Glaucus Atlanticus

     Yes, this critter is real… and dangerous.

     Also known as the sea swallow, blue glaucus, blue dragon, blue sea slug, blue ocean slug, and, more recently, the real life pokemon. Glaucus Atlanticus is found throughout the tropical Atlantic, Pacific, and Indian oceans. This Glaucus is a type of nudibranch, a shell-less mollusk known for their extravagant shapes and colors. A normal sized one averages around three centimeters in length.

     According to the natural history museum, I gleaned the following details about this little blue oddity of the sea.

     The Blue Glaucus is the only species in its genus, “Glaucus”, and one of only two species in the entire family of “Glaucidae”. They float upside down by swallowing air and storing it in their stomachs. And speaking of their stomachs, their primary food is made of hydrozoans (including the Portuguese Man O’ War).  Not only do they eat them, but they store their food’s stings in their own little frilly fingers. Since they collect them instead of creating them, they can actually be more deadly than a Man O’ War.

     In other words, they may be small, they may be pretty, you may want to touch them… DON’T.

     Those frilly little fingers are called cerata. Every Glaucus Atlanticus has up to 84 of them. These fingers hold onto the nematocysts (the stings from the jellyfish it eats) in specialized sacs called cnidosacs.

     Earlier, I said that there was another Glaucus in the family, it is called Glaucilla Marginata. The Marginata has more cerata, up to 137 in total. The Marginata also has a longer tail than the Atlanticus, even though it is actually the smaller of the two. Marginata only reaches 12mm in length compared to Atlanticus, which can grow several centimeters.  (I believe eight centimeters is the largest recorded, but I am still looking for confirmation on that.)