This was the first time for me to see this species of nudibranch, so I spent some time observing it. I must admit, I initially found it rather unpleasant to look at — like a monster out of a bad sci-fi movie!
This hooded nudibranch (Melibe viridis) has what’s called an ‘oral veil’, which it uses to probe the substrate for food. And to catch some! You’ll see in the video that I was very lucky to have recorded this sea slug’s feeding behavior, from start to finish. That was a shrimp that got trapped by the nudibranch’s balloon-like mouth, which closed in on the prey and devoured it. The poor crustacean didn’t stand a chance.
I’ve now seen several more of this nudibranch, most of the time at Dayang Beach and always in shallow waters. This one measured about 15cm long (with the oral veil retracted).
Those leg-like things on either side of its body aren’t appendages — they’re not used for getting around at all. They are cerata, anatomical structures that aid in breathing and in the storage of toxins that the animal extracts from poisonous food. That’s what’s so intriguing about nudibranchs: their immunity from toxic substances in the food they eat, and their ability to recycle these toxins for their own use in self-defense.
While this species may not be easy on the eyes, it’s just as impressive and fascinating as the prettiest of nudibranchs!