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Common otter shell

size:

up to 13 centimeters

color:

creamy white

food:

phytoplankton

enemies:

not eaten much

reproduction:

sexual

  • Dut: Otterschelp
  • Lat: Lutraria lutraria
  • Eng: Common otter shell
  • Ger: Ottermuschel
Common otter shell, foto fitis, sytske dijksen

Common otter shell

The name otter shell is based on a spelling error. The animal has nothing to do with otters. However in the very first publication of this species, the biologist intended name it Lutaria (from lutum = silt) but accidentally wrote Lutraria (from Lutra = otter). It used to be that only single, fossilized common otter shells washed ashore. However since 2000, lots of recent specimen have stranded on the Dutch beaches. This is a sign that this species has returned in the North Sea.

  • Holes

    When lots of otter shells wash ashore, some of the specimen have strange holes in them. The holes are larger on the inside than the outside. Researchers on Texel were curious as to what caused the holes and performed an experiment. When they ticked the outside of an otter shell with a hammer and a large nail, the result was exactly the same as the strange holes. Their conclusion was that the shells were probably pecked at by gulls. Gulls have no hands and need to explore the edibility of the washed up animals with their bills.

  • Distribution and habitat
    Otter shell, sipho, foto fitis, sytske dijksen

    Common otter shells are found along the coast of northwestern Europe from Norway to the Mediterranean Sea and Western Africa. In the North Sea, they dig themselves deep into sandy or muddy sea floors, down to 40 centimeters deep.

  • Mass beaching
    Mass stranding of otter shells in the winter of 2011 on Texel, Sytske Dijksen, www.fotofitis.nl

    After a (winter) storm, live otter shells can wash ashore in massive amounts. That is exactly what happened on February 11 2011 on Texel. There were so many shells that they even made front-page news in the local newspaper, Texelse Courant. The stranded animals made a grand feast for the gulls.

  • Holes

    When lots of otter shells wash ashore, some of the specimen have strange holes in them. The holes are larger on the inside than the outside. Researchers on Texel were curious as to what caused the holes and performed an experiment. When they ticked the outside of an otter shell with a hammer and a large nail, the result was exactly the same as the strange holes. Their conclusion was that the shells were probably pecked at by gulls. Gulls have no hands and need to explore the edibility of the washed up animals with their bills.