February 25, 2009
Crawling Fish Designated As New Species
A new elusive species of fish with eyes on the side of its head and freaky characteristics like a fleshy chin and cheeks has been given a name.
"Psychedelica" appears to be the perfect name for a species of fish that is a mix of tan and peach zebra stripes, according to University of Washington's Ted Pietsch, who is the first to describe the new species in the scientific literature.The bizarre species called Histiophryne psychedelica made the headlines a year ago when divers discovered the fish offshore of Ambon Island, Indonesia.
Pietsch received pictures of the fish and hypothesized it belonged to the Histiophryne genus. He confirmed his belief through genetic and morphological data, and fully described the fish as a new species.
"It is just an absolutely fantastic example of what natural selection can produce," Pietsch told LiveScience. "And it's a fantastic organism in its own right, and that is certainly enough to make it important."
Pietsch's description of the animal is detailed in the journal Copeia.
The fish don't so much swim as hop; each time they strike the seafloor they use their fins to push off and they expel water from tiny gill openings on their sides to push themselves forward.
It's just one of the behaviors of H. psychedelica never observed in any other fish, says Pietsch. His work is funded by the National Science Foundation.
The fish is odd looking. Its gelatinous skin is very fleshy, thick and loose. Unique pigmentation could help the fish blend in among colorful, venomous corals on the sea floor in the area.
"The Psychedelic Frogfish probably joins the long list of dishonest and harmless animals that have evolved to mimic the beauty of venomous animals," said Leo Smith, assistant curator of fishes at The Field Museum in Chicago. "Pietsch and colleagues nailed this when they suggested that it looked just like the venomous corals found in its environment."
The fish also has some plastic abilities.
"This animal seems to have ability to flare its face out and then pull it back again, so when it comes through a small crevice, those eyes become lateral and then it flares its eyes out," Pietsch said. "It's also probably a threat display "” when it shows that oval face with the psychedelic striping, you think that'd scare something away."
Researchers say the fish's jaws are lined with two to four irregular rows of small teeth, which it uses to consume smaller fish, shrimp and other marine life.
Despite the showiness, the fish are shy and secretive, probably one of the reasons they weren't previously spotted. The fish tend to hang out in pairs, and are often so well hidden that they could only be found when divers looked under rubble on the seafloor.
Once uncovered, the fish tried to hide by entering a crevice or hole via rigorous twisting and turning of the body and use of its pelvic fins to manipulate its position.
"It seems that some of these animals do a bit of moving up and down into deeper water," he said. "We know they come up in shallow water to spawn and reproduce, but that cycle should've been noticed in past years and it really wasn't."
Other anglerfish change their coloring depending on the environment, but the new species maintains its wild striping no matter the surroundings.
Image Caption: With its flattened face, the fish's eyes appear to be directed forward and may provide it with binocular vision, a special attribute well developed in humans that provides the ability to accurately judge distance. Only very few fishes have eyes whose radius of vision overlaps in front, providing such vision. Ã© David Hall/seaphotos.com
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