Why these bizarre, leathery turtles are masters of both land and underwater survival

Nature · Published 3 October 2026 Swipe more like this →

In short: Softshell turtles are evolutionary outliers, trading the heavy, protective armor of typical turtles for a flexible, leathery carapace. This adaptation allows them to move with surprising speed on land and navigate muddy waters with ease, while specialized mouth tissues enable them to breathe underwater like fish for extended periods.

The family Trionychidae, described by Leopold Fitzinger in 1826, is defined by its unique morphology. Unlike most turtles, their shells lack horny scutes and possess a pliable, leathery edge. While a solid bone layer exists centrally, the absence of bone at the periphery grants them agility. Their name, Trionychidae, reflects their three-clawed, webbed feet, which are perfectly suited for an aquatic lifestyle. These turtles are ambush predators, often burying themselves in substrate with only their elongated, snorkel-like nostrils exposed to the surface.

Physiologically, these reptiles are remarkable. They possess specialized processes in their mouth cavities that function similarly to fish gills, allowing for prolonged submersion. In brackish environments, some species, such as the Chinese softshell, can even excrete urea while underwater. Their powerful jaws, noted by Ditmars in 1910 for their crushing ability, are capable of inflicting serious injury, including the amputation of a human finger. Unlike the temperature-dependent sex determination found in most turtles, trionychids rely on ZZ/ZW genetic mechanisms involving microchromosomes.

The relationship between humans and softshells is complex, particularly regarding consumption. In East Asia, species like Pelodiscus sinensis have been a culinary staple for centuries, with industrial-scale farming emerging in Japan by the late 19th century. By the mid-1990s, surging demand in China led to massive production, with hundreds of millions of turtles raised annually. Conversely, in the United States, concerns over overharvesting led to significant regulatory shifts. In 2009, Florida implemented strict bans on the trade of wild-caught softshells, following reports that thousands of pounds were being exported weekly. Similar legislative efforts, such as South Carolina's Bill H.3121, have sought to curb the international trade of these animals to ensure their survival in the wild.

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• The leatherback sea turtle is a prehistoric giant that thrives in the open ocean.
• Turtle shells are ribcages worn outside the body
• Why nature keeps reinventing the giant, skin-shelled sea turtle
• Why these ancient Australian turtles tuck their heads sideways instead of pulling them back
• Seven sea turtle species still patrol the world's oceans
• Why your home aquarium is a window into the world's most vibrant ecosystems
• Why this reef fish uses a biological crossbow to survive in the ocean
• Tropicbirds are master aviators that cannot walk, yet they rule the open ocean
• Meet the ancient, tail-wagging ancestor that paved the way for every modern frog
• Beyond the mimicry, what defines the true parrot family in the wild?
• Why these aerial birds are the only swifts capable of perching on branches
• Why the turkey is named after a country that never grew it

More in Vertebrates · More in Nature · Latest · A–Z · All topics