[4] The skin ridge running the length of the sides of the body, spread as far as one-third of the base of the anal fin.

[4] The great sand eel is native to the eastern North Atlantic from Murmansk (70°N) and Spitzbergen (75°N) southwards to Portugal (38°N) including Iceland and the Baltic Sea.

[6] It is to be found from the low water mark down to over 100 metres (330 ft), typically over clean and sandy substrates.

[4] Sand eels form an important part of the diet of many sea birds.

Excessive fishing of sand eels on an industrial scale in the North Sea has been linked to a decline in the breeding success of kittiwakes, terns, fulmars, and shags.