Meet the Glaucus atlanticus, a tiny sea slug that’s only 3 cm long, floating on the surface of an ocean near you. Like many of these uncommon creatures, this one has a lot of names which include a sea swallow, blue angel, blue glaucus, blue dragon, blue sea slug and blue ocean slug. Despite its colorful appearance, this isn’t a creature you’d like to come across as it’s loaded with poison due to its unique diet. It feeds on the venomous Portuguese man o’ war, a creature often mistaken for a jellyfish which also goes by the unsettling name of the “floating terror.”
This small invertebrate eats hydrozoans from the man o’ war, which are fatal to humans, but easily consumed by the Glaucus atlanticus. It has hard disks inside its body that act as protective barriers, secreting a special mucus. After enjoying a meal, the Glaucus atlanticus stores the poison inside its body for the future in order to defend itself. Some scientists think that if this little sea slug has a voracious appetite, it can end up becoming far more dangerous than even the Portuguese man o’ war.
The Glaucus Atlanticus is neither male nor female, but a hermaphrodite with both reproductive organs. After mating, each slug produces eggs, which they lay on driftwood, or on the skeletal remains of their enemies. When food is in short supply, things get a little crazy. When one slug meets another in the neighborhood, rather than wave hello, they’ll simply begin to eat the other head first. Yep, turns out this little pint-sized blue dragon is also a poison-sucking cannibal. Too bad, really, as they are such a lovely shade of blue.
About the Doodlewash
M. Graham watercolors: Cobalt Blue, Cobalt Teal, Ultramarine Blue, and Neutral Tint. Lamy Safari Al Star pen with Platinum Carbon blue ink in a 5″ x 8″ 140 lb. (300 gsm) Pentalic Aqua Journal