[Caitlin]

http://icwales.icnetwork.co.uk/0100news/0200wales/tm_headline=sex-charged-mussels-surge-ahead&method=full&objectid=17893325&siteid=50082-name_page.html

Sex-charged mussels surge ahead
ENDANGERED native mussels with a low libido are surging back after being successfully sexed-up in a project to boost numbers.
An orgy of reproduction among 70 fresh water pearl mussels taken from Welsh rivers have seen the population explode to 70,000.
Experts feared the highly endangered species was heading for extinction as reproduction stood still and its population aged.
River pollution, dredging and poaching had had a catastrophic effect on the notoriously celibate fresh water molluscs.
But intervention by the Environment Agency has reversed a potentially terminal decline.
The agency has presided on a surge in the number of juvenile mussels created at its Mawddach Hatchery in Wales.
Historically they have always been linked to Queen Elizabeth I who appears in many portraits adorned with freshwater pearls.
“From 70 mature freshwater pearl mussels we saved from isolation in Welsh rivers – around 70,000 juveniles have emerged,” said Environment Agency hatchery manager Keith Scriven.
He said as one of England and Wales’ oldest river species it used to be found packed together in dense beds – reproducing through a sort of ’group sex’.
But a massive decline in numbers left many surviving specimens alone in empty beds enduring a non-existent sex life.
“While pearl mussels can be found in small numbers in 22 rivers in England and Wales, they are only reproducing successfully in one of them,” said the Environment Agency’s pearl mussel specialist Anne Lewis.
“The other 21 rivers have ageing adult specimens that are often isolated geographically and no younger mussels are being recruited.
” We are lucky that freshwater pearl mussels can live to be 100 years old, so there is time for us to save the species from extinction in England and Wales.”
She added: “We’re excited about the success we’ve had with the breeding programme so far.”
While millions of larvae were successfully fertilised 12 months ago nobody knew how many would become juveniles.
“At the moment the mussels are still tiny – about three quarters of a millimetre in size.
“They’ll stay in captivity for another four years until they reach around one inch in length.
“Then we hope to be introducing ten’s of thousands of freshwater pearl mussels back into Welsh rivers by the end of the decade.”
She said in the wild 95% of juvenile pearl mussels die before reaching ****** maturity, due to pollution and other factors.
“For now, our goal is ensuring this quality programme stays in place in the years to come so these juveniles and the generations of freshwater pearl mussels to follow survive to maturity and hopefully breed naturally in the wild.”
Freshwater Pearl Mussels (Margaritifera margaritifera L.) have a complicated lifecycle that can be susceptible to changes in the ecosystem.
Sexually mature by the age of 12, females absorb sperm released by the males into the surrounding water.
Fertilised eggs develop into microscopic larvae called glochidia.
Each female will produce around three million glochidia each year but, even in ideal conditions, only 0.01% will survive.
Glochidia attach themselves to the gills of young fish from the salmon family that carry them back upstream, causing the fish no harm.
After a few months the glochidia form shells and drop off their hosts to settle on the riverbed.
Even in healthy rivers only a fraction of 1% of juveniles survive to maturity, but those that do, can live until the age of 100 and grow up to 15cm in length.
Freshwater pearl mussels are internationally recognised as an endangered species. It is illegal to disturb the mussels or their habitat.
The illegal practice of pearl fishing has been cited as one factor in reducing the mussel population density.