Oysters reproduce by releasing sperm and eggs into the water. Within six hours, fertilized eggs develop into larvae, which become fully shelled within 12 to 24 hours and are ready to attach themselves to a solid substrate within three weeks.Continue Reading
Some species of oysters have separate sexes, but their reproductive organs contain both sperm and eggs. They are able to change sex from year to year. Some oysters are hermaphrodites and theoretically can fertilize their own eggs. When food is abundant, females are prevalent, but when food is scarce, there are more males. Spawning is temperature-dependent, and occurs at 68 degrees Fahrenheit. Females release millions of eggs at a time.
When an oyster larva is ready to settle, it grows a foot and finds a place to establish itself. Usually this is an adult oyster shell that is part of an oyster bed, but it might also be broken oyster or clam shells. The young oyster, known as a spat, cements itself to the new surface and slowly metamorphoses into an adult oyster. Oyster beds sometimes form reefs that create complex ecologies, stabilizing bottom sediment, creating breakwaters for shorelines, filtering and cleaning water and creating habitats for a great variety of marine wildlife, including barnacles, sea anemones, worms, crabs and an abundance of fish.Learn more about Marine Life
Male seahorses give birth by releasing their young offspring into the water once the eggs hatch. Fertilized eggs are stored in a brood pouch on the ventral side of the animal during a gestation period ranging from 14 days to four weeks.Full Answer >
The fern life cycle and moss life cycle are similar in that they have alternation between sporophyte and gametophyte stages and that both rely on layers of water so that their sperm can swim from one gametophyte to the eggs of another. This means that both ferns and mosses require relatively moist environments. They are also similar in that their gametophyte stage, unlike other plants, does not rely on sporophytes.Full Answer >
Disadvantages of external fertilization include a reliance on water and the large amount of wasted sperm and eggs that never reach a corresponding gamete, even when the organisms releasing the eggs and sperm are in close proximity. Additionally, the eggs released can have no shells, as these would stop sperm.Full Answer >
There are many different oceanic mollusks, such as clams, octopus and oysters, but there are also mollusks that live on land, such as snails and slugs. Mollusks are the second largest group of invertebrates in the world, with somewhere between 50,000 and 200,000 living species.Full Answer >