Sea turtles are distinguishable by their patterned shells. It’s a feature that makes sets the sea turtle apart from other reptiles. But, have you ever wondered what sea turtles use their shells for?
Sea turtles use their shells to protect themselves from many things. This can include predation, abrasion, and venom from jellyfish. The top of a turtle’s shell is called a carapace. This large and bony body part is lightweight and allows the turtle to swim fast and away from predators.
Now that you’ve learned a couple of things about a sea turtle’s shell, let’s go more in-depth. This guide will go over everything you need to know about sea turtle shells.
Let’s dive in.
What do sea turtles use their shells for?
Sea turtles use their shells for protection. This protection can be from predators or abrasion against rocks.
Sea turtle shells can also host many small organisms. They can also be a feeding station for other species.
There are many reasons why they need their shells. We’ll go over these reasons in more detail.
Predators
Since sea turtles cannot retract into their shell, sea turtles have different methods to prevent being preyed on.
The shell is hard and bony, which prevents a predator from being able to bite the sea turtle’s skin. It’s also lightweight which allows the sea turtle to swim away quicker.
Alongside their shells, their body is streamlined which makes them fast swimmers. This helps adult sea turtles get away from large predators like sharks and killer whales.
With their large fore flippers and small hind flippers, they are powerful swimmers. But, when on land, they aren’t able to move as easily and are very slow.
This is why female sea turtles are often monitored during nesting season. It prevents predators from attacking the female sea turtle and her eggs.
Alongside physical protection, a sea turtle’s shell can help them camouflage. This provides protection before they are attacked in the first place.
Abrasion
Sea turtles like to find food to eat in small crevices. Often, this food is hidden under many rocks with can damage a sea turtle’s skin.
The shell provides armor for the sea turtle and allows it to fit into these spaces without grazing the skin. Injury to the sea turtle’s skin can result in the inability to escape from predators.
It’s important for the sea turtle to be able to swim, as sea turtles can drown if they don’t resurface. They can only hold their breath for 4-7 hours.
Rocks in the ocean are very hard, which can cause a sea turtle to bleed. This is dangerous as it can attract a plethora of nasty predators like sharks.
Depending on where the sea turtle lives and its diet, many species won’t be affected by abrasion. For species like the hawksbill, they need protection from rocks as they eat sea sponges from small gaps.
Prey
Many sea turtles eat jellyfish. Jellyfish make up a large portion of a sea turtle’s diet.
Jellyfish are poisonous, and their sting can be painful for humans. But, the sea turtle has adapted to protect itself from the venom of the jellyfish with its shell.
These adaptions can range from the shell to their skin. All of them help protect a sea turtle from pain and nasty stings. These include:
- A shell that acts as armor
- Thick skin around the mouth
- Lining in their throats and stomach
- Closing their eyes when they attack
First, the turtle attacks from the top. Sea turtles have sharp beaks instead of teeth. This separates the jellyfish from its tentacles which contain the most venom.
Once they eat the jellyfish, the lining of the throat and stomach protects them from the jellyfish stings. It also gets rid of seawater from the jellyfish.
Their hard shell protects them from stings by the jellyfish. The shell does have nerve endings, but not enough to cause major pain to the turtle.
While attacking the jellyfish, turtles close their eyes to stop the venom from entering their eyes. This can be painful for the turtle, so they have learned to hunt jellyfish without their eyes.
Micro-organisms
In the ocean, there are many different micro-organisms. Most of them rely on bigger animals for a home and food.
A sea turtle’s shell often hosts many epibionts, which are small creatures that live on the surface of other animals.
There are different kinds of epibionts, some of which you might be familiar with already. This includes:
- Algae
- Barnacles
- Small crabs
These epibionts can also move from reef to reef, thanks to the sea turtle. This expands their genetic diversity and habitat.
They are harmless to the sea turtle, but if there are too many this can affect the sea turtle. It can weigh down their shell, making it harder to swim.
This is where small fish can help. Fish eat these epibionts off the sea turtle’s shell. This cleans the shell whilst the fish get a nice meal.
This is why sea turtles are very important to the marine ecosystem. They provide food for small fish, and homes for even smaller organisms.
What shape is a sea turtle’s shell?
This often varies between species of sea turtle. Many species can have an oval-shaped carapace, and some can have a heart-shaped carapace.
The coloring of a sea turtle’s shell can be different for each species. Colors can vary from brown to green.
They can also range in size. The leatherback sea turtle has the largest shell, as it’s the biggest sea turtle species.
The patterns can be assorted from species. The pattern depends on the number of scutes on the shell. This can be helpful for identifying species of sea turtle.
The average of scutes on a shell is about 5 central scutes and 4 to 5 lateral scutes. Each species has a different arrangement of the scutes on their shell.
How much does a sea turtle shell weigh?
Each sea turtle has its own shell height and weight. This table below shows all of this information here:
| Species | Carapace length (in.) | Weight (lbs) |
| Flatback | 32 – 39 | 132 – 185 |
| Green | 31 – 47 | 150 – 507 |
| Hawksbill | 21 – 45 | 95 – 201 |
| Kemp’s Ridley | 20.5 – 28 | 66 – 110 |
| Leatherback | 47 – 70 | 441 – 1,984 |
| Loggerhead | 35 – 41 | 220 – 397 |
| Olive Ridley | 20 – 30 | 73 – 110 |
As you can see in the table above, the olive ridley is the smallest species of sea turtle. The loggerhead is the largest species and can grow up to 2,020 lbs.
A sea turtle’s shell length and weight depend on the age of the turtle. Mature sea turtles are larger than their juvenile counterparts.
Should I avoid turtle shell products?
You should never buy products made from turtle shells. These items are often sold in continents like South America including the Caribbean, Asia, and Africa.
The most common turtle shell items are:
- Bracelets
- Earrings
- Rings
- Guitar picks
- Combs
- Fans
Turtle shell products are identifiable by their brown, and/or orange colors. They are also transparent and flexible items.
These items are made from the endangered hawksbill sea turtle. It is illegal to buy, sell or take these items home in the US.
To avoid buying these items, you can ask the seller. The best way to avoid them is to ignore all products that look like turtle shells even if it’s plastic.
In Conclusion
Sea turtles use their shells for protection from predators, abrasion, and jellyfish venom. Their shells can also host many epibionts which can be food for small fish.
Many turtles have an oval-shaped or a heart-shaped carapace. A shell can range in size, color, and pattern based on the species of sea turtle.
Olive ridleys have the smallest shell weight and height. Leatherbacks have the largest shell weight and height.
Avoid buying all turtle shell products when you are going on holiday. These are illegal in the US and are made from the endangered hawksbill sea turtle.
