Cover Image: Glaucus atlanticus. Photograph by Sylke Rohrlach. Source: Wikimedia Commons. Licensed under (CC BY-SA 2.0).

When thinking about our world’s oceans many of us consider these grand animals from whales, dolphins, sharks, and more. Meanwhile our oceans hold a plethora of life that holds unique qualities sometimes overlooked. One of these creatures being Glaucus atlanticus or better known as the Blue Dragon. These creatures are a part of the Nudibranchs family, as they lose their shell in their larval stage and live out their lives in the pelagic zones of the ocean. They were first recorded in 1770 by German scientist Georg Forster in Mexico and later recorded in 1875 when it was collected during one of The Challengers Expedition in the Pacific. They are typically distributed in more tropical regions of the Atlantic, Pacific and Indian oceans. However, in 2022, likely due to climate and current pattern changes, not only have they been found close to Australia, but washed up along the Texas Gulf Coast. They get washed up due to an air sac within their stomachs which allow for them to float atop the water’s surface. This adaptation has led Blue Dragons to rely on the ocean’s currents and winds for transportation. Furthermore, since the sac is within their stomachs this causes their ventral side to face upwards towards the surface, while their dorsal side is facing towards the depths. Their pigmentations however have evolved to correlate with these orientations as their dorsal side is a white/grey coloration to blend in from above and their ventral side is dark blue to blend in from predators below. 

The Blue Dragons do not rely solely on camouflage. In fact, their main source of defense is thanks to their primary prey, the Portuguese Man o’ War. Blue Dragons are immune to the stings of these siphonophores which allow them to deflate their air sac, cling on, and eat the main body plus the stinging tentacles from the bottom. Through a process called kleptoconidia they intake only the most potent nematocysts and turn it into its own defense. They then store these into specialized sacks called cnidosacs found at the tip of their tentacle structures. Thanks to the high concentration within the cnidosacs this causes the strength of the nematocysts to amplify stronger than the Man o’ War itself. Don’t worry, it’s not extremely dangerous to humans. In extreme cases some have died, but they already had health problems. Typically, the worse cases are nausea and vomiting with the most common being a stinging sensation that can be treated. In the end the Blue Dragon is the perfect example of a small unique treasure in a vast ocean we have yet to truly explore.