Snail Tales: All about the Florida Apple Snail

Dr. Rebekah E. Gibble, Research Ecologist

The A.R.M. Loxahatchee National Wildlife Refuge is home to a special invertebrate (an animal without a backbone) called the Florida Apple Snail (Pomacea paludosa Say). These snails are a very important component of the Everglades. Not only do apple snails make up the bulk of the diets of limpkins (Aramus guarauna) and the critically endangered Everglade snail kite (Rostrhamus sociabilis), they also are on the menu for alligators, fish, and crayfish. It turns out that Florida is the only place in the world where this specific snail is found.

Florida apple snailFlorida apple snails are very good at dealing with the constantly changing and often harsh conditions in the Everglades. Adult snails can live up to a year and a half or two years and grow to nearly the size of a small plum. Their relatively large size allows them to survive periodic dryouts – those dryouts are important for maintaining their ideal habitat.

Apple snail eggs After mating, female apple snails lay their eggs on plants sticking above the water surface. The eggs start out pink, but turn whiter as they near hatching. Eggs hatch after about two weeks. Three to four months later, the young snails are ready to mate and lay their own eggs. An apple snail can lay many, many eggs during its short life.

Historically, we believe that apple snails were much greater in number and more widespread throughout Florida – including the Refuge – than they are today. The decline in snails probably is due to a combination of habitat loss to urban and agricultural development, changes in timing and quantity of water flow and depths, and degraded water quality. These declines probably are detrimental to snail kite populations, as well as other species that depend on them as food. Providing ample habitat with the appropriate aquatic plants, water levels, and apple snails are key to conserving snail kites. Therefore, the protection and conservation of apple snails is directly linked to the protection and conservation of snail kites. Fortunately, many organizations and agencies in South Florida are exploring ways to help apple snails.

Apple snail conservation efforts include: (1) management of water levels suitable for apple snails; (2) ongoing research to understand relationships between snail kites, apple snails, and their habitats in order to improve wetland and wildlife management; and 3) efforts to re-populate the Refuge with apple snails collected from other areas or grown in aquaculture facilities. We are doing research at the Refuge to understand the impact of water quality and food quality on apple snail growth, survival, and reproduction. In one study, apple snails were placed in cages in areas having different food and water quality around the Refuge and rates of snail growth and survival were measured. Refuge staff also are working on a snail aquaculture project that will enable Refuge managers to better operate the impoundments for snail kite nesting and foraging.

Restoring and preserving the remaining Everglades must include the native plants and animals that make this system unique. The efforts of many scientists, researchers, and managers to save apple snails, snail kites, and other species will allow current and future generations to explore and enjoy the beautiful resources at the Loxahatchee Refuge.