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Sea slugs are molluscs that have greatly reduced or even lost their shells. The true Nudibranchs have not only lost their shell but have exposed secondary gills around the anus. Many varieties may be seen around the Scottish coastline if you keep your eyes open and are tuned in to what you are looking at. Size varies from just a few millimetres up to around 15 cms. On occasions it may appear that there has been a local "population explosion" of a particular species with large numbers being very obvious, whilst on other occasions none will be seen.Colouring and formation of the true nudibranchs can be spectacular despite their small size. The upper surface in some species is covered with elongated structures termed cerata which are used to store the stinging cells (nematocysts) from their prey, presumably as protection. As there are many distinct species and sub species precise identification is best left to the experts who will often require a magnifying glass or even microscope to do so! |
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Rosehearty, Aberdeenshire
Rosehearty 3/04 |
Sea hare Aplysia punctata Athough effectively a "slug" the sea hare is not classed as a nudibranch. It retains a shell with this being totally internal. Generally seen for only a short period of the year, generally during mid summer, and away from full sunlight. They can on occasion be present in very large numbers. Although they are hermaphrodite and able to produce young without mating, mating pairs are seen on occasion (as photo). It can often be seen at sizes up to about 10cm. Although the chocolate brown colouring is most commonly seen colouration can be from a green-brown through to almost black. |
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Rosehearty
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Tritonia hombergi Feeds on "dead mens fingers" and will generally be found on or adjacent to these. May on occasion be locally common. Although normally sized about 3-5cm, it can attain a very large size up to about15cm in length |
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Sea Lemon Closely resembling the sponge on which it feeds, the sea lemon is generally a pale yellow cream in colour with a roughened skin. It has a ring of plume like gills on its back towards the rear end and 2 pairs of head tentacles. |
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Rosehearty (6/02) |
Goniodoris? |
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Macduff 6/03 |
Janolus cristatus? |
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Rosehearty 3/04 |
Polycera quadrilineata |
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Nudibranch egg spirals |
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Egg frills on Nemertesia - Collie Head |
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