Common Otter ShellLutraria lutraria (Linnaeus)

  • Shell oval and elongated
  • White or yellowish and often tinted pink or purple
  • Up to 130 mm long
  • Shells with outer surface sculpture of fine concentric lines and ridges
  • Surface of shells frequently with brown, peeling, papery covering called the periostracum
  • Shell glossy, brittle, white, light yellow or fawn in colour but can be stained by the mud in which is buried
  • Animal lives a sedentary life in a burrow in the sand or muddy sand
  • Lives on the lower shore or sublittorally (under water) upto a depth of 100m
  • Common off all British coasts
  • Empty shells often washed ashore on beaches after stormy seas
  • The burrow gets deeper as the animal grows bigger
  • Burrow up to 40cm deep
  • Keeps in contact with the surface of the sand by a pair of partly joined tubes called siphons
  • The mollusc cannot fully withdraw the siphons into the body because they are too large

This information has been retrieved from: 

Sea shore of Britain and Europe, Collins Pocket Guide, Peter Hayward, Tony Nelson-Smith and Chris Shields, 1996, ISBN 0 00 219955 6, page 250.

Handbook of the Marine Fauna of North-West Europe, Edited by P. J. Hayward and J. S. Ryland, Oxford University Press, 1995, ISBN 0 19 854055 8 (Pbk), page 608.

MarLIN The Marine Life Information Network for Britain and Ireland run by the Marine Biological Association UK.

British Bivalve Shells – a Handbook for Identification, Norman Tebble (1966), Trustees of the British Museum (Natural History), H.M.S.O., ISBN 0 11 491401 X, page 133.

To see photographs of specimens of Common Otter Shell with the animal still inside and the siphons protruding, click  Otter Shells at Rhossili Bay .


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8 Replies to “Otter Shell – what is it?”

  1. Its good you found paired valves. They are often only single valves and broken when washed up on the beach in my experience. I wanted to go beach combing after the high winds but not got round to it. Thank you for sharing your finds


  2. Thanks for your comment, Tim. I expect the storms that are forecast for the next few days in the UK will bring up a veritable treasure trove of finds for beachcombers.


  3. I’m not certain about this – but I can’t see why you can’t eat Otter Shells – although I can find no reference to anyone actually eating them or any recipes. A similar looking large bivalved species is the Sand Gaper (Mya arenaria) which is also known as the Soft-shelled Clam and that species is eaten in the famous American Clam Bakes.


  4. Hi,my dog dug up an otter shell at our local beauty spot. It’s a body of water about 70 miles from the coast. Just wondering why it would be there as I thought they were only found in coastal areas?

    Liked by 1 person

  5. Hello, Kath. You are right in thinking that Otter Shells are marine, saltwater, organisms. I am wondering if the shell or mollusc that your dog dug up might be a freshwater Swan Mussel (Anadonta cygnaea) which is similarly large bivalve. Do you have a photograph of the specimen?


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