because the tortoise species is mostly land-dwelling meaning that they mostly live on land because of one of the typical features of tortoise being the shell to protect them from predation and threats. There are certain exceptions to this as some of them can be semi-aquatic. 


Features of Tortoise

The very clearly of the visible features of a tortoise is the shell. The shell of most of the tortoises is high domed. The only exception is the pancake tortoise scientifically named as Malacochersus tornieri which have flat shells. A few other types of tortoise species can have nearly spherical shells with a flat base. 

The tortoise can be easily recognised by their unique hind-limb anatomy. Their hind-limbs are elephentine or cylindrical. Each digit in their forefeet and their hind feet contains two or fewer phalanges. To protect themselves from the threat they have the ability to retract their heads and neck directly backwards into the shell, since the hard shell acts the best natural defence for them. 

A unique tortoise information is that among the vertebrates they are the only ones with their pectoral and pelvic girdles are inside the ribcage rather than outside. An interesting of the significant tortoise facts is that they come in all shapes and sizes. They vary in size from two centimeters to two meters. They usually dwell on land and are mostly active during the day but under favourable temperature conditions they can be active during the dusk and the dawn as well. Although the longest living creatures on earth, tortoises are mostly reclusive. On an average the life-span of the tortoise species is 80 -150 years. Some of the longest living tortoises are: Galápagos tortoise noted for having lived over 150 years and Aldabra giant tortoise named Adwaita estimated to have lived for 255 years. An image of the Aldabra giant tortoise provides significant tortoise information about some of the physical features of tortoise as well. 


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Tortoise Life Cycle

The mode of reproduction for the tortoise species includes copulation where the fertilization of the female eggs occurs by the male sperm and the laying off of the eggs by the females. The majority of all types of tortoise lay small clutches of eggs. The clutch sizes may differ but they rarely exceed 20 and in some cases it can be as low as 1 - 2. Egg laying usually occurs at night in the nest dug by alternating scooping movement of their hind limbs. After the egg laying the mother tortoise covers her clutch with soil, and other organic material. Depending upon the species, the incubation of the tortoise begins and takes 60 to 120 days. Upon incubation, the hatchling uses an egg tooth to break free of its shells. After breaking out of their egg-shells they dig out to the surface of the nest and start their own life of survival. An embryonic sac is attached to the young ones when they are hatched, which is the primary source of nutrition for them for the first three to seven days by which they gain some significant strength to roam and find food for themselves. 

Just born their diet can be significantly different from that of their own adult forms because of  different nutritional requirements in their young and adult forms. They then continue their survival with a tortoise life being counted up to hundred to two hundred years. One manner by which the age of the tortoise life can be determined is the number of concentric rings on the shell or the carapace. 

Usually, the tortoises are sexually dimorphic. Although, a point to be noted about tortoise is that the sexual characteristics can vary amongst different tortoise species. One distinguishing feature of the male and female tortoise is that the males have a comparatively larger tail than the females. Also, in accordance with some tortoise information the claws of the male might be larger than their female counterparts. But the most interesting fact of the tortoise facts is their size of the brain. The size of the brain of all the different types of tortoise is quite small. Some of them such as red-footed tortoises from Central and South America are found to lack an area of the brain called the hippocampus which is responsible for emotion, learning, memory, spatial navigation, etc. Instead they use another area of their brain called the medial cortex for emotions. They are known to survive even when their brains are surgically removed.


What Do Tortoises Eat?

Most of the tortoise species are vegetarians. They are highly dependent on grasses, weeds, foliage, flowers and fruits for their nutritional needs. Some of the tortoise breeds which are found in moist forest ecosystems also consume animal matter. As already mentioned above the nutritional availability is highly dependent on what tortoise eat, the feeding habits for a young and adult tortoise can differ. For example, even though belonging to a strictly herbivorous species, the young ones of a particular species of tortoise will consume worms or insects or larvae for additional protein. 

The nutritional requirements can vary in different types of tortoise and can cause several problems when the nutritional balance is not achieved. For example in certain types of tortoise (depending on usually what tortoise eat) too much protein can be dangerous and can result in deforming of their shell. Thus, it becomes very important to know what tortoises eat, in case of pets, strictly falls within their nutritional balanced capacities in case of pets.


Where Do Tortoises Live?

A simple answer to the question where do tortoises live? is - everywhere. Tortoises are entirely terrestrial living organisms. They are found on all continents except Australia and Antarctica. They are also found on numerous islands all around the world. But some of the species of the tortoise might be getting extinct because of human occupation. The tortoise breeds can be found from southern North America to southern South America, around the Mediterranean basin, across Eurasia to Southeast Asia, in sub-Saharan Africa, Madagascar and some Pacific Islands. But as already stated they are absent in Australia. Their species distribution shows that there are at least 15 species distributed from South America to Africa and Asia. An example of such a species is the genus Geochelone found on all three continents mentioned before. There are approximately 49 species of tortoise varying in shapes and having a wide range in sizes. Examples include: Padlopers (Homopus) of Southern Africa with shell lengths of 10 to 15 cm, the Geochelone of Aldabra and Galapagos islands with shells over 1 metre long. 

The tortoise habitat includes a wide variety of ecosystems and is present all around the world. A tortoise habitat can be a desert, arid grassland, wet evergreen forest, semi-arid region, sea level or mountains. Thus, they are present everywhere.


Tortoise and Human Culture

Having such long lives and their existence in almost all the places in the world with diverse tortoise habitat, the tortoise have become an integral part of human culture. Examples of these are given below:

  • In Chinese cultures, the tortoise is the symbol of longevity. This belief arises from the long tortoise life spans.

  • In some chinese cultures, tortoise shells are used as oracle bones to make predictions.

  • In Judaism and early Christianity they are seen as unclean animals. This can be because of the tortoise habitat that includes the wet evergreen forests and wetland habitats.

  • In Greek culture, the tortoise is a symbol of ancient God Hermes.

  • In Hinduism, Kurma is a tortoise who is the second avatar of Vishnu. This avatara is also from the Satya Yuga of Hinduism like that of the Matsya avatar. The upper half is the human form and the lower half is of the tortoise. Kurma sat on the bottom of the ocean after the Great Flood. In another incident, a mountain was placed on his back by other Gods so they could churn the sea and find the ancient treasures coming out of the ocean.

  • The story of the race between the rabbit and the tortoise is a wonderful children’s story with the moral: slow and steady wins the race. This story teaches the importance of slow yet continuous hard work to the children.

Tortoise Facts For Fun

Some of the fun facts about the tortoise are given below:

  • Tortoise are extremely slow creatures. They are placid and move very slowly. They have an average speed of 0.2 - 0.5 km/hr.

  • One of the interesting facts is their survival capacity. Surgically removing the brain of the tortoise does not result in their imminent death. Some tortoises have survived up to 6 months after having their brains removed surgically. 

  • Decapitation also does not lead to the imminent death of the tortoise. There was an incident when a tortoise head was cut-off and yet it survived for 23 days.

FAQ (Frequently Asked Questions)

1. How Long Does A Tortoise Live?

Ans: Tortoise are known to live very long lives. An average life-span of the tortoise is found to be between 60 - 150 years. Some of them are known to live more than 200 years as well. Galápagos tortoise found on the island of Galápagos is said to have lived 150 years. Another tortoise with a significantly long life is the Aldabra giant tortoise known as Adwaita at the Alipore Zoo in Kolkata India. Adwaita has been estimated to have lived for 255 years.

2. Do Tortoises Have Feelings?

Ans: Tortoise are known for small brain sizes. They are known to have feelings and they do exhibit emotional responses. But they lack the area of the brain called the hippocampus which is primarily responsible for the emotions, learning and memory, spatial navigation, etc. Instead they are known to use a different area in their brain called the medial cortex for carrying out their emotional responses. Thus they can be said to be unique in intellectual capacities but are surely known for their ability to express emotions. Owing to this they are emotionally described as calm and compassionate in several human cultures as well. 

3. Do Tortoises Bring Luck?

Ans: There is an ancient and popular belief in some Chinese cultures that the tortoise are harbingers of good luck. Due to their very long life-spans they are associated with longevity and are symbolised as such. In some Chinese cultures, the shells of the tortoise are used as oracle bones to make predictions about the future. This is because of their docile and calm nature along with a long life they are characterized as such. Also, since they are found almost everywhere on Earth, except Australia and Antarctica, they have been integrated into human cultures. In the movie, Kung Fu Panda, Grand Master Oogway is an elderly Galápagos tortoise who is both wise and said to be the pioneer of Kung Fu.

4. What is A Tortoise?

Ans: A tortoise is any member of the family of Testudinidae which falls under the category of Testudines. Scientifically they are classified differently from the turtles although both of them are categorized in the order of Testudines. Tortoises are a species of reptiles that are largely found on the land and are mostly terrestrial living organisms. They are characterized by the hard shells that are present on their backs to protect them against external threats and have the capability to retract their head and limbs back inside the shell for their protection. An example of the species of the tortoise is Testudo graeca.

5. Do Tortoises Bite?

Ans: Yes, the tortoises do bite. Usually the tortoises are docile, calm and composed in their nature and also when faced with threat they have the ability to retract their head and limbs back into the shell. But under certain circumstances owing to a variety of reasons, they are capable of biting by using the strength of their beaks. They can bite other tortoises, other pets or sometimes humans and the reasons may vary. But this aggressiveness can be part of them feeling threatened and an arising need to retaliate with an attack.