Mississippi Map Turtle (Graptemys pseudogeographica kohnii) Care Sheet
The Mississippi Map Turtle is an attractive freshwater turtle native to the central United States, particularly the Mississippi River system and its associated waterways.
Its common name comes from the intricate pale lines covering the carapace, which resemble the contour lines found on a map.
Mississippi Map Turtles are highly aquatic, active turtles that spend considerable time swimming and basking. Although males remain relatively small, females grow substantially larger, meaning adult housing requirements can differ dramatically between the sexes.
They require spacious aquatic accommodation, excellent water quality, powerful filtration, appropriate heating, UVB lighting and a varied diet.
Quick Facts
Scientific name: Graptemys pseudogeographica kohnii
Common name: Mississippi Map Turtle
Family: Emydidae
Origin: Central United States
Adult male size: Approximately 9–13 cm shell length
Adult female size: Approximately 15–25 cm shell length
Lifespan: Commonly 20–30+ years and potentially longer
Diet: Omnivorous, with strong carnivorous tendencies
Activity: Diurnal
Lifestyle: Highly aquatic
Experience level: Intermediate
Temperament: Alert and often shy; generally best appreciated through observation rather than frequent handling
Taxonomy
The Mississippi Map Turtle is traditionally recognised as:
Graptemys pseudogeographica kohnii
It is closely related to the False Map Turtle:
Graptemys pseudogeographica pseudogeographica
Taxonomy within Graptemys has received considerable scientific attention, so keepers should use current reliable sources when identifying animals.
Correct identification is particularly important where several map turtle species are kept or bred.
Natural Habitat
Mississippi Map Turtles inhabit large freshwater systems.
Typical habitats include:
- Rivers
- Large streams
- Lakes
- Oxbow lakes
- Backwaters
- Floodplain waterways
They generally favour areas containing:
- Submerged logs
- Fallen trees
- Aquatic vegetation
- Open basking sites
- Deep swimming areas
Wild turtles frequently bask on branches and logs projecting over the water.
When disturbed, they rapidly dive into the water.
Appearance
Mississippi Map Turtles possess an olive, brown or dark carapace decorated with fine yellow or pale lines.
These markings create the characteristic map-like appearance.
The head and limbs also display yellow striping.
A particularly useful identification feature is the pale crescent or curved marking behind the eye.
The carapace possesses a central keel, which is particularly noticeable in younger animals.
Sexual Size Difference
One of the most striking characteristics of map turtles is the substantial difference in size between males and females.
Adult males commonly remain around:
9–13 cm (3.5–5 in)
Adult females can reach approximately:
15–25 cm (6–10 in)
Females also develop considerably larger heads and stronger jaws.
This difference has important consequences for:
- Enclosure size
- Filtration
- Feeding
- Handling
- Social housing
A keeper purchasing a young turtle should not assume it will remain male-sized.
Lifespan
Mississippi Map Turtles are long-lived reptiles.
With appropriate husbandry they may live:
20–30+ years
and potentially considerably longer.
Their long lifespan should be considered before acquisition.
Housing
Mississippi Map Turtles require spacious aquatic accommodation.
The enclosure should provide:
- Large swimming area
- Substantial water depth
- Powerful filtration
- Completely dry basking area
- Heat
- UVB
- Submerged resting structures
- Environmental enrichment
They are active swimmers and should not be confined to shallow turtle trays or small aquariums.
Enclosure Size
Enclosure requirements depend significantly upon sex.
A small adult male requires considerably less space than a large mature female.
As a general principle, provide the largest practical aquatic enclosure.
Adult females may require aquariums around 120 cm or more in length, with larger systems strongly preferred where possible.
The turtle should be able to:
- Swim freely
- Dive
- Turn comfortably
- Explore
- Surface easily
- Rest underwater
- Bask completely out of the water
Usable water volume is particularly important.
Water Depth
Mississippi Map Turtles are strong swimmers.
Healthy adults should have deep water that allows normal swimming and diving behaviour.
Provide structures such as:
- Driftwood
- Branches
- Rocks
- Submerged platforms
These allow the turtle to rest at different depths.
Young juveniles should initially have numerous easy routes to the surface.
Water Temperature
A useful general water temperature range for healthy adults is approximately:
23–26°C
Juveniles may benefit from slightly warmer conditions.
Temperature should be adjusted according to:
- Age
- Health
- Season
- Room temperature
- Behaviour
Always monitor water temperature using a reliable thermometer.
Water Heating
An aquarium heater may be necessary where ambient temperatures are insufficient.
Any heater accessible to the turtle should be:
- Thermostatically controlled
- Securely mounted
- Appropriately sized
- Protected by a heater guard
Turtles can damage exposed aquarium heaters.
Basking Area
A completely dry basking platform is essential.
The turtle must be able to leave the water completely and dry its:
- Carapace
- Plastron
- Limbs
Map turtles are enthusiastic baskers when they feel secure.
The platform should be:
- Stable
- Non-slip
- Easy to access
- Large enough for the entire turtle
- Positioned beneath heat and UVB lighting
Basking Temperature
A useful basking surface temperature is approximately:
30–33°C
Measure the temperature directly at the basking surface.
The turtle must always be able to leave the heated area.
Basking Security
Map turtles can be nervous baskers.
If the enclosure is located in a busy environment, turtles may repeatedly dive into the water whenever people approach.
Providing:
- Visual barriers
- Elevated basking sites
- Quiet surroundings
- Cover
can help the animal feel secure enough to bask normally.
UVB Lighting
Appropriate UVB exposure is essential.
UVB supports:
- Vitamin D3 production
- Calcium metabolism
- Bone health
- Shell development
Use a reputable reptile UVB lamp positioned appropriately over the basking area.
UVB should not pass through glass or plastic before reaching the turtle.
UVB Monitoring
UVB output decreases as lamps age.
Replace lamps according to manufacturer guidance.
Where possible, use an appropriate UV meter to monitor actual exposure at the basking site.
Correct lamp distance is important.
Lighting
Provide a regular day/night cycle.
Approximately:
10–12 hours of light daily
provides a useful general starting point.
Visible lighting should normally be switched off overnight.
Filtration
Map turtles require exceptionally good water quality.
Powerful filtration is therefore one of the most important components of their accommodation.
External canister filters are commonly used.
Filtration should provide:
- Mechanical filtration
- Biological filtration
- High water turnover
- Large media capacity
Selecting filtration rated substantially above the actual aquarium volume is often beneficial for turtle systems.
Water Quality
Mississippi Map Turtles can be sensitive to persistently poor water conditions.
Poor water quality may contribute to:
- Skin irritation
- Eye problems
- Shell infections
- Increased bacterial growth
- Unpleasant odours
Regular partial water changes remain necessary even with excellent filtration.
Water Testing
Keepers should monitor basic aquarium water chemistry.
Useful parameters include:
- Ammonia
- Nitrite
- Nitrate
- pH
Ammonia and nitrite should remain at safe levels in a properly established biological filtration system.
Water Movement
Map turtles naturally inhabit river systems and generally tolerate moderate water movement well.
Good circulation can:
- Improve filtration
- Prevent stagnant areas
- Increase oxygenation
- Distribute heat
However, water flow should not be so powerful that the turtle is constantly fighting the current.
Areas of calmer water should also be available.
Substrate
Suitable options include:
- Bare-bottom enclosure
- Fine sand
- Large smooth stones too large to swallow
Avoid small gravel that could potentially be ingested.
Fine sand can allow natural digging and foraging behaviour.
Environmental Enrichment
Map turtles benefit from complex aquatic environments.
Suitable features can include:
- Driftwood
- Large branches
- Secure rocks
- Aquatic plants
- Submerged resting areas
- Different water depths
- Visual barriers
All furnishings must be secure.
No underwater feature should create an entrapment hazard.
Driftwood & Branches
Branches and driftwood are particularly appropriate for map turtles.
They can provide:
- Underwater resting areas
- Climbing opportunities
- Surface resting positions
- Environmental complexity
Structures must be stable enough that they cannot collapse onto the turtle.
Diet
Mississippi Map Turtles are omnivorous, although animal-based foods form an important part of their natural diet.
Females in particular develop powerful jaws suited to crushing hard-shelled prey.
Natural foods can include:
- Aquatic insects
- Snails
- Molluscs
- Crustaceans
- Small fish
- Carrion
- Aquatic vegetation
Captive diets should provide appropriate variety.
Commercial Turtle Pellets
A reputable complete aquatic-turtle pellet can form a useful foundation of the diet.
Choose products formulated specifically for aquatic turtles.
Pellets should be supplemented with appropriate fresh and whole foods.
Molluscs
Snails and other appropriate molluscs can provide useful dietary enrichment.
Large females are particularly well adapted to consuming hard-shelled aquatic prey.
Foods should come from safe sources free from:
- Pesticides
- Parasites
- Environmental contamination
Do not collect prey from polluted waterways.
Invertebrates
Suitable foods can include appropriately sized:
- Earthworms
- Snails
- Crickets
- Locusts
- Aquatic invertebrates
Dietary variety is preferable to reliance upon a single feeder.
Fish
Appropriate whole freshwater fish may occasionally form part of the diet.
Whole fish provide:
- Bone
- Organs
- Connective tissue
- Micronutrients
Avoid relying heavily upon one species of fish.
Plant Foods
Plant material can form part of the diet, particularly in mature animals.
Suitable foods may include:
- Dandelion greens
- Endive
- Escarole
- Appropriate aquatic plants
- Other suitable leafy greens
Individual preferences vary.
Calcium
Adequate calcium is essential for healthy shell and skeletal development.
Calcium can be supplied through:
- Balanced commercial foods
- Appropriate whole prey
- Calcium-rich vegetation
- Cuttlebone where suitable
- Supplementation where necessary
Correct UVB exposure is also essential for calcium metabolism.
Feeding Frequency
Juveniles generally require smaller meals more frequently.
Healthy adults can usually be fed appropriately sized meals several times per week.
Feeding should be adjusted according to:
- Age
- Sex
- Size
- Activity
- Body condition
- Water temperature
- Health
Large females naturally require more food than small adult males.
Avoid Overfeeding
Map turtles can become overweight in captivity.
Overfeeding may contribute to:
- Obesity
- Excessively rapid growth
- Poor shell development
- Reduced activity
- Deteriorating water quality
Feeding should be based upon appropriate body condition rather than begging behaviour.
Behaviour
Mississippi Map Turtles are active but often cautious.
Common behaviours include:
- Swimming
- Diving
- Basking
- Foraging
- Exploring
- Climbing submerged structures
- Resting underwater
They may quickly dive from their basking platform when approached.
Temperament
Map turtles are generally not aggressive toward people but may become defensive when restrained.
A frightened turtle may:
- Scratch
- Struggle
- Withdraw
- Bite
Large females have particularly powerful jaws.
Handling
Routine recreational handling should be minimised.
Handling should primarily occur for:
- Health checks
- Veterinary treatment
- Transportation
- Necessary enclosure maintenance
Support the turtle securely with both hands.
Never lift a turtle by its tail.
Hygiene
Aquatic turtles can carry Salmonella and other microorganisms without appearing ill.
Wash hands thoroughly after:
- Handling the turtle
- Touching aquarium water
- Cleaning filtration equipment
- Handling substrate
- Preparing turtle food
Turtle equipment should not be cleaned in areas used for human food preparation.
Sexing
Sexual differences become very obvious in mature Mississippi Map Turtles.
Adult males generally have:
- Much smaller bodies
- Longer tails
- Thicker tail bases
- Longer front claws
Adult females generally have:
- Much larger bodies
- Larger heads
- Broader jaws
- Shorter tails
The dramatic adult size difference is one of the easiest ways to distinguish mature animals.
Female Head Size
Adult females develop substantially broader heads than males.
This adaptation allows females to consume harder prey such as:
- Snails
- Molluscs
- Other shelled aquatic invertebrates
The head of a mature female can therefore appear disproportionately large compared with that of an adult male.
Social Housing
Mississippi Map Turtles do not require companionship.
Housing multiple turtles can result in:
- Aggression
- Biting
- Food competition
- Basking competition
- Mating harassment
- Chronic stress
Male harassment of females can become particularly problematic.
Separate housing is often safest.
Anyone keeping multiple turtles must have permanent separate accommodation available if necessary.
Breeding
Mississippi Map Turtles are egg-laying reptiles.
Breeding should only be considered where suitable long-term accommodation exists for offspring.
Adult females require access to suitable nesting substrate.
Females Without Males
Females may produce infertile eggs even when they have not recently been housed with a male.
Adult females showing reproductive behaviour should therefore have access to an appropriate nesting area.
Possible signs include:
- Restlessness
- Increased exploration
- Attempts to leave the enclosure
- Digging
- Reduced appetite
Nesting Area
The nesting area should provide:
- Diggable substrate
- Adequate depth
- Appropriate moisture
- Suitable temperature
- Privacy
Persistent unsuccessful nesting behaviour should not be ignored.
Egg Retention
Egg retention can become a serious medical emergency.
Possible signs include:
- Persistent restlessness
- Repeated unsuccessful digging
- Straining
- Weakness
- Reduced appetite
- Abnormal posture
Suspected egg retention requires veterinary assessment.
Health
Potential health problems include:
- Shell infections
- Respiratory disease
- Metabolic bone disease
- Nutritional deficiencies
- Eye problems
- Parasites
- Trauma
- Obesity
- Egg retention
Good husbandry prevents many common health problems.
Warning Signs
Seek veterinary advice if the turtle develops:
- Persistent loss of appetite
- Unexplained weight loss
- Swollen or closed eyes
- Nasal discharge
- Open-mouth breathing
- Abnormal floating
- Difficulty diving
- Soft shell
- Shell lesions
- Foul-smelling shell areas
- Persistent lethargy
- Significant behavioural changes
Veterinary care should ideally be provided by a clinician experienced with reptiles.
Shell Health
A healthy shell should generally remain:
- Firm
- Intact
- Free from deep pits
- Free from bleeding
- Free from foul-smelling lesions
Normal scute shedding may occur.
Never forcibly remove retained or shedding scutes.
Respiratory Disease
Possible symptoms include:
- Nasal bubbles
- Wheezing
- Open-mouth breathing
- Reduced appetite
- Lethargy
- Difficulty diving
- Uneven floating
Respiratory disease can become serious and requires veterinary assessment.
Outdoor Housing
Secure outdoor accommodation can be beneficial in suitable climates.
Outdoor enclosures must protect against:
- Escape
- Predators
- Excessive heat
- Excessive cold
- Flooding
- Contaminated water
- Unauthorised access
Natural sunlight can provide excellent UVB exposure.
Shade must always be available.
Brumation
Wild Mississippi Map Turtles experience seasonal temperature changes and may undergo periods of reduced winter activity.
Deliberately brumating captive animals is not required for ordinary pet husbandry.
Controlled cooling should not be attempted casually.
Animals that are ill, underweight or inadequately prepared should never be deliberately brumated.
Captive-Bred Animals
Captive-bred turtles from responsible sources should be preferred.
Before acquisition, establish:
- Correct species identification
- Captive-bred status
- Approximate age
- Feeding history
- Health history
- Sex where known
Correct identification is especially important because several Graptemys species can appear superficially similar.
Conservation & Wild Collection
Several map turtle species face pressures from:
- Habitat degradation
- River modification
- Pollution
- Collection
- Wildlife trade
- Nest predation
- Human disturbance
Responsible keepers should avoid supporting unnecessary wild collection.
Captive-bred animals with known origins are strongly preferable.
Legal Considerations
Wildlife legislation varies between countries and regions.
Depending upon location, restrictions may apply to:
- Ownership
- Collection
- Sale
- Breeding
- Import
- Export
- Transport
Always verify current legislation before acquiring or transferring a Mississippi Map Turtle.
Never release a captive turtle into the wild.
Responsible Ownership
Before acquiring a Mississippi Map Turtle, consider:
- Adult sex and eventual size
- Aquarium dimensions
- Water volume
- Filtration requirements
- Heating
- UVB replacement
- Electricity costs
- Veterinary expenses
- Holiday care
- Potential lifespan
Particularly with females, the eventual adult housing requirement can be far greater than expected when purchasing a hatchling.
Summary
The Mississippi Map Turtle (Graptemys pseudogeographica kohnii) is an attractive, highly aquatic freshwater turtle recognised by its intricate map-like shell markings.
The dramatic difference between the sexes means a small adult male and a large adult female can have substantially different housing and feeding requirements.
Successful captive husbandry requires spacious deep-water accommodation, excellent water quality, powerful filtration, a completely dry basking area, appropriate heat and UVB, environmental complexity and a varied diet incorporating suitable aquatic prey and plant material.
With appropriate facilities and long-term care, Mississippi Map Turtles can make fascinating animals to observe for several decades.
IMPORTANT INFORMATION
This care sheet provides general husbandry guidance and does not replace professional veterinary advice or current species-specific research.
Always research the individual requirements of your turtle and comply with applicable wildlife and animal-welfare legislation.
If you are concerned about your turtle’s health, consult a veterinarian experienced with reptiles.
Information correct at the date of publication.
reptilecommunity.com | Revised: August 2026