Illustration of a Bichir out of “The fishes of the Nile”, CC BY 2.0 via Biodiversity Heritage Library /flickr.com

The fish on the picture on top is a bichir, and it belongs to a fish order quite fascinating for researchers. Especially one representative of the bichirs, that goes by the name of Senegal bichir or “dinosaur eel”, was of special interest lately. The fish of the order of the Polypteriformes (meaning it has lots of fins) has not only lungs and gills, but also ossified, strong pectoral fins, to occasionally walk on land.

The ability to walk and breathe air led to an experiement, when researchers of the McGill University in Canada raised the dinosaur eels for eight months — on land. Of course they had to take care that the fishes won’t dry out. But because they move on land from pond to pond the fishes were kind of used to the situation.

The experimental arrangement consisted of a mesh and enough water for the fishes to stay in normal shape, but also too little water to just swim. The researchers also formed a control group using 38 fish growing up in their usual aquatic environment. The results of the research illustrate very clearly the changes that might have enabled fins to become limbs when some fish decided to trade water for land, around 400 million years ago. And that was, as we all would have to admit, a big step that would help the rise to tetrapods, including almost all land vertebrates from amphibians to mammals.

And the fish walk looks like this, do you see conformities in style to, let’s say, humans?