Northern river terrapin

Northern river terrapin
Conservation status
Critically Endangered (IUCN 2.3)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Testudines
Suborder:	Cryptodira
Family:	Geoemydidae
Genus:	Batagur
Species:	B. baska
Binomial name
Batagur baska (Gray, 1830)
Synonyms
Emys baska Gray, 1830 Emys batagur Gray, 1831 Testudo baska Gray, 1831 Trionyx (Tetraonyx) cuvieri Gray, 1831 Tetronyx longicollis Lesson, 1834 Tetronyx baska Duméril & Bibron, 1835 Tetraonyx lessonii Duméril & Bibron, 1835 Tetraonyx longicollis Duméril & Bibron, 1835 Clemmys (Clemmys) batagur Fitzinger, 1835 Hydraspis (Tetronyx) lessonii Fitzinger, 1835 Emys tetraonyx Temminck & Schlegel, 1835 Tetraonyx batagur Gray, 1844 Batagur (Batagur) baska Gray, 1856 Clemmys longicollis Strauch, 1862 Tetraonyx baska Gray, 1869 Batagur batagur Lindholm, 1929 Tetraonyx lessoni Bourret, 1941 (ex errore) Batagur baska ranongensis Nutaphand, 1979 Batagur ranongensis Nutaphand, 1979 Batagur basca Anan'eva, 1988 (ex errore) Batagur baska baska Stubbs, 1989 Batagur batagur batagur Joseph-Ouni, 2004 Batagur batagur ranongensis Joseph-Ouni, 2004

The northern river terrapin (Batagur baska), is a species of riverine turtle. It is one of the most critically endangered turtle species according to a 2000 assessment by the IUCN.

Description/Identification

River terrapins of different age cohorts: (from top to bottom) hatchling of about a week old, one year old and two years old.

Physical Structure: One of Asia's largest freshwater and brackish turtles. Carapace moderately depressed, with a vertebral keel in the young, which keel disappears in the adult; nuchal broader than long; first vertebral as broad in front as behind, or a little broader; vertebrals 2 to 4 subequal, much broader than long in the young, nearly as long as broad and as broad as the costals in the adult, the postero-lateral border of the third vertebral strongly concave. Plastron large, strongly angulate laterally in the young, convex in the adult, truncate anteriorly, angularly notched posteriorly; the width of the bridge exceeds the length of the posterior lobe; the longest median suture is that between the abdominals, the shortest that between the gulars, the latter never more than half that between the humerals; inguinal large, axillary smaller. Head rather small; snout pointed, produced, directed upwards; jaws with denticulated edge, upper feebly notched mesially; the width of the lower jaw at the symphysis nearly equals the diameter of the orbit. Limbs with transversely enlarged, band-like scales.

Color Pattern: Normally upper surface of shell (carapace) and soft parts olive-brown, lower surface (plastron) yellowish. Males in breeding coloration as having the head and ventral part of the neck black, with the coloration of the dorsal portion of the neck to its base rich crimson or bright red-orange and the whole of the forelimbs as brilliant rosy carmine or rusty to light orange. Hind parts dull reddish purple. During the breeding season, the color of the pupils of a female brown whereas the pupils in the males become yellowish-white. Their neck and head have a dark brown pigmentation and the base of the neck and forelimbs have a reddish pigmentation. This reddish pigmentation makes the Sunderban’s river terrapins a unique species.

Length (carapace): Maximum:60 cm.and Common:40 cm.

Maximum published weight: 18 kg.

Sub-species

Two subspecies was established:

B b baska Gray, 1831

B b ranongensis Nutaphand, 1979

Common names

Bengali: মুখপোড়া কাইট্টা (Mukhpoda kaitta), কেটো কচ্ছপ, বোদো কাইট্টা, বাটাগুর কাইট্টা, কালো-মাথা কাইট্টা, মুখপোড়া কাছিম।

Burmese:

English: Asian river terrapin Batagur, Common batagur, Four-toed terrapin, Giant river terrapin, Giant river turtle, Mangrove terrapin, Northern river terrapin, and River terrapin,

Hindi & Odia: ?

Indonesian: ?

Khemr: ?

Malayan: ?

Thai: ?

Vietvamese: ?

Distribution

Found only in Bangladesh (The Sundarbans and in captivity in Vawal National Park at Gazipur), Cambodia, India (parts- West Bengal & Orissya), Indonesia & Malaysia and Regionally extinct in Myanmar, Singapore, Thailand & Vietnam.

Habitat

Terrestrial & highly aquatic (freshwater & brackish); lives in tidal areas of the estuaries of medium and large rivers and also in mangrove habitat.

Habit

Amphibian. Little known about the natural ecology and behavior of Batagurs, partly because the highly silted rivers of their habitat make observations particularly difficult. Mainly prefers freshwater habitats and go up to brackish river mouths or estuaries in the breeding season. After laying eggs they return to the freshwater. Individuals known to undertake massive seasonal migrations of 50 to 60 miles to the sand banks that constitutes their breeding grounds.

Diet

Omnivorous. Takes waterside plants and small animals such as clams.

Reproduction

Oviparous; usually lays three clutches of between 10 and 34 eggs each during the breeding season in December–March; when she has laid her clutch of eggs she covers the nest with sand and then rises and falls on the surface to compact the sand.

Uses

Used as precious tasty meat-food and also its eggs considered as a delicacy. Over the last century, and until recently, the commercial trade of turtles in Calcutta has been staggering. Immense numbers were shipped into the fish markets of Calcutta from throughout India. Among the Bengali Hindus, the river terrapin was considered the most delectable of all turtles. Play rolls on echo-system by eating plants & small animals and otherwise.

Threat to humans

May pack a painful bite and cause injure if handled, but not aggressive or toxic or harmful otherwise.

IUCN threat status

Critically Endangered (CR).

Conservation status & Cautionary measures

A hatchery and captive breeding project was established in Vawal National Park at Gazipur in Bangladesh and another in Sajnekhali Forest Station in the Sunderban Tiger Reserve in India. There many individuals hatched and hopefilly population increases day by day and the species returned from the eve of the extinction point.

See also

• Southern river terrapin

References

• Das, Indraneil (1989) "Batagur baska in Orissya" Hamadryad: The Journal of the Madras Crocodile Bank Trust 14(1): 2-3
• Gray,J.E. (1857) "Notice of some Indian tortoises (including the description of a new species presented to the British Museum by Professor Oldham)" Annals and Magazine of Natural History 19(2): 342-344

Bibliography

External links

• Centre for Turtle Research and Conservation
• Batagur baska at the Reptarium.cz Reptile Database
• http://www.newindianexpress.com/education/student/article594045.ece
• http://www.turtlesurvival.org/component/taxonomy/term/summary/36/37#.Vejy931y5WE
• http://www.arkive.org/batagur/batagur-baska/
• http://www.asianturtlenetwork.org/field_guide/Batagur_baska.htm