Scots scientists reel in history's 'biggest fish'

Published on Sunday 7 September 2003 01:00

SCOTTISH scientists are unearthing the fossilised remains of what is believed to be the biggest fish that ever existed.

The Leedsichthys is thought to have been up to 100ft long when it swam in the sea around Peterborough, Cambridgeshire, more than 155 million years ago.

The giant filter feeder became trapped in layers of clay after it died. Its bones were preserved until workers quarried the clay two years ago.

The fish has been named ‘Ariston’ by scientists because its excavation has gone "on and on and on" - as the electrical equipment in the Ariston advert does. It is expected it will take another year before the full skeleton is revealed.

Jeff Liston, a custodian at Glasgow University’s Hunterian Museum, said it was difficult to tell the fish’s exact length as its backbone had not been preserved. However estimates, based on the size of other bones, vary from between 65ft and nearly 100ft.

The biggest fish currently alive is the whale shark, which can grow up to 55ft long.

Liston said: "Over the last couple of years I’ve been working on excavating the fish. We’ve had two field seasons and we’re going to go back and get the rest of it.

"The problem usually is you tend to find isolated fragments but [the Leedsichthys] we’ve found in Peterborough is remarkably complete."

He said some information about the fish could be deduced from the shape of its bones.

"It seems to follow the pattern of things like blue whales and whale sharks," Liston said."When you get these huge sizes, the most efficient thing to do is not to go around chasing pray, but to filter food from the water column using gill-rakers. The Leedsichthys was something that was very well adapted for filter-feeding."

Growth rings on the bones show that the Peterborough fish lived for "an exceptionally long time" - up to 100 years. It is also thought the Leedsichthys travelled in a social group rather than alone, based on the behaviour of other filter feeders.

The Leedsichthys was named after fossil hunter Alfred Leeds, who found the first remains of a smaller specimen in 1887.

It remained largely unstudied for years but Liston has become an expert on the fish. The example discovered by Leeds is kept at the Hunterian and will go on public display for the first time on September 19 and 20.

The Peterborough fish will feature on Channel 4’s The Big Dig tomorrow and on a BBC programme called Swimming with Sea Monsters in October.