Lagoon sand shrimps are small animals, growing only to about 2cm in length. Very little is known about their biology or behaviour.
Lagoon sand shrimps get their name because, in England at least, they are found only in the coastal lagoons that form high up on beaches. Lagoon sand shrimps are fully marine in other locations, and have been found at depths of up to 15m in the Mediterranean.
Southern England is the furthest north that lagoon sand shrimps have ever been recorded, and where they do live, they can occur in large numbers. They are, however, only found in a very few locations on the south and east coasts, and this makes them vulnerable. If the lagoons in which they live become polluted or filled in, the colonies of lagoon sand shrimps could be wiped out.
Lagoon sand shrimps have already disappeared from at least one location: they were present in Widewater lagoon, Sussex, but have not been recorded there since 1979.
Lagoon sand shrimps have a limited UK range, and are found on the central southern coast as well as at two isolated east coast sites. They have not been recorded west of Fleet in Dorset and are absent from the lagoons of Cornwall. South from the English Channel, lagoon sand shrimps are found along the Atlantic coasts of Europe to the Mediterranean, and in the Black Sea.
UKBAP Priority Species
Protected under Schedule 5 of the Wildlife and Countryside Act 1981
Species of principal importance for the purpose of conservation of biodiversity under the Natural Environment and Rural Communities Act 2006
Nationally rare species on UK Red List
Gammarus insensibilis (WoRMS)
Gammarus insensibilis (Marine Species Identification Portal)
Lagoon sand shrimps associate with seaweeds and seagrass, in particular with drifting mats of green weed.