The historical myth that seahorses are faithful to one partner for life has today been blown out of the water by new research.

A fidelity test has proved that not only are seahorses shameless flirts with the opposite sex, but most of them are bisexual.

Teams of scientists have spent a month studying the sexual habits of the graceful creatures to test the long-held belief that couples bond together for life.

And the results compiled at Weymouth Sea Life Park have stunned marine biologists after it was shown that out of 3,168 recorded sexual encounters, 37 per cent were same-sex liaisons.

And, of the 1,986 contacts between male and females, many of them were between a number of different partners.

Every individual seahorse showed signs of courtship and flirting a staggering 25 times a day.

The Australian big-bellied seahorses were shown to be the most experimental, with many individuals notching up numerous daily conquests with both male and female creatures.

The Caribbean slender seahorses were also shown to be fairly promiscuous by having a variety of different courtships.

Of the three species of seahorses studied, only the British spiny seahorse remained faithful to their partners.

Paul Bullimore, a Sea Life Centre marine curator, said: "The results of the survey came as a startling revelation to all of us.

"The fabled monogamy of the seahorse really has been exposed as a myth.

"We were pretty sure there was far more promiscuity among seahorses than is generally acknowledged, but we hadn't picked up on the same-sex liaisons.

"This bisexual activity was both a great surprise and a shock to many of us that work with the creatures.

"I expect this is because of the famous theory that seahorses have one lifelong partner.

"Perhaps we shouldn't have been so surprised though, as similar activity does go on with many other animals both in water and on land.

"The observations of big-bellied seahorses suggest that neither males nor females of this species had any preferred partner.

"They really are indiscriminate and shameless creatures.

"We just hope the results don't change people's natural affection for seahorses because clearly they still remain among the most charming and interesting creatures in the world.

"Teams of marine biologists at 15 Sea Life Parks rounded up a total of 90 seahorses to take part in the sex survey.

Scientists at each centre wore latex gloves and used a net to herd up a group of seahorses before putting them in a bucket.

They were then pulled out of the water one by one before a fishing wire lasso with a different coloured identity tag was placed around their neck using tweezers.

Among the breeds that took part were Australian big-belly seahorses, or hippocampus abdominalis in Latin, Caribbean slender seahorses - hippocampus reidi - and the native British spiny seahorse - hippocampus guttulatus.

The male seahorses are particularly distinctive as they have a stomach pouch for a female to deposit an egg into.

The creatures at each centre were then placed in groups of species for one month and visitors were asked to record amorous behaviour between the different coloured tags. They were told to look out for the signs of courtship which include colour changes, knotting of tails and synchronised swimming.

The information was then gathered and studied at the Sea Life pPark's National Seahorse Breeding Centre in Weymouth, where some shocking results were unearthed.

A total of 1,986 contacts' were recorded between males and females - but another 836 were between females and a further 346 between males.

Mr Bullimore said that by far and away the big-bellied seahorses were the most sexually experimental.

He said: "All of the seahorses showed courtship rituals up to 25 times a day.

"These included colour changes, knotting of tails and synchronised swimming.

"The easiest to spot is the famous seahorse dance where couples knot tails and swim together, matching each other's movements almost perfectly."

The aptly-named big-bellied seahorses showed the keenest propensity for fooling around, despite only mating four times a year.

"They appeared happy to engage in courtship and fool around with any other member of the same species in the same tank, sometimes of the same sex.

"The most successful in terms of conquests were definitely the males with the biggest bellies."

There was more evidence of preference for a particular partner among the slender seahorses, with some individuals courting the same partner 40 per cent of the time.

"Only in the case of the spiny seahorses were there clearly pairs that remained faithful to each other.

"Among the males, the ones with the largest bellies or the biggest incubation pouches were by far the sauciest.

"Slender seahorses were observed with the same partner almost half the time, but would also flirt with both the opposite and same-sex fairly regularly.

"The notable exceptions to the rule were the spiny seahorses.

"Most of the spiny seahorse pairs remained 100 per cent faithful to a single partner."

The study was carried out last August in Weymouth and at other Sea Life Parks including Blackpool, Birmingham, Scarborough, Great Yarmouth, Brighton and Oban in Scotland.

German centres in Konstanz and Dresden also took part in the fidelity test.

Mr Bullimore added: "Perhaps the naturalists who first reported monogamy in seahorses had observed it in one or two species and just assumed it would be universal.

"Another possibility is that the sexual behaviour of some seahorse species is different in aquarium conditions to that in the wild."

Weymouth's sea life breeding programme began in 1995 when a fisherman off the Dorset coast accidentally caught seven long-nose spiny seahorses.

Until the capture of this group the species was thought to be almost entirely extinct in British waters as a result of crude Victorian oyster fishing techniques.

Since then hundreds of tropical and temperate seahorses have been bred at the centre.