"World's oldest surviving animal" discovered

Two colonies of the tadpole shrimp, Triops cancriformis, were found at Caerlaverock on the Solway Coast of Dumfriesshire. Experts think there could be more ''hidden'' populations of the crustacean - a designated endangered species - elsewhere. The tadpole shrimp may have the oldest pedigree of any living animal, scientists believe.

Fossil finds show that the shrimp is virtually the same today as it was 200 million years ago, when the first dinosaurs evolved. The shrimps are adapted to living in temporary water pools. When the water dries up, the adults die but leave behind eggs that can remain dormant for years until wet conditions return.

Understanding the animal's unusual lifestyle helped researchers from the University of Glasgow make the discovery announced today. Mud thought to contain tadpole shrimp eggs was sampled from pools around Caerlaverock, dried, re-wetted and placed in small aquaria.

The scientists were startled to find a large shrimp swimming in one of the tanks within a couple of weeks.

Research student Elaine Benzies said: ''I hadn't expected to find it and was just going in to check on the heat and lights. It was great to see everyone in the lab, including the cook from the canteen, gathering round and peering into the tank to look at this ancient survivor from the past.''

The tadpole shrimp was long thought to be confined to a single pond in the New Forest, Hampshire. Then in 2004 Dr Larry Griffin, from the Wildfowl & Wetlands Trust (WWT) discovered what was thought to be an isolated ''fringe'' colony hundreds of miles away in a pool at Caerlaverock.

Dr Griffin said today: ''At the time it seemed that the Caerlaverock colony was a vulnerable, historic outlier on the northern fringe of its past and present population.

''But now that we know how this curious creature survives, we have realised that there's a good chance there are more populations out there.

''Triops matures rapidly and produces hundreds of eggs in just a couple of weeks. The pond they live in may dry out, but the eggs can survive in the mud for many years.

''Although in the UK they are all females, they have both male and female reproductive parts, so just one egg needs to survive to regenerate a whole population.''

WWT, the University of Glasgow, and Scottish Natural Heritage have launched a joint project to look for tadpole shrimp colonies. Professor Colin Adams, from Glasgow University, said: ''It's encouraging to get such a positive early result from this exploratory project. We must now extend its scope to widen the area of search for this rare and charismatic freshwater animal.''


/Telegraph.co.uk/