Nudibranch

During one of my first dives did a dive-master start to behave like he had found a treasure. Curious, I did swim over to him. He pointed at a small colorful object. I had no idea about what it was. Today I know: Nudibranches are a group of soft-bodied, marine mollusks which shed their shell after their larval stage. The name means “naked gills” in Latin. 

Nudibranches are small, but can be very colorful. The bright colors are a warning to predators that they are venomous. Because of their small size can nudibranches be hard to find, which makes their discovery highly appreciated among the divers.