Sea turtles and land turtles are from the same broader family, but there are key differences between these two types of turtles. The most obvious distinction is that sea turtles live in the water and land turtles live on land.
Many other distinctions between sea turtles and land turtles make them entirely unique creatures. Let’s take a closer look.
Sea Turtle vs. Tortoise (Land Turtle): An Overview
The main difference between sea turtles and land turtles is that sea turtles live in the water, while land turtles, also known as tortoises, live on land. There are also physiological differences, such as size, weight, and shell appearance.
Sea turtles are a type of turtle that lives in the ocean. They are reptiles and have a hard shell that protects them from predators.
Sea turtles can grow quite large, with some species reaching lengths of up to six feet. There are seven different sea turtle species, and they are in all oceans except for the Arctic and Antarctic.
Land turtles, also known as tortoises, are a type of turtle that lives on land.
They are reptiles and have a hard shell protecting them from predators. Land turtles can grow to be quite large, with some species reaching lengths of up to four feet.
There are many different species of land turtles, and they are on all continents except for Antarctica.
Now that we’ve looked at an overview of sea turtles and land turtles let’s take a closer look at some of the key differences between these two types of turtles.
| Trait | Sea Turtle | Tortoise (Land Turtle) | Turtle |
| Order | Testudines | Testudines | Testudines |
| Family | Chelonioidea | Testudinidae | Multiple |
| Feet | Flippers | Clubbed feet | Webbed feet |
| Shell | Streamlined shell | Domed shell | Streamlined shell |
| Diet | Omnivores | Herbivores | Omnivores |
| Habitat | Live exclusively in the ocean | Completely terrestrial | Live in freshwater and brackish habitats |
| Adaptations | Limbs and head cannot retract | Limbs and head can retract | Limbs and head can retract |
Sea Turtle vs. Freshwater Turtle
While both these types of turtles live in water, there is a big difference between sea turtles and freshwater turtles.
As their name suggests, sea turtles live in saltwater oceans while freshwater turtles live in freshwater. This means that sea turtles have to adapt to a completely different environment than freshwater turtles.
Sea turtles are much larger than freshwater turtles, with some species reaching lengths of over six feet. Freshwater turtles, on the other hand, rarely grow longer than two feet.
Sea Turtle vs. Snapping Turtle
Snapping turtles are found in both saltwater and freshwater environments and can grow to be quite large, with some species reaching lengths of over four feet.
While snapping turtles may seem similar to sea turtles, there are some key differences between these two types of turtles. Snapping turtles are much more aggressive than sea turtles and have attacked humans.[1]
Snapping turtles have a very different diet than sea turtles. Snapping turtles are carnivores, and sea turtles are omnivores, with some species mostly eating plant matter.
Related: Do Sea Turtles Bite?
Differences Between Sea Turtles and Land Turtles
The main difference between these two types of turtles is their habitat. Sea turtles live in the ocean while land turtles (tortoises) live on land. Each group of turtles has specific adaptations to help them thrive in their respective habitats.
Despite both groups being part of the larger turtle family, there is a big difference between a land-based and sea-based turtle:
- Limb shape and function
- Limb and head retraction ability
- Habitat
- Distribution
- Diet
Flippers vs. Feet
Sea turtles have flippers, while land turtles have legs. These different limbs help each type of turtle to move in its respective habitats.[2]
Sea turtles use their flippers for swimming long distances in the ocean. Land turtles use their legs to walk long distances on land.
For comparison, freshwater turtle species have feet like tortoises, but they are webbed to assist in swimming.
Retracting Limbs
Another difference between these two types of turtles is their ability to retract their limbs. Sea turtles cannot retract their flippers and head while land turtles can.
Sea turtles have a more streamlined shell to reduce drag while swimming. This means sea turtles can’t go into their shell – they don’t have enough internal shell space to accommodate retraction.
Habitat & Distribution
Their group names are rather self-explanatory; sea turtles live in saltwater oceans while land turtles live on land.
Sea turtles and tortoises’ habitats don’t overlap, except for when sea turtles come to shore to lay their eggs. Sea turtles are found in all oceans except the Arctic, while land turtles are on every continent except for Antarctica and Australia.
Diet
Most tortoise species are strictly herbivores, while most sea turtle species are omnivores[3]. There are a few exceptions to this rule. The green sea turtle is a herbivore, but other sea turtles such as the leatherback and loggerhead sea turtles are carnivores.
Tortoises that live in arid habitats often consume animal matter such as insects to get the moisture they need.
Similarities Between Sea Turtles and Land Turtles
The key similarities between these two types of turtles are that they are both reptiles with hard shells. Both groups also lay eggs, although sea turtles lay their eggs on land while tortoises lay their eggs in the sand.
Order Testudines
The group Testudines includes species whose bodies are surrounded by shells that are fused with their ribs and vertebrae. “Turtle” refers to all species in that group – including tortoises and sea turtles. [4]
The word “turtle” describes species that live in water, while the word “tortoise” is for species that live on land.
There is no strict scientific distinction between turtles and tortoises – they are both members of the group Testudines.
Shell Protection
All turtles have a hard shell protecting them from predators and the environment. The shell is in two parts: the carapace (top part) and the plastron (bottom part).
Ectotherm
Turtles and tortoises are ectotherms, which means they rely on the environment to regulate their body temperature.
This is one of the reasons why turtles and tortoises are in a wide range of climates – they can live in both cold and hot environments as long as they can find a way to regulate their body temperature.
Reproduction
Turtles and tortoises reproduce by laying eggs. The females dig a hole in the ground and lay their eggs in it. She then covers the eggs with sand or dirt to protect them from predators and the environment.
The eggs incubate for several weeks before they hatch.
Both groups also have temperature-dependent sex determination, which means that the temperature of the eggs during incubation determines the sex of the hatchlings.[5]
What’s The Difference Between a Freshwater Turtle and a Tortoise?
The main difference between a freshwater turtle and a tortoise is that freshwater turtles are aquatic, and tortoises live exclusively on land. Both are turtles, but tortoises are terrestrial types of turtles.
Aquatic turtles and tortoises are often mistaken and misnamed. All tortoises are technically turtles, but not all turtles are tortoises. Tortoise is a name that refers to completely terrestrial turtles.
There are a few other differences that can help you tell them apart:
- Freshwater turtles are found in ponds, lakes, and rivers, while tortoises are in arid habitats such as deserts.
- Freshwater turtles have webbed feet for swimming, while tortoises have stumpy legs for walking.
- Freshwater turtles have a streamlined shell that helps them swim, while tortoises have a dome-shaped shell that protects them from predators and the environment.
In general, tortoises tend to be more herbivorous as plant matter is more abundant in terrestrial habitats. Freshwater turtles have more choices of prey such as insects, fish, and frogs.
Final Thoughts
The main difference between a sea turtle and a land turtle is their habitat. Sea turtles live in the ocean, while land turtles live on land. Both groups are reptiles and have hard shells. They also lay eggs, although sea turtles lay their eggs on land while tortoises lay their eggs in the sand.
The word “turtle” describes species that live in water, while the word “tortoise” is for species that live on land.
There is no strict scientific distinction between turtles and tortoises – they are both members of the group Testudines.
