diamondback terrapins
The only TRUE terrapins!
Diamondback Terrapins, Malaclemys terrapin, are a North American species of turtle which are found in coastal regions, inhabiting river estuaries, salt water marshes, freshwater rivers, pools and even the open ocean.
The name is derived from the Native American Algonquian word torope and is the only species that correctly uses the word terrapin in its name. The word "terrapin" has since been adopted in Britain to incorrectly describe other species of freshwater turtle.
They are one of the most attractive species of turtle and their small size and intelligent and personable nature makes them very sought after as pets. In the past over-collection from the wild for the for food caused a huge decline in their numbers, fortunately there are some well established captive breeding projects now which helps sustain wild numbers and gives you the opportunity care for these fantastic animals.
Carolina Diamondback Terrapin
Malaclemys terrapin centrata
what makes diamondbacks different from other turtles?
Are they still a turtle?
Yes, Diamondback Terrapins are still turtles of the suborder Cryptodira, meaning "hidden neck" which refers to their ability to draw their head directly in to their body the same as Red-Eared Sliders or Cooters. They are an aquatic species who need a large amount of water but they're also sun-worshippers and love to bask on sandbanks and driftwood. They have large webbed feet and strong swimming muscles, the carapace is streamlined to enable swift movement through strong moving water.
All of the care advice provided on my general care for turtles should be followed, especially in relation to UVB lighting.
Personality
So, what makes them different?
Diamondback Terrapins are by far the most cocky, confident and tameable of any aquatic turtle I have ever kept. Even more friendly than the herbivorous Cooters and Painted Turtles. I keep mine in a large aquarium in my kitchen, which is the heart of my household and occupied nearly all day. Where my Yellow-blotched and Cagle's Maps will instantly dive into the water in their tanks on my approach, the Carolina Diamondbacks will stay on their basking area, allow a head and shell scratch and actively follow me around the tank. They will happily approach my hand in the water for contact and to hand feed, I have never been bitten by them (and they do have strong jaws so I am grateful!). There is an emotional intelligence in their eyes which only the Box Turtles share in my opinion.
Why is this? There was a study done by Alexis Rife in 2007 who made the following observation "This study investigated the social behaviour of juvenile terrapins while they were basking on a restricted site. Groups of familiar kin and nonkin, and unfamiliar kin and nonkin were tested. Familiar kin were found to bask in larger groups and showed a willingness to share the limited basking site. Unfamiliar nonkin also interacted, but were more aggressive. Unfamiliar kin and familiar nonkin were not distinguishable in their behaviors. These results suggest that terrapins form social groups based on both familiarity and relatedness." So in short - Diamondback Terrapins are social animals - I find they live well in groups in appropriate sized tanks, and even extend their personal social family to the other occupants of the house. The Terrapins see me as family!
Here is the full study - it's a great read view (bc.edu)
Fresh or Brackish Water?
One of the first subjects that comes up in Diamondback Terrapin care is "should we keep them in fresh water or brackish water?" A quick search on the internet will immediately throw up the answer that these are a species who inhabit river estuaries, where freshwater meets the sea, making a "brackish" environment. What this means is that the water contains more salt than fresh, but less salt than the open ocean. This assumption is an oversimplification. In realty, wild Terrapins live on average in brackish water. The actual truth is that their environment varies from freshwater rivers and into the open ocean and all of the various salinities in between. So how do we replicate this in captivity and what does it mean for the animal?
We have two issues created here. Firstly Diamondback Terrapins cannot drink saltwater, they NEED fresh water to drink. Secondly, Diamondbacks have not evolved to deal with large amounts of bacteria found in freshwater, instead, they rely on the salt in their brackish environment to kill it.
How do we solve this problem? There are a number of solutions - we can keep them in brackish water at a salinity of 1.014 ppt (parts per thousand) which we can create using aquarium salts and measuring with a handheld refractometer, a hydrometer or a conductivity meter. I won't go in to how to use these tools here. If we choose this approach we need to soak our terrapin in freshwater for 15 minutes once or twice a week to enable it to drink and flush out salts. This, to me, is too convoluted, prone to errors and open for forgetting to give your turtle fresh water. It's also completely unnecessary if we are caring for the aquarium properly.
Alternatively we can keep them permanently in freshwater. If we choose this approach we need to ensure that the water is kept very clean and free from bad bacteria. Fortunately Diamondbacks are strong swimmers which enables us to use powerful filters. Personally I keep mine in freshwater and use a Fluval FX6 filter to keep that water clean. Add airstones to dissolve oxygen into the water, carry detritus from the bottom to the top and promote gas exchange at the surface.
We can detect water quality issues as the terrapins will start to grow white patches of fungus on their skin, usually between the toes. This should be spotted and rectified immediately, a filter clean and partial water change is a good start. Bathing in salt water, cleaning with an iodine solution and dry docking can help to kill the fungus. If it is left untreated it can lead to necrosis and shell rot.
Northern Diamondback Terrapin swimming in the sea, Poquoson, Virginia
Malaclemys terrapin terrapin
Substrate
What to put on the bottom of the tank? The simplest is bare bottom. Easy to see the mess left behind and vacuum out, but it looks unattractive and doesn't give the terrapins the opportunity to dig, forage and bury in the bottom, which is all part of their natural behaviour.
Never use gravel. The turtles swallow it and it can get stuck causing gut impaction which can be fatal.
Children's play sand is sterile and safe and gives a great clean substrate to give them something to dig in. Its a good basic solution.
Crushed Coral is the best option, is it provides a rough, course substrate with a large surface area which helps to cultivate good bacteria to improve water quality. In addition, the coral dissolves in the water and "buffers" or raises the pH level. The terrapins can eat it and it will digest and provide valuable calcium and wear down their crushing plate in their mouth. The only downside is it's VERY expensive at around £10 a kg and that's not even to mention the environmental impacts of harvesting coral.
I use Crushed Oyster shell. It has all the benefits of Crushed Coral and has the advantages that it is a waste by-product of the seafood industry and is very cheap. It can be purchased as chicken grit and costs only £20 for 25 kgs! I use a whole 25 kg bag to cover the bottom of my 6 foot aquarium. If I used Crushed Coral it would cost over £200!
Diet
Diamondback Terrapins are evolved for those coastal regions and their natural diet reflects this. Their jaws have a palette designed to crush shells as they feast on molluscs and crustaceans. They're unlikely to eat much greenery unless by accident. Aquatic turtle pellets can form the bulk of the captive diet and this can be supplemented with prawns, shrimps, muscles etc. Just be aware that fresh seafood will foul the water and leave an oily film. They will only eat in the water as they lack the ability to swallow on land.
Diamondback terrapin subspecies
Location Location Location!
There are currently seven described subspecies of Malaclemys terrapin, the Diamondback Terrapin (there is an argument for only five subspecies, but as things stand, seven it is). The main defining feature is where they are found naturally occurring in the wild and normally it is obvious from the name - Northern, Carolina, Florida East Coast (shown as Tequesta on the map opposite), Mississippi and Texas. The other two subspecies, Ornate and Mangrove are not so obvious.
I will do my best to go into detail as to what separates the subspecies from each other below.
Northern Diamondback Terrapin
Florida East Coast Diamondback Terrapin
Northern Diamondback Terrapin
The Northern Diamondback Terrapin Malaclemys terrapin terrapin, ranges along the Atlantic coast from Cape Cod to Cape Hatteras. Its carapacial central ridge does not have terminal knobs on the vertebral scutes and the sides of the carapace diverge posteriorly. Carapace varies from uniform black to light brown with distinct concentric, dark rings. The plastron can be variable, yellowy orange to grey.
Carolina Diamondback Terrapin
Florida East Coast Diamondback Terrapin
Northern Diamondback Terrapin
The Carolina Diamondback Terrapin Malaclemys terrapin centrata, ranges from Cape Hatteras south along the coast to northern Florida. Its carapacial central ridge has no terminal knobs on the vertebral scutes and sides of the carapace are nearly parallel. The marginal scutes curl upward but it is otherwise so morphologically similar to M. t. terrapin that many cannot tell them apart. M.t.centrata do tend to be more colourful.
Florida East Coast Diamondback Terrapin
Florida East Coast Diamondback Terrapin
Florida East Coast Diamondback Terrapin
The Florida East Coast Diamondback Terrapin Malaclemys terrapin tequesta occurs along the Atlantic coast of Florida. The carapacial ridge has rear facing tubercles or knobs. The carapace is dark or tan with no pattern of concentric light circles. The centre of its vertebral and costal scutes may be slightly lighter than surrounding areas.
Mangrove Diamondback Terrapin
Mississippi Diamondback Terrapin
Florida East Coast Diamondback Terrapin
The Mangrove Diamondback Terrapin Malaclemys terrapin rhizophorarum is restricted to the Florida Keys. Its carapacial ridge has terminal bulbous knobs on the vertebral scutes, and its shell is strongly rectangular. The carapacial scutes have no light centres, and the edges of the marginal and plastral scutes are often highlighted with black. Spots on the neck often fuse to form a streaked pattern, and the hindlegs may be striped.
Ornate Diamondback Terrapin
Mississippi Diamondback Terrapin
Mississippi Diamondback Terrapin
The Ornate Diamondback Terrapin Malaclemys terrapin macrospilota, ranges along the Gulf coast from Florida Bay to the panhandle. Its carapacial ridge has terminal, often bulbous, knobs, and the vertebral and costal scutes contain orange or yellow centres.
Mississippi Diamondback Terrapin
Mississippi Diamondback Terrapin
Mississippi Diamondback Terrapin
The Mississippi Diamondback Terrapin Malaclemys terrapin pileata, ranges along the Gulf coast from the Florida Panhandle to western Louisiana. Its carapacial ridge has termina tuberculate knobs. The carapace is oval shaped and lacks light centres to the vertebral and costal scutes. Top of the head, upper lip, neck, and limbs are black or dark brown, the upturned edges of marginal scutes are orange or yellow, and its plastron is yellow and often dusky.
Texas Diamondback Terrapin
Texas Diamondback Terrapin
Texas Diamondback Terrapin
The Texas diamondback Terrapin Malaclemys terrapin littoralis is found along the Gulf coast from western Louisiana to western Texas, and has a carapacial ridge with terminal knobs offset by deeply dished costal scutes with distinct light centres, the plastron is pale or white, the upper lip and top of head whitish, and the neck and legs greenish grey with heavy black spotting.
Colour variations & Morphs
Speckled
White Concentric
White Concentric
The most common naturally occurring skin colouration. The skin is white or light grey interspersed with many fine black spots, or speckles. Carapace can be golden, caramel or black.
White Concentric
White Concentric
White Concentric
White Concentric Diamondbacks are arguably the most beautiful variation. The skin is pure white and marked with large black blobs or stripes. The carapace is generally golden with thick black rings on each costal and vertebral scute. Strangely the term "Concentric" in relation to Diamondback Terrapins actually refers to the skin markings, and not the concentric rings on the carapace. This does seem counterintuitive and it's use has probably evolved over time as more people keep and breed these turtles in captivity.
Blue Concentric
White Concentric
Blue Concentric
Blue Concentric Terrapins are the same as White Concentric Terrapins other than the fact that the skin has a bluey grey hue which can vary in shade. This colour is rarer, more desirable and therefore more valuable than White.
Golden
Black Velvet
Blue Concentric
The carapace is a light yellowy brown with finer concentric rings giving a golden appearance. The skin can be white or blue and be Speckled or Concentric.
Caramel
Black Velvet
Black Velvet
A darker browner carapace than the golden with thicker concentric rings on the costal and vertebral scutes. Skin can be white or blue, Speckled or Concentric.
Black Velvet
Black Velvet
Black Velvet
A deep black carapace and smoky grey plastron. If the scute rings are visible at all they take on the appearance of black panther leopard spots. Skin white or grey and can be Speckled or Concentric.
Blue
White
White
A specially bred colour morph where the skin markings are diminished and the skin becomes a pale translucent blue. Generally found in the Ornate subspecies. Very desirable, very expensive.
White
White
White
A specially bred colour morph where the skin markings are diminished and the skin becomes pure white. Generally found in the Ornate subspecies. Very desirable, very expensive.
Pink
White
Super Texan
A specially bred colour morph where the skin markings are diminished and the skin becomes a bright translucent pink. Generally found in the Ornate subspecies. Very desirable, very expensive.
Super Texan
Super Texan
Super Texan
Super Texan is short for Super Light Texas Diamondback Terrapins. Malaclemys terrapin litoralis with paler shells, pure white skin and few large black skin blotches.