Researchers from the New Jersey Institute of Technology (NJIT) have discovered a species of cavefish that can walk and climb on walls in the same manner as a land animal, according to a study published in the journal Scientific Reports.
The team first discovered the strange fish — known as Cryptotora thamicola — in a cave in Thailand. The species is completely blind and moves in the same way as tetrapods, or four-limbed vertebrates.
C. thamicola “walks” by sticking to walls or rocks inside the caves where it lives in order to climb up waterfalls. This process, which has never been seen before, takes place completely underwater.
The ability to move on land has been seen in other fish species. However, no others can move in the way as the cavefish, which uses a tetrapod-like “robust pelvic girdle” to make its way up walls.
“It possesses morphological features that have previously only been attributed to tetrapods,” said study author Brooke E. Flammang, an assistant professor in the NJIT Department of Biological Sciences, in a statement. “The pelvis and vertebral column of this fish allow it to support its body weight against gravity and provide large sites for muscle attachment for walking.”
Researchers believe the species behaves in the same way primitive animals did as they made the transition from water to land, making the fish’s behavior especially relevant from an evolutionary standpoint.
Tetrapods first evolved from finned animals some 420 million years ago during the Devonian period, Discovery News reports. Understanding the bizarre cavefish could give scientists a glimpse into the way land-walking animals developed.
“This research gives us insight into the plasticity of the fish body plan and the convergent morphological features that were seen in the evolution of tetrapods,” added Flammang.