Amyda cartilaginea (Boddaert, 1770)

Common Name and Shell Length

Amyda cartilaginea, commonly known as the Asiatic soft-shell turtle, has a shell that reaches 70 to 80 cm (27.6 to 31.5 inches) in length.

Shell Texture by Age

Juvenile individuals have a rough-textured shell, while adult shells are soft and leathery.

Weight Range

This is an average-sized turtle, with typical adult weights ranging from 15 kg (33 lbs) to 25 kg (55 lbs); there are unconfirmed reports of individuals reaching up to 105 kg (231 lbs).

Carapace Shape

Its carapace is oval-shaped.

Carapace Color by Age

Adult carapace color ranges from pale olive to green-brown, while juvenile carapaces are dark brown or black, and this dark color fades with age.

Shell Markings

Yellow dots and occasional black spots mark the shell, and these markings also fade as the turtle ages.

Plastron Sexual Dimorphism

The plastron shows sexual dimorphism: it is white in males and gray in females.

Head Markings

The head can be black or brown, and typically has yellow dots that sometimes fuse into elongated streaks.

Nape Color Change with Age

As the turtle ages, its nape area turns white or gray.

Distinguishing Snout Trait

A noticeably elongated snout is a trait that distinguishes this species from other similar soft-shell turtles.

Snout Breathing Function

This adaptation, combined with the turtle's great flexibility, helps it breathe when it is buried.

Submersion Adaptation

An adaptation called pharyngeal breathing allows increased gas exchange, letting this turtle stay submerged in water for long periods of time.

Neck Tubercles

Amyda cartilaginea has several permanent tubercles on its neck, which can be yellow or black.

Limb Markings

The limbs also have yellow spots, but these are usually fewer in number and hard to tell apart.

Foot Structure

Its feet are wide and flat, and resemble paddles.

Tail Sexual Dimorphism

Males have longer, thicker tails than females.

Native Range Core Areas

Amyda cartilaginea is native to Brunei, Indonesia (Bali, Java, Sumatra, and Kalimantan), Malaysia (Sabah, Sarawak), Singapore, and southern Thailand.

Native Range Extent

Its native range extends from the Thai section of the Malay Peninsula south throughout Island Southeast Asia.

Introduced Populations

Populations in the Lesser Sundas, Moluccas, and Sulawesi are thought to be introduced or traded individuals.

Primary Habitat Types

The species is found in tropical freshwater habitats within rainforest terrestrial biomes, and in aquatic biomes including lakes, ponds, canals, and lowland streams.

Recorded Distribution Locations

It has been recorded across multiple locations in Asia, specifically in Brunei, Bangladesh, Borneo, Cambodia, India, Indonesia, Laos, Malaysia, Myanmar, Sabah, Sarawak, Singapore, Thailand, and Vietnam.

Preferred Low-Elevation Habitats

Amyda cartilaginea prefers wetlands, and can be found in marshes, swamps, and large muddy rivers at low elevations.

General Life Cycle Similarity

The Asiatic soft-shelled turtle follows a life cycle similar to many other turtles worldwide.

Egg Laying Context

It hatches from a clutch of eggs laid in sand along a body of water.

Clutch Size Variation

Clutch size ranges from four to eight eggs, depending on the size and age of the female that laid the clutch.

Incubation Period

The average incubation period is between 130 and 140 days, though incubation length is heavily dependent on climate.

Temperature-Dependent Sex Determination

Climate also influences the sex of most developing turtles: females typically develop at around 30 degrees Celsius, and males at 25 degrees Celsius.

Post-Hatching Hatchling Behavior

After hatching, young turtles must travel quickly to water to avoid predation.

Juvenile Predators

Monitor lizards, crows, and serpent eagles are known to prey on young Amyda cartilaginea.

Juvenile Development

Juveniles that survive these early threats continue growing and developing into sexually mature adults.

Female Sexual Maturity Age

Females reach sexual maturity in around 20 months.

Annual Clutch Production

Once sexually mature, Asiatic soft-shell turtles can produce up to four clutches of eggs per year, though this depends on annual conditions.

Mating Cycle Timing

Their mating cycle relies on the dry season, as this is the only time river banks are exposed enough for egg-laying.

Lifespan Knowledge Gap

While it is known that Asiatic soft-shell turtles can live very long lives, the exact total length of their life cycle is not yet understood.

Cause of Lifespan Knowledge Gap

This gap in knowledge is partially due to the fact that many Asiatic soft-shell turtles are caught for food, where larger and older individuals are more desirable because they produce more meat.