A diamondback terrapin makes a great pet for someone who’s up for a slight challenge. They need brackish water, but the water isn’t difficult to create once you get the hang of it. Terrapins are social, both with their caretaker and with each other. Many people enjoy having larger enclosures with multiple terrapins.
What Is A Diamondback Terrapin?
An adult terrapin has concentric, diamond-shaped grooves and colors on each of their carapace (upper shell) scutes. The color of the carapace ranges from gray, brown, to nearly black.
An adult diamondback terrapin also has pale gray to black skin interspersed with dark spots and stripes.
Males are far smaller than females, only reaching a length of up to 5.5 in (14 cm). Females can reach lengths up to 11 in (27.9 cm). You can distinguish younger females from males because their heads are larger, their tails are shorter, and their jaws are wider. Males often have darker skin with dark spots above their mouth, resembling a mustache.
Diamondback terrapins are aquatic turtles with webbing on their feet. Their large legs are muscular, making them strong swimmers. Unlike other aquatic turtles in Florida, the diamondback terrapin is used to strong currents and tidal changes.
Diamondback terrapins are the only turtles in Florida who live in brackish water. Because they deal with salt, they have glands that remove extra salt from their bodies. These are the same glands that sea turtles have. The glands work by creating tears full of sodium chloride.
- Common Names: Diamondback Terrapin
- Scientific Name: Malaclemys terrapin
- Origin: Eastern & South-central United States
- Diamond Terrapin Size (Length): Up to 11 in (27.9 cm)
- Diamondback Terrapin Lifespan: 25-40 years
- Enclosure Size: 75+ gallons
- Temperament: Peaceful & social
- Ease of Care: Moderate
Diamondback Terrapin Range
Terrapin turtles live along the Gulf coast and the coast of the Atlantic Ocean. They live as far north as Cape Cod, Massachusetts and as far south as Corpus Christi, Texas. In Florida, they live as far south as the Florida Keys.
Diamondback Terrapin Habitat
Diamondback terrapins prefer to inhabit salt marshes and bays with shallow water. They usually stay in brackish water, but you may occasionally see them swimming in the ocean.
Unlike sea turtles, they cannot tolerate seawater for long periods of time. They become dehydrated quickly when exposed to levels of salinity that are too high, so they can’t spend much time in the open ocean.
Behavior & Temperament
A diamondback turtle hibernates over the winter months, burying themselves completely in soft mud at the bottom of tidal creeks. They remain underwater for the entire winter season, staying alive by taking dissolved oxygen from the water.
It is hard to observe these turtles because they are skittish and swim away whenever they sense danger. They are best observed when they are basking on rocks. They seem to be sociable turtles and even bask together, sometimes sitting on top of one another.
Reproduction
Male diamondback terrapins become sexually mature at just 3.5 years of age. Females become sexually mature around six years.
Terrapins mate during early spring, usually between March and April. Large groups of terrapins will sometimes gather in bays to mate. Like sea turtles, terrapins climb onto land to mate and lay eggs. Females seek sandy beaches or sand dunes to dig their nests.
They nest in summer, usually between May and June. Female terrapins lay two to three clutches of eggs a year, each clutch containing 4-23 eggs. It is most common for them to lay 4-8 eggs.
Like sea turtles, diamondback terrapin eggs have low survival rates. The eggs are easy prey for raccoons, seabirds, crows, and large fish.
Incubation lasts for 60-85 days, depending on the temperature of the soil.
Diamondback terrapin hatchlings often overwinter in their nest where it is safer. They emerge from their nest in the spring when the temperature rises.
Terrapins do not spend their whole lives in freshwater. The University of Michigan Museum of Zoology describes where they live at different ages:
“Wild hatchlings may spend their first years upstream in creeks. These creeks may either be brackish or relatively fresh water. As the hatchlings age, they move down to the salty marshes where nutrients and good nesting sites are plentiful.”
What Do Diamondback Terrapins Eat?
Diamondback terrapins are almost completely carnivorous, but they occasionally eat plant matter. Their diet mainly comprises aquatic snails, crabs, mussels, and clams. They have exceptionally powerful jaws with hard plates made for crushing.
Walking along a salt marsh, you’re likely to hear terrapins as they catch their daily meal. The North Carolina Wildlife Resources Commission describes their eating habits:
“Often you will hear a diamondback before observing it in the marsh. The terrapin’s powerful jaws make a popping noise as the terrapin eats the periwinkle snails and other mollusks found in the marsh grass.”
They may also eat carrion, fish, insects, and worms when they’re not dining on hard-shelled animals.
How To Care For A Diamondback Terrapin
Enclosure
Terrapins are one of the harder turtles to take care of because they need brackish water. You’ll need a hydrometer to read the salinity in the tank, and know how to create brackish water.
In the wild, you’ll sometimes see terrapins in freshwater or saltwater for short periods of time. To stay healthy, they need to be in brackish water for most of their lives. In saltwater, they become dehydrated quickly. In freshwater, they become sick from lack of salt.
Their enclosure needs to be deep enough that they can swim and dive. You’ll need at least 75 gallons, but larger is better. The water depth should be at least three times the length of your turtle’s shell.
Most of their enclosure should comprise water, but you’ll want to provide them with a basking spot as well. A rock or small log above the waterline is good.
Diamondback terrapins are messy eaters, so be sure to have good filtration or their shell and skin may develop rot.
Substrate
Crushed coral is the best substrate for terrapins because it provides them with calcium to keep their shells and bones healthy.
Decorations
Terrapins will appreciate a variety of aquatic vegetation, logs, rocks, and driftwood that mimic their natural environment.
Temperature & Lighting
UVB lighting is essential for the health of your turtle’s shell and bones. Position a UVB bulb alongside a heat lamp to create a basking spot. The basking spot should be about 12 in (30.5 cm) from where your turtle sits so they don’t burn. The basking spot should be about 90° F (32° C).
Keep the water temperature between 70-78°F (21.1-26°C). A UVB heat bulb may be enough to keep the water warm, but you may also need to buy a water heater.
Tank Mates
Unlike most turtles, diamondback terrapins are social and prefer the company of other terrapins. They prefer being with members of their immediate family the most, so if you can, try to buy a few siblings from the same breeder.
Ensure that you provide enough space for a group of turtles. Having an overcrowded tank will cause stress and fighting.
Diet
Diamondback terrapins mostly eat meat. Give them a staple diet of commercial turtle pellets along with a mix of dried shrimp, snails, smelt, worms, and other kinds of seafood.
Avoid feeding them meat like chicken and beef. They don’t eat these in the wild, so they likely can’t digest it.
You should feed adults once every other day.
Conclusion
It’s difficult to impossible to get a terrapin in many states. But, if you live somewhere they’re legal, they make wonderful pets. They are bright and colorful, sociable, and have vibrant personalities. They are a bit more difficult to care for than your average aquatic turtle, so be prepared for a challenge if you buy one.
FAQs
Diamondback terrapins have powerful jaws, so they’ll do some damage if they bite you. They’re not likely to bite you though, and are more likely to swim away if they sense danger. Terrapins are social and enjoy interacting with their caretakers.
The International Union for the Conservation of Nature (IUCN) monitored the populations of diamondback terrapins in 2018 and found them to be “vulnerable” with decreasing populations.
Their greatest threats include housing, commercial, urban, and recreational development. They are also in danger from oil and gas drilling, transportation, recreational activities, pollution, invasive species, climate change, and fishing and harvesting.
Whether it’s legal to own a diamondback terrapin depends on where you live in the United States.
For instance, the Florida Fish and Wildlife Conservation Commission (FWC) passed a new regulation in 2021. The new regulation makes it illegal to possess a diamondback terrapin without a permit.
The regulation came about largely because Florida has a tremendous problem with people taking wild turtles to keep as pets or for food. Now that the diamondback terrapins populations are declining, officials are becoming more concerned.
Florida residents who already have diamondback terrapins may keep their pets, they just need to be registered. This includes privately owned pets and educational animals. Going forward, Florida residents cannot buy diamondback terrapins for private or commercial use. It is still possible for educators, exhibitors, and researchers to keep and/or collect terrapins as long as they apply for a permit.
