Mississippi Map Turtle Care Guide (Graptemys pseudogeographica kohnii)
The Mississippi map turtle is a river species needing pristine, highly oxygenated water plus strong basking and UVB — strikingly marked with a crescent behind each eye.
Overview
The Mississippi map turtle (Graptemys pseudogeographica kohnii) is an emydid whose grey carapace carries yellow lines resembling the contour lines of a map. Its hallmark is a crescent-shaped mark that curves around the back of each eye; pure specimens show an unmarked iris.
Natural Range & Size
It is found along the Mississippi River and its tributaries, from Illinois and Missouri southward. The species is strongly sexually dimorphic: females reach about 8 to 10 inches of carapace while males stay much smaller at roughly 3.5 to 5.5 inches.
Aquatic Setup & Filtration
Because map turtles come from flowing-water systems, their care is more demanding than pond and wetland species such as the red-eared slider. Provide a large aquarium with strong filtration; water must hold no more than minimal nitrate, nitrite and ammonia, and even with strong filters nearly complete water changes once or twice weekly are still advised.
Basking & UVB / Temperature
These turtles, including juveniles, spend much of the day basking and need a basking site where they can dry completely, kept around 90 °F. Indoor setups require full-spectrum lighting with UVB so the turtle can synthesize vitamin D3 for calcium metabolism and healthy shell growth — UVA alone is inadequate.
Diet
Map turtles are largely carnivorous with some plant matter taken occasionally. Favourite foods include freshwater mussels and snails plus aquatic insects such as caddisflies and stoneflies; in captivity they readily take turtle pellets, ideally supplemented with crustacean-based feeds.
Health & Longevity
Like other turtles this is a long-term commitment, and proper diet, housing and water quality underpin long-term health. The biggest risks come from poor water quality and inadequate UVB, which lead to shell and bone disease over time.
Common Mistakes
- Treating it like a hardy red-eared slider and tolerating poor water quality.
- Skipping frequent water changes despite a strong filter.
- Providing no UVB or relying on UVA alone, risking metabolic bone disease.
- Omitting a proper dry basking site kept around 90 °F.