How would a zebra mussel reproduce??
One of the reasons that the zebra mussel was such a threat to organisms once it moved to the USA was because of how much it reproduces. Zebra mussels, as an invasive specie, are very dangerous to the ecosystem they invade because ability they have to make their population spike. Zebra mussels are capable of laying 30,000 to 1 million eggs per year (1). Females reach adulthood by around the second year of their lives, allowing them to mature much quicker then humans and many other organisms. Zebra mussels mate by the male and the female releasing their gametes into the water, fertilizing the eggs that then turn them into a larvae called veligers(2). these larvae are very small and are actually naked to the human eye and can only survive for three to four weeks without attaching to a hard surface.
In the United States, zebra mussels had only been recored to live up to three years, but in their original European habitats they are known to live up to six years(3). Once the gametes are released into the water and the eggs are fertilized, it will take about a year for the zebra mussel larva to grow into a one inch zebra mussel (most zebra mussels grow up to two inches; fingernail size)