Rock Climbing Pleco
Jan. 29, 2009 -- A newly identified catfish from tropical South America adroitly climbs rocks by grasping them with its tail and mouth, according to American Museum of Natural History officials and a paper published in American Museum Novitates.
Since the world's only other catfish climbers are restricted to another remote region in the Andes, scientists now believe the two types of athletic fish share a common ancestor that could have once flourished in the upland streams of the Amazon and Orinoco river basins.
With their suction-like mouths, the new catfish, Lithogenes wahari, can hold fast to substrates in their gushing water homes without expending much energy. These fish athletes are also nearly unstoppable by obstacles that might drown human and animal swimmers.
"The ability to climb, both while under water and while on exposed rock, such as waterfalls, is likely an ability to move upstream in situations of high water velocities so as to maintain their occupancy of such habitats and even recolonize headwater stream regions following flood events, which tend to wipe out the aquatic fauna in places," co-author Scott Schaefer told Discovery News.
When Schaefer, Curator of Ichthyology at the museum, first saw the fish, he thought "it looked like it was run over by a truck." His team plucked 84 specimens off of rocks in the Guyana Shield region of Venezuela, revealing that the unusual fish also has a nearly naked, meaning relatively unplated, body, which is odd for a member of the armored catfish family, called Loricariidae.
The new species also lacks certain teeth in its upper jaw, perhaps to facilitate suction, as well as expected dermal teeth on its pelvic fin pad.
Both of the known catfish climbers rock climb similar to the way a well-known insect moves.
"In these two groups, both the mouth and the pelvic fins are used simultaneously to grasp and, via alternating grasp and release and by moving the pelvic fins forward and backward, these fishes can move and climb much like an inchworm," Schaefer explained.
Further analysis of the fish by Schaefer and colleague Francisco Provenzano of Venezuela's Central University, determined that the new species bridges two catfish families. Despite its relative nakedness, L. wahari does possess bony plates on its head and tail, linking it to the armored catfish group.
Its specialized fin, which decouples from its body to allow for the climbing motion, is more linked to a subfamily called Lithogeninae, which includes the Andean climbing catfish.
The scientists aren't certain if the ability to climb evolved once, through the common ancestor, or independently in both of the climbing catfish.
Richard Vari, a research zoologist and curator in the Division of Fishes at the Smithsonian Institution, told Discovery News he was impressed by the research.
"I was particularly fascinated by the evidence for the ability of these fishes to climb rocky surfaces," Vari said. "This is a very unusual, but clearly invaluable ability in the swift river systems that they inhabit."
The researchers don't know whether or not the Venezuelan fish climbers are endangered, but Schaefer said it's possible they are confined to a narrowly restricted geographic region, meaning not many of them may exist.
He said the indigenous Piaroa peoples, who engage in subsistence farming and fishing, now occupy the region and have kept it "pristine."
"It is also remote and difficult to access, so incursions by tourists and collectors for the ornamental fish trade are very few," he concluded, but ominously added that the "situation may not last for much longer."
Jan. 29, 2009 -- A newly identified catfish from tropical South America adroitly climbs rocks by grasping them with its tail and mouth, according to American Museum of Natural History officials and a paper published in American Museum Novitates.
Since the world's only other catfish climbers are restricted to another remote region in the Andes, scientists now believe the two types of athletic fish share a common ancestor that could have once flourished in the upland streams of the Amazon and Orinoco river basins.
With their suction-like mouths, the new catfish, Lithogenes wahari, can hold fast to substrates in their gushing water homes without expending much energy. These fish athletes are also nearly unstoppable by obstacles that might drown human and animal swimmers.
![](/forums/proxy.php?image=http%3A%2F%2Fdsc.discovery.com%2Fnews%2F2009%2F01%2F29%2Fgallery%2Fcatfish-540x300.jpg&hash=81842e2780e07e6551b7114afd555893)
When Schaefer, Curator of Ichthyology at the museum, first saw the fish, he thought "it looked like it was run over by a truck." His team plucked 84 specimens off of rocks in the Guyana Shield region of Venezuela, revealing that the unusual fish also has a nearly naked, meaning relatively unplated, body, which is odd for a member of the armored catfish family, called Loricariidae.
The new species also lacks certain teeth in its upper jaw, perhaps to facilitate suction, as well as expected dermal teeth on its pelvic fin pad.
Both of the known catfish climbers rock climb similar to the way a well-known insect moves.
"In these two groups, both the mouth and the pelvic fins are used simultaneously to grasp and, via alternating grasp and release and by moving the pelvic fins forward and backward, these fishes can move and climb much like an inchworm," Schaefer explained.
Further analysis of the fish by Schaefer and colleague Francisco Provenzano of Venezuela's Central University, determined that the new species bridges two catfish families. Despite its relative nakedness, L. wahari does possess bony plates on its head and tail, linking it to the armored catfish group.
![](/forums/proxy.php?image=http%3A%2F%2Fdsc.discovery.com%2Fnews%2F2009%2F01%2F29%2Fgallery%2Fcatfish2-324x205.jpg&hash=293a5af2dc0d6e31d46ab748dbc95bd2)
Its specialized fin, which decouples from its body to allow for the climbing motion, is more linked to a subfamily called Lithogeninae, which includes the Andean climbing catfish.
The scientists aren't certain if the ability to climb evolved once, through the common ancestor, or independently in both of the climbing catfish.
Richard Vari, a research zoologist and curator in the Division of Fishes at the Smithsonian Institution, told Discovery News he was impressed by the research.
"I was particularly fascinated by the evidence for the ability of these fishes to climb rocky surfaces," Vari said. "This is a very unusual, but clearly invaluable ability in the swift river systems that they inhabit."
The researchers don't know whether or not the Venezuelan fish climbers are endangered, but Schaefer said it's possible they are confined to a narrowly restricted geographic region, meaning not many of them may exist.
He said the indigenous Piaroa peoples, who engage in subsistence farming and fishing, now occupy the region and have kept it "pristine."
"It is also remote and difficult to access, so incursions by tourists and collectors for the ornamental fish trade are very few," he concluded, but ominously added that the "situation may not last for much longer."