These Acrobatic Beach Hoppers Shred All Night Long
As the sun sets, hordes of tiny crustaceans called beach hoppers — also known as sand hoppers — emerge from underground burrows to frolic and feast. They eat so much decaying seaweed and other beach wrack that by morning all that’s left are ghostly outlines in the sand.
TRANSCRIPT
As the sun sinks behind the waves, these performers awaken and get ready for their all-night show.
They take cues from the tides, the moon, and their appetite, emerging from sandy underground burrows.
You might know them as sand fleas, but they don’t bite and they aren’t fleas. They’re called beach hoppers.
These crustaceans are as small as an ant or as large as a cricket.
Their eyes are made up of hundreds of cells called ommatidia, but they don’t see much detail — just blurry shapes, light and dark.
They’re drawn toward shadowy blobs on the horizon. They hope it’s kelp, their favorite food.
When they find it, they eat and eat.
Sometimes they even eat one another.
This large beach hopper is piercing the other right behind its eye, holding it in place with its claws.
For protection, they dig burrows about a foot deep where the sand is damp and cool.
And males will fight over control of burrows, especially if there are females inside.
Deep in the night, the beach hopper acrobatics build into a dazzling show.
A powerful flick of their curled-up tail launches them skyward.
They do not stick the landing.
A beach hopper can jump as high as your knees, dozens of times the length of its body.
It’s a quick way to travel — toward food or mates. Or to get out of harm’s way.
Beach hoppers’ diets are mostly beach wrack — anything natural that washes ashore. Wrack is an essential source of nutrients for sandy beach ecosystems.
These shredders break down the wrack into smaller parts. It’s the first step in sending nutrients into the food chain.
When predators like shorebirds or insects eat beach hoppers, they can carry these nutrients further inland.
Without these hungry acrobats, beaches the world over would be strewn with rotting seaweed.
After a night of fighting and feasting, they leave only silhouettes behind.
As the sun rises, the beach hoppers retreat to their burrows, just beyond the tide’s reach.
The performers need their rest.
Another spectacle is just a night away.
While we’re on the subject of unconventional crustaceans, check out this episode about Mantis Shrimp — their eyes see colors we can’t even comprehend.
After that, jump on over to Terra, a shiny new science channel from PBS Digital Studios. You’ll travel to Antarctica, fly with drones, see inside a wildfire. Link in the description and tell them Deep Look sent you.