The snake-headed Gollum fish turns out to be a living fossil
Creatures with heads like a snake living in rock formations underground with waterrecently discovered in southern India, constitute a new family of fishes bone.
Using computed tomography, molecular genetic and morphological methods, researchers at the Senckenberg Institute further reveal that the new family Aenigmachannidae separated from its sister group Channidae long ago and represents a so-called "living fossil." The study was published in the journal Scientific Reports.
The coastal strip of Western ghats, a mountain range in western India, gave rise to an endemic fauna of organisms that inhabit groundwater. "Ten species of fish are known in this area till the date. The first species was already described in this habitat in 1950, but the latest discovery: the bony fish Aenigmachanna gollum, named after Gollum, the character that lives in the caves of The Lord of the Rings "was made only a year ago", explains Dr. Ralf Britz of the Senckenberg Natural History Collections in Dresden. "We are now applying new research methods to take a closer look at this fish, whose external appearance is reminiscent of a snakehead fish."
Based on computed tomography, molecular genetics, and morphological methods, Britz and her international colleagues were able to detect several significant differences between Aenigmachanna and other snakehead fish in the Channidae family.
"The most striking features are the shortened swim bladder that ends in the center of the body, and the lack of the accessory respiratory organ ", explains the Dresden biologist, adding:" Both the morphological and genetic differences are large enough to justify the assignment of Aenigmachanna gollum to its own new family Aenigmachannidae! "
Furthermore, the researchers claim in their study that the slender fish, approximately four inches long, exhibits several rather primitive characteristics. These can be explained by the evolutionary history of the animal. Phylogenetic analysis shows that the new family and its sister group, the Channidae, separated at least 34 million years ago, and possibly up to 109 million years.
"It seems plausible that the Aenigmachannidae represent an evolutionary lineage that survived the disintegration of the supercontinent Gondwana about 100 million years ago and subsequently drifted north with the Indian subcontinent; therefore, these animals could be considered a 'living fossil' within from the group of snake-headed fish, "adds Britz.
However, the extraordinary lifestyle of fish can, ultimately, pose a threat to their survival. The two species in the family just described live underground in aquifers, which consist of laterite rocks that contain water. "These groundwater reservoirs are exploited by more than six million private wells, and further extraction of water would literally drain the very basis of the existence of these bony fish," says Britz in conclusion.