Outdoor pond that housed several male ornates.

   The care of diamondback terrapins raises several issues that distinguish it's captive husbandry from that of other aquatic turtles.  The objective of this section is not to provide detailed information about the general maintenance and set-up of aquatic turtles, but to address those issues that are specific to the genus Malaclemys.  There is currently plenty of web space devoted to the care and maintenance of aquatic turtles in general, and this information will be linked to appropriately.


    Diamondback terrapins, like all other native chelonia, can be housed either indoors or outdoors.  While there are advantages and disadvantages to either method, outdoor setups are preferable.  Indoor housing is restrictive in size and the use of artificial sunlight is necessary.  However, this method does provide protection from predators as well as the elements and tends to be easier to maintain.  Outdoor setups, while demanding a little more maintenance, affords the keeper and the terrapins access to more expansive housing.  This is important since females can grow up to 9 inches in length.   Adult terrapins can easily be accommodated in outdoor ponds, but if kept indoors, at least a 60 gallon tank would be required.  A word of caution though: all terrapins should be adequately protected from potential predators if kept outdoors.

   Another reason for providing generous space in housing diamondbacks is because terrapins tend to be very messy eaters.  Terrapins are naturally conditioned to bite into the hard shells of crabs, mussels, snails, etc. so their prey is seldom swallowed whole.  Instead, they break off chunks of food with their powerful jaws, leaving  unwanted scraps to float around in their water.  Consequently, unless one feeds them in a separate environment (which is a good practice), terrapins will foul up their water very quickly, even with adequate filtration.

    In addition to a generous body of water, diamondbacks also require a large basking area.  Most aquatic turtles benefit from periods of drying out and diamondbacks are certainly no exception.  Providing an adequate basking area will help cut down on fungal infections that can attack the skin and shell.  Basking sites can easily be built from slate rock, river rocks, cork bark, etc.    Care must be taken to ensure that all natural rocks be devoid of sharp edges that could injure the terrapins.  Artificial sites can also be purchased from pet supply stores or shows in the absence of natural ones.

    The basking site should be illuminated by a heat lamp (temperature should be in the mid 80's F at the basking spot) and a UVB light if housed indoors.  The heat lamp will simulate the warmth of the sun's rays while the UVB bulb provides proper wavelengths of light that stimulate essential vitamin and calcium synthesis.  Photo periods should be equivalent to the natural day cycle for the particular season.


    Adequate filtration is absolutely essential to the health of diamondbacks.  Good water quality provides a stress free, pollutant free and oxygen rich environment that will support vibrant and healthy terrapin.  Unfiltered water however, will be rich in toxic ammonia and nitrite gases derived from terrapin waste.  Both ammonia and nitrite have devastating effects on the health of terrapins and can cause bacterial and fungal infections, both internally and externally on the shell and skin.  Neonate diamondbacks are especially sensitive to poor water quality and the keeper must be extra diligent in ensuring premium water conditions for them.

    The most essential method of filtration is biological filtration.  Biological filtration is basically the culturing of nitrifying bacteria that convert ammonia and nitrite into less harmful nitrate.  In fact, nitrate gases are only harmful in extremely high concentrations.  The culturing of bacteria is done on material that contain large amounts of surface area.  Examples of biological filters are wet dry filters, Bio-wheels, sand filters and undergravel filters.

    Mechanical filtration also plays an important role in the terrapin environment.  This method employs media such as sponges and floss to trap waste particles.  However, although the particles may have been removed from our sight, please bear in mind that they are still in the terrapins' environmental system and must still be disposed of effectively and frequently through rinsing.  Examples of mechanical filtration are canister filters, power filters, submersible filters, diatomic filters and box filters.

    Chemical filtration is often employed alongside mechanical filtration.  Simply put, chemical filtration removes odors and colors through chemical reactions.  Examples of chemical media are carbon and zeolite.

    In addition, other filters to take into consideration when setting up diamondback environments are protein skimmers and U.V. sterilizers.  However, most protein skimmers are ineffective in freshwater and are only effective in brackish water with a specific gravity of 1.019 or more.

Brackishwater Debate

    There is currently much debate over whether diamondback terrapins can thrive in freshwater as they do in their natural brackish environments. Most hobbyists would rather not have to contend with the hassles of a brackishwater setup, while others would prefer to house their terrapins with other freshwater species in a community environment.  Numerous herpetocultural writers and suppliers alike have touted the ability of diamondbacks to be housed in freshwater, while others cite research suggesting that diamondbacks are susceptible to skin and shell ailments when kept in freshwater.

    The Diamondback Terrapins eGroup is itself divided on this subject with advocates for both types of environments.  The fact that there are keepers who maintain their diamondbacks in both fresh and brackish environments seem to suggest that the species is tolerant of extreme fluctuations in salinity levels.  There are numerous documented cases of diamondbacks that have adapted well to living in freshwater.  This seems to be the case particularly in captive bred specimens.  This may be due to the observation that hatchling diamondbacks usually start off upstream in the early parts of their lives and then gradually head downstream towards brackishwater estuaries and lagoons.  An unpublished description of diamondbacks compiled by Kathy Nemec of U.S. Fish & Wildlife has the following interesting observations:

    "the appetite of terrapins held in seawater, without access to freshwater, gradually becomes depressed, reducing their normal intake of food by 46-78% (Davenport and Ward, 1993), and possibly reducing their incidental intake of sodium."
    "adult terrapins are capable of spending several weeks in seawater without access to freshwater, but they cannot survive indefinitely.  Hatchlings are also severely affected by long exposure to seawater.  In the laboratory, hatchlings were not capable of growth in concentrations of 100% seawater.  Limited growth was achieved in 50% and 35% seawater with periodic access to freshwater, and in pure freshwater.  However, a very distinct growth optimum was seen in hatchlings raised in 25% seawater concentration (Dunson, 1985)."
    "early trappers holding terrapins for sale found that providing freshwater ensured greater survival (Dunson, 1970), and reported seeing them drinking rainwater in the wild."

    Consequently, the Diamondback Terrapins eGroup advocates neither freshwater or brackishwater but leaves the decision solely to the discretion of the keeper.  The exception to this would be in the case of wild caught individuals or captive bred specimens in poor health - these should best be kept in brackishwater.  Salt acts as a very effective disinfectant and very likely protects terrapins from various shell and skin infections that could occur in freshwater.  There are various bacteria and parasites that are found in both freshwater crustaceans like crayfish and shrimp, which if fed to diamondbacks can cause severe shell and skin infections.  However, sufficient salt in the system (1/2 cup of rock salt per ten gallons of water) would quickly neutralize such pathogens.  In fact, commercial grade marine salt mixed to a specific gravity of 1.006-1.007 is probably pretty close to the 25% seawater concentration cited earlier.


    Diamondback terrapins are ravenous eaters by nature and will consume a variety of foods readily when well adapted.  Captive bred specimens have no problem eating commercial turtle foods such as Aquamax, Reptomin and other food sticks.  However, older wild caught specimens can be quite stubborn in their refusal to eat prepared foods and the owner may have to resort to replicating their diet in the wild.  If such is the case, smelt is a good staple food for terrapins and is more nutritious, not to mention cheaper than feeder goldfish.  Cooked shrimp is also a good food source but should be offered only in moderation for fear of pathogenic contamination.  Freshwater crayfish, which carry bacteria that cause shell rot, must be avoided at all costs.

    Adult terrapins should be fed once daily while hatchlings and juveniles should be fed several times a day.  In addition, calcium should be offered to terrapins for good shell and bone development.  Several good sources for calcium are crushed coral (used as a substrate), calcium blocks and cuttlebones that are sold in pet supply stores for birds.


    Sexual maturity in diamondbacks are dependent upon size and not necessarily on age.  Males reach maturity at 4" while females can be sexually mature at 6".  Hence, captive bred male diamondbacks can be sexually mature as early as 1.5 years and females at 3.  However, growth rates in wild diamondback populations are much slower and usually take twice the amount of time for wild individuals to become sexually mature.

    Here are some hints to sexing diamondbacks:

1) Length of the tail - males tend to have a larger and longer base to their tails.  Their cloacal opening is further from the base than females'.  Overall, a male's tail is about 1.25x longer than a similarly sized female's.  Females have have only a short base to their tails which tapers down in a skinny, almost concave manner.

Female diamondback          Male diamondback

2) Height of shell - males tend to have flatter shells than females.
3) Females tend to have large and bulky heads, whereas males have skinny necks and small heads.
4) Overall look - females are generally bulkier in appearance while males tend to be thinner and more streamlined.

   Copulation occurs in the waters in early spring and females start depositing their eggs from April through late July on the sandy banks of marshes, estuaries and lagoons.  A single female can lay anywhere from 4 to 12 eggs per clutch, and multiple clutches are common, especially in captivity.

    Diamondback eggs should be incubated in moist vermiculite at a temperature of 80-85 degrees Fahrenheit, taking care not to change the orientation or position of the eggs.  Interestingly enough, the sex of diamondback terrapins can be determined by incubation temperature.  Males are hatched at lower temperatures whereas females are determined at higher temperatures.  Phil Allman, an environmental specialist from Collier County, FL states that "the sex determination period for eggs is during the second trimester between stages 22-28 based on Miller's (1982) 31 stages of turtle development.  Time wise, this corresponds to 30 to 45 days (based on a 60 day incubation)...  It is during these stages that the steroidogenic hormones are produced and it is these hormones that determine which steroids are produced, thus determining the sex."

Hatchling emerging from its shell.

 Hatchling Ornate Diamondback Terrapin showing remnants of its yolk sac.  Photos from Jungle Exotic Petshop, Japan.

    Diamondback eggs will incubate for about 2 months before hatching.  Hatchling diamondbacks will break through their leathery shells with their egg tooth located at the tip of the snout.  After hatching, babies may spend anywhere from hours to several days in their egg shells before venturing out into the world.  During this time, the hatchlings are surviving on the nutrients stored up in their umbilical sac, which is a rather gross looking liquid filled protrusion in the middle of their plastron.  The sac shrinks as the nutrients are used up until the only evidence left of it will be a slit in the plastron.  This too, along with the egg tooth will disappear within weeks.

Newly hatched Northern Diamondbacks from Jungle Exotic Petshop, Japan.

Newly hatched Ornate Diamondbacks from Jungle Exotic Petshop, Japan.

    Hatchling diamondbacks should be offered a variety of live foods at the beginning.  Black worms, blood worms, small snails, guppies and small crickets are good food sources.  Prepared foods should be introduced once the hatchlings are eating well; the hatchlings should slowly be weaned off live foods as a staple.

Side view of Northern Diamondback hatchling (L) and Ornate Diamondback Hatchling (R) from Jungle Exotic Petshop, Japan.


    Hibernation in diamondback terrapins is dependent on geographic location.  Generally, northern populations hibernate through the fall and winter months, whereas southern populations do not hibernate at all.  Thus, depending upon the subspecies kept, diamondbacks may not have to be hibernated at all in captivity and still be reproductively active.

    It is generally recommended that juvenile terrapins not be hibernated in captivity until two years of age due to their fragile size.  In other words, the keeper must be aware of the overall health and robustness of his/her specimens if he/she decides to hibernate them through the fall and winter.  Specimens that are to be hibernated must have adequate fat stored up from the spring and summer months.  Specimens with poor health should be over wintered as with hatchlings and juveniles.


     The main ailments that affect diamondbacks are bacterial and fungal infections.  With the exception of skin blisters, shell rot is probably the most common form of infection to attack diamondbacks.  Shell rot comes in many forms and can be caused by algae as well as bacteria and fungi.  Septicemic cutaneous ulcerative disease (SCUD) is the most severe form and is characterized by ulcers, hemorrhage, loss of claws/digits, and paralysis.  SCUD is caused by the bacteria Citrobacter freundii.  Another form of shell rot is caused by Baneckea chitinovora, which causes shell plates to shed, raw ulcers, and a brownish and slimy membrane to grow on the skin.  Freshwater crustaceans are carriers of this bacteria.

    While diamondback owners should go to great lengths to isolate the cause and prevent further occurrence of  any disease, most infections can be treated with topical treatments such as Nolvasan, Betadine or Silvadene cream.  Victims of shell rot should have the topical medication applied to affected areas and be left out of water for 10 hours a day.   They should then be allowed to return to clean water after their daily treatment.  Please use sound judgment in the case of possible dehydration.  Specimens that appear dehydrated (loose, saggy skin) should not be left dry, but should be treated with baths of diluted Nolvasan or Betadine instead.

    On occasion, terrapins can succumb to various internal diseases which are much more complicated in nature than shell and skin infections.  These diseases should be tended to immediately by a competent veterinarian.  Some tell-tale signs are loss of appetite, loss of equilibrium in the water, stiff and swollen joints, puffy eyes and internal bleeding.

    Respiratory illnesses can also affect terrapins, usually indicating an environment that is maintained at too low a temperature.  Respiratory problems are evidenced by liquid nasal and oral discharges, normally in a foamy constituent.  Raising the temperature to the mid 80's F is generally sufficient to cure minor respiratory problems.  Please refer to the Terrapin Disease page for more in depth information regarding diseases and treatments.

    Overall, diamondback terrapins are hardy and active turtles which can provide the keeper with many years of rewarding enjoyment when maintained and cared for properly.  In fact, if maintained well and housed in pairs, the keeper should be able to enjoy successive generations of terrapins to last a life time and more!