Rīga Zoo gives hand in restoring rare snail population

Zoologist Ginta Jansone inspects the terrariums housing Partula snails of various ages. These snails are currently found only in 15 zoos. The species is critically endangered, as they have gone extinct in the wild.

"We breed them so they can be kept in captivity, to prevent the species from disappearing entirely and to eventually restore wild populations," explained Jansone. "Following the London Zoo’s recommendation, they are kept in special terrariums, in a warm, humid environment. They are very sensitive to sudden temperature changes. We use food prepared by the London Zoo for their diet."

Partula snails are part of the culture of the French Polynesian islands. The shells of each species reflect the cultural identity of each island. It was the only place on Earth where these snails lived. They went extinct after giant African land snails were introduced to the islands in 1967 for food production. They escaped from the farms and devoured the plants in the wild that the Partula snails relied on for food.

"Then, to control the giant snails, the North American predatory rosy wolfsnail was introduced with the idea that it would help. But as it turned out, they preferred to eat the Partula snails," explained the zoologist.

In 1991, researchers in French Polynesia managed to find the last nine remaining Partula snails, and subsequently began breeding them. Later, specialists from the Rīga Zoo also received snails to help preserve the species. Last summer, 500 specimens bred in Rīga were transported to Germany.

Some were left in Germany to establish a new captive population. The rest were sent to French Polynesia, where they were released into the wild around New Year’s, and the first results are now in.

"A drop of colored glue mixed with ultraviolet dye is applied to the snails’ backs. And what does that mean? Since they are active at night, these snails are searched for using ultraviolet lamps, and they glow. Scientists have already found a snail that doesn’t have this drop of glue on its back, and it was apparently born in the wild, in its natural habitat. This gives hope that we’ll be able to restore the population,” said Māris Lielkalns, a representative of the Riga Zoo.