[1] Stramonita haemastoma contains the following subspecies:[1][2] The red-mouthed rock shell occurs widely in tropical and warm water areas of the Western Atlantic Ocean.

It is also found in the Eastern Atlantic: tropical Western Africa and Southwestern Africa, including Cape Verde and Angola, and in European waters, including Macaronesian Islands, the Mediterranean Sea and the southwest coast of Apulia.

[1][3][4] Its once abundant population in the Eastern Mediterranean collapsed early in the 21st century and had entirely disappeared by 2016.

[7] Through feeding behaviors such as attacking the margin or lip of shells where defenses are weakest, Stramonita haemastoma insert its proboscid between the valves injecting proteolytic enzymes and a toxin that causes bivalves to gape.

[2][8] The shell was one of two principal sources of Tyrian purple, a highly prized dye used in classical times for the clothing of royalty, as recorded by Aristotle and Pliny the Elder.