SCIENCE

This research appears in the Proceedings of the National Academy of Sciences.

-- David Brown

Fish Is Smallest With Backbone

Biologists have identified what appears to be the smallest animal with a backbone on Earth -- a minuscule creature they dubbed the stout infantfish.

Only six specimens of the fish have been found, exclusively from around Australia's Great Barrier Reef and the Coral Sea. The largest is the only female, which measures about one-third of an inch in length -- no longer than the width of a pencil, H.J. Walker Jr. of the Scripps Institution of Oceanography in San Diego and William Watson of the National Marine Fisheries Service in La Jolla reported last week in the latest issue of the journal Records of the Australian Museum.

If 500,000 of these fish were weighed together, they would add up to no more than one pound, the researchers calculated.

The fish, which replace the dwarf goby as the new record holder of the world's smallest vertebrate, are transparent except for their eyes. They have no teeth, scales and other characteristics typical of other fishes. They also have a lifespan to match their size -- only about two months.

"It is interesting that these animals experience several generations each year," Watson said. "This suggests that they could evolve very quickly, as well."

-- Rob Stein