Northern Black-knobbed Map Turtles are found only in the upper portions of the Alabama and Tombigbee River systems of Alabama and Mississippi. With colors shaded more golden/tan than their cousins, the Southern Black-knobbed Map Turtles, Northern Black-knobs are easily differentiated by their almost complete absence of plastral (belly) markings.
One of the narrow headed maps, Black-knobs (also called Black- knobbed saw backs) are excellent swimmers, and spend a lot of time foraging the bottom and searching underwater objects for food. They do very well in set ups with lots of water circulation, often swimming into the current for hours on end. Black-knobs love insects, they will take pellets and some water plants or even Romaine lettuce. They love to bask, and dive back in once startled, as they are very cautious on the surface, but once underwater they seem oblivious to observers, and put on an active display, making them a fine tank turtle.
This species has been on the losing end of interaction with humans for some time now, and it's future in the wild is in jeopardy. Only a handful of breeders have had success with Black knobs, so availability is very limited.