Crabs

Crabs are some of the hardest-working members of a saltwater cleanup crew, and they bring a surprising amount of personality along with the labor. Many of the species you will find here are hermit crabs, the shell-dwelling scavengers that spend their days combing rock, sand, and frag racks for leftover food, film algae, and detritus that would otherwise fuel nuisance algae or foul your water. They come in everything from the workmanlike blue and red-legged hermits that quietly keep a tank tidy to standout characters like the Halloween Hermit, whose fiery banded legs make it as much a display animal as a janitor. Watching them trundle around the rockwork, sift sand, and occasionally squabble over real estate is half the fun of keeping them.

A couple of things are worth knowing before you stock. Hermit crabs grow, and growing means trading up to a larger shell, so keeping a selection of empty shells in a range of sizes on hand goes a long way toward preventing them from evicting your snails for a new home. Keeping them well fed does the same. Most are reef safe with corals and mix well with peaceful inverts and small reef-safe fish, though as opportunists they can hassle very small tankmates if they are hungry. They are generally easy to care for and suit tanks of nearly any size as long as parameters are stable, which makes them a great entry point into the cleanup crew side of the hobby. Browse the species below for the specifics, since size, temperament, and diet vary from one crab to the next.