The weather on the morning of 8th November 2017 did not look promising, but I had been out of Assynt for nearly a week, on trains and in cities, and needed some fresh air. It was fresh indeed along the coast from Culkein Bay to Rubh’an Dunain, where huge breakers were crashing over the rocks. However there was a fair amount to see on the beach and close inshore, including up to twelve colourful turnstones, our first this autumn, redshanks, curlews and ringed plovers, a pair of red-breasted mergansers, diving gannets and a bottling common seal.
Having completed a very windy circuit, we retreated to the car with watering eyes for hot drinks. We, Gwen Richards and I, then moved on to Clashnessie beach (NC0531) to see if recent northerlies had brought in anything special. Detailed searching was discouraged by blowing sand, but we did strike lucky, with four spotted cowries Trivia monacha and a single shell of an unfamiliar small limpet.
The shell was delicate, just 16mm long and 14mm wide, with a low offset apex. Although it was rather worn, there were signs of broken brownish markings radiating from the apex. The underside was pale brown, with a darker centre containing a pale muscle scar. From these characters and on-line illustrations, I was able to identify it as a common tortoiseshell limpet Testudinaria testudinalis (a.k.a. Tectura tessulata). It is one of just two members of the family Acmaeidae found in British waters, and its habitat in life is described as ‘on boulders and small stones, particularly those encrusted with red algae such as Lithothamnion’, from low water neap tides down to 50m.
Although tortoiseshell limpet is widely distributed around the western and northern coasts of England, Wales and Scotland it was new to us; a nice find on a challenging day.