Hermit crabs are small crustaceans of the family Paguroidea. They are not very closely related to true crabs, but have enough visual similarities that most people just consider them crabs. Hermit crabs are best known for their propensity to take on an abandoned shell of another animal. They do this to protect their relatively soft abdomens. Hermit crabs usually take on the shells of sea snails, and have actually evolved to be able to better latch on to the inside of those shells. They remain in a sea snail shell until they become too large for it, then shed it and find a larger one.
Hermit crabs are popular pets, as well. They are found in many home and professional aquariums, both because of their novelty, and because they help support the ecosystem of the aquarium by eating various debris and algae found in the aquarium. There are a number of different hermit crabs used as pets, with the most common being Caribbean hermit crabs and Ecuadorian hermit crabs. The scarlet hermit crab is also a popular species, with a bright red body that makes it visually very stimulating.
Hermit crabs eat all sorts of things, as omnivores. They eat both plant life, such as algae, and scavenged meat. When keeping hermit crabs as pets, it is important to make sure your crabs eat a well-balanced diet. Most people opt to use a commercial diet as the basis of their hermits crabs’ meals, ensuring that they get all of the nutrients they need. At one point it was thought that hermit crabs lived for only a few months in captivity, but this was largely due to a poor understanding of what hermit crabs eat and poor environmental care; when properly cared for hermit crabs can live for up to twenty years.
The commercial food for hermit crabs comes in two main forms, both pellets and canned food. Different crabs eat different forms as a preference, and it appears to be largely a matter of individual taste whether they like one over the other. Most hermit crabs eat anything since, as scavengers, they aren’t particularly picky. Some, however, can be finicky, in which case trying different brands and styles until finding one the crab loves can help keep them healthy.
The pellets hermit crabs eat should be given once a day, and in the case of younger, smaller hermit crabs, they should be ground up and wet. Canned foods should be served depending on the instructions given, as some are richer than others. No matter what type of food is used, uneaten food should be removed at the end of each day to keep it from going stale or rancid.
In addition to a commercial food base, hermit crabs eat and appreciate small treats just like any other pet. Since they’re scavengers, they can actually eat a wide range of different foods without many problems. Nonetheless, there are some foods that hermit crabs seem to like more than others, and which seem to keep them healthiest. This includes various meats, which should always be cooked and given only in very small amounts, eggs, fish food, seaweed, crackers, and various fruits and vegetables, including grapes, bananas, mangos, strawberries, melons, carrots, broccoli, spinach, and watercress.
In addition to commercial food and treats, it can be helpful to have your hermit crabs eat supplements, which can keep them healthy by adding calcium to support their exoskeletons. This can include ground up egg shells, calcium vitamin supplements, ground up oyster shells, and cuttlebone.