Beach Hoppers

You find them crawling or hopping along the sand or nestled in washed up clumps of seaweed and eel grass on which they feed, protected there from predators such as shore birds. They are beach hoppers or sand fleas, small, highly mobile crustaceans that inhabit the wave-washed beaches between the Capes. Beach hoppers are collectively known as the Talitrid amphipods. Two species inhabit our beaches, the smaller Traskorchestia traskiana, and larger Megalorchestia corniculata (formerly M. califoriana), which grow to almost an inch long. Both of these crustaceans live mostly out of water, their gills acting almost as lungs, entering water only occasionally to wet the gill surfaces. They are mostly nocturnal, moving at night to the water’s edge where they scavenge for food.

Traskorchestia is uniformly a creamy brown. When you lift a pile of washed up seaweed or eelgrass, you will see an explosion of frenzied individuals that quickly dissipate to other piles of seaweed or burrow in the sand. Often you can see a halo of burrows around washed up vegetation (right). Sometimes you can feel them nibbling when you sink your feet into wet sand.


Megalorchestia has a rather drab gray-brown body and beautiful orange-pink antennae. It seems to be more solitary than Traskorchestia, not bunching as much under seaweed, but living in burrows during the day high up on the beach. Walking the beach, you can see excavated sand from their distinctive burrows that make elongated and crisscrossing patterns in the sand (pictured below). Megalorchestia digs head first by flicking sand grains with its legs up to ten or more inches away from the hole. It will dig oriented in one direction for a few moments, and then it will turn 180 degrees and flick sand in the opposite direction for a few moments more. It keeps repeating these 180-degree turns, piling sand in two directions until it completes its burrow. Females are guarded in their burrows by males, which will often battle with each other over females for the privilege of mating.

Beach-Hoppers-4 Beach-Hoppers-3

Text and Photographs by Jim Young
Oceanside, Oregon


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