Our marine environment is full of the grandest and most dynamic of creatures - whale sharks, manta rays, humpback whales and dolphins - these animals cannot fail to grab attention. They make us feel humble. But our marine environment is also home to a startling diversity of macro life, tiny critters that you may need to look hard to find. Nestled in a field of fluffy bryozoans, sheltered by the forest that is the kelp, you will find the nudibranchs, colourful sea slugs. When urchins strip the kelp and remove the forest, the habitat changes and you can be left with bare rock, devoid of the richness and variety of life that a simple kelp stalk can host. Here I give you Roboastra luteolineata, a nudibranch that hides in plain sight with its brilliant gold and blue velvet stripes. When seeking to understand and protect our marine environment it is not enough to consider the big animals, we need to consider the small inhabitants too. They are no less important for their diminutive size.