Channeled Apple Snail (Pomacea canaliculata) (福壽螺) is a large-sized snail. The globular-shaped shells can have a wide variation of color with banded patterns of black, brown, green or yellow. Their bodies can be 6 cm wide to 8 cm tall with the shell extending up to 15 cm.
Bright reddish-pink eggs are laid on rice plants in groupings of 200-600. The eggs are bright red due to their high levels of carotenoid (organic pigment) components.
The aggressive and successful invasion of the apple snail in irrigated rice systems in many parts of Asia have led to significant economic damages. Direct-seeded rice suffers significantly more damage than trans-planted rice, because the snails consume greater amounts of the younger, more succulent plants. Snail damage in uncontrolled fields can be as high as 100% for rice seedlings in the germinating stage, as opposed to 20% on average in the transplanting stage. Overall most rice varieties tend to be directly seeded as opposed to transplanted, making them more susceptible to Pomacea canaliculata. Farmers in the infested areas are faced with the options of paying additional costs to control the spread of snails, replanting damaged areas of paddy, or ignoring the problem all together at the risk of potentially large yield losses.
Pomacea canaliculata transmits the rat lungworm Angiostrongylus Cantonensis which can infect humans if they eat raw or undercooked Pomacea Canaliculata. The parasite Angiostrongylus Cantonensis causes eosinophilic meningitis, which undetected will slowly destroy the human brain and is very fatal.
The snail, indigenous to South America, was introduced into Taiwan from Argentina for commercial production in the 1980s. From Taiwan, the snail was distributed to developing countries to help the rural poor earn additional income through backyard rearing and to supplement protein in their diets. The snail was introduced without prior studies on market demands or its impact on the ecosystem. The snail has spread from South America to Southeast Asia and reached Hawaii in the 1990s.
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