Tortoises
or land turtles
are land-dwelling reptiles of the family of Testudinidae
, order Testudines. Like their marine cousins, the sea turtles, tortoises are shielded from predators by a shell. The top part of the shell is the carapace, the underside is the plastron, and the two are connected by the bridge. The tortoise has both an endoskeleton and an exoskeleton. Tortoises can vary in size from a few centimeters to two meters. Tortoises tend to be diurnal animals with tendencies to be crepuscular depending on the ambient temperatures. They are generally reclusive animals.
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TORTOISE TICKETS
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Turtles, tortoises and terrapins
Although the word turtle is widely used to describe all members of the order
Testudines, it is also common to see certain members described as
terrapins
,
tortoises
or
sea turtles
as well. Precisely how these alternative names are used, if at all, depends on the type of English being used.
- British English normally describes these reptiles as turtles if they live in the sea; terrapins if they live in fresh or brackish water; or tortoises if they live on land. However, there are exceptions to this where American or Australian common names are in wide use, as with the Fly River turtle.
- American English tends to use the word turtle for all freshwater species, as well as for certain land-dwelling species (e.g. box turtles). Oceanic species are usually referred to as sea turtles, and tortoise is restricted to members of the true tortoise family, Testudinidae. The name terrapin is typically reserved only for the brackish water diamondback terrapin, Malaclemys terrapin
; the word terrapin being derived from the Algonquian word for this animal.
[http://www.bartleby.com/61/1/T0120100.html]
- Australian English uses turtle for both the marine and freshwater species but tortoise for the terrestrial species.
To avoid confusion, the word
chelonian
is popular among veterinarians, scientists, and conservationists working with these animals as a catch-all name for any member of the superorder
Chelonia which includes all turtles, tortoises and terrapins living and extinct, as well as their immediate ancestors. It is based on the
Ancient Greek word
?e????
(
chelone
, modern Greek
?e???a
), meaning tortoise.
Biology
Birth
Female tortoises dig nesting burrows in which they lay from one to thirty eggs.
[1] Egg laying typically occurs at night, after which the mother tortoise covers her
clutch with sand, soil, and organic material. The eggs are left unattended, and depending on the species, take from 60 to 120 days to incubate.
[2] The size of the egg depends on the size of the mother and can be estimated by examining the width of the
cloacal opening between the
carapace and
plastron. The plastron of a female tortoise often has a noticeable V-shaped notch below the tail to facilitate passing the eggs. Upon completion of the incubation period, a fully-formed
hatchling uses an
egg tooth to break out of its shell. It digs to the surface of the nest and begins a life of survival on its own. Hatchlings are born with an embryonic egg sac which serves as a source of nutrition for the first 3 to 7 days until they have the strength and mobility to find food. Juvenile tortoises often require a different balance of nutrients than adults, and therefore may eat foods which a more mature tortoise would not. For example, it is common that the young of a strictly
herbivorous species will consume
worms or insect
larvae for additional protein.
Lifespan
thumb in
Rainbow Basin near
Barstow, California
There are many
old wives tales about the age of turtles and tortoises, one of which being that the age of a tortoise can be deduced by counting the number of concentric rings on its carapace, much like the cross-section of a
tree. This is not true, since the growth of a tortoise depends highly on the access of food and water. A tortoise that has access to plenty of
forage (or is regularly fed by its owner) will grow faster than a
Desert Tortoise that goes days without eating.
Tortoises generally have lifespans comparable with those of human beings, and some individuals are known to have lived longer than 150 years. Because of this, they symbolize longevity in some cultures, such as
China. The oldest tortoise ever recorded, almost the oldest individual animal ever recorded, was
Tu'i Malila
, which was presented to the
Tongan royal family by the British explorer
Captain Cook shortly after its birth in 1777. Tui Malila remained in the care of the Tongan royal family until its death by natural causes on May 19, 1965. This means that upon its death, Tui Malila was 188 years old.
[3] The record for the longest-lived vertebrate is exceeded only by one other, a
koi named
Hanako
whose death on July 17, 1977 ended a 215 year life span.
[4]
The
Alipore Zoo in
India was the home to
Adwaita
, which zoo officials claimed was the oldest living animal until its death on March 23, 2006. Adwaita (sometimes spelled with two d's) was an
Aldabra Giant Tortoise brought to
India by Lord Wellesley who handed it over to the Alipur Zoological Gardens in 1875 when the zoo was set up. Zoo officials state they have documentation showing that Adwaita was at least 130 years old, but claim that he was over 250 years old (although this has
not
been scientifically verified).
Adwaita was said to be the pet of
Robert Clive.
[5]
Harriet
, a resident at the
Australia Zoo in Queensland, was apocryphally thought to have been brought to England by Charles Darwin aboard the
Beagle. Harriet died on June 23, 2006, just shy of her 176th birthday.
Timothy
, a
spur-thighed tortoise, lived to be approximately 165 years old. For 38 years she was carried as a
mascot aboard various ships in Britain's
Royal Navy. Then in 1892, at age 53 she retired to the grounds of
Powderham Castle in
Devon. Up to the time of her passing in 2004 she was believed to be the
UK's oldest resident.
According to articles published by the
Daily Mail and the
Times in December 2008,
Jonathan
, a
Seychelles Giant tortoise living on the island of
St Helena may be as old as 176
[6] or 178 years.
[7] If this is true, he could be the current oldest living animal on Earth.
Sexual dimorphism
Many, though not all, species of tortoises are
sexually dimorphic, though the differences between males and females vary from species to species. In some species, males have a longer, more protruding neck plate than their female counterparts, while in others the claws are longer on the females.
In most tortoise species, the female tends to be larger than the male. Some believe that males grow quicker, while the female grows slower but larger. The male also has a
plastron that is curved inwards to aid reproduction. The easiest way to determine the sex of a tortoise is to look at the tail. The females, as a general rule have a smaller tail which is dropped down whereas the males have a much longer tail which is usually pulled up and to the side of the rear shell.
General Information
Giant tortoises move very slowly on dry land, at only 0.17 miles per hour.
[8]
Diet
Most land based tortoises are
herbivores, feeding on grazing grasses, weeds, leafy greens, flowers, and some fruits. Pet tortoises typically require a diet based on
alfalfa,
clover,
dandelions, and some varieties of
lettuce. Certain species occasionally consume
worms or
insects, but too much protein can be detrimental as it can cause shell deformation and other medical problems. Cat or dog foods should not be fed to tortoises, as these do not contain the proper balance of nutrients for a reptile; in particular, they are too high in protein. Additionally, it should not be assumed that all captive tortoises can be fed on the same diet. As different tortoise species vary greatly in their nutritional requirements, even commercial food pellets should be offered only to the species specifically listed on the label or packaging. However it is important to note that the proper size pellets should be used as tortoises have been known to rupture their oesophagus which begins the onset of choking and/or a slow painful death. The best approach to determining the proper diet is to consult a qualified
veterinarian, a
herpetologist, or a care sheet provided by a reputable source.
Taxonomy
The following species list largely follows Ernst & Barbour (1989), as indicated by The Reptile Database. However, the newly erected genera
Astrochelys
,
Chelonoidis
, and
Stigmochelys
have been retained within
Geochelone
.
- Chersina
- *Chersina angulata
, Bowsprit Tortoise
- Cylindraspis
(All species Extinct)
- *Cylindraspis indica
, synonym Cylindraspis borbonica
- *Cylindraspis inepta
- *Cylindraspis peltastes
- *Cylindraspis triserrata
- *Cylindraspis vosmaeri
- Dipsochelys
- *Dipsochelys abrupta
(Extinct)
- *Dipsochelys arnoldi
, Arnold's Giant Tortoise,
- *Dipsochelys daudinii
(Extinct)
- *Dipsochelys dussumieri
, Aldabra Giant Tortoise, common synonyms Geochelone gigantea
, Aldabrachelys gigantea
- *Dipsochelys grandidieri
(Extinct)
- *Dipsochelys hololissa
, Seychelles giant tortoise
- Geochelone
- *Geochelone carbonaria
, Red-Footed Tortoise; sometimes placed in distinct genus Chelonoidis
- *Geochelone chilensis
, Chaco or Chilean Tortoise; sometimes placed in distinct genus Chelonoidis
- *Geochelone denticulata
, Yellow-Footed Tortoise; sometimes placed in distinct genus Chelonoidis
- *Geochelone elegans
, Indian Star Tortoise
- *Geochelone nigra
, Galápagos Giant Tortoise; sometimes placed in distinct genus Chelonoidis
- *Geochelone pardalis
, Leopard Tortoise; sometimes placed in distinct genus Stigmochelys
or in Psammobates
- *Geochelone platynota
, Burmese Star Tortoise
- *Geochelone radiata
, Radiated Tortoise; sometimes placed in distinct genus Astrochelys
- *Geochelone sulcata
, African Spurred Tortoise (Sulcata Tortoise)
- *Geochelone yniphora
, Angulated Tortoise, Madagascan (Plowshare) Tortoise; sometimes placed in distinct genus Astrochelys
- Gopherus
- *Gopherus agassizii
, Desert Tortoise
- *Gopherus berlandieri
, Texas Tortoise
- *Gopherus flavomarginatus
, Bolson Tortoise
- *Gopherus polyphemus
, Gopher Tortoise
- †Hadrianus
- *Hadrianus corsoni
(syn. H. octonarius
)
- *Hadrianus robustus
- *Hadrianus schucherti
- *Hadrianus utahensis
- Homopus
- *Homopus aerolatus
, Parrot-Beaked Cape Tortoise
- *Homopus boulengeri
, Boulenger's Cape Tortoise
- *Homopus femoralis
, Karroo Cape Tortoise
- *Homopus signatus
, Speckled Cape Tortoise, Speckled Padloper
- *Homopus bergeri
, Berger's Cape Tortoise, Nama padloper, synonym Homopus solus
- Indotestudo
- *Indotestudo elongata
, Elongated Tortoise
- *Indotestudo forstenii
, Travancore Tortoise, Forsten’s Tortoise
- *Indotestudo travancorica
, Travancore Tortoise
- Kinixys
- *Kinixys belliana
, Bell's Hinge-Backed Tortoise
- *Kinixys erosa
, Serrated Hinge-Backed Tortoise
- *Kinixys homeana
, Home's Hinge-Backed Tortoise
- *Kinixys lobatsiana
, Lobatse Hingeback Tortoise
- *Kinixys natalensis
, Natal Hinge-Backed Tortoise
- *Kinixys spekii
, Speke's Hingeback Tortoise
- Malacochersus
- *Malacochersus tornieri
, Pancake Tortoise
- Manouria
- *Manouria emys
, Brown Tortoise (Mountain Tortoise)
- *Manouria impressa
, Impressed Tortoise
- Psammobates
- *Psammobates geometricus
, Geometric Tortoise
- *Psammobates oculifer
, Serrated Star Tortoise
- *Psammobates tentorius
, African Tent Tortoise
- Pyxis
- *Pyxis arachnoides
, Madagascan Spider Tortoise
- *Pyxis planicauda
, Madagascan Flat-Tailed Tortoise
- Stylemys
(Genus extinct)
- *Stylemys botti
- *Stylemys calaverensis
- *Stylemys canetotiana
- *Stylemys capax
- *Stylemys conspecta
- *Stylemys copei
- *Stylemys emiliae
- *Stylemys frizaciana
- *Stylemys karakolensis
- *Stylemys nebrascensis
(syn. S. amphithorax
)
- *Stylemys neglectus
- *Stylemys oregonensis
- *Stylemys pygmea
- *Stylemys uintensis
- *Stylemys undabuna
- Testudo
- *Testudo atlas
, Atlas tortoise, Colossochelys (Extinct)
- *Testudo graeca
, Greek Tortoise (Spur-Thighed Tortoise)
- *Testudo hermanni
, Herman's Tortoise
- *Testudo horsfieldii
, Russian Tortoise (Horsfield's Tortoise, or Central Asian Tortoise)
- *Testudo kleinmanni
, Egyptian Tortoise, incl. Negev Tortoise
- *Testudo marginata
, Marginated Tortoise
- *Testudo nabeulensis
, Tunisian Spur-thigh Tortoise
In religion
In
Hinduism,
Kurma
(
Sanskrit:
?????) was the second
avatar of
Vishnu. Like the
Matsya Avatara also belongs to the
Satya Yuga. Vishnu took the form of a half-man half-tortoise, the lower half being a tortoise. He is normally shown as having four arms. He sat on the bottom of the
ocean after the
Great Flood. A
mountain was placed on his back by the other
gods so that they could churn the sea and find the ancient treasures of the
Vedic peoples.
Tortoise shells were used by ancient Chinese as
Oracle Bones to make predictions.
Cultural depictions
Gallery
References
- Tortoise Trust Egg F.A.Q
- Tortoise egg incubation
- Tortoise Believed to Have Been Owned by Darwin Dies at 176 - Science News
- Hanako
- World
- Jonathan the 176-year-old tortoise revealed as world's oldest animal in Boer War photo Daily Mail, December 5, 2008
- Boer War memento puts years on Jonathan the tortoise. The Times, December 4, 2008
- 2003 Grolier Encyclopedia, The Great Book of Knowledge, The Speed of Animals, pp. 278]