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VietNamNet Bridge – A strange kind of snail has appeared on the Thi Vai
River, which nibble shrimp and fish on the river. While local residents say they
have never seen this kind of snail before, experts say it is not a strange
species, but cannot say exactly what kind the snail is.
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The snails that nibble fish and shrimp
After four hours of fishing, Cam Van Thoai, a farmer, drew up a net and saw a 100 gram shrimp caught in the net and felt excited. However, when he came closer to pick the shrimp, he saw snails sticking on the shrimp and said immediately: “I have to drop the shrimp to the river, once again.”
Seeing that people did not understand his words, he showed the snails and said: “The snails have nibbled the shrimp meat already. What you can do with it now, if you don’t give it back to the river?” he said.
Thoai, who has been fishing on the Thi Vai River for the last 25 years, Thoai said that he never saw the species of snail that suck the meat of shrimp and crab. He has affirmed that the species has just appeared for the last year.
Nguyen Van Thau, who has been fishing for 50 years on the river, related that 3-4 months after the illegal discharging of waste water to the Thi Vai River by Vedan and other factories was discovered and stopped, fishe have re-appeared.
The strange snails first appeared in early 2010 on the river area near the Cam Pha cement port, and they have been multiplying rapidly. “We once were very glad when seeing a lot of shrimp, crab and fish caught in the nets. However, we later found some snails on them. What we could see was the shell and bone,” Thau said.
What do scientists say?
Pham Van Mien, a scientist from the HCM City Institute for Environment and Development, after considering thoroughly the snails brought by reports, has said that this is not a new species of snail. According to him, the snail belongs to Buccinidae family, a kind of carnivores.
When asked why the snail mostly lives on the river areas near the Cam Pha cement port, Mien said that it is possible that on the area, the water has the suitable salinity to the snails, while there is much nutrition for snails at the bottom of the river.
Meanwhile, Ngo Quang Xuan, MA, Head of the environmental management division of the HCM City Institute of Tropical Biology Vietnam, who has been researching about invertebrate species in coastal areas, said that the snail may belong to Class Gastropoda and Nassariidac family.
Xuan said that some documents in the world mention this species of snail, but there are very few materials about it. Meanwhile, Xuan has not read any Vietnamese document on the species. It is possible that someone has made research on the snails, but he has not released the result.
Quang agrees with Mien that this might not be a new kind of snail, and that the snails have only appeared recently, because in the past, the Thi Vai river area did not have favorable conditions for them to develop.
In another supposition, the snails are an exotic species which has been following ships to evacuate to the region, where they meet favorable conditions to multiply.
Xuan has denied the opinion that this kind of snail has appeared due to the pollution of the Thi Vai River.
Dr Nguyen Minh Nien from the Aquaculture Research Institute NO 2 has also said he does not think this is a completely new species. He said that carnivore snails are not strange to scientists.
However, to date, no one can know exactly the name of the snails.
Source: Dat Viet
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