Chitra indica

Geographic Range

Chitra indica is widely distributed throughout south Asia. It can be found within the river systems of India, Nepal, Pakistan, Myanmar, Malaysia and Bangladesh. Distribution, while extensive, can be irregular and restricted. This may be the result of both its large body size as well as specialized habitat requirements.

• Biogeographic Regions
• oriental oriental
  • native native

Habitat

The ideal habitat for Chitra indica is rivers of moderate to large size, preferably with sandy bottoms and low turbidity. Chitra indica will bury itself in the sandy sediment of these rivers and spend most of the day submerged. Females require sandy or sandy loam beaches to dig nests and lay eggs.

• Habitat Regions
• freshwater freshwater

• Aquatic Biomes
• lakes and ponds
• rivers and streams

Physical Description

The narrow-headed soft shell turtle, Chitra indica , tends to be relatively large, with a carapace of up to 1.10 m in length. This carapace tends to be bluish grey or olive with intricate wavy reticulations present. This pattern is also present on the neck and forelimbs. The shell is oval, flattened and soft with the presence of four plastral callosities. Between the first pair of costals a single neural is present. The head is long and narrow with a short proboscis present on the end. The plastron is a pink or cream color. Males usually have longer tails when compared to females; however females tend to achieve a greater overall size. Overall mass can be up to 250kg.

• Other Physical Features
• ectothermic ectothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• female larger

Development

There has been limited study of the development of Chitra indica . Once a clutch of eggs is laid incubation typically takes 40-70 days at 25.5 to 36 degrees Celsius for emergence to occur. Upon emergence juveniles experience indeterminate growth throughout their life. No research has been done into the possibility of temperature-dependent sex determination in this species. However, previous studies indicate that temperature has no effect on sex-determination in other soft-shell turtles.

• Development - Life Cycle
• indeterminate growth indeterminate growth

Reproduction

Due to its secretive nature little is known about the reproductive habits of Chitra indica . However, females must come onto sandy beaches in order to excavate holes and lay clutches of eggs.

Chitra indica nests at different times depending on the area. In the Ganga River system nesting occurs at the height of the monsoons, usually from late August to mid-September. In Bangladesh nesting may occur from February to May, with up to three clutches being laid in this time. In both areas the females will emerge on sandy beaches and excavate a flask-shaped nest with an egg chamber typically 15 by 23 cm in diameter. These eggs are then covered again with sand and allowed to incubate. This incubation period lasts for 40 to 70 days at 25.5 to 36 degrees Celsius. Sexual maturity is determined by both mass and length of an individual. Newly mature individuals will have a length of 44 to 55cm and a mass of 12 to 16 kg.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
• oviparous oviparous

The parental investment of Chitra indica is limited to provisioning occurring both before and during fertilization and the act of laying and burying the fertilized eggs. After the laying of an individuals eggs Chitra indica is uninvolved in the rearing of its offspring.

• Parental Investment
• no parental involvement
• pre-fertilization
  • provisioning
• pre-hatching/birth
  • provisioning

Lifespan/Longevity

Little is also known about the average life expectancy of Chitra indica . Although specimens in captivity have lived past 70 years and it has been reported that they can live up to 140 years old in the wild.

Behavior

The behavior of Chitra indica is poorly studied, however when captured, it has been known to inflict serious bite injuries. Chitra indica may also strike with the snout, rather than biting. These strikes with the head and neck have been known to cause damage to small fishing boats.

• Key Behaviors
• motile motile
• solitary solitary

Home Range

There is currently no known research on the home range of Chitra indica .

Communication and Perception

There is little known about the communication or perception of Chitra indica . However, it has been noted that when handled it produces a musky odor, which could be used to signal distress.

• Communication Channels
• chemical chemical

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

A known ambush predator, Chitra indica buries itself in the sandy sediment of river beds and lays in wait for prey. When a prey item passes by, usually a fish or other aquatic invertebrate, Chitra indica will shoot out its head and lunge at the prey. Small items may be swallowed whole while larger ones may be more slowly swallowed. If an item is too large it may use its forefeet and jaws to tear apart the item before consuming it. Plant material can also occasionally be found in the stomach contents of Chitra indica .

• Primary Diet
• carnivore carnivore
  • piscivore piscivore
  • eats non-insect arthropods
  • molluscivore molluscivore
  • vermivore
  • scavenger scavenger
• omnivore omnivore

• Animal Foods
• amphibians
• fish
• carrion carrion
• insects
• terrestrial non-insect arthropods
• mollusks
• terrestrial worms
• aquatic crustaceans

Predation

Predation of adult Chitra indica by other animals is not well documented. However, eggs and hatchlings are subject to predation by humans, jackals as well as monitor lizards.

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Indian narrow-headed turtles are predators of fish and other aquatic invertebrates and hatchlings may be predated by monitor lizards and jackals. Chitra indica has also been known to feed on carrion and dead carcasses. Besides this, relatively little is known of the role of Chitra indica in their ecosystem. There are no known parasites of Chitra indica , however, the closely related Chitra chitra may be subject to parasitism by members of Pentastomida (parasitic invertebrates).

• Ecosystem Impact
• biodegradation biodegradation

Economic Importance for Humans: Positive

While fairly uncommon, Chitra indica has been hunted throughout its distribution. The meat can be found at local markets in India, Bangladesh and Nepal, where it is known as a delicacy. More important however, is the extensive hunting of Chitra indica for the harvest and sale of its outer cartilaginous rim or “calipee”. The dried calipee is then exported for use in traditional medicine or as the stock of a luxury soup.

• Positive Impacts
• pet trade pet trade
• food food
• body parts are source of valuable material
• source of medicine or drug source of medicine or drug

Economic Importance for Humans: Negative

There are no known adverse effects of Chitra indica on the ecology of humans. Captured Chitra indica may cause bodily harm to humans either by biting or head-butting.

• Negative Impacts
• injures humans
  • bites or stings

Conservation Status

Despite high reproduction rates, Chitra indica is listed on the IUCN Red List and in the Schedule II of the Indian Wildlife Act of 1972 as Endangered. This status is likely due to extensive human predation and exploitation, as well as the continued degradation and encroachment of habitat. In response to this, the government of India has initiated several conservation projects on the Ganga river system. Both the animals themselves as well as their nesting grounds are protected from exploitation. However greater monitoring and control of the illegal trade of this species is necessary to further protect Chitra indica . Upgrading the species to Schedule I of the Indian wildlife act as well as protection under wildlife laws of countries such as Pakistan, Nepal and Bangladesh would help the conservation efforts of Chitra indica . Due to the difficulty of maintaining this species in captivity, conservation efforts should focus on hatch-and-release programs and the reduction of mortality in mature individuals.

Additional Links

Encyclopedia of Life

Contributors

Kyle Hanus (author), University of Wisconsin Stevens Point, Christopher Yahnke (editor), University of Wisconsin-Stevens Point, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

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