Crabby Antennae
These colorful, feathery stalks are the antennae of a mole crab, also known as a sand flea. You may have seen these little critters burrowing into the sand at the beach as the waves wash over the shore. They use these antennae to filter food from the water and sweep it into their mouths.
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DownloadCrabby Antennae
These colorful, feathery stalks are the antennae of a mole crab, also known as a sand flea. You may have seen these little critters burrowing into the sand at the beach as the waves wash over the shore. They use these antennae to filter food from the water and sweep it into their mouths.
What am I looking at?
Here we see two antennae from a mole crab (Emerita). The antennae have feather-like projections (1) attached to a segmented main stalk (2), which allows them to sweep their antennae through the water like a net to catch and eat small food particles.
Biology in the Background
Mole crabs, also known as sand fleas, sand fiddlers, or sand crabs, are found in most coastal areas of tropical, subtropical, and even some temperate regions. They are fairly common and can often be observed burrowing into the sand for protection as the water recedes following a wave washing onto the beach.
As another wave rolls in, they will emerge from their burrows, extend their antennae, and sweep the water for small plankton and other food particles. Once they have captured their meal, they run these antennae through their mouthparts, scraping the food into their mouths. Then they wait for another wave to start the process over again.
Mole crabs can grow up to 5 centimeters, about the size of your thumb, and their antennae can be as long as their bodies when extended.
Technique
This image was created using confocal microscopy.
Igor Siwanowicz, HHMI's Janelia Research Campus