24 January 2014
Africa’s Tigerfish was caught jumping out of the water . . . into the air . . . catching a bird . . . in flight . . . and taking it home for dinner.
[video] tigerfish dining alfresco
It’s bad enough that sea creatures can attack us when we go into the water. About 40 years ago, the film, Jaws, scared movie-goers to the point that people stopped going to beaches for fear of being attacked by sharks — but only if the swimmers went in the water! The next film, Jaws II, had promotional trailers warning: “Just when you thought it was safe to go back in the water.” But at least you were safe on dry land.
Poster: Jaws II
In 1975, the first in a series of SNL sketches took away that last safe place – dry land. The Saturday Night Live writers introduced the world to the “Land Shark” — a predator that could strike on land or sea. In each sketch, a city-dweller would hear a knock at the door and a voice would call out, “telegram,” “plumber,” etc. When the door was opened, in plunged the “Land Shark” (or a giant foam rubber version of the “Land Shark”).
Like a few other fictional villains, the “Land Shark” developed a real life copycat, the “Land Catfish.” Introduced to France’s River Tarn, about 20 years ago, a common species of catfish was starving as its food of choice, crayfish, decreased in numbers. Most species would have the good graces to continue to starve and die out. Not these catfish. Instead, they made a different choice and “learned” to do something no member of their species has ever done before – catch and eat land animals.
Hovering in the water, near flocks of pigeons, these catfish wait for one of the birds to get “too close” to the water. Then, these (sometimes, four-foot long) cats jump out of the water, grab a pigeon and take it home for dinner.
Fisherman, who saw the Land Catfish at work, found it – really creepy. And, so do I. Underwater creatures intentionally jumping out of the water to grab some land animal, drag it back into the water, and eat it? I’ve seen stuff like this in old horror movies!
“Catfish grabs pigeon” [video]
Study of these Land Catfish revealed another upsetting fact. Those catfish that learned to hunt “land prey” developed a taste for land animals. These fish stopped eating their usual crayfish and started eating almost nothing but land animals. Being a land animal, myself, I don’t find any of this comforting . . . at all!
Also, in the last year, we found out about another sea creature that just won’t stay in the sea. A few months ago, an octopus was caught crawling out of the ocean and leisurely shopping for snacks on a California beach. But, unlike the catfish, the octopus didn’t suddenly “choose” to start hunting on land in the last week or so.
Octopus experts say that octopuses have always done this. These creatures jump out of the water onto land all the time. (I don’t know that I wanted to know that.) The only thing that was unusual was that the octopus starring in the video was shopping on the beach during the day. Usually, octopuses crawl out of the sea and go trolling for a meal on land — in the dark of night. Well, that’s the end of my evening strolls on the beach! But, it gets worse. Octopuses even jump onto crab-fishing boats, climb into barrels of crabs (their favorite food), and pig-out.
Just when you thought it was safe to go near the water.
But just as this “year of discovery” of the real Land Sharks was ending, another safe place was invaded by predator fish.
Welcome the “Air Shark.”
A Tigerfish was caught on video jumping out of the water . . . into the air . . . and catching birds in flight. The Tiger is just the sort of fish you don’t want jumping out of the water and catching passing . . . animals. Who knows what else it might catch when it’s up there — water-skiers, parasailers, . . . small aircraft?
Called the “African piranha” the Tigerfish has no winning smile, but it sure has a toothy grin. [image] Hoping for some comfort, I looked up the tigerfish on Wikipedia. After saying that game fisherman call these fish “the African piranhas,” the entry goes on, reassuringly, to say that the two fish aren’t so much alike because the tigerfish and piranha are two different species. (I sigh with relief.)
But, then, the entry goes on to say that tigerfish and piranhas do have just a few things in common. Both have “interlocking, razor-sharp teeth”, “are … extremely aggressive … predators”, and “often hunt in groups.” Oh, don’t let me forget to mention that each member of the tigerfish “pack” weighs about 110 pounds. And another thing, tigerfish have been known to attack humans.
Really makes you want to book that ski vacation at Africa’s Lake Malawi, doesn’t it?
Unlike the Land Catfish, the “Air Shark”/Tigerfish didn’t just choose to start hunting flying birds — yesterday. There have been stories of this fish jumping out the water and grabbing birds in flight since the 1940’s. But, like the octopus’s strolls on the beach, the flight of the tigerfish was never caught on video until this year.
Nico Smit, director of the Unit for Environmental Sciences and Management at North-West University in Potchefstroom, South Africa, was part of the team that caught the “Air Shark” catching a quick bite. He said that the whole “event,” (meal for the fish, “big sleep” for the bird) happens so fast that it took a while before the researchers were sure what they were seeing.
It didn’t just happen fast. It happened often. They saw 20 “catches” the first day and about 300 during the next two weeks. The “event” was caught on video for the first time by team member Francois Jacobs. The team’s findings were published in the Journal of Fish Biology and Nature.com.
With this report, yet another element of our environment, the air, is threatened by killer fish. I can hear someone say, “Yeah, but unless you’re a bird flying over a lake in Africa you’re safe.” Well, 20 years ago, French pigeons thought they were safe from catfish attacks on the shore of the River Tarn. Then, one fine day, a catfish just “chose” to become a Land Catfish and start jumping out of the water, onto land, to grab and eat the nearest animal. You wouldn’t have wanted to be the next unlucky pigeon that went to get a drink of water from the river!
This “choosing” thing worries me. Now, animals just “choose” to eat completely different things than they’ve been eating for the last few thousand years. Just a couple of weeks after I heard about the Land Catfish, I visited an evening holiday light display at the Missouri Botanical Garden. In the freezing cold, I walked along the dark paths admiring the beautiful lights. I thought back to the Garden, in the summer, with giant koi fish in the large pond surrounded by the Japanese Garden. You can feed these large fish as they gather around the bridges and shoreline to gobble up food pellets.
Gee, I thought, those fish must have rough time under the frozen ice. They go for months with little food. I bet they get really hungry. Looking out into the pitch blackness a few yards off the path, I wondered how close I was to the water. No, I reassured myself. I’m safe. After all . . . koi fish couldn’t be dangerous. These fish look like giant goldfish. The only difference is some have those whisker-looking things. You know, . . . like . . . catfish!? Those clever, predatory, and hungry river-beasts that are scarfing down pigeons in France!
I stuck to the paths farthest from the water.
I didn’t like this new trend toward “choice” with fish deciding to leave the water and eat anything that happened by. But I didn’t think it was a too big a problem until I stumbled across a story about another sea animal. One that jumps out of the water regularly and sails through the air. Everyone says this creature just jumps out of the water and dives back into the water without “eating an in-flight meal.” But, now, I know that sea creatures can just “choose” to change their feeding habits any time.
Jun Yamamoto of Hokkaido University and his team were tracking squid in the ocean east of Tokyo when 20 of these ten-legged creatures flew out of the water for a distance of about 30 meters. They like to fly. They spread out their fins and legs like wings to stay in the air. They’ve even been seen flapping their fins to stay in the air a little longer!
Same story, different day – there were rumors about flying squid for years, but this was the first time they’ve been caught on film. Yamamoto said, “[W]e should no longer consider squid as things that live only in the water.” [!]
Welcome the Air Squid.
Everyone’s worried about the safety of the flying squid. Birds might eat them while they’re flying through the air. Sure, but what happens to the birds when the flying squid decide they’re hungry? “Oh, but these flying squid don’t eat birds or . . . (glup) . . . water-skiers.” Of course, not. Not yet. Not until, like the French Land Catfish, they “choose” to start eating birds, people, . . . small aerial drones. Who knows?
Some will say, “But only small squid fly.” “It’s not like the flying squid were those giant 12 foot long, 330 pound squid that live deep in the ocean.” Correction: Just because they’ve never been caught on video, doesn’t mean giant squid don’t fly. And, even if they’ve never flown before, what make you so sure they won’t choose to fly in the future. Suppose they do. And suppose they choose to flap their fins so fast that they start flying like birds. That’s all we need — giant flying squid trolling the air above the water like a bunch a pterodactyls.
First, there was Jaws with its great white shark.
Don’t go in the water!
Then, the Land Shark “inspired” imitators — the Land Catfish and Land Octopus.
Don’t go near the water!
Finally, the Tigerfish becomes the “Air Shark.”
Don’t fly above the water!
M Grossmann of Hazelwood, Missouri
& Belleville, Illinois
THURSDAY: Over the Rainbow . . . on Venus?
27 March 2014
Venus in the News Image
How do you remember those strange formulas for science class? One trick for remembering one formula was this poem:
Little Timmy took a drink,
but he will drink no more.
For what he thought was H2O
The rhyme helps you remember the formula, but the poem makes a point. There’s a big difference between water ( H2O) and sulfuric acid ( H2SO4). Who would have guessed that rainbows appear not only in an atmosphere filled with water (H2O) vapor but, also, in an atmosphere filled with sulfuric acid (H2SO4) vapor? Yes, the vapor of this highly caustic acid works as well, or better, than water vapor for producing rainbows. But it doesn’t work half so well for producing a pleasant atmosphere. On earth, we’re happy enough with our water vapor. And the planet Venus gets by with its sulfuric acid vapor.
But this left a mystery. Researchers have known for some time that sulfuric acid vapor is great for producing rainbows. And they’ve also known that the atmosphere of Venus is full of sulfuric acid. So, when we looked at Venus, we should have seen some rainbows. But we didn’t.
So, why would the atmosphere of the planet Venus, an atmosphere filled with sulfuric acid vapor, never produce a rainbow? Most suspected that there was something else in the air. Something that absorbed the light before it could be reflected out of the vapor as a rainbow. No one could figure out what this (ultraviolet) “uv absorber” was.
But we need a word about words. A rainbow isn’t just white light passing through water vapor to create a half circle of colors in the sky. Whether something is a rainbow or not depends on where you are when you see it. If you’re standing on the ground looking up after a light rain, it’s a rainbow. If you’re looking down, at the same thing, from above – let’s say you’re an aviator flying high in the air, an astronaut orbiting the earth, or a satellite sending back pictures – you’ll see a full circle of colors. And, instead of a rainbow, it’s called a “glory.”
No one has every stood on the surface of Venus. No probe has successfully landed on the planet’s surface and, then, aimed its camera up into the sky. So, there’s really no chance of seeing “a rainbow” on Venus. But, whether through the lens of an earth telescope or a camera on a probe orbiting the second planet, the view from above should have revealed a glory.
In 2011, as reported in the Journal, Icarus, Wojciech Markiewicz, of the Max Planck Institute for Solar System Research in Gottingen, Germany, and his colleagues maneuvered the European Space Agency’s Venus Express spacecraft in an effort to find a glory. And maneuvering was needed. To see a glory, you not only have to be watching from above, but the sun must be directly behind you. So, if you’re not looking down with the sun to your back, there’s no chance you’ll see a glory..
On July 24, 2011, after more than a little maneuvering, the group found and photographed the first rainbow (glory) ever seen on Venus. Still, no one is sure why they are so hard to find. With the sulfuric acid in the atmosphere, they should be a relatively common thing. Again, it may be that other elements in the atmosphere affect the reflectivity and refraction of the vapor.
Venus, our nearest neighbor in the solar system, seems to get little attention in comparison to the red planet Mars. Maybe, this is because its solid surface is a less than friendly place to visit with a fairly constant temperature between 400 and 500 degrees. Venus is about the size of the earth and actually passes closer to the earth than Mars. While Venus rotates around the sun is the same direction as the earth and all the other planets, it’s rotation on its axis is reversed. So, to someone standing on the planet’s surface, the sun appears to rise in the west and set in the east.
Viewed from the earth, Venus appears to have a bluish cast. But the second planet from the sun is actually white, or at least, white is the color of this planet’s constant, thick cloud-cover. Like all the planets, but particularly the moon, Venus reflects the light of the sun. So, with a telescope, or just binoculars, Venus is seen in a crescent phase. This bright point of light in sky is easy to mistake for an aircraft. Venus enjoyed something of a notorious reputation during the 50’s and 60’s as an official or “stock” explanation for reports of UFO sightings.
This apparently bluish star is so large that, even with the naked eye, you can almost make out the spherical shape of the planet. Night or day, Venus is the third brightest thing in the sky – only the sun and moon are brighter. Never too far from the sun, Venus appears sometimes above the eastern horizon before the sunrise and sometimes above the western horizon shortly after sunset.