Understanding the strangest fish in the world, which can move on land by running and jumping and even climb trees, brings us to a fish called Periophthalmus variabilis. This fish is a member of the white goby family and looks similar to the star goby, but it has rough skin and big bulging eyes on the top of its head.
Fish that can climb trees mostly live in places where rivers meet the sea and in warm areas near the coast, like India, Australia, Indonesia, the Philippines, Thailand, and Vietnam. There are 32 different types of these small fish on our planet.
In Vietnam, you can often find tree climbing fish in coastal areas with muddy forests called mangrove swamps. Some specific places include Can Gio, Nhon Trach, Go Cong, Bac Lieu, Ca Mau, and the northern waters of Ninh Binh.
According to the World Creatures organization, tree climbing fish are considered one of the six “weirdest” animals on Earth. They are very adaptable because they can live in water, mud, and even move on land by climbing trees to find food. These fish are usually about 10-15 cm long, which is similar to the size of a finger.
Mudfish prefer to live in marshy areas near where rivers meet the sea and on muddy beaches. They usually stay submerged in water that is no deeper than 2 meters. Often, they dig burrows in the mud that are about 20-30 cm deep, and multiple fish can live together in each burrow. When the water level goes down, they come out of their burrows to find food.
A group of scientists from the University of Edinburgh studied these fish in their natural home in Central Java, Indonesia. They found out something amazing about how the fish move in water. Instead of swimming, they use their body to glide and move forward. This allows them to go pretty fast, about 1.7 meters per second.
During the study, the scientists recorded videos of the fish jumping from the land, quickly moving across the water, and jumping back onto the land. When they looked closely at each video frame, they noticed that the fish pushes itself out of the water by moving its tail in rapid zigzag patterns. The fish’s tail acts like a propeller, helping it move up and out of the water.
When the fish lands, it moves its tail quickly to avoid sinking and get ready for the next jump. The scientists watched different kinds of mudskippers and found that P. variabilis was the only one that climbed trees and jumped on water. This special behavior might be how they protect themselves from predators. The mudfish can also make sudden turns while jumping, which helps us understand how they find their way around.
In the future, the research team wants to study the skin of mudskippers and compare it to the skin of fish that cannot climb trees or jump on water.