Study finds repeated waves of Giant African Snail invasion in Kerala

The Giant African Snail found in Kerala.

The Giant African Snail found in Kerala.

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A recent study on the Giant African Snail ( Achatina fulica ) in Asia and Africa has found that the dangerous pest species had multiple episodes of invasion in India, particularly Kerala, and that new snail populations continue to arrive in India from snail-infested countries across the world.

The study observed that its population found in India had a higher genetic variety than those in the native African continent. “The higher genetic diversity found in our country indicates that the snail continues to have multiple invasions from different countries,” said Keerthy Vijayan, assistant professor, Kalasalingam Academy of Research and Education (KARE), Tamil Nadu.

The study done along with researchers from the Environmental Agency, UAE; Nottingham University; and Natural History Museum, London; found the same genetic strains of the snail population in India and the UAE.

“The populations in India and the UAE share the same haplotypes (a set of genes within an organism inherited together from a single parent). The snail could be introduced repeatedly back and forth in the UAE and India, considering material movement between the two countries,” said Dr. Keerthy.

Study period

Conducted at the Kerala Forest Research Institute (KFRI) with the support of the Kerala State Council for Science, Technology and Environment (KSCSTE) between 2016 and 2020, the study was published in the biological journal of the Linnean Society.

According to Dr. Keerthy, the snail reached Kerala for the first time when a researcher brought them from Annamalai University, Tamil Nadu, and accidentally released them at Elapully in Palakkad in the early 1950s.

Population spread

The snail population spread rapidly in the State, spurred by two more waves of invasion in the 1970s and in 2005.

The import of timber from two dozen snail-infested countries sped up their spread in Kerala. “In 2005, this snail was recorded only in Palakkad, Ernakulam and Pathanamthitta. But by 2020, it has spread to all districts except Idukki,” said Dr. Keerthy.

One of the worst invasive species declared by the International Union for Conservation of Nature (IUCN), the Giant African Snail is suspected to spread eosinophilic meningitis, septicaemia and peritonitis in humans.

Many cases of eosinophilic meningitis were reported among children in Ernakulam and Thiruvananthapuram.

Dr. Keerthy said controlling this snail would be difficult because of its repeated invasions.

“What we need is a long-term strategy to control and eradicate this invasive species,” she told The Hindu.

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Printable version | Feb 13, 2022 9:04:05 am | https://www.thehindu.com/sci-tech/energy-and-environment/study-finds-repeated-waves-of-giant-african-snail-invasion-in-kerala/article33262455.ece