The Turtle's Plight: De-Shelled And Vulnerable

De-shelled turtles, or softshell turtles, are a taxonomic family of turtles characterised by a flattened shell. Unlike other turtles, softshell turtles lack epidermal scutes (large scales) and have reduced ossification of the shell, meaning that it is covered only by skin. Softshell turtles are found in Africa, Asia, and North America, with extinct species known from Australia. They are the world's largest freshwater turtles and are able to adapt to living in brackish water. They have long necks and streamlined heads with elongated snorkel-like snouts, and they often lie buried in mud, sand, and shallow water, breathing by extending their necks to the surface.

Softshell turtles are faster on land and in water due to their light and flexible shells

Softshell turtles, or Trionychidae, are a taxonomic family of turtles that are native to parts of Africa, Asia, and North America. They are unique among turtles in that they lack the typical hard shell, instead possessing a soft, flexible, and leathery carapace. This lack of horny scutes or scales makes them more vulnerable to attacks in the wild, but it also confers several advantages. The light and flexible shell allows softshell turtles to move with greater ease and speed in open water and navigate muddy lake bottoms more effectively.

The ability of softshell turtles to move swiftly in water is further enhanced by their elongated, snorkel-like nostrils and disproportionately long necks. These adaptations enable them to breathe surface air while their bodies remain submerged in the substrate, with only their snout protruding above the surface. This ability to breathe while partially submerged provides softshell turtles with an advantage when hunting or evading predators.

On land, the softshell turtle's flexible shell and webbed, three-clawed feet also contribute to their agility. They are capable of moving much faster on land compared to most other turtle species. This agility, both in water and on land, makes them a challenging prey item for predators such as raccoons, alligators, and snapping turtles. When faced with danger, softshell turtles can quickly dive into the water and conceal themselves in mud, utilizing their flexible shells to their advantage.

The softshell turtle's shell is not entirely devoid of protection. While the outer edges lack the solid bone structure typical of turtle shells, the central part of the carapace does have a layer of solid bone beneath it, similar to other turtles. Additionally, some species possess dermal bones in the plastron, providing some additional structural support. The color of the carapace tends to match the sand or mud of the turtle's habitat, providing camouflage and aiding in their ambush hunting strategy.

The shell's colour helps turtles camouflage

The shell of a turtle plays a crucial role in its survival, providing effective camouflage that helps them blend seamlessly into their surroundings. The colour and pattern of a turtle's shell vary depending on the species and their natural habitat, demonstrating a remarkable ability to adapt to their environment.

For example, the saw-shelled turtle (Myuchelys latisternum), native to Australia, has a shell that is mainly brown to dark brown, often with dark blotches. This colouring allows them to blend in effectively with the mud, sand, or vegetation of their natural habitat, making them less visible to both predators and potential prey. This advantage of camouflage is further enhanced by the shape and texture of the shell, which can have serrations or other features that help break up their outline and make them even harder to spot.

Similarly, the softshell turtles of the Trionychidae family have shells that tend to match the sand or mud colour of their specific geographical region. This adaptation is particularly advantageous for their "lie in wait" feeding strategy, as it enables them to remain concealed from prey until the opportune moment to strike. The flexibility of their shells also allows them to move more easily in open water or on muddy lake bottoms, further enhancing their hunting capabilities.

The colour and pattern of a turtle's shell are not just for camouflage, but also for communication. Different species of turtles have unique shell patterns and colours that can serve as a form of identification, both for potential mates and for asserting territorial claims against rivals. Additionally, the shell's colour and patterning can provide some protection from the elements, such as helping to regulate body temperature or providing some level of waterproofing.

Overall, the shell of a turtle is an incredibly important aspect of its anatomy, and its colour and patterning serve a variety of functions, with camouflage being a key factor in their survival strategies.

Turtles can be identified by their plastrons

The plastron is the flat underside of a turtle's shell, also known as the turtle's 'belly'. The plastron is made up of nine bones, and two epiplastra at the front are homologous to the clavicles of other tetrapods. The rest of the plastral bones are homologous to the gastralia of other tetrapods. The plastron is an exoskeleton, like osteoderms of other reptilians, but it also possesses osteoblasts, the osteoid, and the periosteum.

The plastron is a useful tool for identifying turtles. The relative lengths of the seam segments on the plastral scutes can be used to identify a species of turtle. There are six laterally symmetric pairs of scutes on the plastron: gular, humeral, pectoral, abdominal, femoral, and anal. The abdominal and gular scute seams are approximately the same length, and the femoral and pectoral seams are approximately the same length.

The plastral formula is also used to compare the sizes of the individual plastral scutes. For example, for the eastern box turtle, the plastral formula is: an > abd > gul > pect > hum >< fem.

The plastron can also be used to determine the sex of a turtle. The plastron of a male turtle is concave, whereas the female's is convex. This is because of the mating position; the male's concave plastron allows it to more easily mount the female during copulation.

The shape of the plastron can also be used to identify a turtle. For example, the male Blanding's turtle has a flat plastron, while the female's is arched.

The colour of the plastron can also be used to identify a turtle species. For example, the plastron of the saw-shelled turtle is yellowish, while the carapace is brown to dark brown.

In summary, the plastron of a turtle can be used to identify the species, sex, and even the individual of a turtle, depending on the characteristics described above.

Turtles can be male or female depending on the shape of their plastron

De-shelled turtles, or softshell turtles, are a taxonomic family of turtle genera that include some of the world's largest freshwater turtles. They are called "softshell" because their carapaces lack horny scutes (scales). The carapace is leathery and pliable, particularly at the sides. The central part of the carapace has a layer of solid bone beneath it, but this is absent at the outer edges.

The shape of a turtle's plastron (the underside of its shell) can indicate its gender. Male turtles have a concave (curved inwards) plastron, while females have a flat one. This allows male turtles to fit over a female's shell during mating without rolling off, and gives females more room to grow eggs internally.

Other ways to determine the gender of a turtle include:

• Checking the turtle's tail length and thickness—male turtles tend to have longer and thicker tails than females.
• Examining the turtle's claws—male turtles have longer front claws than females, which they use during mating rituals and to fight and defend their territory.
• Looking at the turtle's cloaca (the small hole located under the tail)—the female's cloaca is rounder and more star-shaped, while the male's is longer and more slit-like. The female's cloaca is also found closer to her body, while the male's is located in the last third of the tail, towards the tip.
• Checking the turtle's size—male turtles tend to be smaller than females, although this can vary depending on the species.
• Analysing the turtle's shell markings and coloration—in some species, such as the American box turtle, male and female turtles have different-coloured irises.

The hawksbill turtle shell has been used for decorative items

The hawksbill turtle, also known as the hawksbill sea turtle, is a critically endangered species of sea turtle. Its shell, or carapace, has been used for decorative items throughout history. The shell has an amber background, patterned with an irregular combination of light and dark streaks, with predominantly black and mottled brown colours radiating to the sides. The shell typically has serrated edges, with overlapping scutes, giving it a distinctive saw-like appearance.

The hawksbill turtle shell, also known as "tortoiseshell", has been used to create a variety of decorative items and jewellery. In the past, it was commonly used in the West and China to make small decorative items. Ancient Greeks and Romans also harvested the shells for jewellery such as combs, brushes and rings. In Japan, the scutes of the hawksbill turtle shell, known as "bekko", were used for various personal items such as eyeglass frames and shamisen picks.

The unique and beautiful patterning of the hawksbill turtle shell has made it highly valued and sought-after in markets, where it is sold as "tortoiseshell". In recent decades, East Asia has been a significant market for tortoiseshell items. The shell is carved and crafted into hair clips, combs, jewellery, and other trinkets. The brown and yellow carapace plates are particularly desirable for manufacturing decorative items.

The hawksbill turtle is protected under the Convention on International Trade in Endangered Species (CITES), which regulates the international trade of hawksbill turtles and products derived from them. Despite this protection, illegal hunting and trade of hawksbill turtle shells continue to pose a significant threat to the species.

Frequently asked questions