Nudibranchs are my personal ground zero and are solely responsible for igniting my obsession with underwater photography in the first place. I eventually expanded my horizons to include other creatures, but even after all of this time, I cannot resist shooting photos of Nudibranchs. Common or not there is something irresistible and appealing to me that compels me to yell Nudi Alert! underwater whenever I see one posing just right.

Nudibranchs are all classified under the phylum of mollusks, which are a group of invertebrates. This group includes creatures such as octopus, cuttlefish, snails and even many bivalves. They belong to the class Gastropoda and the subclass of Opistobranch. It's safe to say that nudibranchs encompass more than 2,000 described species but actually belong in the order under Opistobranchs. Commonly, we just call them “Slugs" or "Nudis”.

Nudis come in many different shapes and sizes. They are often brightly coloured and are detailed with flamboyant designs. It’s the endless combination of colours, textures, shapes, and slow movements that makes them a perfect subject for budding photographers and experts alike. The Indo-Pacific is the most bio-diverse body of water in the world and nudibranchs are certainly the most diverse fauna. Take a few minutes on your next dive and observe how many different nudibranchs can be found, and remember to tell your friend by yelling, Nudi Alert!

Mike Bartick was born and raised in Southern California, not far from the ocean in Huntington Beach. After finding his first nudibranch on an Open Water checkout dive, he was immediately hooked on diving. Bartick, who splits his time between the Indo-Pacific and the Eastern Pacific as a freelance photographer, photojournalist and field guide, shoots with a Nikon D300 and D300s, Sea and Sea housings, and YS-D1 and YS 250 pro strobes. To see more of his work, visit saltwaterphoto.com.