Scientists find world's tiniest fish
A NEW world record holder in the tiniest vertebrate category has emerged. It is a 7mm fish - stout infantfish - of Australia's Great Barrier Reef. Its life span is believed to be just two months, enabling it to produce 12 generations in just one year.
Stout infantfish or Schindleria brevipingus, displaces former record holder of "world's smallest vertebrate", the 1cm-long dwarf goby fish.
The infantfish, which is no longer than the width of a pencil, is described in the Records of the Australian Museum.
The first specimen of the tiny creature was collected in 1979 by the Australian Museum's Jeff Leis, during fieldwork in the Lizard Island region of the Great Barrier Reef.
But the creature was not properly studied for years, until HJ Walker of the Scripps Institution of Oceanography, California, U.S., and William Watson of the Southwest Fisheries Science Centre, La Jolla, U.S., picked up the case.
"It was a really good day when I first looked under the microscope and recognised something that I knew was a new species," said Walker. "But at the time I didn't realise that I was looking at the world's smallest vertebrate."
Only six specimens of the stout infantfish have ever been found.
The females � at around 8.4mm - seem to be bigger than males, who usually measure in at a diminutive 7mm. They are what scientists termed "paedomorphic", which means they retain many infantile characteristics, even when adult.
The stout infantfish gets its name from its babyish features, and the fact that it is unusually stout compared to other species of infantfish.
Its tiny frame is matched by its short lifespan, which is thought to be a mere two months. This quick turnover might actually work in the fish's favour, allowing it to keep up with a world that is changing fast.
"It's interesting that these animals experience several generations a year," said Dr. Watson. "This suggests they could evolve quickly as well.
"They live in a specialised habitat that could be threatened by global warming or human development, but they may have the ability to evolve as fast as their environment changes."
Curator of the Scripps Marine Vertebrates Collection, Philip Hastings, says the identification of the stout infantfish is another demonstration that scientists do not yet have a complete picture of marine animals.
"Anytime a scientist identifies an 'extreme' in the world it is important," said Hastings. "Think about the whole envelope of life. Most of us systematists describe things that fill in the dots in the middle of the envelope.
"This new discovery is pushing the edge, increasing the size of the envelope.
"It's important because it demonstrates that we're still expanding our knowledge of the limits of the diversity that's present on this planet and there are still significant discoveries to be made."`
