Category Archives: Sharks & Rays

Gluttony

Vice Week continues with The Seven Deadly Sins. The next seven posts will describe an animal or animals that exemplify Gluttony, Greed, Sloth, Envy, Wrath, Pride, and Lust. And no, “Sloth” will not be a Sloth, because I have already done the Sloth, because I cannot plan ahead.

When I think of animal gluttons, the first thing to come to mind is the Wolverine, whose other name is “the Glutton.” In fact, his scientific name, Gulo gulo, is Latin for “Glutton glutton.” The largest of the weasels, wolverines make up for in ferocity what they lack in stature. The adamantium skeleton doesn’t hurt, either.


You wanna dance, bub?

A wolverine can bring down a moose. They’re not particularly fast, but because of their broad feet they can outrun almost anything in deep snow. They’ve been known to challenge grizzly bears for a meal. And while they can eat a lot in one sitting, because they don’t eat often in those Arctic winters, they’re not the most gluttonous animal I can think of.

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C is for Cookiecutter Shark

Shark Week continues! Now for something really scary.

The cookiecutter shark earns its name from its habit of removing round plugs of flesh from its victims. In fact, its original name was “demon whale-biter.” And it’s not just whales that fall prey to this parasite: dolphins, seals, larger sharks, squid, and large fish like tuna have all been found with craters bitten out of their sides. In fact, certain Samoans once believed that the tuna that entered their bay willingly sacrificed pieces of their flesh to their chieftain god when they came near the shore; now we know they were terrorized by the shark equivalent of a lamprey.

They have a particularly insidious trick to lure their large prey to them. Like the lanternsharks, they have bioluminescent photophores on their bellies to blend in with the light of the sky. But they also have dark collars without photophores. To animals below, the dark collars look vaguely like very small fish, while the rest of the shark just looks like the sky. The attraction is enhanced by the fact that cookiecutter sharks often travel in schools, emulating the prey of their prey.

And that mouth! The cookiecutter removes its mouthful of meal by suctioning down on the skin of its victim, digging in with its slender upper teeth. Then those lower, jack-o-lantern jagged lower teeth bite down and vibrate, effectively becoming electric carving knives. These are not sharks that eviscerate or destroy. They recognize that the world is round and made of meat, and have the knife and fork to take one good gulp at a time, a modest portion. There is something scarier, I think, about an animal that doesn’t want to finish you off, but paces itself, keeping you alive to satisfy itself again later. A predator that knows that there’s plenty and enough of you to go around.


Instructions For Vanishing Into The Sky

Shark Week continues here on The Quantum Biologist. Today: The world’s smallest shark, and how to camouflage with the sky.

And here it is, the dwarf lanternshark. Found only in the deepest waters off the coast of Venezuela, it measures an incredible six inches… so, not exactly Jaws. With almost 400 species of shark in the world, you have to imagine that most of them are not very scary… sharks tend to be small and skulking and often very lazy. But the elasmobranchs, the cartilaginous fishes that include sharks, are also wonderfully diverse, including the 60-foot whale shark, a gentle plankton-eater that is the largest fish in the world, and the diminuitive dwarf lanternshark, and the whip-tailed thresher shark, and the ray-like angelshark. And what makes the dwarf lanternshark more interesting than its shrimpy size is another item of shark diversity: it glows in the dark.

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Here Be Monsters

You know what I miss? Sea serpents.

There they were, on old maps of the world, corkscrewing through the waters of the Arctic and the South Atlantic, warning sailors, Keep Out. In the Bible, the world was encircled by a giant sea serpent, Leviathan. In Norse mythology, it was girdled by Jörmungandr. In both cases, the message was clear: The spine of the Earth is a monster. Don’t venture too deep.


RAWR I WILL EAT YOU JACQUES CARTIER

Sea serpents have been largely forgotten by modern culture, but the ancients knew them by name: Scylla in The Odyssey, Labbu to the Babylonians. Aristotle included them in the world’s first field guide. The Saint of Greenland recorded one in 1794, and American sightings were so common in the 17th-19th centuries that the New England Linnaean Society actually classified a deformed terrestrial snake as a juvenile sea serpent. So, just one question: What is a sea serpent? Below the cut, a few of my favorite candidates for the honor, and my plea to save both the real animals and the myth.

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I Sing The Body Electric

The human body generates more bioelectricity than a 120 volt battery and over 25,000 BTUs of body heat. Combined with a form of fusion the machines had found all the energy they would ever need. – Morpheus

Lately, I’ve been talking about animals in relation to machines. Today, let’s talk about animals not as conduits and generators. Let’s talk about bioelectromagnetism.

The American Paddlefish is a large freshwater fish living in the larger rivers of North America, such as the Mississippi. It has, as you can see, both an impressive schnoz and an enormous piehole. The two complement each other. Early naturalists first thought that its spoon-like nose was used to dig vegetation out of the river muck, but it turns out that its diet consists entirely of plankton. It gulps huge amounts of water and filters the plankton out with its gills, like a basking shark. And that paddle? It’s electroreceptive. It senses the weak bioelectrical field surrounding a cloud of plankton; the same bioelectric aura that surrounds all living things, and is, in fact, the essence of life.

As you know, every neuron in your body uses electricity to function. Every time your heat beats, you send an electrical impulse into the atmosphere. Every time you have a thought or sensation, you send out electricity in what we call a brainwave. Bioelectricity was discovered by the scientist Luigi Galvani, from whom we get the term galvanism, the contraction of a muscle when stimulated by an electrical current. Galvani discovered it by shocking dead frogs and watching them spasm; for an even more extreme illustration of bioelectromagnetism by torturing frogs, keep reading.

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