Crabs usually eat algae. Crabs are omnivorous, meaning that they will eat both plants and other animals for sustenance.
Various species of crab have slightly different diets. They have a very strong digestive system that permits them to eat fungi, mollusks, bacteria, worms and even other crustaceans, such as shrimp or barnacles. In times of desperation, they have been known to eat the offal from the sea floor, which can include dead and decaying animals.
Like most omnivores, crabs require a balanced diet to maintain the highest degree of health and reach their maximum growth potential. Their systems need both the protein found in meat as well as the vitamins present in undersea vegetables to sustain quality digestion.Learn More
Shore crabs feed primarily on invertebrates such as molluscs, clams, crustaceans and worms, but they eat practically anything they can get a hold of, including the remains of dead organisms. Their voracious appetites have lead to the regional decline of several species. Shore crabs are an invasive species due to their easily accomodated diets and widespread dispersion.Full Answer >
Most ocean crabs are considered carnivores and eat just about any meat they can find. There are a few species that are omnivores, however, and eat plants as well as meat.Full Answer >
Ocean or marine hermit crabs are omnivorous and consume both plant and animal matter. They are opportunistic scavengers rather than hunters and prefer to eat algae and dead animals. In captivity, marine hermits function as tank cleaners by eating leftover food and detritus from the tank floor.Full Answer >
Red claw crabs, also known as red-clawed crabs, are omnivores and eat both animal-based and plant-based material. Shrimp pellets and other sinking foods are ideal for feeding pet red claw crabs.Full Answer >