What kind of fertilization do most fish have?

Most fish species exhibit external fertilization. This means that the eggs are fertilized outside the female's body.

Here's how it works:

1. Spawning: The female releases her eggs into the water.

2. Fertilization: The male releases sperm into the water, which then fertilizes the eggs.

This process typically occurs in specific areas called spawning grounds, which can be freshwater or saltwater depending on the species.

While external fertilization is the most common method, some fish species, like sharks and rays, have internal fertilization. In these cases, the male inserts a specialized organ called a clasper into the female's cloaca to deposit sperm.

Key differences between external and internal fertilization in fish:

| Feature | External Fertilization | Internal Fertilization |

|---|---|---|

| Fertilization location | Outside the female's body | Inside the female's body |

| Egg protection | Typically less protected | Often more protected |

| Parental care | Often minimal | Usually more extensive |

| Number of offspring | Often large numbers | Typically fewer offspring |

| Examples | Salmon, trout, catfish, goldfish | Sharks, rays, guppies |

Therefore, while most fish utilize external fertilization, it's important to note that there are exceptions with internal fertilization in certain species.