The Assam roofed turtle or Sylhet roofed turtle (''Pangshura sylhetensis'') is a

turtle Turtles are an order of reptiles known as Testudines, characterized by a special shell developed mainly from their ribs. Modern turtles are divided into two major groups, the Pleurodira (side necked turtles) and Cryptodira (hidden necked tu ...

species of the family

Geoemydidae The Geoemydidae (formerly known as Bataguridae) are one of the largest and most diverse families in the order Testudines (turtles), with about 70 species. The family includes the Eurasian pond and river turtles and Neotropical wood turtles. Memb ...

found in the

Brahmaputra The Brahmaputra is a trans-boundary river which flows through Tibet, northeast India, and Bangladesh. It is also known as the Yarlung Tsangpo in Tibetan, the Siang/Dihang River in Arunachali, Luit in Assamese, and Jamuna River in Bangla. It ...

Meghna The Meghna River ( bn, মেঘনা নদী) is one of the major rivers in Bangladesh, one of the three that form the Ganges Delta, the largest delta on earth, which fans out to the Bay of Bengal. A part of the Surma-Meghna River System, ...

drainage in

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

(

Assam Assam (; ) is a state in northeastern India, south of the eastern Himalayas along the Brahmaputra and Barak River valleys. Assam covers an area of . The state is bordered by Bhutan and Arunachal Pradesh to the north; Nagaland and Manipur ...

) and parts of eastern

Bangladesh Bangladesh (}, ), officially the People's Republic of Bangladesh, is a country in South Asia. It is the eighth-most populous country in the world, with a population exceeding 165 million people in an area of . Bangladesh is among the mos ...

. It was formerly placed in the genus ''

Batagur ''Batagur'' is a genus of large turtles from South and Southeast Asia. All members of the genus are seriously threatened. With a recent merger with members from two other genera,Praschag, Peter; Hundsdörfer, Anna K.; and Fritz, Uwe (2007)''Phylo ...

'' and the defunct genus ''

Kachuga ''Kachuga'' (roofed turtles) is an obsolete genus formerly used for several species of Asian turtles, now placed in ''Batagur'' and ''Pangshura'': * '' Batagur dhongoka'' – three-striped roofed turtle * ''Batagur kachuga'' – red-crowned roofed ...

''.

Description

The species has a triangular and elevated carapace with a prominent spiked keel and 26 strongly serrated marginal plates. The carapace is olive brown, with a lighter (yellowish to beige) keel. The head is small and has a weakly hooked upper jaw; a narrow pink stripe runs from the back of each eye to the middle of the back of the head. Adults may attain a maximum length of 20.5 cm, although body sizes of 16 cm are more common. The species' local names include ''dura kaso'' (দূৰা কাছ) in Assamese, ''śileṭi kaiṭṭa'' (সিলেটি কাইট্টা), ''śileṭi kori kaiṭṭa'' (সিলেটি কড়ি কাইট্টা), ''kãṭa kachim'' (কাঁটা কাছিম) and ''kaṭua~xaṭua/kauṭa~xauta'' (কাটুয়া/কাউটা) in

Bengali Bengali or Bengalee, or Bengalese may refer to: *something of, from, or related to Bengal, a large region in South Asia * Bengalis, an ethnic and linguistic group of the region * Bengali language, the language they speak ** Bengali alphabet, the w ...

Distribution and habitat

The species occurs in the north-eastern and south-eastern parts of

, in

(

) and possibly in

Bhutan Bhutan (; dz, འབྲུག་ཡུལ་, Druk Yul ), officially the Kingdom of Bhutan,), is a landlocked country in South Asia. It is situated in the Eastern Himalayas, between China in the north and India in the south. A mountainous ...

. It is found in terrestrial and freshwater habitats in areas with upland tropical moist forest, and fast-flowing streams and perhaps also small rivers. Oxbow lakes may also be inhabited, but shell morphology suggests an adaptation to fast-flowing waters.

Ecology

The species is

amphibious Amphibious means able to use either land or water. In particular it may refer to: Animals * Amphibian, a vertebrate animal of the class Amphibia (many of which live on land and breed in water) * Amphibious caterpillar * Amphibious fish, a fish ...

. In the cooler months of the dry season, from December to February, it basks during most of the day; individuals living in cooler hill streams may do so year round. The turtle is shy and never basks on river banks, but only on emergent logs or rocks. At the slightest disturbance, it will dive quickly to the middle of the river, hiding between rocks. Juveniles often flee into accumulations of dead leaves for camouflage and remain motionless.

Reproduction

Assam roofed turtles nest between late October and February, corresponding with the cool, dry season, and produce clutches of 6 to 12 eggs. Hatchlings appear mainly between March and April, at the beginning of the southeast

monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal oscil ...

s. The eggs need to undergo a

diapause In animal dormancy, diapause is the delay in development in response to regular and recurring periods of adverse environmental conditions.Tauber, M.J., Tauber, C.A., Masaki, S. (1986) ''Seasonal Adaptations of Insects''. Oxford University Press It ...

at cooler temperatures lasting between 6 and 8 weeks in order to hatch successfully.

Conservation

The Assam roofed turtle is a rare species known only from a few individuals; it is believed to have one of the narrowest distributions of any south Asian geoemydid. It is exploited for its meat and eggs for local consumption and collected for the pet trade, especially in Asia where this turtle fetches high prices as pets. Habitat destruction by logging and incidental capture in fishing gear are also thought to present threats. The species is currently classified as critically endangered by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

References

External links

* {{Taxonbar, from=Q2701972 Pangshura Reptiles of India