Hermit Crab
Main Characteristics of Crustaceans
- There are 67,000 species of crustaceans.
- The most well-known are pistol shrimp, cleaner shrimp, coconut crab, hermit crab, mantis shrimp, water flea, barnacle, fiddler crab, brown crab, lobster, and spiny lobster.
- The body structure of crustaceans is so varied that they share only a few common features.
- All crustaceans have two pairs of antennae, which means they have a total of four. One pair is often really long – like in the case of lobsters.
- All crustaceans breathe using gills.
- Crustaceans have a tough shell made of calcium and a horn-like material called chitin.
- They grow throughout their entire lives. As they get bigger, they molt. They have to shed their old exoskeleton that has become too small and grow a new one.
- Most crustaceans have 10 legs. They are paired together. On each side, they have five legs.
- In certain species, the first two legs have changed into pincers. These pincers help protect them, catch food, and communicate with their peers.
- Most crustaceans live in the sea. However, there are also species that occasionally come ashore and burrow into the wet sand. Terrestrial hermit crabs and woodlice live exclusively on land.
- Crustaceans are omnivores. They mainly eat fish, shellfish, sea urchins, and other crustaceans. They also consume algae and plankton.
- The largest land-dwelling crustacean is the coconut crab. It is a terrestrial hermit crab. It can grow up to 15 inches (40 cm) in body length, have a wingspan of up to 39 inches (1 meter), and weigh as much as 9 pounds (4 kg).
- The fastest crustacean in the water is Henslow's swimming crab. It can reach a speed of 4.2 feet (1.3 meters) per second. That translates to approximately 2.8 mph (4.6 km/h).
- The fastest crab on land is the ghost crab. It can reach speeds of 13 feet (4 meters) per second. That translates to about 8.6 mph (14 km/h).
