(Lacepède, 1788)
Indian flapshell turtle
Recognition
The oval, domed, unflared adult carapace (to 37 cm) is unique among trionychids in having a series of peripheral bones along the posterior rim (these are not considered homologous with the peripherals of hard-shelled turtles). A prenuchal is also present. Two neural bones separate the 1st pair of costals, and the seven or eight neurals lie in a continuous series. The 7th and 8th pair of costals touch medially. Rib ossification is extensive, and ribs protrude beyond the costals. All carapacial bones are finely granulated. Juveniles have wrinkled carapaces with longitudinal rows of small tubercles, but the adult carapace is much smoother. The adult carapace varies from uniform brown to olive brown or dark green with small dark-brown or large yellow spots; the plastron is cream colored. There is a hinge on the plastral forelobe which allows it to partially close the anterior opening, thus protecting the head and forelimbs. This hinge lies at the point of attachment of the epiplastra to the entoplastron. The hyo- and hypoplastra are fused, and posterior extensions are absent from the entoplastron. Seven plastral callosities occur in adults, but none in juveniles. The skull is short and dorsally convex; its bony snout is much shorter than the greatest diameter of the orbit. The interorbital space is also much narrower than the diameter of the orbit. The triturating surface of the maxilla lacks a ridge. There is prefrontal-vomer contact. The fleshy proboscis is short with no lateral ridge on the internasal septum. The head is olive to brown with several elongated and wide yellow stripes: on the snout, one between the orbits, one passing backward on the side from the orbit to the tympanum, and sometimes one from the corner of the mouth backward along the throat. A series of yellow stripes also occurs on the neck. The limbs are olive or brown.
As with other trionychids, Lissemys has 66 chromosomes; 16 metacentric and submetacentric, 12 subtelocentric, and 38 acrocentric and telocentric (Singh et al., 1970; Stock, 1972).
Males have long, thick tails; females have short tails. Females grow larger than males.
Distribution
Lissemys punctata occurs in the Indus and Ganges drainages of Pakistan, northern India, Sikkim, Nepal, and Bangladesh, southward through peninsular India to Sri Lanka, and in the Irrawaddy and Salween rivers of Myanmar, to extreme western Thailand. Kuchling (1995) found the species being sold on local markets in Yunnan Province, China, and speculated that it may naturally occur there. It has been introduced in the Andaman Islands (Das, 1991).
Geographic Variation
Three subspecies are recognized (we follow the taxonomy of Webb, 1980a, also accepted by Das, 1995). Lissemys punctata punctata (Lacepède, 1788), the Indian flapshell turtle, occurs in peninsular India and on Sri Lanka; it includes the formerly recognized, but no longer valid subspecies L. p. granosa (Schoepff, 1801). Its carapace is uniformly olive brown to brown, and the 1st peripheral is only slightly larger than the 2nd; the head is olive to brown with three oblique, parallel black stripes, at least in the young; and the plastron has an entoplastral callosity that is moderate in size and gray brown in color. L. p. andersoni Webb, 1980a, the Indo-Gangetic flapshell turtle, occurs in the Indus, Ganges, and Brahmaputra drainages in eastern Pakistan, northern India, Sikkim, southeastern Nepal, Bangladesh, and northern coastal Myanmar. Its carapace is gray green with numerous large black-bordered yellow spots, and the 1st peripheral bone is much larger than the rest. The greenish head also contains numerous yellow spots, and the white plastron has a small entoplastral callosity. L. p. scutata (Peters, 1868), the Burmese flapshell turtle, lives in the Irrawaddy and Salween rivers of Myanmar, and occurs in northeastern Thailand, and possibly in Yunnan Province, China (Kuchling, 1995). It has an olive-brown to brown carapace with some dark spotting (in juveniles) or reticulations (in adults), and the 1st peripheral is smaller than the 2nd. The head is olive to brown with an indistinct dark stripe extending backward from each orbit and another passing backward between the orbits. The entoplastral callosity is large and may contact the hyo-hypoplastral callosities.
Webb (1982; pers. comm.) suggested that the configuration of its peripheral bones, and the advent of well-developed plastral callosities at a relatively short length, indicating a small maximal size, as well as its geographical isolation may mean that L. p. scutata is a distinct species. However, Meylan (1987), in the latest revision of the Trionychidae, thought scutata more likely a subspecies of L. punctata; therefore it is conserved in that rank.
Habitat
Lissemys punctata lives in the shallow, quiet, often stagnant waters of rivers, streams, marshes, ponds, lakes and irrigation canals, and tanks. Waters with sand or mud bottoms are preferred.
Natural History
Courtship and mating were observed by Duda and Gupta (1981) during April in wild Lissemys and from May to July in captives. The male swims above and around the female, with his neck and limbs extended, periodically stroking the female's carapace with his chin. When receptive, the female faces the male with her neck extended and they bob their heads vertically three or four times in a sequence repeated five to eight times. She then settles to the bottom and the male mounts from the rear. Near the end of copulation, the male releases his grip on the female's carapace and rotates so as to face the opposite direction from her. They remain attached in this position for as long as 15 minutes, during which the female may drag the male about. Finally copulation ends and the pair separates.
Nesting occurs from September to November (Das, 1991; Sarker and Husain, 1996); Vyas (1996) reported the period June-October for western India. Preferred nest sites are in loamy soil in swampy areas near bushes or vegetation where sunlight is available (Sarker and Husain, 1996). Nest cavities are 6-20 cm deep, 8-16 cm wide and 20-21 cm long (Das, 1991; Sarker and Husain, 1996; Vyas, 1996). Females begin ovipositing at 2-3 years of age at 21-23 cm carapace length (Sarker and Husain, 1996).
Two to 16 eggs are laid at a time, and a female may lay a total of 34-40 eggs in 2-3 clutches each year (Sarker and Husain, 1996). The white eggs are spherical (26.0-28.6 x 26.0-27.8 mm; Vyas, 1996) with brittle shells; those of the first clutch may be larger than those from subsequent clutches (Sarker and Husain, 1996). The young hatch in June-August of the next year after a natural incubation period of 241-409 days; hatchlings have 34.8-37.0 mm carapaces (Vyas, 1996).
In northern India, Lissemys hibernates between November and February (Das, 1991, 1995). During dry summer periods it may either aestivate in the mud or wedged into debris under grass tussocks on land, or it may also migrate overland to other waterbodies (most migrators are females; Auffenberg, 1981b). Predation is heavy, particularly on small individuals by vultures, when the softshell is on land (Auffenberg, 1981b; Bhupathy and Vijayan, 1989). This species often basks on sandbars, banks, and floating vegetation.
Lissemys is omnivorous. Deraniyagala (1939) reported it feeds on frogs, fishes, crustaceans, aquatic snails, bivalves, and earthworms in Sri Lanka, but Minton (1966) has observed them eating aquatic vegetation in Pakistan. Molluscs comprised 26%, fish 20%, insects 20%, and plant materials (stems, leafs, flowers, seeds) 34% of fecal samples examined by Bhupathy and Vijayan (1993) in India. The percentages of animal foods in scat were 59% in the wet season and 76% during the dry season. Both Smith (1931) and Deraniyagala (1939) observed L. punctata come on shore at night and feed on carrion or decaying matter.
This flapshell is generally mild mannered, but newly caught individuals, especially large adults, may bite.
IUCN Red List Status (1996)
Lissemys punctata scutata (listed as Lissemys scutata) is considered Data deficient; the other subspecies are not listed.