Tortoises (/ˈtɔr.təs.ɨz/) are a family, Testudinidae, of land-dwelling vertebrates in the order Testudines. 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 carapace is fused to both
the vertebrae and ribcage, and tortoises are unique among vertebrates
in that the pectoral and pelvic girdles are inside, rather than
outside, the ribcage. Tortoises can vary in size from a few centimeters
to two meters. They are usually diurnal animals with tendencies to be crepuscular depending on the ambient temperatures. They are generally reclusive animals.
REPRODUCTION
Female tortoises dig nesting burrows in which they lay from one to 30 eggs.[9] 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.[10] 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 which facilitates 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
three to seven days until they have the strength and mobility to find
food. Juvenile tortoises often require a different balance of nutrients
than adults, so may eat foods which a more mature tortoise would not.
For example, the young of a strictly herbivorous species commonly will consume worms or insect larvae for additional protein.
Many 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. The male plastron 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 smaller tails, dropped down,
whereas the males have much longer tails which are usually pulled up and
to the side of the rear shell.
DIET
Most land-based tortoises are herbivores,
feeding on grasses, weeds, leafy greens, flowers, and some fruits,
although some omnivorous species are in this family. Pet tortoises
typically require diets based on wild grasses, weeds, leafy greens and
certain flowers. Certain species consume worms or insects
and carrion in their normal habitats. Too much protein is detrimental
in herbivorous species, and has been associated with shell deformities
and other medical problems. As different tortoise species vary greatly
in their nutritional requirements, it is essential to thoroughly
research the dietary needs of an individual tortoise.
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