Instruct: Given a question, retrieve documents that can help answer the question.
Query: How many species of turtle are there?
Turtles are diapsids of the order Testudines (or Chelonii[3]) characterized by a special bony or cartilaginous shell developed from their ribs and acting as a shield.[4] "Turtle" may refer to the order as a whole (American English) or to fresh-water and sea-dwelling testudines (British English).[5] The order Testudines includes both extant (living) and extinct species. The earliest known members of this group date from million years ago,[1][6] making turtles one of the oldest reptile groups and a more ancient group than snakes or crocodilians. Of the 356 known species[2] alive today, some are highly endangered.[2]
In many jurisdictions, turtle soup is illegal because many species of turtle are listed as threatened or endangered, and cannot legally be captured, let alone killed. Generally speaking, turtle populations cannot quickly recover from the loss of a breeding adult; thus, killing these turtles to make soup can depress populations below sustainable levels.
The Chinese softshell turtle is the most commonly raised species in China's turtle farms. According to the data obtained from 684 Chinese turtle farms, they sold over 91 million turtles of this species every year; considering that these farms represented less than half of the 1,499 registered turtle farms in China, the nationwide total could be over twice as high. These turtles are considered a delicacy in many parts of Asia. Turtle soup is made from this species. In Japan, they may be stewed with hōtō noodles and served as a winter delicacy. Many Koreans, even today, generally have a taboo against eating turtles which has origins in native Korean Shamanism.
A total of 2,927 marine species have been recorded in the Spratly Sea, including 776 benthic species, 382 species of hard coral, 524 species of marine fish, 262 species of algae and sea grass, 35 species of seabirds, and 20 species of marine mammals and sea turtles. Terrestrial vegetation in the islands includes 103 species of vascular plants of magnolia branches (Magnoliophyta) of 39 families and 79 genera. The islands that do have vegetation provide important habitats for many seabirds and sea turtles. Both the green turtle ("Chelonia mydas", endangered) and the hawksbill turtle ("Eretmochelys imbricata", critically endangered) formerly occurred in numbers sufficient to support commercial exploitation. These species reportedly continue to nest even on islands inhabited by military personnel (such as Pratas) to some extent, though it is believed that their numbers have declined.
Although the common box turtle has a wide range and was once considered common, many populations are in decline as a result of a number of diverse threats. Agricultural and urban development is destroying habitat, while human fire management is degrading it. Development brings with it an additional threat in the form of increased infrastructure, as common box turtles are frequently killed on roads and highways. Collection for the international pet trade may also impact populations in some areas. The life history characteristics of the common box turtle (long lifespan and slow reproductive rate) make it particularly vulnerable to such threats. The common box turtle is therefore classified as a Vulnerable species on the IUCN Red List. The common box turtle is also listed on Appendix II of the Convention on International Trade in Endangered Species (CITES), meaning that international trade in this species should be carefully monitored to ensure it is compatible with the species’ survival. In addition, many U.S. states now regulate or prohibit the taking of this species.
Like many other box turtle species, the Florida box turtle spends an extreme majority of its life (80-90%) buried in the underbrush or underground, and their activity varies significantly at different times of the year. During the dry, cool parts of the year (November - February) they enter a dormant stage and are inactive and difficult to find. They exhibit higher levels of activity during the warm, wet months (April - October). However, unlike other species of box turtle, the Florida box turtle does not actually enter a complete state of hibernation during this time of year. This is most likely to the warm and stable temperatures throughout its Florida range. As a result, it exhibits longer annual activity than other box turtle species. It is less tolerant to colder conditions than other common box turtle subspecies.
The coastal zone, which has a long beach extending to nearly , is the nesting ground for turtles popularly known as the "beach-resting turtles (tortugas)". They are found on the beaches, and also many of these species are reported from the canal banks. The main species to lay eggs during the winter months of February to July are: hawksbill, loggerheads, green, and leatherbacks. Large parts of the park have been semi-legally clearcut, giving access to the habitat of the endangered green sea turtle. Seven species of Land turtles, the manatee or sea cow, the crocodile, and a variety of crustaceans are found here, as are 30 species of freshwater fish, gar, eel and bull shark.
This leech is found almost exclusively on the green sea turtle ("Chelonia mydas"), but it occasionally occurs on other species of turtle. A green sea turtle in the Persian Gulf was found to have about 1400 leeches of this species, about 300 in each of the axillary and inguinal areas beneath the limbs, and about 200 on the throat, in front of the intergular scute. Also present on this turtle were some crustacean eggs and many barnacles on the carapace, but the turtle did not seem inconvenienced by this burden.
Box turtles appeared "abruptly in the fossil record, essentially in modern form". The absence of strong changes in their morphology might indicate that they are a generalist species. It is therefore complicated to establish how their evolution from other turtles took place. The oldest finds of fossilized box turtles were found in Nebraska (U.S.), date from about 15 million years before present (in the Miocene) and resemble the aquatic species "T. coahuila" most, which indicates that the common ancestor was also an aquatic species. Fossilized specimens of "T. ornata" and "T. carolina" were dated circa 5 million years before present and indicated that those main lineages also already diverged within the Miocene. The only recognized extinct subspecies ("T.c. putnami") dates from the Pliocene and was, with a carapace length of , much larger than other species.
The Virgin Islands National Park covers approximately 60% of the Island of St. John and nearly all of Hassel Island. The national park has more than 140 species of birds, 302 species of fish, 7 species of amphibians and 22 species of mammals. The tropical Virgin Islands are home to a huge variety of wildlife, including many unique species endemic to the archipelago. There are three species of sea turtles in the USVI that inhabit the local waters and utilize beaches for nesting: the green sea turtle, the hawksbill sea turtle and the leatherback sea turtle. Several species of sharks, manatees and dolphins roam the seas.
The smallest turtle is the speckled padloper tortoise of South Africa. It measures no more than 8cm (3.1in) in length and weighs about 140g (4.9oz). Two other species of small turtles are the American mud turtles and musk turtles that live in an area that ranges from Canada to South America. The shell length of many species in this group is less than 13cm (5.1in) in length.
Tour de Turtles empowers audiences with ways to help combat sea turtle threats. This level of community involvement and public support has a significantly positive impact on sea turtle populations around the world. Using information gained through Tour de Turtles, the public will understand how to fight and eliminate human-caused threats to sea turtles. The scientific community also benefits All data collected will be applied to research about these endangered species and their little-known migratory patterns.
The movement of bog turtles between colonies facilitates genetic diversity. If this movement were to be prevented, or limited in any significant way, the species would have a higher likelihood of becoming extinct because genetic diversity would fall. Some aspects of a bog turtle's movement that remain unresolved include: phenomena that motivate bog turtles to move outside their natural habitat; the distances an individual can be expected to travel each day, week, and year; and how separation of small groups affects the genetics of the species.
While there are several turtle species at risk, the loggerhead sea turtle ("Caretta caretta"), which made the IUCU endangered animals list in 1996, and the leatherback sea turtle ("Dermochelys coriacea") which has been experiencing a decline in numbers, are both still being hunted or killed due to human impact. Another turtle species that can be hunted (not commercially) while considered as special concern at the Canadian and Ontarian level is the snapping turtle ("Chelydra serpentin"). Hawksbill sea turtles have been hunted for their shells primarily to make jewelry. Tourists will often buy items without being informed of the source of the material. Green sea turtles eggs are poached and eaten in many countries; this is also a tourist attraction and taking sea turtle shots, consuming raw turtle egg with whiskey or beer is popular in places like Costa Rica. 
Nearly 100 species of reptiles occur in the Eastern Ghats. Many endangered species are also present, including the mugger crocodile "(Crocodylus palustris)", Indian black turtle "(Melanochelys trijuga)", Indian flapshell turtle "(Lissemys punctata)", Indian tent turtle "(Pangshura tentoria)", Indian star tortoise "(Geochelone elegans)", Leith's softshell turtle "(Nilssonia leithii)", many of which are found in the northern rivers and riverine valley tracts.
Marine sea turtles are caught worldwide, although it is illegal to hunt most species in many countries. A great deal of intentional marine sea turtle harvests worldwide are for food. Many parts of the world have long considered sea turtles to be fine dining. Ancient Chinese texts dating to the fifth century B.C.E. describe sea turtles as exotic delicacies. Many coastal communities around the world depend on sea turtles as a source of protein, often harvesting several sea turtles at once and keeping them alive on their backs until needed. Coastal peoples gather sea turtle eggs for consumption. 
In February 2011, the Tortoise and Freshwater Turtle Specialist Group published a report about the top 25 species of turtles most likely to become extinct, with a further 40 species at very high risk of becoming extinct. This list excludes sea turtles, however, both the leatherback and the Kemp's ridley would make the top 25 list. The report is due to be updated in four years time allowing to follow the evolution of the list. Between 48 and 54% of all 328 of their species considered threatened, turtles and tortoises are at a much higher risk of extinction than many other vertebrates. Of the 263 species of freshwater and terrestrial turtles, 117 species are considered Threatened, 73 are either Endangered or Critically Endangered and 1 is Extinct. Of the 58 species belonging to the family Testudinidae, 33 species are Threatened, 18 are either Endangered or Critically Endangered, 1 is Extinct in the wild and 7 species are Extinct. 71% of all tortoise species are either gone or almost gone. Asian species are the most endangered, closely followed by the five endemic species from Madagascar. Turtles face many threats, including habitat destruction, harvesting for consumption, and the pet trade. The high extinction risk for Asian species is primarily due to the long-term unsustainable exploitation of turtles and tortoises for consumption and traditional Chinese medicine, and to a lesser extent for the international pet trade.[91]
Belize has many different species and types of turtles. There are 3 different species of Hard-Shelled Sea Turtles such as the Loggerhead, which on average is 2.3 m (7.5 ft) long and 540 kg (1190 lb.). They are found in the open oceans and coastal waters of Belize. Another is the Green Sea Turtle which on average is 1.5 m (5 m) and can weigh up to 100 kg (220 lb.). Green Sea Turtles migrates across open seas but are primarily found in shallow coastal waters. The third type of hard-shelled Sea Turtle that can be founding Belize is the Hawksbill Turtle. This sea turtle is only about 1 m (3.3 ft) and does not exceed 50 kg (110 lb.), and they are usually found near coral reefs or rocky areas of the sea. 5 species of Mud and Musk Turtles are found in the fresh water bodies of Belize: Narrow-Bridged Musk Turtles, Tabasco Mud Turtles, White-Lipped Mud Turtles, Scorpion Mud Turtles, and Mexican Giant Musk Turtles. 2 of the species of turtles that live primarily on land in Belize are the Furrowed Wood Turtle and the Slider Turtle. Some other species of turtles commonly found in Belize are Central American river turtles which live in fresh water bodies and average size is about 65 cm (25 in), and Snapping Turtles which can tolerate any type of body of water, and on average are about 47 cm (18 in).
In Canada, the spotted turtle is federally endangered, while in the United States the spotted turtle is currently under review by the Fish and Wildlife Service for protection under the Endangered Species Act. It is listed by the IUCN as endangered, and has "listed" status in many of the states where it occurs. For example, in Indiana the spotted turtle is listed as an endangered species. In the Northeast, it has protective status in five of the six New England states and is listed as a species of special concern in New York.
There are many reptiles in the islands, including five species of geckos, eight species of skinks and two species of snakes: the Pacific boa and the Australoasian blindsnake. The marine life is magnificent and much concentrated around the colorful coral reefs. The Samoan ocean is a home to sea turtles as hawksbill sea turtle, olive ridley sea turtle, leatherback sea turtle and the green sea turtle. Five species of dolphins live in the area: spinner dolphin, rough-toothed dolphin, bottlenose dolphin, pantropical spotted dolphin and striped dolphin.
How turtles and tortoises breathe has been the subject of much study. To date, only a few species have been studied thoroughly enough to get an idea of how those turtles breathe. The varied results indicate that turtles and tortoises have found a variety of solutions to this problem.
The African softshell turtle or Nile softshell turtle ("Trionyx triunguis") is a large species of turtle from fresh-water and brackish habitats in Africa (larger parts of East, West and Middle Africa) and the Near East (Israel, Lebanon, Syria and Turkey). It is the only extant species from the genus "Trionyx", but in the past many other softshell turtles were placed in this genus; they have now been moved to various other genera. Despite the name "African softshell turtle", it is not the only species or genus of softshell turtle in Africa (the genera "Cyclanorbis" and "Cycloderma" are also African).
Conservation experts view the effect of China's turtle farming on the wild turtle populations of China and South-Eastern Asia – many of which are endangered – as "poorly understood". Although they commend the gradual replacement of turtles caught wild with farm-raised turtles in the marketplace – the percentage of farm-raised individuals in the "visible" trade grew from around 30% in 2000 to around 70% in 2007 – they worry that many wild animals are caught to provide farmers with breeding stock. The conservation expert Peter Paul van Dijk noted that turtle farmers often believe that animals caught wild are superior breeding stock. Turtle farmers may, therefore, seek and catch the last remaining wild specimens of some endangered turtle species.
While many of the things that endanger sea turtles are natural predators, increasingly many threats to the sea turtle species have arrived with the ever-growing presence of humans.
The sea waters along the Malay Peninsula favor molluscan growth, and there are about 280 edible fish species belonging to 75 families. Of those, 232 species (69 families) are found in mangroves and 149 species (51 families) reside in seagrass; so 101 species are common to both habitats. The sea also hosts many vulnerable fauna species, including dugong ("Dugong dugon"), several dolphin species, such as Irrawaddy Dolphin ("Orcaella brevirostris") and four species of sea turtles: critically endangered leatherback turtle ("Dermochelys coriacea") and hawksbill turtle (Eletmochelys imbricata) and threatened green turtle ("Chelonia mydas") and Olive Ridley turtle ("Lepidochelys olivacea"). There are only about 150 dugongs in the Andaman Sea, scattered between Ranong and Satun Provinces. These species are sensitive to the degradation of seagrass meadows.