Sunday Science Blog

Tiny Real-Life 'Dragon' Makes A Stunning Rare Appearance



Meet the blue dragon — probably among the most beautiful animals on the planet. And he's a sea slug, no less.

The blue glaucus, blue sea slug, blue ocean slug, blue dragon

If you heard about a tiny, funny-looking animal that spends its life floating upside-down on the surface of the Pacific, Atlantic, or Indian Ocean thanks to an air bubble which it swallows and keeps inside its belly, going wherever the currents and the wind take it, you would probably think it was just a harmless creature that likes to relax in the water. But this slender, up-to-3-centimeter-long animal, which is called the blue glaucus, blue sea slug, or blue ocean slug, is not nearly as innocent as it seems. 

The first trick it’s got up its sleeve is a form of camouflage called countershading that protects it from both flying and swimming predators while it floats. The underside of the blue glaucus, which faces upward, is blue, helping it blend into the water’s surface when seen from above, while its back, which faces downward, is a more grayish color, helping it blend into the ocean when seen from below. 

The second tricky feature of the blue glaucus is even more amazing. It feeds on hydrozoans (a group of animals in the same phylum as jellyfish), especially the highly poisonous Portuguese Man-O’-War. Although a sting by a Portuguese Man-O’-War is very painful to a human, the blue glaucus, like some other sea slugs, can swallow its prey’s stinging cells (known as nematocysts) without hurting itself. It may keep itself safe from the poison by releasing protective mucus and by hard barrier-like discs inside its skin.

But the blue glaucus does more than simply protect itself against these stings. It stores the swallowed poison inside the up to 84 finger-like structures or cerata sticking out of its body, and then uses this poison to defend itself against other predators!


Thanks for the link in your email, JB!
















ON ANOTHER SUBJECT:


For those who prefer messages of "Peace on Earth, Goodwill Toward Men," here's a message from a Christian, Jerry Falwell, Jr., who's the head of a Christian University, Liberty U.  

Isn't this just the sort of message Jesus would want his followers to be spreading as they celebrate the coming birthday of the Prince of Peace?:


“It just blows my mind that the president of the United States [says] that the answer to circumstances like that is more gun control,” he said to applause. 

 “If some of those people in that community center had what I have in my back pocket right now …,” he said while being interrupted by louder cheers and clapping. 

“Is it illegal to pull it out? I don’t know,” he said, chuckling. 

“I’ve always thought that if more good people had concealed-carry permits, then we could end those Muslims before they walked in,” he says, the rest of his sentence drowned out by loud applause while he said, “and killed them.”