for National Geographic News
An eel-like catfish can wriggle out of the water to stalk prey, scientists report. The discovery may shed light on how some prehistoric fish species evolved into land animals.
Like many fish, the eel catfish is a typical suction feeder when it's in the water. It sucks in a mouthful of waterand prey.
But on land the eel catfish uses a completely different method. The creature lifts the front part of its body and bends its head down toward the ground.
This ability is essential to thriving on land, write the researchers whose findings will be published tomorrow in the journal Nature.
Evolution at Work?
The fish is significant for anyone studying evolution, says biology professor Dominique Adriaens of Ghent University in Belgium.
"It shows that a transition from aquatic feeding to terrestrial feeding is possible without the necessity of a lot of spectacular [body form] and functional changes and can thus be explained by Darwinian evolution," said Adriaens, who co-authored the new study.
The eel catfish doesn't have the articulated neck or the primitive limbs of Tiktaalik roseae. That "missing link" fossil fish made headlines last week and appears to be a transitional form between fish and land animals with spines, including you and me.
But the eel catfish does show what Adriaens calls "a high degree of evolutionary plasticity [adaptability] in its total body plan."
The catfish has successfully adapted to life in swampy patches of forest terrain, the researchers say. Normally only much smaller fish thrive in these shallow waters.
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