A Coat of Sharp Spines
A species that need no introduction, Venus Comb Murex are predators, eating other mollusks (see previous blog entry on the species.) In turn, they can be food for large bottom-feeding fish such as stingrays and some sharks. Their sharp, long spines, however, may ward off those large predators. They also surround the snail's head and foot when the animal is moving or active, forming a "cage" around the snail that may help prevent other predators, such as small crabs, from approaching. In mollusks, a specialized tissue known as the mantle edge makes the shell, gradually adding more material onto the edge of the opening (aperture). In Venus Comb Murexes (and in other spine-bearing mollusks), the spines are formed at intervals as the shell grows. Narrow, tube-like expansions of the mantle edge project outward, secreting shell material from the inside to form the hollow spines, all as a part of the shell-making process.