Strange New Fish May See Like Humans [LiveScience 2008-04-02]
[Photo] The leglike pectoral fin for walking is the clue that this newly found fish is an anglerfish, even though it does not have a lure on its head for attracting prey. Its flat face and forward-looking eyes are just two of a host of reasons why University of Washington professor Ted Pietsch thinks the fish found in January probably represents a new family of vertebrate animals. Credit: M. Snyder, starknakedfish.com/divingmaluku.com
While diving in the harbor of a small island in Indonesia recently, husband and wife Buck and Fitrie Randolph, with dive guide Toby Fadirsyair, found a strange fish and took some pictures.
The oddball creature looks like an anglerfish, but different. Its eyes, unlike those of nearly all fish, point forward and may allow the fish to gauge depth the way humans do.
The flat fish has tan- and peach-colored stripes and rippling folds of skin that obscure its fins. About the size of a human fist, it is soft and pliable enough to slip into narrow crevices of coral reefs — perhaps why it's never been seen before.
The divers could not find the fish in any reference books, so they consulted an expert.
"As soon as I saw the photo I knew it had to be an anglerfish because of the leglike pectoral fins on its sides," said University of Washington fish expert Ted Pietsch today. "Only anglerfishes have crooked, leglike structures that they use to walk or crawl along the seafloor or other surfaces."
Anglerfishes are found the world over and typically have lures growing from their foreheads that they wave or wiggle to attract prey.
The newly found fish has no lures so it burrows into a reef to find food.
"Several times I saw these fish work themselves through an opening that seemed much smaller than the fish, sometimes taking a minute or more to get all the way through," says David Hall, an underwater natural history photographer who was able to dive with Maluku Divers and take additional photos of the newfound creature. "They must have pretty tough skin to keep from being scraped and cut, but there is no evidence of superficial injury or scars in my photographs."
With its unusual flattened face, the fish's eyes appear to be directed forward, something Pietsch says he's never seen in 40 years studying the structure, classification and habits of fishes. Most fishes have eyes on either side of their head so that each eye sees something different. Only very few fishes have eyes whose radius of vision overlaps in front, providing binocular vision, a special attribute well developed in humans that provides the ability to accurately judge distance.
Whether the new fish represent a new family will entail DNA testing and a close examination of a specimen, says Pietsch, whose anglerfish work is currently funded by the National Science Foundation. Scientists have already described 18 different families of anglerfishes and this is probably a 19th, Pietsch says. Families are large groupings; for example, all dog species belong to the larger family that includes wolves, coyotes and hyenas.