Facts about Turtles!

Information From: Turtle - Wikipedia

 Today I will be talking about Turtles.

Chapters:

1: 10 Interesting Facts about Turtles

2: Turtles about, Types, Speciality, And more.

3: Naming and etymology

4: Anatomy and physiology

4.1: Size

4.2: Shell

4.3: Head and neck

4.4: Limbs and Locomotion

4.5: Senses

4.6: Breathing

4.7: Circulation

4.8: Osmoregulation

4.9: Thermoregulation

5: Behaviour

5.1: Diet and feeding

5.2: Communication and intelligence

5.3: Defense

5.4: Migration

6: Reproduction and Lifecycle

6.1: Courtship and mounting

6.2: Eggs and hatchlings

6.3: Lifespan

7: Systematics and evolution of turtles

7:1 Fossil history of turtles

7:2 External Relationships of turtles

7:3 Internal Relationships of turtles

7:4 Differences between the two suborders

8: Distribution and turtles Habitats on where they stay at

8:1 Conservation

8:2 Human Uses for the turtles

8:3 Popularity for pets for exotic turtle’s pets

10 Interesting Facts About Turtles!

1. Green Sea turtle’s diet.

Green sea turtles are unique among many sea turtles in what they eat because they mainly eat herbivores, eating mostly seagrasses and algae. This diet is what gives their cartilage and fat a greenish color ( it is not their shells which some people think ), but it’s the food they eat that gives the name green sea turtles.

2. Sea turtles lay their eggs in a nest they dig into the sand with their rear flippers. The group of eggs under the sand is called a clutch.

They usually lay 100 to 125 eggs per nest and will nest multiple times, about an insane amount of two weeks, over several months. As soon as the eggs hatch ( roughly about two months later when they are born ), the hatchlings dig out of their nest. This process generally takes a few days once. But once they emerge from the eggs, the tiny, small turtles try to rush and hurry to the sea and make their way offshore into the open ocean. Sea turtles face many threats as there are holes in the sand and tons of danger and predators coming to them, and those that survive become adults and become decades old in the future and will repeat the process of what their mom did to them.

3. Sand temperature for turtles is very important.

The gender of sea turtles isn’t born with random gender, but they are born with a specific gender with a particular heat of the sand; the cooler incubation temperatures produce male hatchlings turtles, and warmer incubation temperatures make female hatchlings. Temperatures that fluctuate between two extremes have a mix of male and female hatchlings.

4. Hawkbill turtles use their beaks to help extract their favorite prey.

Hawksbill turtles are typically found near the coral reefs or on the coral reefs, which are homes to their preferred food. The shape and sharpness of their beak enable them to reach small holes around coral reefs and also into the coral reefs to be able to find food for them to eat.

5. One sea turtle species nest during the day.

Most sea turtles nest at night. Kemp’s ridleys are the only sea turtles that routinely nest during the day instead of the night, which is very weird.

6. Leatherback Sea turtles have existed in their current form since the age of dinosaurs in the ancient times!

Leatherback Sea turtles are highly migratory, some swimming more than 10,000 miles a year in the water between nesting and foraging grounds. They are also accomplished divers with the deepest recorded dive of a turtle nearly reaching 4,000 feet. That is very deep 4 with 3 0’s that is crazy and for comparison its deeper than most marine mammals. They have a spiny “ papillae “ lining their mouth and esophagus – these spines help them trap and consume their main  prey species, just like jellyfish is one of their preys.

7. Logger heads spend the first 7 all the way to 15 years at max or average ( 12 years ) of their lives  in the open ocean.

Then they migrate to nearshore costal areas where they continue to grow and mature in the water but nearly the shore instead of the open sea. Through satellite tracking, researchers have discovered something crazy about logger heads. Logger heads that stay in the Pacific Ocean have a highly migratory life stage. Hatchlings enter the ocean from nesting beaches for example in Japan and Australia too. Some individuals undertake a trans-Pacific developmental migration across most of the entire Pacific Ocean to feeding grounds just off the coast of Baja California, Or Mexico, Or Peru, And finally Chile. That’s almost 8,000 Miles just to get to an area. That is crazy for a turtle or a Logger head to be travelling 8000 Miles to get to a shore area.

8. Sea turtles don’t retract into their shells.

Unlike other turtles, Sea turtles actually cannot retract their flippers and heads into their shells. This is because their streamlined shells and large paddle shaped flippers that they use to go swim around the sea or ocean make them very agile and graceful swimmers. In the water, their rear flippers are used as rudders, for steering and moving.

9.  Some turtles nest in large groups, called “ arribadas. “ And that’s in Spanish. But in English it actually means “ arrival. “ Only the two ridley turtles, Kemp’s Ridley, and the olive ridley, display this arribada nesting behaviour.

During an “ arribada “ or “ arrival “ large groups of females gather near the offshore and goes to the beach to nest in insane large numbers, generally over a period of several hours. There are many theories on what triggers an “ arribada “ “ arrival “, including offshore winds, or lunar cycles, and the release of pheromones by females. Many turtles come ashore together, and many nests are laid and hatch at the same time. This reduces the number of eggs and hatchlings that can be killed by predators because there are many of them at the same time and for them to catch a lot of them will be hard as they are moving a lot together and they probably can’t decide which one to go for.

10. Sea turtles are deep divers and can stay under water for a long period of time many times.

As turtles being reptiles, sea turtles off course have to breathe air, but they have the ability, under natural conditions, to remain submerged for hours at a time and ridiculous amount of time in just 1 time. They even sleep underwater, and just going to say they still have to breath air. Most seas turtles spend their entire life at sea, only returning to nesting beaches to lay eggs to make more turtles come into the sea. However, in the Pacific Islands, green turtles often come ashore to bask on the beach.

 

 

 

 

 

 

Time to actually talk about turtles:

Turtles are an order of reptiles or known as “ Testudines, “ characterized by a shell developed mainly from their ribs. Modern turtles are divided in to two major groups, there is the side of side necked turtles and the hidden neck turtles, which both differ in the way the head retracts. There are 360 living and recently extinct species of turtles which is pretty sad and not just including that there are also the land dwelling tortoises and freshwater terrapins, which also went extinct. They mostly found on most continents, some islands and, in this specific case of sea turtles, much of the ocean. Like other reptiles, birds, and also mammals, they breathe air and do not lay eggs underwater, although many other species live in or around water. Genetic evidence typically places  them in close relation to crocodilians or crocodiles, and even birds.

Turtle shells are actually made mostly of bone like our human bone but turtle type. The upper part is the domed carapace while the underside Is the flatter plastron or belly plate. Its outer surface is cover with scales like fish skin but made out of keratin and way bigger, the material of hair, the horns, and even the claws. The carapace bones develop from ribs that grow sideways and develop into broad flat plates that join up to cover the body. Turtles are actually ectotherms or “ cold blooded “, which means they are generally opportunistic omnivores and mainly feed on plants and animals with tiny, limited movements of moving. Many turtles migrate short distances seasonally. Sea turtles are actually the only turtle to be seen by human that can actually migrate long distances to lay their eggs on their favoured beach of kind.

Turtles have appeared in  many myths and folktales all around the world. Some terrestrial and freshwater species or turtles are widely kept as pets as some parts around the word. But what is sad about turtles is that turtles have actually been hunted for their meat for decades and maybe century now for their shells which sell for a lot and also their meat and for some reason for use in traditional medicine in parts of the world. Sea turtles are sometime often killed accidently as bycatch in fishing nets. Turtle habitats around the world are being destroyed by the second right now. As a result of all these pressures happening in this world, many species are unfortunately dying and are being threatened with extinction in the upcoming years.

How the word turtle was created.

The word turtle is derived from the French word “ tortue “ or “ tortre “ ( “ turtle, “ and “ tortoise” ). And I don’t know why but so many of these animal names are from French for some reason. It’s like French has made every animal name for some reason in the old times. It is a common name and also may be used without knowledge of taxonomic distinctions. In North America, It may denote the order as a whole. In England or you can say In Britain which now called UK, the name is used for sea turtles as opposed to fresh water terrapins and land dwelling tortoises. In Australia, which lacks true tortoises ( family “ Testudinidae “ ), non marine turtles were traditionally called tortoises, but more recently turtle has been used for the entire group of the species.

Now we are going to be talking about the Anatomy and physiology of turtles like size shell and more.

The Size.

The largest living species of turtle ( which is actually the 4^th! Largest reptile in the world! ) is the leather back turtle, which can astonishingly reach up to over 2.7 m tall or you can say ( 8 ft and 10 in tall ) in length and can weight up to over 500 kg ( 1,100 lb ). The largest known turtle was the Archelon ischyros, a Late cretaceous sea turtle up to 4.5  m ( 15 ft ) long, and up to 5.25 m ( 17 ft ) wide between the tips of the front flippers. Wow that seriously long! That’s like a human and a half tall of the average adult size. And they have been estimated to have weight a whopping over 2,200 kg ( 4,900 lb ). Now about the smallest living turtle is called “ Chersobius signatus “ and lives at the South Africa area. And it none of them have measured over 10 cm long ( 3.9 in ) in length and weighing a tiny 172 g ( 6.12 oz ). It was so light that they had to measure it in to oz instead of lb because it would be too tiny of an amount.

The Turtles shell.

The shell of a turtle is very unique among the vertebrates and serves to protect the animal and provides them shelter from the elements of rain and predators and more. It is primarily made out of around 50 to around 60 bones and consists of two parts. The “ domed, “ The “ dorsal ( back ) “ and the “ flatter, “ and the “ ventral “ ( the belly ) plastron. They are connected by lateral ( side ) extensions of the plastron.

The carapace is fused with the vertebrae and ribs while the plastron is formed from the bones of the shoulder girdle, sternum, and the gastralia ( abdominal ribs ). During the development of the ribs, the ribs grow sideways into a carapacial ridge, unique to turtles, entering the dermis ( inner skin ) of the back to support the carapace of the turtle shell. The development is signaled locally by proteins knowns as the “ fibroblast growth factors “ that include “ FGF10. “ The shoulder girdle in turtles is actually only made up of two bones, the scapula, and the coracoid. Both the shoulders and pelvic girdles of turtles are located within the shell and hence are effectively actually within the rib cage. The trunk ribs in the shell grow over the shoulder girdle during the development of the turtle.

The shell is covered in epidermal ( the outer skin ) scales known as “ scutes “ that are actually made out of the material “ keratin “, the same substance that makes up their hair and fingernails. Typically, a turtle has 38 scutes ( the scales ) on the carapace and 16 on the plastron, giving them a total of 54 total scutes on their shell. Carapace scutes are divided into “ marginals “ around the margin and “ vertebrals “ over the “ vertebral “ column though the scutes that overlay their necks are actually called a “ cervical “. “ Pleurals “ are presented between the marginals and also the vertebrals. Plastron scutes also include the gulars ( the throat ), humerals, pectorals, abdominals, and finally the anals for the last one. Side necked turtles additionally have “ intergular “ scutes between their gulars ( the throat of their bodies ). Turtle scutes are usually structured like mosaic tiles like the mosaic arts it looks like that. But some species of turtles, for example like the hawk’s bill sea turtles, have actually been overlapping scutes around on the carapace.

The shapes of turtle shells vary with the adaptions of the individual species of turtles, and maybe something it has to something with their gender. Land dwelling turtles are more dome shaped, which makes them appear to make them more resistant to being crushed by large things like large predators or animals to go over them.  Aquatic turtles which go into the ocean have a flatter and more smoothed out shells than other turtles which allows them to cut through the water easier. Sea turtles in particular have stream lined shells that reduce drag and increase stability in the out and open ocean. Some turtle species have a pointy or you can say spiky shell that provides them with extra protection from predators near by and can also camouflage them against the leafy and green grass. The lumps of a tortoise shell can tilt its body when it gets flipped over so it doesn’t get stuck, and so it allows its self to flip back to the original side. In male tortoises, the tip of the plastron is thickened and used for butting and ramming during combat with another predator or animal.

Shells can vary in flexibility. For example, some species, such as the box turtles, lack the lateral extensions of a normal turtle and instead have the carapace bones fully fused or “ ankylosed “ together. Several species have hinges on their shells, usually on  the plastron, which allows them to go expand their shell and contract them. Soft shell turtles have a rubbery edge, due to the loss of bones in their shells. For example, the leather back turtle has hardly any bones in its shell, but it does have a thick “ connective tissue “ and an outer layer of leathery skin.

Head and Neck of the turtle.

The turtle’s skull is very unique among the living amniotes ( which also includes reptiles, birds and mammals ), it Is a sold and rigid with no openings for muscle attachment ( temporal fenestrae ).  Muscles instead attach to the back of the recess’s skull. Turtles’ skull can vary in many shapes, from the long and narrow skulls of the soft shell turtles to broad and flattened skull of the “ mata mata “. Some turtle species have developed large and very thick heads, which are allowing them for a greater muscle mass and stronger bites.

Turtles are carnivorous or durophagous (eating hard shelled animals ) have the most powerful bites. For example, the “ durophagous “ Meso clemmys nasuta has an insane bite force of 432 lb force ( 1,920 N ). Species that are insectivorous, piscivorous ( fish eating ), or omnivorous have a lower bite force. Living turtles just lack the teeth but for cutting meat, serrations for clipping pants, or broading plates for breaking mollusks.

The neck of turtles  is highly flexible, possibly to compensate for their rigid shells. Some species, like sea turtles have a very short neck while others, such as snake necked turtles, as by its name has very long necks. Despite this, all turtle species have eight neck verte brae no matter anything, a consistency not found in other reptiles but similar to mammals. Some snaked necked turtles “ the long neck turtles “ have both long necks and large heads, limiting their ability to be able to lift them when they are not in the water. Some turtles have folded structures in the larynx or glottis that vibrate to produce sound. Other species have elastin rich vocal cords.

Limbs and Locomotion

Due to the turtles very heavy shells, turtles are moving in like slow mo on land. A desert tortoise only moves at a very slow pace at 0.22 – 0.48 km/h ( 0.14 – 0.30 mph ). By contrast, sea turtles can swim up to 30 km/h ( 19 mph ). The limbs of turtles are adapted for various means of locomotion and habits and most have five toes. Tortoises are specialized for terrestrial environments and can have like column like eggs with feet just like elephant and short toes. The gopher tortoise has very flat  / flattened front limbs for digging in the substrate. Freshwater turtles have more flexible legs and longer toes with webbing, which gives them the thrush in the water. Some species, or such as the snapping turtles and also the mud turtles, mainly walk along the bottom of the water, as they would on land. Other such as terrapins, they swim by paddling with all of their four limbs, switching between opposing front and hind limbs, which keeps their direction stable.

Sea turtles and the pig nosed turtle are the most specialized for swimming. Their front limbs have evolved over time into flippers while the shorter hind is shaped more like rudders. The front limbs provide most of the thrust and the movement for swimming. While the front limbs provide the movement the hind limbs are mostly used for stabling them. Sea turtles such as the green sea turtle rotate the front limb flippers just like a bird wing to produce a propulsive force on both the upstroke and on the downstroke. This is in contrast to similar sized fresh water turtles ( measurements having been made on young animals in each case ) such as the “ Caspian Turtle “, Which use the front limbs the oars of a rowing boat, creating substantial negative thrust on the recovery stroke in each cycle. In addition, the steam lining of the marine turtles reduces drag. As the result of that, Marine turtles produce a propulsive force twice as large, and swim six times ass fast, as fresh water turtles. The swimming efficiency of young marine turtles is similar to that of fast swimming fish of open water, just like the “ mackerel “.

Compared to other reptiles, turtles tend to have a reduced tail, but these vary in both length and also thickness among other species and between genders. Snapping turtles and the big headed turtle have longer tails; the latter uses it for balance while climbing.

Senses

Turtles make use of vision to find food and mates, avoid predators, and also to orient themselves. The retina’s light sensitive cells include both rods for vision in low light, and cones with three different photopigments for bright light, where they have full color in their vision. There is possibly a fourth type of cone that detects “ ultra violet “ which as hatchling sea turtles respond experimentally to “ ultra violet “ light but it is unknown if they can distinguish this from longer wave lengths. A Fresh water turtle, the red eared slider, has an exceptional seven types of cone cell.

Sea turtles orient themselves on land by night, using visual features detected in dim light. They can use their eyes in clear surface water. Unlike in terrestrial turtles, the cornea, the curved surface that lets light into the eye, does not help to focus light on the retina, so focusing underwater for turtles are fully handled entirely by the lens, behind the cornea. The cone cells contain oil droplets placed tot shift perception toward the red part of the spectrum, improving color discrimination. Visual acuity, studied in hatchling, is the highest in a horizontal band with retinal cells packed about twice as densely as elsewhere. This gives the best vision for the turtle along with the visual horizon. Sea turtles do not appear to use the “ polarized light “  for orientation as like many other animals do. The deep diving leather back turtles lack specific adaptations to low light, such as large eyes, large lenses, or a reflective tapetum. It may rely on seeing the bioluminescence of prey when hunting in deep water.

Turtles have no ear openings; for example, the ear drum is covered with their scales and encircled by a bony “ otic capsule “, which is absent in other reptiles. Their hearing thresholds are high in comparison to other reptiles, reaching up to 500 HZ in air, but when they are underwater, they are more attuned to a lower frequency. The logger head sea turtle has been shown experimentally to respond to low sounds, with maximal sensitivity between to a low hertz of only 100 hz and 400 hz.

Turtles have “ olfactory “ ( smell ) and vomeronasal receptors along the nasal cavity, the atter of which re used to detect chemical signals. Experiments on green sea turtles showed they could learn to respond to a selection of different odorant chemicals such as the “ triethylamine “ and also the “ cinnamaldehyde “, which were to be detected by olfaction in the nose. Such signals could be used in navigation.

Breathing

The rigid shell of turtles is not capable of expanding and making room for the lungs, as in amniotes, so they had to evolve a special adaption for respiration. The lungs of a turtle have connected directly to the carapace above while below, connective tissue attaches them to the organs. They have multiple lateral ( their side ) and medial ( their middle ) chambers ( this number of which varies between species ) and one terminal ( the end ) chamber.

The lungs are ventilated using specific groups of abdominal muscles connected to the organs that pull and push on them. Specifically, the turtles large liver is the one that actually compresses the lungs. Underneath the lungs, in the coelomic cavity, coelomic cavity, the liver is connected to the right lung by the root, and the stomach is directly attached to the left lung, and to the liver by a mesentery. When the liver is pulled out, it starts inhale called inhalation and so it begins. Supporting the lungs is a wall or a septum, which is thought to prevent them from able to collapse. During exhalation, the contraction of the “ transversus abdominis muscle “ propels the organs into the lungs and expels air. Conversely, during the inhalation of the turtle, the relaxing and flattening of the oblique abdominis muscle pulls the transversus back down, so it is able to allow the air back into the lungs.

Although many turtles spend large amounts of their lives underwater, all turtles breathe air and must surface on to the land or into the air to be able to refill their lungs. Depending on the species, immersion periods vary between to a minute all the way up to an hour. Some species can respire through the cloaca, which contains large sacs that are line with many finger like projections that take up dissolved oxygen from the water.

Circulation

Turtles share the link circulatory and pulmonary ( the lungs ) systems of vertebrates, where the three chambered heart pumps deoxygenated blood through  the lungs and the pumps the returned oxygenated blood through the body tissues of the turtle. The cardiopulmonary system has both structural and physiological adaptations that distinguish it from other vertebrates. Turtles have large lung volume and are able to move their blood through non pulmonary blood vessels, including some within the parts of the heart, to avoid the lungs while they are not breathing. They can hold their breath for long that usual sometimes, by when they are not breathing underwater, they can breathe longer times than some other reptiles and they can tolerate the resulting low oxygen levels. They can moderate  the increase in acidity during anaerobic ( non oxygen based ) respiration by chemical buffering and they can lie dormants for months in aestivation or brumation.

The heart actually has two atria but only one ventricle. The ventricle is subdivided into three chambers. A Muscular ridge part which is able to enables a complex  pattern of blood flow so that blood can be directed either the lungs via the pulmonary artery, or to the body via the aorta. The ability to separate the two outflows varies between species and kinds. As for example, the leatherback has a powerful muscular ridge enabling almost complete separation of the outflows, supporting its actively swimming lifestyle. The ridge is less well developed in the fresh water like freshwater turtles and like the sliders too ( Trachemys ).

Turtles are capable of enduring periods of anaerobic respiration longer than many other vertebrates. This process breaks down sugars incompletely to lactic acid, rather than all the way to carbon dioxide and water as in aerobic ( oxygen based respiration ). They make use of the shell as a source of additional buffering agents for combating increased acidity, and as a sink for lactic acid.

Osmoregulation

In sea turtles, the bladder of theirs is one unit and in most freshwater turtles it is double lobed. Sea turtle’s bladders are connected to two small accessory bladders, located at the side of the neck of the urinary bladder and also the pubis. Arid living tortoises  have bladders that serve as reserves of water, storing up to 20% of their body weight in fluids. They fluids and normally low in “ solutes “ but higher during the droughts when the reptile gains potassium salts from its plant diet. The bladder actually stores these types of salts until the tortoise find fresh drinking water to be able to  get hydrated again. To regulate the amount of salt in their bodies, sea turtles and “ diamond back terrapins “ secrete excess salt in their thick sticky substance from their tea gland. Because of this, sea turtles may appear to look “ crying “ when on land but they are actually not.

Thermoregulation

Turtles, like other reptiles, have a limited ability to regulate their body temperature, this ability can be able to vary between different species and with their body size. Small pond turtles are able to regulate their temperature by crawling out the water and basking in the sun, while the small terrestrial turtles move between sunny and shady places to be able to adjust their temperature to keep warm. Large species for example both terrestrial and marine have sufficient mass to give them substantial thermal inertia, meaning that they heat up or cool down over many hours. For another example, the Aldabra giant tortoise can weigh up to some 60 kgs ( 130 lb ) and is able to allow its temperature to rise to a hot temperature of 33 C ( 91 F ) on a hot day and to naturally around 29 C ( 84 F ) by night. Some giant tortoises seek out shade to avoid overheating on sunny days. On the Grand Terre Island, food is scarce on the land, shade is scarce near the cost, and the tortoises compete for space under the few trees on hot days. Large males may push smaller females out of the shade, and some sadly overnight and sadly die on the island.

Adult sea turtles, have large enough bodies that they can to some extent control their temperature. The largest turtle known as the leatherback can swim in the waters off Nova Scotia, which can be as cold as 8 C ( 46 F ), while their body temperature has been measured at up to 12 C ( 54 F )  warmer than the water surrounding the area. To help keep their body temperature up, they have a system of counter current head exchange in the blood vessels between their body core and their skin on the flippers that they use. The vessels supply the head by the fat around their neck.

 

Behaviours

Diet and feeding

Most turtle species are opportunistic omnivores, land-dwelling species are most herbivorous, and aquatic ones are more carnivorous. Generally lacking speed and agility, most turtles fed either on plant material or on animals with very limited movements just like larvae, worms, mollusks and more. Some species, such as the African helmeted turtle and snapping turtles, eat fish, amphibians, reptiles ( also including the other turtles too ), birds, and mammals. They may take them by ambush but also scavenge. The alligator snapping turtle has a worm-like appendage on its tongue area that they use to lure fish into its mouth. Tortoises are the most herbivorous group, mostly consuming grasses, leaves, and fruits. Many turtle species, including tortoises, supplement their diet with eggshells, animal bones, hair, and droppings for extra nutrients.

Turtles generally eat their food in a straight forward way, though some species have special feeding techniques to eat their food. The yellow-spotted river turtle and the painted turtle may need a filter feed by skimming threw the water surface with their mouth and throat open to collect particles of food. When the mouth closes, the throat constricts, and the water is pushed out through the nostrils and the gap in between the jaws. Some species employ a “ gape and suck method ” where the turtle opens its jaws and expands its throat widely, sucking the prey in.

The diet of an individual within a species may change with the age, gender, and also then seasons, and may also differ between the population of the turtle species. In many species, juveniles are generally carnivorous but become more herbivorous as adults. With Barbour’s map turtle, the larger female mainly eats mollusks while the male usually eats arthropods. Blanding’s turtle may feed mainly on snails or crayfish, but it mostly depends on the population. The European Pond turtle has been recorded as being the most carnivore when eating most of the time the past year but switching to water lilies during the summer. Some species have developed specialized diets such as the hawksbill, which usually eats sponges which is very weird and then the leatherback which usually feeds on jellyfish, and the Mekong snail-eating turtle.

Communication and Intelligence

While popularly thought of as mute, turtles make various types of sounds to be able to communicate with other turtles. Tortoises may bellow when courting and mating. Various species of both freshwater and sea turtles emit short, low-frequency calls to others from the time they are in the egg to when they are adults. These vocalizations may serve to create group cohesion when migrating. The oblong turtle has a particularly large and loud vocal range; able to produce sounds described as clacks, clicks, squawks, hoots, various kinds of chirps, wails,  hooos grunts, growls, blow, bursts, hows, and finally drum rolls from just that one species oblong turtle.

Play behavior has been documented in some turtle species. In the laboratory, Florida “ red bellied “ cooters can learn novel tasks and have demonstrated a long-term memory that can stay for at least a whopping 7.5 months to stay in their brain. Similarly, giant tortoises can learn and remember tasks and master lessons much faster when they are trained in groups together. Tortoises appear to be able to retain operant conditioning up to nine years after their initial training learning how to do it and that is just crazy for an animal or a tortoise to be able to remember something for 9 years after their initial learning lesson group together.

Defense

When turtles sense danger, some turtles may flee the scene and hide some where, or some will just freeze and stay still till the danger is gone or it goes away or withdraws into their shell to be able to hide away from danger. Freshwater turtles are able to flee into the water because they are fresh “ water “ turtles, though the Sonora mud turtle may take refuge on land as the shallow temporary ponds they inhabit makes them vulnerable. When startled, a soft shell turtle may dive underwater in a pond or a sea and bury itself on the floor of the pond / sea to be able to hide away from the danger. If a predator persists, the turtle may bite or discharge from its cloaca. Several species produce foul-smelling chemicals from musk glands to be able to get the predator away or the danger around them. Other tactics include threat displays and “ Bel’s hinge-back tortoises “ can play dead when there are predators around them so they won’t go after them just like what most people do when they see a certain time of bear but this time the turtle will do it to get the predator away and for them to not to eat them. For the big-headed turtle when they get attacked, they usually squeal and possibly try to make the predator start to startle.

Migration

Turtles are the only reptiles that migrate long distances, more specifically the marine species that can travel up to thousands and thousands of kilometers. Some non marine turtles, such as the species of “ Geochelone “ ( terrestrial turtle ), “ Chelydra “ ( freshwater turtle ), and the “ Malaclemys “ ( estuarine turtle ), migrate seasonally over much shorter distances, to up around 27 km ( which is 17 mi ) to lay their eggs. Such short migrations are comparable to those of some lizards, snakes, and crocodilians. Sea turtles’ nest in areas in specific like a beach, leaving the eggs to be hatched unattended. The young turtles leave that area, migrating long distances in the few years to decades in which they will start growing to maturity and then seemingly return to the same exact area to find a turtle to mate and to lay eggs to where they were born, though the precision varies between species and populations. This “ natal homing “ has appeared to remarkable to biologists, though there is now plentiful evidence for it, including the genetics.

How sea turtles navigate to their breeding beaches right now are still remained unknown to scientists to find their exact beach. One possibility is imprinting as in salmon, where the young learn the chemical signature, effectively the scent, of their home waters before leaving, and remember that when the time comes for them to return as adults. Another possible way for them to remember is the orientation of the earth’s magnetic field at the natal beach. There is evidence which is still experimental that turtles have an effective magnetic sense of the earth magnetic field, and that they use this in navigation to find their beach where they were born. Proof that homing occurs is derived from genetic analysis of populations of loggerheads, hawksbills, leatherbacks, and also the olive ridleys by nesting place. For each of these species, the population in different places have their own DNA called the “ mitochondrial DNA “ genetic signatures that persist over the past years. This shows that the populations are distinct, and that homing must be occurring reliably.

Reproduction and lifecycles

Turtles have a wide variety of mating behaviours but do not form pair-bonds or social groups. In green sea turtles, female generally outnumber the males in turtles. In terrestrial species,  males are often larger than females and fighting between males establishes a dominance hierarchy for access to mates. For most semi-aquatic and bottom-walking aquatic species, combat occurs less often. Males of these type of species instead may use their size as an advantage to mate forcibly with the females. In fully aquatic species, males are often smaller than the female’s species of the type of turtle and rely on the courtship displays to gain mating access to females.

Courtship and mounting

Courtship varies between species, and with habitat. It is often complex for the aquatic species, both marine and freshwater, but simpler in the semi-aquatic mud turtles and snapping turtles. A male tortoise bobs his head to then subdues the female by biting her and butting her before mounting. Another turtle called the scorpion mud turtle male approaches the female from the rear side of her, and often resorts to aggressive methods such as biting the female’s tail or hind limbs, followed by a mounting.

Female choice is important in some of the species, and the female green sea turtles are not always as receptive. As such they have evolved many times about their behaviours about to avoid the males attempts at copulation, such as swimming away from them, confronting the male followed by biting them, or taking up a refusal position with her body turning vertically, her limbs widely outspread, her plastron facing the male. If the water is too shallow for the refusal position, The female likes to resort to another way of rejecting him by resorting to beaching themselves, as the males do not follow the females to the shore area.

All turtles fertilize internally; mounting and copulation can be difficult. In many types of species, males have a concave plastron that interlocks with the female’s carapace. In species just like the “ Russian Tortoises “, the male has a lighter shell and also long legs than usual. The high, rounded shape of like a box turtle is a particular obstacle for mounting. The male “ eastern box turtle “ leans backward and likes to hook onto the back of the female turtle plastron. Aquatic turtles mount into the water, and female sea turtles support the mounting male while swimming and digging. During the copulation, the male turtle aligns his tail with the females so they both can do the thing together to be able to make babies. And some females can store multiple sperms from multiple turtles so that the egg clutches and can have multiple sires of turtles or tortoises I forgot what I was writing about now, but I think its turtles maybe.

Eggs and hatchlings

Turtles, including sea turtles, they like to lay their eggs on land, although some eggs close near water that rises and falls in level, submerging the eggs. While most species build nests and lay eggs where they forage, some travel miles. The common all knowing snapping turtles only walks around 5 km ( 3 mi ) on land, while on the other hand sea turtles can swim further; and finally, the leatherback can swim up to 12,000 km ( 7500 mi ) to its nesting beaches. Most turtles like to create a nest for their eggs. Female choose nesting locations based ono  the environmental factors such as the temperature of the area, and the humidity of the area, what are very important for the eggs to develop embryos. Depending on the species, the number of eggs laid varies from one to over 100. Larger females can lay eggs that are greater in number or bigger in size. Compared to freshwater turtles, tortoises only lay fewer eggs, but they are larger eggs. Females can lay multiple turtles throughout the season, particularly in species that experience unpredictable monsoons.

Most mother turtles do no more in the way of parental care than covering their eggs and then right after covering they leave immediately, though some species of turtles they like to guard their nest of eggs for days or weeks. Eggs vary between rounded, oval, elongated, and between if it’s a hard egg or a soft shelled egg. Most species have their gender determined by their temperature. In some species, higher temperature produces females and also cold temperature also produce extreme amounts of females just like the higher temperature and then mild temperature likes to produce males. There is a experimental evidence that the embryos of “ Mauremys reevesii “ can move around inside their eggs to select the best temperature for development, thus influencing their sexual destiny. In other species, gender is determined genetically. The length of incubation for turtle eggs varies from two to three months for temperature species, and four months to over a year for tropical species. Species that live in the warm temperature climates can delay their development.

Hatchlings young turtles likes to break out of their eggs while using an egg tooth, a sharp projection that exists temporarily on their upper beak of their mouth. Hatchlings dig themselves out of the nest and finally find some safety in vegetation or water. Some species stay in the  nest for longer, be it for overwintering or to wait for the rain to loosen the soil for them to dig out. Young turtles are highly vulnerable to predators because of their defensive less acts and how small they are. Mortality is very high  during this period of time but significantly decreases when they reach the adulthood of their stage of species. Most species grow quickly during their young years, and they slow down aging when they start to mature in their life.

Lifespan

Turtles can live a very long life. As the oldest living turtle and land animal is said to be called the “ Seychelles giant tortoise “ named Jonathan, which turned 187 years old in 2019. A Galapagos tortoises named Harriet was collected by Charles Darwin in 1836; it sadly died in 2006 at the age of 176 years old. Most wild turtles never reach that age most of the times. Turtles keep growing new scutes under the previous scutes every year, allowing researchers to estimate how long they live for. They also age very slowly. The survival rate for adult turtles can reach all the way up to 99% per year.

 

Systematics and evolution

Fossil History

Zoologists have south to explain how the evolutionary origins of the turtles, and in particular about their unique shells. In 1914, Jan Versluys proposed that bony plates in the dermis, called osteoderms, fused into the ribs beneath them, later called “ Pola Dot Ancestor “ by Olivier Rieppel. The theory accounted for the evolution of fossils Pareiasaurus from Bradysarus to Anthodon, but not for how the ribs could have become attached to the bony dermal plates.

More recent discoveries nowadays they have painted a new different scenario for the evolution of the turtle’s shell. The stem-turtles Euntosarus of the Middle Permian, Pappochelys of the Middle Triassic, and Eorhynchochelys of the Late Triassic lacked carapaces and plastrons but had shortened torsos, expanded ribs, and lengthened dorsal vertebrae. Also in the Late Triassic, Odontochelys had a partial consisting of a complete bony plastron and an incomplete carapace. The development of a shell reached competition with the Late Triassic Proganochelys, with its fully developed carapace and plastron. Adaptions that lead to the evolution of the sell may have originally been for digging and a fossorial lifestyle.

The oldest known members of the Pleurodira lineage are the Platychelyidae, from the Late Jurassic. The oldest known unambiguous cryptodie is Sinaspideretes, a close relative of soft shell turtles, from the Late Jurassic of China. During the Late Cretaceuous and Cenozoic, members of the pleurdie families Both Emydidae and Podocnemidid became widely distributed in the Northern Hemisphere due to their coastal habits. The oldest known soft shelled turtles and sea turtles appeared during  the Early Cretaceous. Tortoises originated in Asia during the Eocene. A late surviving group of stem turtles, called the " Meiolaniidae “, survived in Australasia into the Pleistocene and Holocene.

External relationships

The turtle’s exact ancestry has been disputed. It was believed they were the only living surviving branch of the ancient evolutionary grade Anapsida, which includes group such as the “ procolophonids and “ pareiasaurs. All anapsid skulls lack the temporal opening while the other living amniotes have  temporal opening. It was later suggested from the people that the anapsid like turtle’s skull may be due to the backward evolution rather than to the anapsid descent. Fossil evidence has shown that early  stem turtles possessed small temporal openings.

Some early morphological phylogenetic studies have placed turtles closer to Lepidosauria ( tuataras, lizard, and also snakes ) than to Archosauria ( crocodilians and birds too ). By contrast, several molecular studies place turtles within the Archosauria, or more commonly as like a sister group to extant archosaurs, although an analysis conducted by the person Tyler Lyson and colleagues at ( 2012 ) decided to do an experience and analysed 248 nuclear genes from  16 vertebrates and suggested that the turtles share a more recent common ancestor with birds and also crocodilian. The date of separation of turtles and birds and crocodilians are estimated to go all the way back up to 255 million years ago during the Permian!! Through the genomic scale phylogenetic study of ultra conserved elements ( UCEs ) to clarify that the placement of the turtles within the reptiles, Nicholas Crawford, and colleagues ( at 2012 ) similarly found that turtles are closer to birds than the crocodilians that they are also related too.

Using the draft ( unfinished ) genome sequences of the green see turtle and the Chinese soft shell turtle, Zhuo Wang, and colleagues ( 2013 ) concluded that the turtles are likely a sister group of crocodilians and birds. The external phylogeny of the turtles is shown in the cladogram below this text.

Internal relationships

Modern turtles and they extinct relatives with a complete shell are classified within the clade “ Testudinata “. The most recent common ancestor of the living turtles, corresponding to the split between the Pleurodira ( the side necked species ) and also the Late Triassic. Robert Thompson and the colleagues ( at 2021 ) comment that living turtles have a low diversity, relative to how long they have been existing for. Diversity has been able to stable, ,according to their analysis except for a single rapid increase around the so called Eocene Oligoecene Boundary  some 30 million years ago, and a large regional extinction at roughly the same time. They suggest that global climate change has caused both of those events, as the cooling and drying of the land to become more arid and the turtles to become more extinct there, while new continental margins opened up by the climate change ahs provided habitats for the other species to start evolving.

The cladogram, from Nicholas Crawford and colleagues 2015, shows the internal phylogeny of the Testudines down to the level of the families. The analysis by Thompson and the colleagues in 2021 supports the same structure to down to the family level.

Differences between the two suborders

Turtles are divided into two living suborders: Cryptodira and Pleurodira. The two groups that I just said differs in the way that their neck is retracted for their protection. Pleurodirans retracts their neck to their side and in front of the shoulder girdles area, where as the cryptodirans retract their neck in a backward position into their shell. These motions are enabled by the morphology and arrangement of their neck vertebrae. Sea turtles (  which belongs to the Cryptodira ) have mostly lost the ability to retract their heads.

The adductor muscles in the lower area of their jaws create a pulley like system in both of their subgroups. However, the bones that the muscles articulate with differ. For example, in Pleurodira the pully is formed with the pterygoid bones of the palate, but on the other hand the Cryptodira the pully is formed instead of its pterygoid bones it is formed with its otic capsule. Both systems help to vertically redirect the adductor muscles and maintain such a powerful bite.

A further difference between the suborders is the attachment of the pelvis. Like in Cryptodira, the pelvis is free, linked to the shell already only by the ligaments. But for Pleurodira, the pelvis is sutured, joined with bony connections, to the carapace and to the plastron, creating a pair of large columns of the bone at the back and the end of the turtle’s area, linking the two parts to the shell.

Distribution and habitat

Turtles are widely distributed across the world’s continents, the oceans, and also the islands with terrestrial, fully aquatic, and also the semi aquatic species. Sea turtles are mainly tropical and een also subtropical, but the leatherbacks turtle can be found in the colder climates or the colder area than usual like in the parts of the Atlantic and the Pacific Ocean. Living Pleurodira all lie in the fresh water areas and are found only in the Southern Hemisphere area. The Cryptodira include terrestrial, fresh water, and also the marine species, and these range more widely. The world regions richest non marine turtle’s species is called the Amazon basin, found by the gulf area of Mexico drainages of the United States and also parts of the south and southeast Asia parts.

For turtles in the colder climates area, their distribution is limited by the constraints on about their reproduction, which is reduced by the long hibernations. North American species can barely range by just above the Southern Canadian border. Some turtles are found even at high altitudes. Just for an example, the species “ Terrapene ornate “ can be found all the way up to 2,000 m ( 6,600 ft ) in New Mexico. Conversely, the leatherback sea turtle can even dive over 1,200 m ( 3,900 ft ). Species of the genus “ Gopherus “ can tolerate both below freezing temperatures and even over 40 C ( 104 F ) which is very hot in body temperature, though they are mostly active around the 26 Celcius ( 79 f ) to all the way to 34 C ( 93 F ) temperature area. Which is very warm for the average fish species and that they can survive water under the temperature over freezing temperature is crazy for a turtle so yeah that is very crazy.

Conservation

Among many vertebrates, turtles are only the second to primates in the percentage of threatened species. For specifics 360 modern species have existed since the 1500 AD. Of these 51 to 56% are considered threatened and the other 60% is consider threatened or extinct. Turtles are facing many dangers and threats ahead of them in this modern time for example like their habitat areas being destroyed by us human kind from global warming and climate change, harvesting for consumption, pet trade, light pollution. Asian species have a particularly high extinction risk, primarily due to their long term unsustainable exploitation for their food and medicine. And about a high amount of 83% of Asia’s non marine turtle species are considered threatened. As of 2021 a year ago, the turtle extinction is progressing much faster than before when the Cretaceous Tertiary extinction. At this rate all turtles could be extinct all species in just a few centuries which is very fast saying that turtles have been around of centuries even before the 1500 AD.

Turtle’s hatcheries can be set up when protection against for example like flooding, erosion, predation, or heavy poaching are required for protecting them. Chinese markets have south to satisfy an increasing demand for turtle meat with farmed turtles which is also a reason why turtles are going extinct. All the same, wild turtles are still continuing to be caught by other people being sent to markets to be sold at in large amounts of meat, resulting in what conservationists have called “ the Asian turtle crisis “. In the words of the biologist named George Amato, the hunting of turtles “ vacuumed up the entire species from areas in the Southeast Asia area ”, even as the biologists still don’t know how many species live in the region. In 2000, all of the Asian box turtles were placed on the CITIES list of the endangered animals not to kill them and not the eat them for the meat even though the high demand for it.

Harvesting wild turtles is some of what legal is some American states, and there has been a growing demand for American turtles in China. For example, The Florida Fish and Wildlife Conservation Commission estimated in 2008 that around 3,000 pounds of softshell turtles were exported weekly in the Tampa International Airport. However, the great majority of the turtles exported from the US between the time frame of 2002 to 2005 were framed.

Large numbers of sea turtles were accidently killed in the longlines, gillnets, and also the trawling nets as bycatch. A 2010 study suggested that around or over 8 million turtles have been killed in just the short amount of time during 1990 to 2008. In just nearly 2 decades they were able to kill 8 million turtles which are now what are causing the issue in 2021 and 2022 right now. The Eastern Pacific and the Mediterranean were identified as among the areas worst affected right now. Since the 1980’s, the United States has required all shrimp trawlers to fit their nets with the turtle excluder devices that prevents turtles from being tangled by the nets and getting stuck and sadly drowning in the water. More locally, other than that other human activities are affecting the marine turtles. For example, in Australia the Queensland’s shark culling program, which uses shark nets and drum lines, has sadly killed over 5,000 turtles as bycatch between the span of 1962 to 2015; which also includes 719 loggerhead turtles and 33 hawksbill sea turtles, which are listed as very critically endangered. It is isn’t as much as the 8 million turtles killed over the 2 decades of 1990 to 2008 but still 5,000 turtles is still a lot and very crucial to nowadays population of the amount of turtles and the demand for the meat of the turtles and the endangered species of the turtles all of them and nearly endangered and all can be extinct in just a few centuries.

Native turtle populations can also be threatened by the invasive ones. The central North American red eared slider turtle has been listed as the a “ world’s worst invasive species “, pet turtle having been released globally they appear to complete with native turtle species in eastern and western of the North America, Europe, and also Japan.

Human Uses

Turtles have been in many humans cultures all across the world since the ancient times. They are generally vied positively despite not being that “ cuddly “ nor “ flashy “, their association with the ancient times and old games have contributed with their now endearing image.

THIS IS BASED ON MYTHOLOGY ( believe if you want or not )

In Hindu mythology, the World Turtle, named Kurma or you can say Kacchapa, supports four elephants on his back, they, in turn, carry the weight of the whole world on their backs. The turtle is one of the ten avatars on incarnations of the god called as the “ Vishnu “. The yoga pose Kurmasana is named for the avatar. World turtles are found in Native American cultures including that Algonquian, The Iroquois, and also the Lenape. They tell many versions of the creation of the story of the turtle Island. One version of the turtle island has a Muskrat pile up earth on the Turtle’s back, creating the continent of North America. An Iroquois version has the Sky Woman fall through a hole in the sky between the tree roots where she was caught by the birds who landed her safely on the Turtle’s back; the Earth grows around here the turtle here is altruistic, but the world is a heavy burden and the turtles sometimes shakes itself to relieve the load, causing the earth quakes.

A turtle was the symbol of the Ancient Mesopotamian god Enki from the 3^rd millennium BCE onward. An ancient Greek origin myth was told only the tortoises refused the invitation of the gods Zeus and Hera to their wedding, as it preferred to stay at home. Zeus then order it to carry its house with it ever after. Another of their gods, Hermes, invented a seven stringed Iyre made with the shell of a tortoise. In the Shang dynasty Chinese practice using the oldest known form of the Chinese characters, burning the plastron, and interpreting the resulting cracks. Later, the turtle was one of the four sacred animals in the Confucianism, while in the Han period steles were mounted on top of stone turtles, later linked with the Bixi, the turtle shelled son of the Dragon King. Marine turtles feature significantly in Australian Aboriginal art. The army of the Ancient Rome used the testudo ( other words it means “ turtles “ ) formation where the soldiers would form a shield wall for protection.

In Aesop’s Fables, “ The tortoises and the Hare” tells how unequal race may be won by the slower partner. Lewis Carroll’s 1865 Alice’s Adventures in Wonderland features a Mock Turtle, named for a soup meant to imitate the expensive made from real turtle meat. In 1896, The French playwright named Leon Gandillot wrote a comedy in three acts named as the Lay Tortue that was “ a Parisian sensation “ in its run in France and came to Manhattan Theatre, Broadway, New York, in 1988 as “ The Turtle “. A “ cosmic turtle “ and the island motif reappear in Gary Snyder’s 1974 novel called Turtle Island, and again in Terry Pratchett’s Discworld series as the Great A’Tuin, starting with the 1983 novel called  “ The Colour of Magic “. It is supposedly of the species Chelys glactica the galactic turtle, complete with four elephants on its back to support Discworld. Turtles have been featured in many comic books and a lot of animations such as the 1984 well known the Teenage Mutant Ninja Turtles.

As pets

Some turtles, particularly small terrestrial and freshwater species, are kept as pets for people. The demand for turtles as pets has increased widely in the 1950’s, with the US being the main supplier, particularly of farm bred red eared sliders. The popularity for exotic animals as their pets has led to an increase in illegal wildlife trafficking. Around 21% of the value of the live animal’s trade is in reptiles, and turtles are supposedly the more popular traded species in the trade market. Poor husbandry of tortoises can cause chronic rhinitis ( nasal swelling ), overgrown beaks, hyperparathyroidism ( which often softens their skeletons ), constipation, various reproductive problems, and injuries from dogs. In the early 20^th century people in the United States have organized and gambled on the turtle races.