Ecuadorian hermit crab

Features and identification

Coenobita compressus is a member of the phylum Arthropoda and the class Malacostraca. They can be up to 12 millimetres (0.47 in) in length and are thought to be one of the smallest species of land hermit crabs. They have four walking legs, a small pincer, a large pincer, and antennae. Many people who keep these hermit crabs as pets notice that Ecuadorians can be relatively fast walkers, even faster than Caribbean hermit crabs, and that they are quite active. The eyes of Ecuadorians are more oval-shaped when compared to the round eyes of Caribbean hermit crabs and are thicker. Their big claw has 4 or 5 small ridges on the upper part. The tips of the second pair of walking legs are darker than the rest of the leg. The abdomen of the Ecuadorian hermit crab is short and fat.

Ecuadorian hermit crabs vary greatly in colour, some are bright (yellow, dark grey, or orange), but more often they are a tan colour. Sometimes they may have a blue or green tint to their bodies or the insides of their legs. They also have comma-shaped eyes, unlike the "purple pincher" (Coenobita clypeatus), which has dot-shaped eyes.

When choosing a shell, they tend to give preference to shells with a wide and round aperture. As with all hermit crabs, painted shells are harmful to them, as they often eat the paint chips and can be poisoned with chemicals used in the paint. This significantly shortens their life span.

Habitats

Native to Ecuador and Chile, these hermit crabs live on the Pacific seashore around tidal pools and high-tide zone. Their bodies have adapted to this seashore existence and in captivity, they require access to seawater as they must metabolize the salt in it and bathe in it to maintain gill moisture. Failure to provide access to seawater (real or artificial) will result in death.

Like most hermit crabs they are scavengers and will consume seaweed, dead fish and other detritus that washes up on the shore.

Studies

Coenobita compressus prefers the odors of foods that they have not recently eaten. The hermit crabs that were exposed to one food for at least 9 hours preferred foods having other odors for the next 6 hours. It is this short-term avoidance of food (like human beings who get bored with the same meals over and over again) that compels the crabs to seek out a wider range of food. This might be advantageous to the hermit crab, possibly through the consumption of a more nutritionally-balanced diet.Scientists do not know how, but Ecuadorian hermit crabs can make a chirping sound to communicate with each other.

As pets

Hermit crabs overall were once seen as a "throwaway pet" that would live only a few months, but species such as Coenobita clypeatus have a 23-year lifespan if properly treated  and some have lived longer than 32 years. Similarly Ecuadorian hermit crabs have been known to live to over 30 years. In general, and despite their moniker, hermit crabs are social animals that do best in groups. They also require a temperature and humidity-controlled environment (ideally 70%-78% humidity and 75-85F), and adequate substrate to allow them to bury themselves while molting.