Lagoon sandworm

Armandia cirrhosa


The rare, bristly lagoon sandworm is less than 1cm long.  It is ribbon-like in appearance and its body is divided into about 26 segments, with a pair of slender short gills on most.   Very little is known about the lagoon sandworm. 

It has been found at only three places on the south coast of England, which represent the most northerly records for this worm in Europe.  The first sighting of this worm was in Hampshire, where a group of about 500 animals were discovered, although this colony appears to have since disappeared.  A very small number of lagoon sandworms have also been found at two sites in Dorset. 

The lagoon sandworm is thought to prefer to live in gravelly sediment, although it is also found in mud or sand.  Worms of this type can swarm up out of the sand into the seawater to spawn, but no one has yet been able to record that behaviour in lagoon sandworms.

Threats to this worm are thought to be loss of its lagoon habitat from natural causes and as a result of reclamation, coastal defence, pollution and sea level rise.  Sea level rise, however, may present opportunities for creation of new lagoon habitat where seawater inundates freshwater areas – this might be good news for animals such as the lagoon sandworm.


European distribution

The lagoon sandworm has been found at just three sites in Dorset and Hampshire.  The south coast of England is thought to represent the northerly limit of its range.  In Europe, the sandworm occurs in the Mediterranean region, the Adriatic, around Madeira and the eastern Atlantic coasts.


Conservation status/need

  • Lagoon Sandworm FactThis is a UK BAP Priority Species (BAP species are now Species of Principal Importance/Priority Species).
  • Species of principal importance for the purpose of conservation of biodiversity under the Natural Environment and Rural Communities Act 2006
  • Protected under Schedule 5 of the Wildlife and Countryside Act 1981
  • Nationally rare marine animal
  • The coastal lagoons in which the sandworms can be found are a UKBAP Priority Habitat and are listed on Annex I of the Habitats Directive


Further information

Marine Life Information Network

World Register of Marine Species

JNCC - UK BAP Priority Species and Habitats