Life Cycle of a Gilled Snail

An aquatic snail

Gilled snails (Prosobranchs) comprise a large family of aquatic snails that have gills for breathing and are found around the world. The snails, normally found in freshwater lakes, depend on oxygen within the water to live. Due to their dependency on oxygen-rich water, they cannot tolerate pollution. The snails often live up to five years; their whole lifespan is spent within the water. A popular addition to many aquariums, the gilled snail is easy to keep and care for in captivity.

Sexes

A vast majority of gilled snails are hermaphrodites, which means they have both male and female reproductive organs. A few gilled snail varieties occur as either male or female; however most gilled snails lay eggs within their aquatic environment. The trap door snail is either male or female. The female trap door snail gives birth to live young.

Egg Production

Hermaphrodite gilled snails mate with themselves. The male and female gilled snail varieties mate with each other. Eggs are produced in an abundant jelly-like mass that sticks to surfaces such as rocks and aquatic foliage. A few gilled snail varieties lay their eggs on the surface of the water or in a moist muddy location.

Egg Appearance

When the eggs are first laid they are a clear jelly-like substance, but over the course of a few days dark dots begin to develop within the clear jelly. Infertile eggs appear clear and then begin to develop a white substance as they decompose. Egg gestation takes three to six weeks depending on the gilled snail variety.

Baby Snails

The young baby gilled snails are defenseless and often consumed by fish. As they grow they develop a trap door that is a hard substance that they pull over the opening to their shell as they enter the shell for protection.

Uses

Many gilled snail varieties are kept in captivity within the confines of an aquarium. They eat leftover fish food, consume algae that accumulate on the glass and offer an interesting life form to be observed. The drawback to keeping gilled snails within an aquarium environment is their prolific breeding. Snails also enjoy consuming fish eggs. Newly bought gilled snails often carry diseases or parasites that can be transferred to aquarium fish.

References

• The Poweshiek Skipper Project: Aquatic Snails
• Natural Aquariums: Snails (Gastropoda)
• Soil & Water Conservation Society of Metro Halifax: Class Gastropoda Snails
• Fish Pond Info: Robyn's Snail and Clam Page

Resources

• Stream Study, University of Virginia: Gilled Snail