Beach Hopper—Megalorchestia californiana

Reach down with your hand and flip over a pile of seaweed that is decomposing on the beach. If you are lucky, out will jump a beach hopper. If you are really lucky, a shower of them will hop out. Sometime called “sand fleas,” they are not related to fleas. In fact, they aren’t even insects. They are amphipod crustaceans that live burrowed in fine beach sand and feed on dead and decaying seaweed. So don’t worry, they won’t bite.

Two species are common on our beaches. The California Beach Hopper can be recognized by bright orange section at the base of its antennae. They can reach just over an inch in length. During the day, beach hoppers burrow in the sand or beneath seaweed piles seeking shelter from predators and to stay cool and moist. At night, they roam the sand surface, hopping around in search of decaying seaweed and other organic material. Beach hoppers are really terrestrial animals. They stay out of the water—otherwise they’ll drown.

Male beach hoppers are very competitive. They will often fight over desirable burrows, food and for access to female beach hoppers. Fighting behavior is often costly to animals, who risk their lives, injury or being displaced from good habitat if they lose. Some ecologists think that fighting is common among male beach hoppers because it is easier for one beach hopper to claim another’s burrow that to dig one for himself.

Beach hoppers play an important ecological role on the beach. Vast in numbers, they recycle large amounts of decaying seaweed, breaking it into minute bits and assisting the decaying process. They are, in turn, an important food source for beetles and shorebirds. Raccoons and moles are even known to feed on larger specimens.

Do The Math!

How far can a beach hopper hop? Beach hoppers have very powerful jumping legs and can launch themselves into the air, jumping as much as ten times their body length. The record for a human doing a broad jump from a standing position is just over 12 feet. That’s just about two times an adult male’s height. How tall are you? How far could you jump if you had legs as strong as a beach hopper?