Polychaetes · Phyllodocida · Nereididae

Estuary Ragworm

Nereis diversicolor

Not Evaluated

It has not yet been assessed against the IUCN criteria. See full glossary

An estuarine ragworm, greenish or reddish with a clearly visible red dorsal line marking the blood vessel. It lives in burrows in estuarine mud, tolerates enormous changes in salinity and feeds on detritus, algae and small animals. It is now also known as Hediste diversicolor.

Size

6 cm – 12 cm

Lifespan

3 years

Diet

Omnivore

Combines animal and plant food depending on availability.

Social structure

Solitary

Lives and hunts alone, joining others only to breed.

Sighting difficulty

Unknown

OceanOmnivore Solitary Ocean Worm

13countries 29parks 34dive sites

Fun facts

As well as eating detritus, it weaves a mucus net inside its burrow to filter the water it pumps through, and then eats the net along with everything caught in it.
It is a traditional and highly valued bait in European inshore fishing and a key prey of the wading birds that winter in estuaries.
It has an eversible pharynx armed with two black jaws that it shoots out to seize prey or to fight its neighbours.
It is one of the few marine animals able to live across the whole gradient of an estuary, from almost fresh water to full marine salinity, which is why it dominates European estuarine muds.
It eats everything: it filters, gathers detritus and hunts as well. To filter, it spins a mucus net inside its burrow, pumps water through it and then eats the whole net along with whatever it has caught.
It has an eversible pharynx with two black chitinous jaws that it shoots out to seize prey or cut algae.
It is the mainstay prey of wintering waders: estuarine muds feed thousands of migratory birds largely thanks to this worm.
It is dug for fishing bait on a large scale, and that extraction is a recognised pressure on estuaries.
Its currently valid name is Hediste diversicolor.