Reproductive System
Asexual Reproduction vs. Sexual Reproduction
Mitosis vs. Meiosis
[1]http://www.diffen.com/difference/Asexual_Reproduction_vs_Sexual_Reproduction
[2]http://www.diffen.com/difference/Meiosis_vs_Mitosis How do garden snails reproduce?
First off, garden snails are hermaphrodites, meaning they possess both male and female reproductive organs. Each snail has a penis and vagina. [1] They can self-fertilize because they are hermaphrodites, which means they can produce both male and female gametes but they prefer to reproduce with another snail. Garden snails are usually sexually mature around one year. Courtship time is around early summer. Garden snails start by caressing each other with their tentacles, nibble at the lips, and rock their bodies back and forth. This is known as courtship. Then they pierce each other with a long, sharp spear containing calcium carbonate called a love dart. The mucus in the love dart is used to help with the survival of the sperm. It doubles the chance of producing offspring.[2] It also sexually stimulates the snails and signals the begin of them mating. Later, mating occurs. They align their bodies and simultaneously insert each others' penis in each others' vagina. They exchange sperm stored in a special pouch and fertilize their eggs. [3] Also the chromosome haploid for a garden snail is 27. (diploid is 54) [4] The snails separate after mating. The sperm continues to be stored inside the snail until the egg is "ripe" or fertilized. When the egg is fertilized, the snail digs pits in the moist soil and lays the eggs. [2] The eggs look like small white pearls. They take two-four weeks to hatch. [3] [1]http://www.bbc.co.uk/nature/life/Helix_aspersa [2]http://www.arkive.org/garden-snail/helix-aspersa/#ref4 [3]http://www.welcomewildlife.com/?folder=pages/urban%20wildlife/other/snails [4]http://www.ewart.org.uk/biology/index.php?l=11 DevelopmentHow do snails develop?
A garden snail will generally lay around 100 eggs after they mate. Snails hatch from the egg in two to four weeks. As soon as they hatch, they eat their egg shell in order to get calcium to support their shell. After three months, they will be completely formed. They stay in a nest with their parents during these three months. The baby snails have clear shells that later change to blue than to brown when they are adults. They have parental care until they are completely developed and leave their parents and also change into a different shell. [5] It take about one year for the snail to reach sexual maturity. Their life expectancy is around 3 - 5 years. In conclusion, they start off as eggs, then young snails, then adult snails after they mate and lay eggs. (refer to diagram below) [5] http://www.snail-world.com/How-do-Snails-Reproduce.html |