Context: During a biodiversity impact assessment study, researchers have found an acute bladder snail called Physella acuta, from the Edappally canal in Kochi.

About Physella acuta

• It is a species of small, air-breathing freshwater snail. It is an aquatic gastropod mollusk in the family Physidae.

Physical Feature

• It is tiny snail with a striking, pellucid golden-yellow shell.
• Small in size, the snail can grow to 16 mm in height and 9 mm in width.
• The dead, vacant shell is brownish-yellow while that of the live individuals are translucent golden-yellow with a mottled appearance.

Habitat and Distribution

• Native to North America but is now found in all continents except Antarctica.
• This species lives in freshwater rivers, streams, lakes, ponds, and swamps.
• It can survive well under temporary harsh conditions like extreme temperature and water pollution.
• The acute bladder snail is globally branded as highly invasive.
• It plays host to worms that can cause food-borne diseases and skin itches in humans.
• Its rapid growth rate, air-breathing capability, and tolerance to pollution makes it a potential competitor to native fauna.
• It also has an ability to quickly dominate new environments endanger native species, even causing serious economic loss.

What is an invasive species?

• An invasive species can be any kind of living organism that is not native to an ecosystem and causes harm.
• It can be an amphibian (like the cane toad), plant, insect, fish, fungus, bacteria, or even an organism’s seeds or eggs.
• They can harm the environment, the economy, or even human health.
• These species that grow and reproduce quickly, and spread aggressively, with potential to cause harm, hence given the label “invasive.”

Invasive species thrive in a new location because

• There are no predators that hunt them in the new location.
• They outcompete native species for food.

How are they spread?

• Invasive species are often introduced into new places accidentally.
• Ships carry aquatic organisms in their ballast water, while smaller boats may carry them on their propellers.
• Some invasive species are deliberately introduced for the purpose of pest control.
• Other invasive species descended from pets that escaped or were released into the wild.
• Higher average temperatures and changes in rain and snow patterns caused by climate change will enable some invasive plant species to move into new areas.

List of threats posed by them
The direct threats of invasive species include

• preying on native species
• outcompeting native species for food or other resources
• causing or carrying disease
• preventing native species from reproducing
• killing a native species' young.
• They can change the food web in an ecosystem by destroying or replacing native food sources.
• It may provide little to no food value for wildlife.
• They can also alter the abundance or diversity of species that are important habitat for native wildlife.