If you’ve ever walked along a pond or stream and came across a mass of bright pink eggs on the vegetation, you’ve just encountered signs of the invasive apple snail (Pomacea maculata and Pomacea canaliculata). While these snails can be enticing with their magnificent size and colorful eggs, they are detrimental to human and habitat health. Luckily, there are ways you can help manage their populations to keep our Texas wetlands flourishing with just a click and a squish.
What are Apple Snails?
Apple snails are large species of mollusks native to tropical regions of South America. Their globular shells come in varying shades of green with brown banding, and they can grow up to 15 centimeters with five or six whorls. Living in freshwater, these snails feed primarily on aquatic vegetation, but they often supplement a protein-filled diet with decaying fish and insects. Apple snails will also feast on eggs from other snail species. After a mature female snail has mated with a male, she will find a plant, rock, or wooden structure of her liking and deposit 1,000 to 2,000 bright pink eggs. Pretty, right? Wrong. Once these baby snails hatch, they will grow up to be wetland annihilators. To make matters worse, a single female apple snail will store supplies from her first pairing to lay up to 56,000 more eggs in her lifetime.
Apple snail laying eggs on a plant
Why Do Apple Snails Matter?
Apple snails are invasive to the southern United States, including Texas. Invasive species are not only non-native organisms, but they also cause ecological and economical harm and can pose significant health threats to humans. The introduction of apple snails to North America through the aquarium trade and aquaculture has had negative impacts on our native aquatic plant and snail populations. Water hyacinth, duckweed, and cattails are just a few native aquatic plants decimated by apple snails. Agricultural crops that require wet conditions, like rice grown in many Texas counties, are also at risk of apple snail destruction, creating huge economic losses each year.
From a human health standpoint, apple snails are important rat lungworm transmitters. The rat lungworm is a parasitic nematode which requires a rat and a gastropod (snail or slug) to complete its lifecycle. Humans can contract lungworms by eating raw or uncooked apple snails or by eating vegetation an infected snail has come into contact with.
Apple snail commune in the water on a plant
Source: The Bugwork Network through the Encyclopedia of Life
How can I help?
Recently, apple snail eggs have been reported in The Woodlands. To assist in combatting the population within Lake Woodlands, aquatic vegetation is treated during maintenance visits to cut down on the apple snail’s food source. Residents are responsible for the removal of apple snail eggs on their private property.
To stop apple snails in their slimy tracks, you can report sightings to Texas Invasives and destroy egg clusters. If you find a live snail, empty shell, or the infamous pink mass of eggs, take a photo and submit a detailed report including your contact information and the coordinates of your observation. To destroy apple snail eggs, you can either prod the cluster into the water with a stick to disrupt their survival, stomp on them with your favorite pair of boots, or crush the eggs with a hard object. Never use your bare hands to crush the eggs, as they contain a neurotoxin we can absorb through our skin.
Together, we can protect our environment, our ecosystem, and ourselves.
For more information, contact the Environmental Services Department at enviro@thewoodlandstownship-tx.gov or 281-210-3800.