African Catfish Hunts On Land

Dave Knott writes "The journal Nature will be publishing a report on an African catfish that hunts its prey on land. The fish wriggles out of the swamps to catch land-based prey. From the article: 'The eel catfish, Channallabes apus, catches unsuspecting victims by arching upwards and descending upon prey, trapping an insect against the ground before sucking it up. The same trick may have been used by the very first vertebrates to venture onto land, the researchers speculate.' There is a video of the fish in action."

Comments

Re:Let's see...

[nwbvt]

I would say going onto land to hunt insects (as opposed to merely hunting insects from the water or merely going on land) makes this interesting. No, its not a halt the presses type of news, but that doesn't keep it from being an interesting article.

Now Explain How They Develop Feet

[Proto23]

Given a lot of time, how do fish start to crawl out of the water just because they catch insects this way?

Re:Now Explain How They Develop Feet

[TapeCutter]

Probably due to the environment found in temporary waterways, freshwater eels often go across fields from dam to stream or vica-verse at nighttime. The eels use dams to breed, usually during or after rain. In Australia the lungfish goes from pond to pond using it's fins to push it along. Most permanent water in the Australian outback is in artesian springs seperated by desert but every few years the desrt floods, fish and frogs "come out of the sand" and water birds somehow "know" the inland sea has formed. Within days, pelicans, ibis, storks, gulls,,, that usually live on the coast converge in their millions on the inland sea to feast on the explosion of fish, frogs and bugs.

There are lots of places in Africa and Australia where water almost dries up, feeding from land or mudflats could be a distinct advantage over other creatures confined only to water. However I think that feeding is insignificant compared to the survival potentintial given by the ability of a species to move from a small evaporating pond to a larger body of water, even if that means laying eggs in the rapidly drying mud and hoping a flood will nuture your offspring.

Moving over land (or surviving dry periods) lets you exploit virgin aquatic environments first and is a means of escape (at least at the species level) from dying ones, getting a snack on the journey would seem to be just an added bonus. The interesting thing about TFA is that the catfish seems to habitually hunt on land.

Re:Another Nail

[spacebird]

Just wondering... how does this disprove ID? I'm not aware of anywhere in the Bible or in ID theory that says that there's no such thing as a lungfish, eel-fish, amphibian, or anything else this remarkable...

Re:it was sarcasm

[Anonymous Coward]

Let's suppose that it's true that evolution is the best explanation we have for the origin of life.

If you start with that assumption then you're not going to get anywhere at all. The theory of evolution says nothing about the origin of life, nor does it set out to. Evolution is all about what happens once replicative life is in place.

Why "Africa"?

[aaron.rowe]

Why is it "the tropical swamps of Africa", rather than an idea about the countries involved?

Africa is a huge place, The Worlds second largest and second-most populous continent after Asia with a hugely diverse population in 61 countries and territories.

My point is if you hear about animals found in "tropical swamps of" Asia, or North or South America you would normally hear the actual country or even state within the country it was found in otherwise you have no idea what sort of environment to imagine.

From "tropical swamps" we can only derive that it's one of the countries in Sub-Saharan africa that fall in the tropics, and that's the biggest, most diverse part and it's not one big swamp!

I could forgive them if these fish eel things are swimming all over sub saharan africa but then I would have to say what the hell have they been doing all this time?

If they are everywhere then I've probably eaten a few of these myself. Mmmm.

Re:Let's see...

[Rxke]

You could see it as a very early, primitive stage of going-to-the-land.

Probably, when there were no earth dwelling creatures bigger than insects, those insects would be an easy catch to anything that started to jump out of the water to get at them, because they had no defenses for something like that happening (why would they, it never happened, evolving strategies against such attacks would be wasteful, and not help them in their fitness...)
So fish that adapted this strategy would've had had ample, 'unsuspecting' prey, as opposed to water-bourne prey, which would've obviously had survival (evasive) strategies to big fish. So these fish were probably quite successful in surviving, even when food in the water was getting scarce for whatever reason.
So, that catfish demonstrates a *very* hunt-efficient evolution, and over time it would stay longer out of the water, go deeper inland, while evolving the stuff to survive outside the water (lungs)
What it shows is quite convincingly the incentive/bonus behind becoming a land-animal: more readily/easily available food.

First fish out of the water didn't hunt insects

[DoorFrame]

Maybe I drastically misunderstand evolution, but it seems highly unlikely that the first fish-like-thing out of the water would have been hunting insects. Theoretically it wouldn't have been hunting ANYTHING, it would have been all alone on the land. Right? It could have tried to hunt, but it would have been awfully lonely and fruitless endeavour.