External fertilization is a process in which the fusion of gametes, the sperm and the egg, takes place outside the body of the organism. This process is common in aquatic animals, such as fish, frogs, and some invertebrates, where the gametes are released into the water.
Disadvantages of external fertilization include:
- Low success rate: In external fertilization, many gametes are released into the environment, and only a few of them are fertilized. The rest of the gametes are wasted, resulting in a low success rate.
- Vulnerability to predators: The release of gametes into the water makes the organisms vulnerable to predators, which can eat the gametes before fertilization can occur.
- Environmental factors: External fertilization is highly dependent on environmental conditions, such as temperature, pH, and salinity. Any changes in these factors can affect the fertilization process and reduce the success rate.
- Lack of parental care: In external fertilization, there is no parental care for the offspring. The fertilized eggs and larvae are left to survive on their own, making them vulnerable to predation and environmental factors.
- Competition for mates: In organisms that practice external fertilization, there is often a high competition for mates, which can result in aggression and physical damage to individuals. This can reduce the success rate of fertilization and increase the risk of injury to the organisms.