Giant snail stopped at NZ border

Photo / Ministry for Primary Industries

An invasive giant hermaphrodite snail had its bid for a new life in New Zealand thwarted at the border.

The Giant African Snail was intercepted at Auckland airport. It was travelling with a couple returning from Madagascar.

"At nearly 15cm long, it was the largest [snail] many of our staff had ever seen," said Craig Hughes of the Ministry for Primary Industries.

The unwanted visitor was carrying passengers of its own.

"When our inspector tapped the shell, a number of eggs fell out. We could have had a whole family take residence in Auckland if there hadn't been border controls in place," Mr Hughes.

The beast was banned from New Zealand because of its destructive tendencies.

Authorities said the snail, if it gained a slime-hold here, would threaten agriculture, the environment and human health.

The giant gastropod could damage plaster and stucco structures and even carried the disgusting-sounding rat lungworm parasite that could cause meningitis in humans.

The mega-snail might move slowly, but that hadn't stopped it causing mayhem in environments it infiltrated.

In the mid-20th century, it took ten years and $1 million to eradicate the animal from Florida. But the giant slimeball returned in 2011 and the state had to resume the battle.

The highly adaptable tropical snail could survive cold conditions, even snow, by hibernating. Giant African Snails were hermaphrodites and after a single mating could produce several batches of fertile eggs over a few months, the Ministry said.

Mr Hughes said passengers commonly declared Giant African Snails as sea shells.

"They don't realise that the snail will often hibernate unseen at the tip of the shell and only emerge when conditions are favourable."

Mr Hughes said the couple collected the snail from a forest. "The good thing is they declared the snail on their arrival card, thereby alerting our inspector of the biosecurity risk."

The snail was denied a return trip to Madagascar and destroyed, along with its eggs.