The blue dragon, known scientifically as Glaucus atlanticus, is a captivating and unique type of sea slug. This small marine creature, often referred to as a nudibranch, possesses a striking appearance. Though it might seem like a mythical being, the blue dragon is a real animal inhabiting the world’s oceans.
Understanding the Blue Dragon
The blue dragon exhibits vibrant blue and silvery-gray coloration. Its body is flat and tapers, featuring six appendages that branch into finger-like cerata. These creatures typically reach about 3 centimeters (1.2 inches) in length. The blue dragon floats upside down on the ocean’s surface, a position maintained by a gas bubble in its stomach. Its bright blue underside faces upwards to camouflage it against the ocean’s blue, and its silvery-gray back blends with the surface when viewed from below.
These sea slugs live a pelagic lifestyle, inhabiting the open ocean rather than coastal areas or the seafloor. They drift with ocean currents and winds, which can lead to them washing ashore. The blue dragon is a carnivore, feeding on other pelagic organisms, especially venomous ones. Its diet often includes the Portuguese Man o’ War (Physalia physalis), the by-the-wind-sailor (Velella velella), and the blue button (Porpita porpita).
Their Potent Defense
The blue dragon’s defense mechanism is derived from its diet. It has the ability to consume and store undigested stinging cells, called nematocysts, from its venomous prey. These nematocysts are transported and concentrated within specialized sacs, known as cnidosacs, located at the tips of the blue dragon’s cerata. When threatened, the blue dragon can release these concentrated stinging cells, delivering a sting more potent than that of its original prey.
Contact with a blue dragon can result in symptoms in humans. Reactions include severe pain at the site of contact, nausea, and vomiting. Skin irritation, such as redness, small bumps (papules), and fluid-filled blisters, may also occur. In some instances, contact can lead to acute allergic contact dermatitis.
While the sting is intensely painful, it is rarely fatal for healthy individuals. The severity of the reaction can vary based on individual sensitivity, the amount of venom injected, and pre-existing health conditions. The potential for severe reactions, particularly in sensitive or allergic individuals, means that stings should be taken seriously.
Encountering a Blue Dragon
Blue dragons are found in the tropical and temperate waters of the Atlantic, Pacific, and Indian Oceans. Due to their pelagic nature, they can sometimes be washed ashore by strong winds or storms. These wash-ups can occasionally involve large groups, sometimes referred to as “blue fleets.” Even a blue dragon that appears dead can still deliver a sting, as the nematocysts remain active.
If you encounter a blue dragon, observe it from a safe distance and avoid touching it. Their small size and striking appearance might seem harmless or tempting to pick up, but direct contact should be prevented. This caution extends to any blue dragons found washed up on beaches.
Should a sting occur, first aid involves rinsing the affected area with saltwater, not fresh water, as fresh water can cause more nematocysts to discharge. Any visible stingers should be carefully removed, if present. Applying heat, such as immersing the area in hot (but not scalding) water, can help to alleviate pain by denaturing the venom. Medical attention should be sought if pain is severe, symptoms worsen, or if signs of an allergic reaction, such as shortness of breath or swelling, develop.