Blue Sea Slugs (Glaucus atlanticus)

Blue Sea Slugs are shell-less gastropods with the unique ability to float upside down. Surface tension allows them to be guided by wind and ocean currents. 

These unique types of mollusks are silvery grey on the top side, while the underbelly carries dark and pale blue hues. Their bodies exhibit dark blue stripes and six finger-like projections called cerata. This form of countershading camouflaged them from would-be attackers.

Despite their average size of 1.2 inches, it's critical to understand these critters are more dangerous than they appear. The tips of their cerata are full of venom from their cnidarian-rich diet. Touching them can induce painful stings, causing symptoms such as nausea, vomiting, and allergic reactions.