Gastropod Life Cycle

The Gastropod family of organisms includes both snails and slugs, including marine slugs or sea slugs. The main aspects of the life cycle for gastropods include the egg stage, growth and immature stages, adult stage, courtship and fertilization. The estivation and hibernation phases of the gastropod life cycle are only present in some types of gastropods. Although both snails and slugs both belong to the same phylum, which is Mollusca, they have unique life cycle characteristics.

  1. Snail Life Cycle

    • A snail is developed fully by a year of age and capable of mating. There is a ritual courtship that occurs before mating and this can last as long as 10 hours. Terrestrial snails are hermaphroditic, which means that they are capable of producing both eggs and semen. During the mating phase, the two snails fertilize one another, meaning that both will lay fertilized eggs. The eggs begin to develop immediately and hatch after a period of four weeks. Their outer shell is already forming. At this stage, snails are colorless and nearly transparent. As they begin to feed regularly, their colors appear, and they already look like miniature versions of their adult stage.

    Snail Life Span

    • There are different life spans for different spans. The Achatinidae snail can live as long as seven years. The Apple snail, an aquatic variety, does not generally live for more than a year. In captivity, however, an Apple snail can live as long as 12 years. Snails can spend as long as three years growing to reach their full adult size. Sexual maturity is reached at one year, meaning that snails can produce new offspring before they have reached full adult size.

    Slug Life Cycle

    • There are three main stages that make up the life cycle of the slug, which are the egg stage, the immature stage and the adult stage. Slugs are hermaphroditic, meaning that they possess both male organs and female organs. Every slug, then, is capable of laying as many as 300 eggs in batches from 10 to 50. The eggs are approximately 3mm to 4mm and are not unlike tapioca in shape and texture. They can take between 10 and 100 days to hatch depending on season, with warmer weather hatching eggs sooner. The immature stage lasts for less than a year before the adult stage is reached and mating can begin anew.

    Slug Life Span

    • The adult stage for most slug varieties is reached within less than a year. Once the adult stage is reached, the slug can mate and lay eggs of its own with the potential to produce as many as 40,000 offspring in its life. The average life span for a slug is approximately four years, with three of those years falling in the adult stage of growth.

    Hermaphroditism and Pulmonata

    • In some varieties of gastropods, the slugs or snails are nearly always hermaphroditic. What this means is that they contain both female and male reproductive organs and are capable of producing eggs and semen. What this allows is for any hermaphroditic gastropod to mate with any other mature animal as long as the species is the same. Some gastropod varieties also possess Pulmonata, which is the ability for the gastropod to self-fertilize. A few species of gastropods are also capable of reproducing without any fertilization of the eggs.