Deciphering the oddest fish on Earth, which can run, jump on land, and climb trees, leads us to the tree climbing fish, scientifically known as Periophthalmus variabilis. Belonging to the white goby family, this amphibious creature shares a similar shape with the star goby but stands out with rough skin and large bulging eyes on top of its head.
Tree climbing fish primarily inhabit estuaries and tropical coastal areas such as India, Australia, and Southeast Asian countries like Indonesia, the Philippines, Thailand, and Vietnam. A total of 32 dwarf fish species of this kind are found on Earth.
In Vietnam, tree climbing fish are commonly found in coastal regions with mangrove swamps, such as Can Gio, Nhon Trach, Go Cong, Bac Lieu, Ca Mau, and the northern waters of Ninh Binh.
Considered one of the six “weirdest” animals on the planet by the World Creatures organization, tree climbing fish exhibit exceptional adaptability. They can live in water, mud, and even navigate on land, climbing trees in search of food. Adults of this species are typically 10-15 cm long, roughly the size of a finger.
Mudfish dwell along marshes in estuaries and muddy beaches, submerging to a depth of no more than 2 meters. They often burrow under the mud at a depth of 20-30 cm, with several fish residing in each cave. When the tide recedes, they emerge from their burrows to feed.
A team of scientists from the University of Edinburgh conducted a month-long study of these fish in their natural habitat in the Mang Khang area of Central Java, Indonesia. During their research, they made a groundbreaking discovery about the fish’s locomotion method, which involves using their body to propel themselves forward as they glide through the water. This allows them to reach speeds of approximately 1.7 m/s.
Throughout the study, the team captured footage of the fish leaping from the shore, darting across the water, and jumping from the water back onto the shore. Analysis of each frame revealed that the mudskipper propels itself out of the water using rapid zigzag movements of its tail. The fish’s tail functions like a propeller, assisting the mudskipper in propelling itself upward and out of the water.
Upon landing, the fish vigorously thrashes its tail to prevent sinking below the water’s surface, preparing for the next leap into the air. The researchers observed various species of mudskippers, and P. variabilis was the only one observed to both climb trees and jump on water. This unique behavior could be their way of escaping predators. The mudfish also exhibits the ability to make sharp turns during jumps, providing insights into their navigation techniques.
In their future endeavors, the research team plans to analyze the mudskipper’s skin and compare it with that of fish unable to climb trees or jump on water.