Tortoises are some of the most interesting and majestic creatures that live on our planet. Members of the Testudinidae family, tortoises are often confused with their similar-looking relative turtles. Although the two are genetically and physiologically different.
Between the two, turtles are often considered the swimmers, although this does raise an important question: can tortoises swim?
Oftentimes, tortoises will use shallow waters to cool themselves off on hot days. That being said, tortoises can’t swim.
For the most part, this can be attributed to the tortoises’ physiological shortcomings. Sea turtles have flippers, and freshwater turtles have webbed feet. Tortoises, on the other hand, have elephantine feet.
These elephant-like feet are large and sturdy, featuring short nails that are great for walking on long stretches of uneven land. In a general sense, tortoises’ feet are great at walking, but not great at swimming.
Additionally, the tortoises’ shell doesn’t help its aquatic inefficiencies. Aquatic turtle’s shells are streamlined and aerodynamic, allowing them to cut through the water with ease. Tortoises’ shells are high-domed and incredibly bulky, which gives the tortoise a great bit of difficulty while trying to swim.
The tortoises’ habitat may also play a role in why the species isn’t able to swim. Over time, they’ve adapted to live on land, using their elephantine legs to navigate the grasslands and forests they live in.
Because of their relatively dry habitat, tortoises have never had the need to learn how to swim, or to adapt their legs or shells to make swimming easier. Instead, they have a sturdy shell that protects them from predators. And their legs are evolved so they can traverse difficult terrains.
Finally, land tortoises are unable to hold their breaths for long periods of time. Unlike turtles, if tortoises are submerged in water for too long, they will drown.
Although, this answered your question, we will cover everything in more depth. There is a significant amount of physiological data that elaborates on the tortoises’ inability to swim. Continue reading below, and we will go over those in more depth.
Adaptations
Both turtles and tortoises are reptiles, and part of the Testudinidae family as mentioned above. What does that mean?
It’s easiest to think about the turtle and the tortoise as cousins. Two species that share a recent, common ancestor, but are genetically different nonetheless.
That recent common ancestor (referred to as a RAC in genetics), probably featured a mixture of the turtle and tortoises traits. But it’s hard to know for sure. Whatever the case, a group of these species was probably separated from the rest, and over time evolved traits that helped it survive in its new environment.
Whether this new group evolved traits that helped it live in the water, like the turtle, or traits to help it live on land, like tortoises, is unclear. Statistically, it’s likely that they both evolved in some way to help better survive.
The turtle needs physiological adaptations to survive like:
- Flippers or webbed feet to help with swimming
- Streamline shells
- Ability to stay underwater for hours at a time
Tortoises, on the other hand, need physiological adaptations like:
- Strong, club-like feet to aide with walking long distances
- Large shells that help with defense
The Physiology Of A Tortoises’ Feet
That being said, they have several specific physiological differences in their feet that contribute to the difference in their swimming ability.
Sea turtles have flippers instead of feet. That makes them very clumsy on land, but incredibly efficient in the water. Evolutionarily, this makes sense. Because the sea turtle spends almost the entirety of its life in the water. Only going on land to lay eggs.
Freshwater turtles differ from sea turtles in that they have feet, rather than flippers. Although, unlike tortoises, the freshwater turtle’s feet are webbed, allowing them to spend time on land and water.
Finally, unlike the freshwater or sea turtle, tortoises have elephantine feet. They are called that because of their resemblance to elephant feet.
Thick, large, and sturdy, the tortoises’ feet are ideal for walking long distances over difficult terrain. With that said, they’re absolutely awful at swimming. Imagine trying to swim, but being unable to spread your fingers to catch water! That’s what tortoises has to deal with.
The Physiology Of A Tortoises’ Shells
Aquatic turtle’s shells, whether freshwater or sea turtles, are incredibly hydrodynamic. That allows them to glide through the water with minimal drag.
The hydrodynamics of a turtle’s shell are accomplished through a particular shedding mechanism. Turtles shed their old shells as a new one grows underneath. That helps prevent the shell from becoming domed.
Unlike turtles, tortoises’ shells are high-domed, because they don’t shed their shells as a new one grows beneath. While this makes for a bulky shell that isn’t fit for swimming, it also helps protect tortoises from any predators that might attack them.
How Habitat Plays A Role In Physiology
Luckily for tortoises, they don’t, usually, find themselves in situations where they have to swim. In fact, while some turtles spend their whole lives in the water, tortoises live exclusively on land. And usually land that doesn’t feature many water outlets.
Because of this, it’s alright that tortoises aren’t capable of swimming! In fact, if tortoises were capable of swimming, despite its non-aquatic habitat, it would be an evolutionary anomaly.
Unfortunately, that means that if tortoises are left alone in a large body of water, it will most likely drown. This is especially true if tortoises are submerged in the water. Otherwise, if they’re floating in a lake or pond, they could potentially float to the edge and climb out.
Although they cannot swim, tortoises love to soak in shallow water. Cooling themselves and hydrating at the same time. Make sure, if you are responsible for one of these reptiles, that they have enough water to drink and cool off in, but not enough to drown in!
