Flat periwinkle

Eggs in jelly


Flat periwinkles place a long and flat jelly-like sack of eggs on the seaweed where they live. A female can lay several jelly-like sacks, each of which can contain several hundred eggs. In the beginning these sacks are almost transparent or white in colour, but as the young shells develope the sacks became darker. The young develope fully within the sacks, and when mature (0,5 mm in size), small miniature copies of their parents creep out of the sack.
    Because of its size, the periwinkle pictured above cannot have layed the egg sack, as it has not became sexually mature.
    It is not possible to determine the specie of the egg sacks; but most of those that are found on bladder or toothed wrack originate from Littorina fabalis, while those found on knotted wrack originate from Littorina obtusata.

Bo Johannesson

Pervious page

Page 2 of 2

Differences between the specie

Eggs in jelly

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Bo Johannesson | Martin Larsvik | Lars-Ove Loo | Helena Samuelsson