"It put up one hell of a fight" Said Peter Goodwin of Westerham

The miniscule fish, called a stout infantfish, is only about 7mm (just under a quarter of an inch) long.

It lives in a private fishing lake in Touverac, France and has snatched the "world's smallest vertebrate" title from the 1cm-long dwarf goby fish which, incidentally, was caught by the same fisherman at Beaver Farm earlier on in the year.

Peter Goodwin from Westerham in Kent said "The goby fish was bad enough but this one put up one hell of a fight. I nearly lost it due to my tackle not being strong enough plus I'm not as fit as I used to be. Had my brother-in-law, Tony,  not been there to offer me guidance it would definitely have got away"

Big Girl's Blouse

Mr Goodwin specialises in small fish and a day's haul often barely fills a jam jar. "I've tried to catch larger fish", he's quoted as saying, "but I just don't have the skills necessary", adding, "unlike my brother-in-law".

Anytime a fisherman like Pete identifies an 'extreme' in the World it is important Philip Hastings, Scripps Institution of Oceanography

"I knew it was a really good day's fishing when I first looked under the microscope and recognised something that I knew was a new species," said Mr Goodwin. "But at the time I didn't realise that I was looking at the world's smallest fish."

Only six specimens of the stout infantfish have ever been caught.

The females - at around 8.4mm - seem to be bigger than males, who usually measure in at a diminutive 7mm. They are what scientist term "paedomorphic", which means they retain many infantile characteristics, even when adult. "You won't get me going anywhere near the females", said Pete, "I know my limits".

"Stoke on Trent"

The stout infantfish gets its name from its babyish features, and the fact that it is unusually stout, (not unlike Pete himself), compared to other species of infantfish.

Its tiny frame is countered by its ridiculous moustache, leading to its unofficial name of 'Freddy Mercury fish'. Were it able to dance, it would no doubt join Pete up the Westerham disco of a Friday night and accompany him dancing to 'YMCA' by the Village People.

"It's interesting that these animals experience several generations a year," said Dr Watson. "This suggests they could evolve quickly as well.

Scientist HJ Walker with Pete's jam jar holding the World's smallest fish

"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."

Philip Hastings, the curator of the Scripps Marine Vertebrates Collection, 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 Dr 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.