Ships worm

Eats wood and plankton

Wood contains cellulose that is composed of a great many sugar molecules. With the help of bacteria, the ships worm can split the cellulose and use it as food. Living on just sugar is difficult, so the ships worm filters plankton out of the water. Via the inhalent siphon, that sticks out through a little hole in the wood, it is able to suck in water that contains oxygen and plankton. The ships worm eats plankton in much the same way as the blue mussel.
    The ships worm has the ability to draw in its siphons and close the hole with its two palets. Enclosed in this manner the ships worm can survive a period, even if its habitat is washed up onto a beach or finds itself in freshwater.

Fertilization in the sea or in the exhalent siphon

Methods of fertilization vary between the different specie. With certain specie fertilization takes place externally when the male and female release their sperms and eggs into the water, very much like the life cycle of the mussel. With certain other specie the male releases its sperm into the water, while the female keeps her eggs in the canal that leads to the exhalent siphon. For fertilization to take place, the female has to suck in the sperms via her inhalent siphon. This life cycle resembles the oysters. The ships worm resembles the oyster in another way by the fact that it can change between the sexes. When the larvae are mature they try to find a shady place, and if the foundation is of wood they will stay and transform into small worms and bore into the wood. The end of the worm where the siphons are situated holds the pallets and these are not moved during the whole of the mussels life. When the mussel starts growing, it bores the other end into the wood.
    Ships worms are found globally, but because they cannot survive in brackish water, many well preserved wrecks can be found for example in the Baltic, even if they have lied there several hundred years.

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Bores with its shell

Eats wood and plankton

Fertilization in its exhalent siphon

Different worm-like borers

Ships worm     More facts     Other names
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Bo Johannesson | Martin Larsvik | Lars-Ove Loo | Helena Samuelsson