Skye News: Doris reveals all as Nudibranch of the Week

Disco Doris was found to be partying it up at Ardmore on Skye last week. Sporting a star-studded mantle, its ‘acid’ habit is well known…………

Now placed within the genus Geitodoris, the former Discodoris planata is an uncommon northern dorid which may reach 65mm in length. It is often confused with its ubiquitous relative Archidoris pseudoargus, commonly known as the Sea Lemon. G. planata can be distinguished from A. pseudoargus by the light coloured stellate patterns on the mantle (the acid glands), and also by the more flattened shape. The colouration usually shows a brown or purple dominance. The underside of the animal is also important with Geitodoris having brown spots on the mantle, and conspicous oral tentacles, both characters lacking in A. pseudoargus. There is a wide range of colour in the latter species, ranging through yellow, orange, brown, pink, green and white pigments. In living animals there is also a difference in texture, Geitodoris being crisper, harder and flatter. Another species that might be confused is Jorunna tomentosa. This species is characterised by the velvety appearance of the mantle which is often very pale (with paired brown blotches running down the dorsum) – very different from the warty surface of Geitodoris.

There is much more Skye News to come in the next issue of Mollusc World….

Geitodoris planata (Photo: Steve Wilkinson)