Climbing Gourami

Image: Brian Gratwicke

Not all fish out of water are created equal!

There are 34 species of Climbing Gourami living in parts of Africa and Asia, each reaching somewhere between 10 and 30 cm (4 inches and a foot) long and all belonging to the Anabantidae family.

They have what's known as a labyrinth organ, which allows them to breathe oxygen from the air. It means these freshwater fish can survive in stagnant, oxygen-poor pools and lakes and still have all the energy they need to chase after prey. All they have to do is swim up, take in a mouthful of air and precious oxygen will diffuse into their system.

And if worst comes to worst, they can up and leave.

Video: donflan

The family name comes from the Greek anabasis, which means "climbing up". And that's just what they do! They clamber out of the stultifying atmosphere of their old lake and use their fins and tail to push themselves along the ground.

It all looks very strange and haphazard, but they really are moving along in an actual direction even though it still looks reminiscent of the desperate thrashings of a fish who really can't deal with being on land.

Climbing Gouramis will do this on damp days or cool nights and apparently some of them can survive on land for a good 6 to 8 hours, or "man to fool" on Napoleon's scale of sleep. Hopefully that'll be enough time to find somewhere nice to live, though I'm sure they would appreciate some GPS.

Video: sOhAm mukherjee
Great minds think alike

This must be the most impressive use of the labyrinth organ. Aside from the Climbing Gouramis, the other Labyrinth Fish are the Kissing Gouramis and another group simply called Gouramis.

One of the Gouramis is Macropodus opercularis, the Paradise Fish. It's famous for being the second aquarium fish imported to the west, after the goldfish. They survived the journey in 1869 (over 250 years after the goldfish) because they can tolerate a wide range of tempertaure and their labyrinth organ meant they could breathe air as the water around them stagnated.

Anyway, it's a good thing we land-lubbers evolved from tetrapods instead. Imagine if we got around on land by pushing ourselves forward with a huge, powerful tail. We'd be mermaids!