The Blue-Rayed Limpet

The Kelp Forest

Kelp forests are the anchor of nearshore ocean wildlife communities across the south coast of Cornwall, sustaining marine biodiversity by providing shelter, habitat and even food for an array of fish and invertebrates. They reduce the force of storm-driven tides and surges at the bottom of the shoreline and act as a fence to help retain nearshore sand, preventing erosion. The blue-r

Limpet Lunch

Blue-rayed limpets often feed on a species of kelp known as Laminaria digitata; a large brown fingered seaweed that grows on rocky shores and is usually only accessible at the lowest of low tides. They feed on the kelp itself, creating a little pit on the kelp frond as they munch away. During the autumn the limpets move down the kelp to avoid being cast adrift if the kelp frond is dama

Perfect Profile

The limpet appears as a small oval shell, no more than two centimetres in length. They are translucent and pale brown in colour but with two to eight distinctive dashed kingfisher blue lines. The lines are absent in juveniles (under one centimetre long). It is this blue that catches your eye amongst its brown, much darker surroundings.

A Bling Batch

Blue-rayed limpets are usually found in small clusters where the fronds of the kelp meet the stipe. Due to their minuscule size finding them can be difficult. Prisk Cove is one of the most biodiverse places in the UK and is home to these elusive molluscs. After turning over many pieces of oarweed, they started to make an appearance, particularly nearer the low tide mark. Due to sunlig

Shining in the Shallows

Snorkelers can find these limpets out to twenty-five metres deep. Their vibrant blue stands out within the forest of kelp. It is thought that this colouration protects the limpet from potential predators, the stripe patterns and colour might serve to mimic toxic or otherwise distasteful organisms in its habitat that use similar visual features to advertise their unpalatabili

Shells of Crystal

The bright colour of the limpets’ stripes originates from light interference in a periodically layered zig-zag architecture of calcite within the shell. Beneath the top layers of the shell, a random arrangement of light- absorbing particles provides contrast to the blue colour. This unique display of two distinct optical elements at specific locations within the structure of the l