plankton and detritus
4-5 inches (12 cm)
blue mud shrimp, beach ghost shrimp; family Callianassidae
Alaska to Baja California in the intertidal zone or mudflats
A resident of marine sloughs and bay flats on the west coast of North America, ghost shrimp burrow in seafloor sediments. These burrows protect the shrimps' soft, white bodies. But more important, as the shrimp wriggle along, they collect food from the sediments and from the water flowing through the burrows.
Fishermen collect ghost shrimp for bait by using a plunger that sucks the shrimp out of their burrows. In 1980, it was estimated that 5,953 pounds (2,700 kg) of shrimp are taken yearly in the San Diego and Los Angeles areas alone.
Even small amounts of oil, carried in by the tide and temporarily stranded in the intertidal zone, are likely to have serious effects on ghost shrimp and other slough animals.
The sediment that ghost shrimps spew out of their burrows can cover and destroy beds of young oysters.
Hardy animals, ghost shrimp can survive without oxygen for as long as six days.
To find enough food, ghost shrimp tunnel almost constantly, reworking the sediment to a depth of as much as 30 inches (76 cm). Their burrows are attractive to other small invertebrates as well—both for protection from predators and for leftover food. Other inhabitants of a ghost shrimp's burrow might include pea crabs, scale worms and snapping shrimp. A clam might even put its siphon into a shrimp's burrow.