The evolution of aquatic animals into terrestrial ones might be better understood with the help of a weird cave fish found in Thailand. The blind and very mobile fish has the ability to crawl out of the water and up the walls of its home.
While there are other fish capable of walking, the cave fish found by New Jersey Institute of Technology scientists is unique. Named Cryptotora thamicola, this is the only creature of its kind that can swim, walk and climb on cave walls. Its tetrapod features give it the ability to move like the ancient creatures that started to walk on land, roughly 420 million years ago.
The first creatures to ever walk on soil on four legs were the tetrapods, mostly because they evolved and thus developed stiff spines composed of interlocking vertebrae, but also pelvises that are crucial for walking.
The researchers that found Cryptotora thamicola have reported the creature has many tetrapod features. According to Brooke Flammang, study co-author and ichthyologist from the Museum of Comparative Zoology of Harvard University,
“It possesses morphological features that have previously only been attributed to tetrapods. 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.”
Furthermore, the pelvic girdle of the cave fish contributes to its side to side movement, quite similar to the one of salamanders. This is described by the researchers as “standing wave”. Other fish capable of walking move with a swaying or undulating motion.
The study was published in the Nature Scientific Reports open-access journal last Thursday. However, the walking fish is reported to have been discovered back in 1985. While it is considered a rare species, Cryptotora thamicola is native to Thailand and makes its home in caves.
The team had to visit the creature right in the cave since the species is protected. Therefore, they took a couple of videos and did further research on preserved specimens from museums in Thailand.
The discovery has the potential of offering a better insight into the process of evolution. The first tracks made by tetrapods are dated about 400 million years ago in European caves. Since the earliest evidence is only 375 million years old, the cave fish might help us understand the way animals left their homes underwater and took to earth.
Image Source: Segodnya