Seahorses breed successfully in a Cornish fishtank

A hundred young seahorses are growing to maturity in the warm tanks of a Cornish pet shop, in what may be a world-record breeding success.

The small long-snouted fishes, which have fascinated people for centuries and are now endangered in many parts of the world because of their very popularity, are difficult to raise in captivity.

Often only a few individuals survive from broods which many contain hundreds or even thousands of young fish, known as fry.

But at Mid-Cornwall Aquatics, a fish emporium attached to St Austell Garden Centre, 100 of the 160-strong brood from a pair of the tropical species Hippocampus reidi are now four-and-a-half months old and are well on the way to adulthood. They are 4in long, compared to their 7in-long parents.

Les Wiley, the proprietor, says he believes the collection is the biggest single brood of the species to have been successfully raised in commercial captivity in the world. The success is due, he says, to devising a working diet, which includes tiny shrimps caught in local estuaries, and even smaller marine animals known as rotifers.

Hippocampus reidi, first classified in 1933, is one of 32 known seahorse species and is found in the western tropical Atlantic, from North Carolina all through the Caribbean down to the coast of Brazil.

Yellowy-brown, though able to change its colour to suit its surroundings, it is called the slender seahorse by British marine biologists, and the longsnout seahorse by Americans. In the wild, seahorses can produce anything from 200 to 1,600 fry.

The World Conservation Union classes its conservation status as "vulnerable".

Mr Wiley said the breeding pair in his shop were caught off the Brazilian coast and legally imported, via California. He said he thought tank-bred species could help depress demand for those caught in the wild.

"We have looked at all the breeder's registers, and no one has ever reared this number before, as they are not common seahorses," he said.

"As far as we are aware it is a world first – we have heard about one or two surviving in America, but we have never heard about more than 100 before."

Mr Wiley said he had been keeping fish since he was a toddler, and seahorses for about eight years. When they are mature, his new brood will be on sale for £50 a pair.

In many parts of the world seahorses are increasingly at risk, most of all from fishing to supply the trade in traditional Chinese medicine. Millions of dead seahorses pass every year through Hong Kong, the main trading centre.

Project Seahorse, run by Dr Amanda Vincent, a professor at McGill University in Montreal, and Dr Heather Hall, London Zoo's curator of lower vertebrates, is trying to make the trade sustainable while learning more about the seahorse's curious biology.

They are helping coastal communities in the Philippines, which is the centre of seahorse fishing, and other tropical countries learn how not to over-exploit the seahorse populations and, in some cases, suggesting alternatives.

Seahorses are fish, related to sticklebacks. They display a rare natural trait – it is the male who gets pregnant. The female deposits her eggs inside the male, who nurtures them until giving birth, complete with labour agonies.

Seahorses pair for life, and greet each other every morning with a ritual swimming dance, linking tails and promenading through the sea-grass beds and reefs in which they live.