Why in News?
The Giant African Snail (Lissachatina fulica) is recently in the news due to its rapid and alarming spread across school campuses and residential areas in Tirunavaya panchayat of Kerala.
Key Facts & Overview
- Scientific Name: Lissachatina fulica (formerly Achatina fulica).
- Invasive Status: Listed by the International Union for Conservation of Nature (IUCN) as one of the world's 100 worst invasive alien species.
- Origin: Native to East Africa but introduced globally via pet trade, meat trade, or accidental shipping routes.
- History in India: First introduced to India in 1847, reaching Kerala by the 1950s. It has now spread across all 14 districts of Kerala and several parts of other states like Telangana and Rajasthan.
- Lifespan: Can live up to 6–10 years under favourable tropical conditions.
Biological Features
- Physical Size: Adult shells typically measure 50 to 100 mm but can reach an enormous length of 200 mm (8 inches).
- Appearance: Long, narrow, cone-shaped light brown shell marked with darker vertical stripes.
- Diet: Extremely polyphagous, eating over 500 types of plants, agricultural crops, decaying organic matter, and even garbage.
- Reproductive Capacity: They are hermaphrodites (possessing both male and female organs) and can lay up to 2,500 eggs annually, allowing their population to explode overnight.
- Aestivation: During unfavourable dry or cold periods, they seal themselves with a mucus layer and can stay dormant inside their shells for months.
Threat and Impact
- Biodiversity Loss: They fiercely outcompete native snail species for food and space, disrupting local ecosystems.
- Zoonotic Threat: Secretions and slime tracks contaminate fruits, vegetables, and play areas, transferring dangerous microscopic parasites to humans and pets.
Control and Eradication Measures
- Manual Collection: Catching snails using gloves or boots, then destroying them.
- Organic Traps: Setting up community traps laced with wheat, yeast, and jaggery to attract the pests.
- Chemical Treatment: Spraying specialized copper sulphate solutions or using metaldehyde baiting pellets under strict agricultural supervision.
- Natural Remedies: Deploying a tobacco decoction, which has proven highly effective and eco-friendly.
- Destroying Eggs: Locating and crushing their tiny white, lizard-like eggs to prevent the next generation from hatching.
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