Black-knobbed Map Turtle

Overview

A small map turtle with a dark shell topped by prominent black knobs (spines) on the midline of the vertebral scutes. It is restricted to river systems draining into Mobile Bay and is a bottom-feeding forager that basks on branches. Females are larger than males.

Classification

The Black-knobbed Map Turtle belongs to the suborder Cryptodira (hidden-neck turtles) and the family Emydidae. It is a largely North American family of mostly semi-aquatic freshwater turtles, including the box turtles that are largely terrestrial. Its scientific name is Graptemys nigrinoda.

Appearance & Distinguishing Features

They typically have smooth, low-domed or moderately domed shells, webbed feet, and a marked pattern of stripes or blotches; box turtles have a hinged plastron that can close completely.

Habitat & Distribution

They inhabit ponds, lakes, rivers, marshes, and damp woodlands across North America, with a few species in Eurasia. Some box turtles are almost entirely terrestrial.

Diet & Feeding

They are generally omnivorous, eating aquatic plants, insects, fish, amphibians, and carrion, with plant matter increasing in adult box turtles.

Behavior & Conservation

Many bask communally and overwinter by burrowing into mud. The red-eared slider is one of the most widely kept pet turtles, whereas several box turtles are protected owing to declining wild populations.

Popularity & Recognition

The red-eared slider in particular has become the world's most common pet turtle and an invasive species in many regions.