Elusor macrurus (Mary River Turtle)

The Elusor macrurus, commonly known as the Mary River Turtle, is a freshwater turtle species native to Australia. This unique turtle is known for its algae-covered head and distinctive long tail, setting it apart from other turtle species.

Scientific Classification

• Kingdom: Animalia
• Phylum: Chordata
• Class: Reptilia
• Order: Testudines
• Family: Chelidae
• Genus: Elusor
• Species: E. macrurus

Common Names

• Mary River Turtle
• Green-haired Turtle (due to algae growing on its shell and head)

Identification

• Description: The Mary River Turtle is medium to large in size, with adults reaching up to 50 cm in shell length. Its dark brown or olive-green shell is smooth and streamlined, allowing it to glide easily through fast-flowing waters. One of its most distinctive features is its long tail, which can be almost as long as its body. Another peculiar trait is the green algae that often grows on its head and body.
• Sexual Dimorphism: Males are generally smaller than females but have significantly longer tails, which helps distinguish between the sexes.

Native Origin and Distribution

• Geographical Range: The Mary River Turtle is found exclusively in the Mary River in Queensland, Australia. Its limited distribution makes it highly vulnerable to habitat changes.

Preferred Habitat

Elusor macrurus prefers fast-flowing, clear rivers with abundant aquatic vegetation and rocky substrates. It thrives in areas where it can bask and forage with ease, and it spends much of its time in water.

Behavior

• Feeding Habits: This turtle is an omnivore, feeding on both plant matter, like algae and aquatic plants, as well as invertebrates such as snails and small crustaceans.
• Predators: Hatchlings and juveniles are preyed upon by birds, large fish, and occasionally, humans. Adult turtles have fewer natural predators, though they are at risk from introduced species like foxes and cats.

Reproduction

• Breeding Season: The Mary River Turtle breeds during the spring and summer months, typically between October and January.
• Reproductive Method: Females lay clutches of 10-25 eggs in sandy riverbanks. The incubation period can last up to 75 days, depending on environmental conditions.

Conservation

• Extinction Status: Endangered
• Threats: Habitat destruction, particularly from dam construction and land clearing, has severely impacted their population. Illegal pet trade has also posed a significant threat in the past.
• Conservation Measures: Efforts to protect the Mary River and its ecosystem are ongoing, with several breeding programs and habitat restoration projects in place to help preserve the species.

Economic Importance

The Mary River Turtle has no direct economic value but plays an essential role in maintaining the ecological balance of its riverine habitat by controlling plant and invertebrate populations.

Interesting Facts

• The Mary River Turtle can absorb oxygen through its cloaca, which allows it to stay underwater for extended periods, up to three days.
• It was once a popular pet in Australia in the 1960s and ’70s, known as the “Penny Turtle,” before its formal scientific discovery in the 1990s.