Summary of TURTLES CAN DO WHAT?! – Zoo Atlanta:
The author debunked the idea that turtles can breathe out of their butts and explained the function of cloacal bursae in some turtles. These sac-like extensions on the sides of the cloaca allow turtles to exchange oxygen and carbon dioxide with water, similar to how gills function in fish. Cloacal bursae also help with buoyancy control. However, not all turtles have them, and it seems that the presence or absence of cloacal bursae is related to their environment and evolutionary adaptations. The Diamondback terrapins, for example, do not have cloacal bursae because they live in brackish water, where saltwater should not come in contact with their bloodstream. The author’s research students studied these terrapins and discovered this peculiar characteristic. Overall, this article provides facts and explanations about the respiratory mechanisms of turtles and their evolutionary adaptations.
Summary:
– Turtles cannot breathe out of their butts but have a unique adaptation called cloacal bursae.
– Cloacal bursae are sac-like extensions on the sides of a turtle’s cloaca.
– These bursae exchange oxygen and carbon dioxide between the bloodstream and water.
– Turtles with cloacal bursae can rely on them for gas exchange when they cannot reach the surface to breathe.
– Freshwater turtles that actively swim tend to have cloacal bursae, while turtles that primarily walk on the bottom do not.
– Diamondback terrapins and sea turtles do not have cloacal bursae, likely due to their habitat and the need to avoid saltwater contact.
Turtles Can Do What?! Unveiling the Fascinating Adaptation of Cloacal Bursae
Have you ever heard the strange notion that turtles can breathe out of their butts? While this claim is not entirely accurate, a remarkable aspect of turtle biology lends some credence to the idea. Enter the world of cloacal bursae, a unique adaptation showcasing nature’s incredible diversity. Let’s dive into the intriguing world of turtles and explore the fascinating world of cloacal bursae.
First things first, turtles cannot breathe out of their butts. Lungs, responsible for respiration, are connected to the trachea, mouth, and nose, not the posterior end of a turtle. However, this does not mean we should dismiss the entire concept. We must dig deeper to uncover the truth behind the intriguing idea. So, what exactly is happening with turtle butts?
In the world of reptiles, including turtles and birds, a single opening exists in the body called the cloaca. The cloaca serves as a conduit for various bodily functions, including eliminating digestive and nitrogenous wastes and expulsing reproductive products like sperm, eggs, or live-borne babies. It is a versatile opening that serves multiple purposes in these animals.
But let’s focus on the turtles. In some turtle species, the cloaca possesses two sac-like extensions on its sides. These extensions are lined with tiny finger-like structures called villi, similar to those found in the human intestine. These villi are loaded with blood vessels, allowing for the efficient exchange of oxygen and carbon dioxide between the bloodstream and the surrounding water.
So, while turtles are not truly breathing out of their butts, these sac-like extensions, known as cloacal bursae, function like gills in fish. When turtles expand their cloacal opening, they draw water into the cloaca and direct it into the bursae. The exchange of gases occurs within the bursae, enabling the turtle to obtain oxygen and eliminate carbon dioxide. It’s an ingenious adaptation that allows turtles to survive in unique environmental conditions.
One of the primary advantages of cloacal bursae is their usefulness during periods when turtles are trapped underwater, unable to reach the surface to breathe. For example, turtles in ponds covered with ice during winter rely on these pseudo-gills in their butts for survival. They can extract the necessary oxygen from the surrounding water, ensuring survival until they can access fresh air again. It’s an extraordinary feat of adaptation that highlights the resilience of these creatures.
Additionally, cloacal bursae play a role in buoyancy control, reminiscent of how submarines employ ballast tanks to adjust their depth in water. While most freshwater turtles possess cloacal bursae, it’s important to note that not all do. Turtles such as snapping, which predominantly walk on the bottom rather than swim, lack these sac-like extensions. Nonetheless, many active swimmers among freshwater turtle species possess cloacal bursae to aid in gas exchange and maintain buoyancy.
Interestingly, not all turtle species exhibit cloacal bursae. Take the diamondback terrapins, for instance. These turtles, closely related to sliders and map turtles that do possess cloacal bursae, do not have this adaptation. A closer examination leads us to conclude that terrapins inhabit brackish water, which contains a mixture of salt and freshwater. Similarly, sea turtles also lack cloacal bursae. This absence can be attributed to the potential harm saltwater could inflict on their bloodstream. Just as sailors adrift at sea cannot survive by consuming seawater due to its high salt content, turtles have also evolved to avoid saltwater contact.
In biology, we refer to the absence of certain structures as “secondary evolutionary losses.” Diamondback terrapins and sea turtles have lost their cloacal bursae over time, adapting to their respective environments. This evolutionary change ensures their survival and prevents the potential harm associated with saline waters. On the other hand, box turtles, which inhabit terrestrial environments, have also secondarily lost their cloacal bursae since they no longer serve a purpose for these land-dwelling creatures.
Next time you visit the zoo, pay close attention to the yellow-bellied sliders and map turtles as they adjust their depth in the water. Witness the mechanism of cloacal bursae in action. Marvel at the versatility and adaptability of these remarkable creatures as they navigate their aquatic habitats. And don’t forget about the diamondback terrapins, which employ a different mechanism due to their unique existence in brackish water.
Nature never ceases to amaze us with its intricate and diverse adaptations. Behind the seemingly strange claims lie scientific truths waiting to be discovered. So, let’s continue exploring the immense wonders of the animal kingdom, celebrating the unique and awe-inspiring aspects that make turtles and their cloacal bursae deserving of our fascination.
Dr. Joe Mendelson,
Director of Research
