Asian forest tortoise
| Asian forest tortoise | |
|---|---|
| File:Manouria-emys-asian-forest-tortoise.jpg | |
| Manouria emys from Kaeng Krachan National Park in Thailand | |
| Scientific classification Edit this classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Testudines |
| Suborder: | Cryptodira |
| Family: | Testudinidae |
| Genus: | Manouria |
| Species: | M. emys
|
| Binomial name | |
| Manouria emys | |
| Synonyms[2] | |
|
List
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The Asian forest tortoise (Manouria emys) is a species of tortoise in the family Testudinidae. The species is endemic to Southeast Asia. It is believed to be among the most primitive of living tortoises, based on molecular and morphological studies.
Taxonomy
[edit | edit source]There are two recognized subspecies: M. e. emys, which is native to southern Thailand, Malaysia, Sumatra, Borneo; and M. e. phayrei, which is found from northwestern Thailand to northeastern India. The latter was named after Sir Arthur Purves Phayre (1812–1885), British Army officer in India who became Commissioner of British Burma.[3]
Based on a variety of phylogenetic characteristics, the genus Manouria is regarded as comparatively primitive and basal to other Testudinidae.[4]
Common names
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This species is known through several common names, which include the Asian forest tortoise, Mountain tortoise, Burmese mountain tortoise, and Asian brown tortoise. Other common names that are not as well-known include the brown tortoise, Asian mountain tortoise, Asian wood tortoise, Burmese brown mountain tortoise, and Asian giant tortoise, among others.[5]
Description
[edit | edit source]M. emys is the largest tortoise in mainland Asia. The largest adults of the northern subspecies (M. e. phayrei) can reach 25 kg (55 lb) in the wild and much more in captivity. It has a broad, flattened upper shell and a large lower shell, with distinctive features on its head, limbs, and skin that set it apart from other tortoises.
The carapace is considerably depressed (flattened), its depth less than half its length. Anterior and posterior margins are reverted (upturned) and strongly serrated (toothed). A nuchal (neck) shield is present, along with two supracaudal (above the tail) shields. Dorsal shields show concentric striations (grooves) and are often concave. Vertebral shields are much broader than long and at least as broad as costals (side plates). The lower shell (plastron) is large, with the gular region (throat area) produced (slightly extended) and typically notched (indented). The hind lobe (rear section) is deeply notched (indented). Pectoral shields may be widely separated or joined by a short median suture (seam). The axillary (armpit) shield is very small, while the inguinal (groin) shield is large. The head is moderate in size, featuring two large prefrontal shields and a large frontal shield. The beak is not hooked. Jaws are feebly denticulated (weakly toothed), with a strong median ridge (raised line) on the upper jaw's alveolar surface (inner surface). Anterior forelimb surfaces have large, bony, pointed, imbricate tubercles (overlapping bumps) in four or five longitudinal series. Hind limbs bear large bony tubercles (bumps) on the plantar surface (sole), with larger, conical, spur-like tubercles (bumps) on the heel and a group of even larger conical tubercles (bumps) on each side of the thighs' posterior. Adults are dark brown or blackish. Juveniles have a yellowish-brown carapace with dark-brown markings.[6]
Distribution
[edit | edit source]M. emys occurs in countries across Asia, which includes Bangladesh, Cambodia, India, Indonesia, Malaysia, Myanmar, Thailand, and Vietnam.[1]
Diet
[edit | edit source]This species has been observed in the wild to consume whole fungi, shoots of koster's curse (Miconia crenata), leaves and petioles of elephant ears (Alocasia sarawakensis and Alocasia scabriuscula), shoots of Begonia sp., shoots of Phrynium sp., shoots of vegetable fern (Diplazium esculentum), and flowers of wild ginger (Etlingera coccinea). Most commonly eaten were plants of the genus Alocasia, with individuals observed standing nearly vertical to reach leaves. In captivity, individuals have accepted a wide variety of food, predominantly being herbivorous but occasionally consuming frogs, snails, or carrion when presented.[7]
Reproduction
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M. emys is the only tortoise which lays its eggs above ground in a nest, which the female constructs of leaf litter. The female uses both front and rear legs to gather material for the nest and lays up to 50 eggs deep inside it. She then sits on and near the nest to protect it, and will "chase" predators and intruders away.[8]
Preliminary research has been conducted into Temperature-Dependent Sex Determination (TSD) in the southern subspecies (M. e. emys), and an estimated pivotal temperature of 29.29°C was determined. Incubation temperatures higher than this produce high rates of female hatchlings, and lower than this produce high rates of males.
A correlation was also seen between temperature and incubation time, with higher temperatures resulting in a shorter incubation time, and lower temperatures resulting in a longer incubation time. Incubation time ranged from 60 to 90 days.[8]
Cited references
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- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ Beolens, Bo; Watkins, Michael; Grayson, Michael (2011). The Eponym Dictionary of Reptiles. Baltimore: Johns Hopkins University Press. xiii + 296 pp. Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).. (Manouria emys phayrei, p. 205).
- ^ Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
- ^ https://www.zoochat.com/community/search/11168474/?q=manouria+emys&t=xengallery_media&o=relevance
- ^ Boulenger GA (1890). The Fauna of British India, Including Ceylon and Burma. Reptilia and Batrachia. London: Secretary of State for India in Council. (Taylor and Francis, printers). xviii + 541 pp. (Testudo emys, p. 22).
- ^ Høybye-Mortensen K. 2004. M. Sc. Thesis, University of South Denmark. p. 100
- ^ a b Lua error in Module:Citation/CS1/Configuration at line 2172: attempt to index field '?' (a nil value).
Further reading
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- Blyth E (1854). "Notices and Descriptions of Various Reptiles, New or Little-known. Part I". J. Asiatic Soc. Bengal 22 [1853]: 639–655.
- Schlegel H, Müller S (1844). "Over de Schildpadden van den Indischen Archipel ". In: Temminck CJ (1839–1847). Verhandelingen over de natuurlijke geschiedenis der Nederlandsche overzeesche bezittingen, door de leden der Natuurkundige Commisie in Oost-Indie en andere schrijvers. Leijden folio. Afd. 1 Zoologie in 12 afleveringen, met 45 gekl. pl. - Vitg. door C.J. Temminck, Leiden, Leuchtmans u. Hoeck in comm.: 29–36. (Testudo emys, new species, p. 34 + Plate IV). (in Dutch).
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External links
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