- Sand hoppers are very small flee-like bugs, called amphipods, which are not insects but related to crabs and shrimp (crustaceans).
- When viewed from above, they appear laterally flattened (i.e. flattened from the sides); viewed from the side, they have a curved, (“C”-shaped) body.
- They are usually abundant, especially under algae washed up on beaches. Although they are well camouflaged (sandy brown to opaque in colour), their presence on a beach is easily detected by lifting stranded algae. This induces the hoppers to spring repeatedly into the air.
- Size: up to 5 mm.
What to Observe
Search area for 30 minutes and record under the following categories-
- Abundant - found easily with little searching
- Frequent - found with minimal searching
- Rare - only 1 or 2 individuals found with intensive searching
- Not found - not present during search
ClimateWatch Science Advisor
Sand hoppers are important links in coastal food webs: they eat stranded seaweeds, and are in turn eaten by other larger animals. They are also interesting experimental subjects because they have a very strong sense of direction (they know where the sea is on their local beach); if transported to a new beach, it can take them several days to adjust. Sand hopper distributions might change as a direct response to climate change, or as a response to changing distributions of kelps. This interesting question makes sand hoppers an excellent subject for observation.
When To Look
Throughout the year, but particularly when there is plenty of seaweed on the beach (particularly kelp).
Where To Look
- On beaches, at or above the high-tide mark, especially under decaying seaweed.
- QLD, WA, TAS, NSW, VIC, SA, NT
Sand hoppers are sometimes confused with isopods (pill bugs). They are quite easy to tell apart, though, because pill bugs don’t hop, and they are also flattened from top to bottom, rather than from side to side.
Did You Know?
As the name suggests, sand hoppers tend to hop, when disturbed. They jump several centimetres into the air, similar to fleas.
Although related to crabs and hermit crabs, sand hoppers are well adapted to living out of water, and some species are even completely land-dwelling (a life-style aided by their tendency to carry and hatch eggs, rather than releasing eggs or larvae into the ocean, which most other crustaceans do).
It takes roughly one hour for a sand hopper to moult its old shell.
Hoppers have a very strong sense of direction, and know where the sea is on their local beach. If transported to a new beach, it can take them several days to adjust.