Muricanthus nigritus

Muricanthus nigritus, the Northern Radix or Black-and-White Murex or Black Murex, is a species of sea snail, a marine gastropod mollusc in the family Muricidae, the murex snails or rock snails. It is commonly known as the black murex shell.

Distribution
The black murex shell is commonly found in the Gulf of California (Sea of Cortez), in the Western Mexico.

Habitat
These sea snails can be found in the intertidal and subtidal waters, with sand and gravel substrate, at depths up to 60 m.



Description
Shells of Muricanthus nigritus can reach a length of 75 - 200 mm. These large shells are black and white with black or dark brown stripes. The shell surface bears short spikes around the body whorl and spire. The aperture is porcelaneous white.

This species is quite similar to Hexaplex radix. The shells of these two species mainly differ in the length, width and in the proportion of black versus white. Moreover, shells of H. nigritus are more oblong and show more spines in black.

Biology
These sea snails feed primarily on clams.