National Geographic Tales of the Weird

by David Braun

  “An octopus without shells can swim away much faster by jet propulsion,” he said. “But on endless mud seafloor, where are you fleeing to?” In other words, a coconut-carrying octopus may be slow, but it’s always got somewhere to hide.

  TRUTH:

  AN OCTOPUS CAN HAVE NEARLY 2,000 SUCKERS ON ITS ARMS.

  What a Tool

  So, what makes the veined octopus’s behavior tool use, versus, say, the hermit crab’s use of seashells as armor?

  Worn nearly constantly, a hermit crab’s adopted shell isn’t considered a tool, because it’s always useful. Tools, by definition, provide no benefit until they’re used for a very specific purpose—showing that the animal is capable of what you might call advance planning. The octopus’s coconut carrying qualifies as tool use, Finn said, because the shells provide only “delayed benefits.”

  Octopuses of many species are well known for their intelligence. In captivity they’ve been known to navigate mazes, seem to be able to remember past events, and are cunning escape artists.

  “While the octopus carries the coconut around there is no use to it—no more use than an umbrella is to you when you have it folded up and you are carrying it about … The coconut becomes useful to this octopus when it stops and turns it the other way up and climbs inside it.”

  Tom Tregenza

  evolutionary ecologist

  Octopus Tool Use Surprising

  Tool use, once thought to be a uniquely human behavior, is seen as a sign of considerable mental sophistication among nonhuman animals. It’s been known for years now that chimpanzees use whole “tool kits,” that some dolphins attach sponges to their beaks for fishing, and that crows fish for insects using sticks and leaves, for example.

  Even so, the octopus discovery stands apart. “I really wasn’t expecting to see tool use appear in cephalopods”—squid, cuttlefish, and octopuses—said biological anthropologist Craig Stanford, co-director of the Jane Goodall Research Center in Los Angeles, who wasn’t involved in the new study.

  That the octopuses weren’t using their tools to rustle up dinner only added to Stanford’s surprise. “Even chimps,” he added, “do not use natural materials to create shelters over their heads.”

  HALF BAKED?

  Lobster Caught

  “Half Cooked” in Maine

  Batman fans will remember Two-Face, the villain with a mug that’s half handsome and half gruesome. In 2006, a Maine lobsterman caught a different kind of two-faced prey—a lobster that looks half raw and half cooked.

  Alan Robinson of Steuben, Maine, hauled up an unbelievable catch near the town of Bar Harbor in 2006: It was a rare two-toned lobster. Half of the animal was mottled brown while the other was bright orange—the color lobsters turn after they’ve been boiled. In his 20 years of catching the crustaceans, Robinson says, he has never seen anything like it.

  Robinson spotted the animal while bringing in his catch. “I thought someone was playing a trick on me,” he told the Bangor Daily News. “Once I saw what it was … it was worth seeing.”

  TRUTH:

  LOBSTERS HAVE POOR EYESIGHT BUT HIGHLY DEVELOPED SENSES OF TASTE AND SMELL.

  Two-Toned Lobster

  He wanted others to see it, too, so Robinson donated his unusual catch to Maine’s Mount Desert Oceanarium, where experts were able to shed some light on the find. Two-toned lobsters, they explain, are rare but not unheard of. The shells of American (also called Maine) lobsters usually sport a combination of yellow, red, and blue pigments. But the animals grow symmetrically, with each half of the body developing independently of the other. In the case of Robinson’s catch, half of the lobster’s shell was lacking the blue pigment, giving its body the appearance of having been cooked to a turn.

  The rare half-brown, half-orange lobster (Photo Credit 11.11)

  All this makes Robinson’s 50–50 find one for the record books, the Oceanarium’s staffers say. The aquarium has received only three two-toned lobsters in 35 years. Lobsters can sport other odd colorations—1 in 2 million is all blue and 1 in 30 million is all yellow. But the odds of finding one that’s exactly half blue and half orange are much higher: 1 in 50 million.

  Record-Setting Catch

  The largest lobster recorded was caught off the coast of Nova Scotia, Canada. It weighed 44.4 pounds and was between 3 and 4 feet long. Scientists think it was at least 100 years old.

  FREAKY FISH

  Weird Fish With Transparent Head

  Bringing new meaning to the phrase “I see right through you,” the Pacific barreleye lets you see exactly what’s on—and in—its mind.

  With a head like a fighter-plane cockpit, a Pacific barreleye fish shows off its highly sensitive, barrel-like eyes—topped by green, orblike lenses. The fish, discovered alive in the deep water off California’s central coast by the Monterey Bay Aquarium Research Institute (MBARI), is the first specimen of its kind to be found with its soft transparent dome intact. The 6-inch (15-centimeter) barreleye (Macropinna microstoma) has been known since 1939—but only from mangled specimens dragged to the surface by nets.

  A see-through Pacific barreleye fish (Photo Credit 11.12)

  I’m Looking Through You

  The beady bits on the front of the Pacific barreleye fish aren’t eyes but smell organs. The grayish, barrel-like eyes are beneath the green domes, which may filter light. In this picture the eyes are pointing upward—the better to see prey above in the darkness of the barreleye’s deep-sea home. Since the eyes are upright tubes, “It just looked like [they only] looked straight up,” MBARI marine technician Kim Reisenbichler said. But by watching live fish, the scientists discovered that the eyes can pivot, like a birdwatcher pointing binoculars.

  The transparent-headed Pacific barreleyes may steal fish from siphonophores, jellyfish that can grow to more than 33 feet (10 meters) long. The barreleye’s flat, horizontal fins may allow it to swim very precisely among the siphonophore’s stinging tentacles—and if the fish fumbles, the clear, helmet-like shield may protect its eyes.

  “Look. I’m all for sushi. But see-through-shi?”

  Stephen Colbert

  comedian, on the discovery of the barreleye fish

  Deep Down

  The barreleye lives more than 2,000 feet (600 meters) beneath the ocean’s surface, where the water is almost inky. The transparent-headed fish spends much of its time motionless, eyes upward. The green lens atop each of the fish’s eyes filters out what little sunlight makes it down from the surface. Then the eyes rotate forward to follow the prey, allowing the fish to home in on its meal.

  UNDERWATER ALIENS

  Strange Sea Species

  Found off Greenland

  Five of the weirdest-looking fish you’ve ever seen are now swimming in the waters off Greenland.

  A recent study found 38 fish species swimming in Greenland’s waters for the first time. Ten of the species new to Greenland are new to science too. Despite their outwardly weird appearances, there is much to be learned from these fish.

  Led by biologist Peter Møller of the Natural History Museum of Denmark in Copenhagen, the study says that rising ocean temperatures due to global warming—which could be drawing unfamiliar fish to the region—and increased deep-sea fishing may account for the spike in fresh fish faces seen off Greenland, according to the study published in the journal Zootaxa.

  FISH 1

  Iceland Catshark

  The Iceland catshark species, including the fish caught during the study period, is among several sharks recently found in Greenland waters for the first time. The small shark has been found in other oceans at depths of between 2,645 to 4,625 feet (800 to 1,410 meters), where it feeds on fish, marine worms, and crustaceans such as lobster and crabs.

  (Photo Credit 11.13)

  FISH 2

  Longhead Dreamer

  Looking like a creature from the Alien movies, this not-so-beautiful “longhead dreamer” anglerfish (Chaenophryne longiceps) was until recently an alien species t
o Greenland waters. The nightmarish-looking dreamer grows to a not-so-monstrous 6.7 inches (17 centimeters) in length.

  (Photo Credit 11.14)

  FISH 3

  Monkfish

  It may be unappetizing to look at, but this newly arrived species of anglerfish, Lophius piscatorius—that’s “monkfish” to seafood fans—could prove a tasty addition to Greenland’s fishery, according to study leader Møller.

  Though monkfish remain rare in Greenland, they appear to be taking advantage of the island’s warmer sea temperatures—as are fellow relatively shallow-water species, including Mueller’s pearlsides, whiting, blackbelly rosefish, and snake pipefish. “Monkfish is so expensive and popular” that it stands out as a potential commercial species from all the other new fish recorded in the survey, Møller said.

  (Photo Credit 11.15)

  FISH 4

  Atlantic Football Fish

  Scaly oddities trawled up from seas around Greenland since 1992 include the Atlantic football fish, a type of anglerfish that lures prey by waggling its fleshy “bait.”

  (Photo Credit 11.16)

  The stubby, deep-sea species belongs to an anglerfish group in which the males attach themselves to the much larger females like parasites. The tiny male—little more than a sperm donor—is nourished by the female until her eggs are fertilized.

  FISH 5

  The Swallower

  Chiasmodon harteli belongs to a group of fishes known as swallowers because of their ability to swallow prey larger than themselves. It’s also among the 38 species never before seen off Greenland. Hundreds of yards above Chiasmodon harteli’s deep habitat, Greenland has been extensively fished for more than a century.

  At these shallower depths, it’s reasonable to assume that “any unknown species offish occurring in today’s catches are in fact new in the area,” the study team writes.

  (Photo Credit 11.17)

  COLOSSAL CATFISH

  Grizzly Bear-Size Catfish

  Caught in Thailand

  Measuring as big as a grizzly bear, a huge catfish caught in 2005 in northern Thailand still holds the record for the largest freshwater fish ever.

  It wasn’t your typical fish story when a team of fishermen on the Mekong River struggled for more than an hour to haul the creature in. It tipped the scales at 646 pounds (293 kilograms) and measured nearly 9 feet long (2.7 meters). Thai fisheries officials had hoped to release the adult female after stripping it of eggs for a captive-breeding program. Unfortunately, the fish didn’t survive its ordeal.

  It died and was later eaten by villagers.

  This giant catfish measured nearly 9 feet (2.7 meters) long. (Photo Credit 11.18)

  World’s Biggest Catfish?

  The giant catfish has been the focus of a World Wildlife Fund (WWF) and National Geographic Society project to study the planet’s biggest freshwater fish. “It’s amazing to think that giants like this still swim in some of the world’s rivers,” said project leader Zeb Hogan, a National Geographic Society emerging explorer and a WWF conservation science fellow. “We believe this catfish is the current record-holder,” Hogan added. “I have heard of 3-meter-plus (10-foot) catfish in Bulgaria, 500-kilogram (1,100-pound) stingrays in Southeast Asia, and 5-meter (16-foot) arapaima in the Amazon, but up until now we have not been able to confirm these reports.”

  Other contenders for the title of world’s largest freshwater fish include the Chinese paddlefish and dog-eating catfish—another Mekong giant. Hogan says such big species are poorly studied and in urgent need of protection. “In many locations they are now so rare that the opportunity for documentation and study may soon be lost,” he said.

  “Fishing is the most easily identifiable threat to the Mekong giant catfish. Dams, navigation projects, and habitat destruction also threaten the giant catfish. In the Mun River, the largest tributary to the Mekong, a dam blocks the migrations of giant catfish.”

  Zeb Hogan

  researcher and conservationist, Mekong Fish Conservation Project

  Meditating Megafish

  International efforts are underway to save the species. It is now illegal in Thailand, Laos, and Cambodia to harvest the giant catfish. However, enforcement of fishing restrictions in many isolated villages along the Mekong is nearly impossible, and illicit and bycatch takings do continue.

  There’s a long tradition of giant catfish fishing in Thailand and Laos. Hogan says cave paintings of the fish in northeast Thailand show it has captured the imagination of people living along the Mekong for more than a thousand years. “Mekong people believe it’s a sacred fish because it persists on plant matter and ‘meditates’ [in the deep, stony pools of the Mekong River]—somewhat like a Buddhist monk,” Hogan said.

  BEWARE THE PINK MEANIE!

  New Jellyfish

  Attacks Other Jellies

  Off the Florida Keys swims a newly discovered species of jellyfish nicknamed the “pink meanie.” It has hundreds of stinging tentacles used to hunt its favorite prey: other jellies.

  When pink meanies were first observed in large numbers in the Gulf of Mexico in 2000, they were thought to be Drymonema dalmatinum, a species known since the late 1800s and usually found in the Mediterranean Sea, the Caribbean Sea, and off the Atlantic coast of South America.

  Recently, though, scientists using genetic techniques and visual examinations have revealed that this pink meanie is an entirely new species—Drymonema larsoni, named after scientist Ron Larson, who did some of the first work on the species in the Caribbean.

  TRUTH:

  A JELLYFISH CAN BE AS SMALL AS A THIMBLE OR AS LARGE AS TWO WASHING MACHINES.

  A New Family

  Moreover, the pink meanie appears to be so different from other known scyphozoans, or “true jellyfish,” that it forced the scientists to create a whole new animal family, a biological designation two levels above species. The new scyphozoan family—the first since 1921—is called Drymonematidae and includes all Drymonema species.

  “They’re just off by themselves,” said Keith Bayha, a marine biologist at the Dauphin Island Sea Lab in Alabama. “As we started to really examine Drymonema both genetically and morphologically, it quickly became clear that they’re not like other jellyfish and are in their own family.”

  Hundreds of stinging tentacles dangle from a “pink meanie”—a new species of jellyfish with a taste for other jellies. (Photo Credit 11.19)

  Bayha and Michael Dawson, an expert on the evolutionary history of marine creatures at the University of California, Merced, detailed the new Drymonema jellyfish species and family in the journal The Biological Bulletin.

  A Taste for Its Own Kind

  According to the new analyses, this Gulf of Mexico Drymonema species is genetically distinct from its Mediterranean cousin, D. dalmatinum. Regardless of where they live, all Drymonema species have an appetite for moon jellyfish, which the Drymonema feed on almost exclusively as adults. Larger Drymonema can ensnare multiple moon jellyfish at once—one had been found with 34 moon jellyfish in its tentacles.

  “They just spread their tentacles out, and as soon as they come into contact with a moon jellyfish, they get more tentacles around them and pull them in,” the Dauphin Island Sea Lab’s Bayha explained.

  Adult Drymonema do the majority of their digestion using specialized “oral arms” that dangle alongside their tentacles. The oral arms exude digestive juices, which break down the prey.

  “As a rule, jellyfish tend to be relatively understudied compared to other animals, and we are constantly uncovering new information fundamental to our understanding of these interesting animals and how they interact with humans and the marine environment.”

  Keith Bayha, Ph.D.

  biologist, Dauphin Island Sea Lab

  Gulf War

  Drymonema can vary greatly in size. Some are only a few inches across, while others can grow to several feet in diameter. “They just keep growing, but most jellyfish live only a year,” Bayha explained. “They’
ll breed and then they’ll kind of stop eating and, in essence, shrivel up, and die.”

  While Drymonema jellyfish feed mainly on other jellyfish, the stinging cells in their tentacles are potent enough to be felt by humans. “They’re really bad stingers,” Bayha said. “The more tentacles come into contact with you, the worse the sting is going to be. And these guys have hundreds and hundreds of tentacles.”

  Since many jellyfish look very similar, past researchers assumed that there are very few jellyfish species. But UC Merced’s Dawson has revealed many cryptic jellyfish—jellies that look the same but are actually separate species.

  While the discovery that a single global species might actually be multiple species may seem trivial, it can become important when studying jellyfish ecology, since different species might behave differently. “It changes the way in which we can study these guys and how they interact with humans and the marine environment,” Bayha said. “And they’re being recognized more and more as a major pest around the world.”

  TRUTH:

  A GROUP OF JELLYFISH IS CALLED A “SMACK.”