A gorgeous flash of colour in a murky loch: how nudibranchs won my heart

With a beauty that belies its name, the sea slug is an invertebrate that reminds me of a happy Scottish summer

It has been a long time since I've thought about nudibranchs, let alone spotted one. But a lifetime ago, as a zoology undergraduate at Glasgow University, I spent hours underwater, swimming through kelp forests, corals and shipwrecks, looking out for the tiny, colourful creatures.

Diving on the west coast of Scotland is spectacular for all the reasons you might expect: the drama of the islands, bays and meandering sea lochs against the mountains, the rugged rocky shores, the awe-inspiring wildness.