IDENTIFICATION
Mole crabs are also known as sea lice. They are not lice however, but are related to the hermit crabs. Mole crabs have barrel-shaped bodies which allow them to be rolled up and down the shore by the waves. Emerita is the most abundant species and is a light grey/brown in colour. Hippa is a mottled grey colour and is flatter and broader. Emerita has long tentacles that extend back to about the middle of the body, while Hippa has short antennae.

DISTRIBUTION
Both species inhabit tropical and subtropical regions and occur on our coast from the Eastern Cape northwards into Mozambique. They live on sandy beaches and move up and down the shore with the tides. Hippa occur in coarse sand which is usually close to rocks, while Emerita usually occur in finer sand.

FEEDING
Emerita are filter feeders and use their long antennae to sieve tiny organisms from the water. The antennae of Emerita create a characteristic V-shaped ripple in the water of receding waves while the animal is feeding. These remarkable antennae can be rolled up under the mouth-parts when the animal prepares to surf up and down the beach with the waves. Hippa is a scavenger, eating organisms such as bluebottles that are washed up by the waves.

REPRODUCTION
Male and female mole crabs are reproductively active throughout the year although Hippa females are less active during winter months. Female Emerita can produce several thousand eggs throught the year. Larvae spend about a month at sea before settling on sandy beaches.

GROWTH
Female Emerita mole crabs grow to about 2.8 cm in length within a year while the males grow much slower. Males live for about a year, and females for about two years.

FISHERY
Mole crabs are widely used as bait to catch fish such as pompano and stumpnose. They are eaten by humans in some parts of the world and are preyed on by fish, birds and crabs.

MANAGEMENT