Black-knobbed map turtle

Black button - bump turtle Graptemys nigrinoda nigrinoda

The black button - bump turtle ( Graptemys nigrinoda ) is a native to Alabama and in small parts of Mississippi species in the genus of Map turtles, which belongs to the family of New World pond turtles.

Appearance

The black button - bump turtle is one of the smaller turtles. The females of this species are 10 to 15 centimeters long, almost twice as large as the males, which reach a length of 7.5 to 10 centimeters. The black button - bump turtle has a characteristic pronounced carapace: Situated each Vertebralschild a "black button", these are particularly pronounced in the second and third Vertebralschild. In the males, these buttons appear more clearly than in the females. The carapace is green to brown covered with yellow rings or semicircles. The plastron is colored variable. Some specimens have small black pattern, others are mainly pigmented. The head of the Black button - bump turtle is crisscrossed with narrow yellow stripes. Two to four head stripe running the eye down together. The males have very often elongated front claws, which play a role in courtship behavior.

Subspecies

There are two known sub-species of the Black button - bump turtle. The nominate is the Northern Black Button hump turtle ( Graptemys nigrinoda nigrinoda ). She has light skin and the plastron is yellow with black markings on each hem.

The Southern Black Button hump turtle ( Graptemys nigrinoda delticola ) was described in 1969 by Folkerts and Mount. She has a darker skin and black pattern reach the plastron and cover it extensively.

Distribution and habitat

The Northern Black Button hump turtle lives in the rivers of Alabama River, Tombigbee, Coosa, Black Warrior, Cahaba and Tallapoosa River. Fast Flowing water with a sandy bottom, are the preferred habitats of the animals. The Southern Black Button hump turtle lives only in the rivers of the Mobile Bay with slower flow.

Way of life

The black button - bump turtle is the day to watch their sun baths. She sits on roots or branches, which are surrounded by water, but also riparian zones are used when a flood makes it necessary. It shows a great loyalty to a location and used again and again the same sun spots, under which she often hides at night. The Black Button Map turtles leave only for spawning rivers. They are very shy and show no attempts to bite.

Nutrition

The Black Button Map turtles are omnivorous. Males feed mainly aquatile insects, but also terrestrial insects are not spurned when they fall into the water. The females, however, also eat plant food. Both snails and freshwater clams are on the menu.

In the Southern Black Button Map turtles was observed that they also eat barnacles. This is an indication that the animals live on the border of salt water area of Mobile Bay.

Enemies

Raccoons and herons are among the most dangerous enemies of nest in the wild. Otter and waders are a hazard for young animals and hatchlings. Chance of fall adult animals alligators prey.