Researchers are currently studying a newly discovered type of African fish which can live outside of water for as long as two years, and even crawl on land to get to objects. This crawling fish is known as polypterus or bichir, and is being studied to determine if it had ancestors that left water to live on land through a process of evolution.
This fish is well adapted for walking on land, and has the ability to develop land walking skills as well as grow limbs that enable it to move on land. It has gills for surviving in water, and tough lungs for living on land for as long as possible. In fact, its ability to transit from fin to limb is extraordinary and after eight years on land, it is seen to raise its head better in a walking gait to allow it walk easier, and it develops this skill after growing a pectoral skeleton on its chest.
According to Emily Standen, a biologist from the University of Ottawa, and Hans Larsson with Trina Du from the McGill University, “we are interested in the fin-to-limb transition. These guys use one fin after another in a kind of side-to-side gait. We looked at skeleton and behavior…how they changed their gait; they didn’t slip as much as the fish that were raised in water. It appears to be more effective walking; what you expect of something that walks well or is improving the walking ability.”
The natural behavior of the polypterus fish to take to walking on land in the face of its limbs is also exciting to these researchers. They want to determine the behavior of this fish vis-à-vis what might have obtained in its ancestors in time past over evolution. According to Standen, “from the fossil record, it’s very difficult to glean behavior. We know what the bones looked like, but we don’t know how they may have moved,” hence the need to study living fish like the polypterus to get a glimpse into whether its extinct ancestor which lived 400 million years ago ever left water to live in land.