Fish lay a large number of eggs because only a few of them, out of thousands, will be fertilized and produce a fish. This is because they are fertilized outside of the body and are highly sensitive to temperature changes and external factors.
Why do salmon release so many eggs?
Student Example Explanation: “Salmon lay so many eggs because they face a lot of adversity on the journey to becoming adult coho salmon!” Teacher Example Explanation: “Since so many salmon die before reaching spawning adulthood, laying more eggs increases the probability for successful reproduction and a sustaining population of salmon”.
One answer is, Some salmon lay eggs only once and other species spawn many times. In the fall, mature salmon change color, and return from the ocean to the spawning beds from where they were hatched.
Why do salmon lay their eggs upstream?
As we mentioned earlier, the biggest reason salmon lay their eggs upstream is to protect them from washing away in the ocean and from predators. Salmon have learned that many more of their eggs will survive longer if they are in a habitat that protects them. A small stream far away from the ocean is perfect for this.
One of the next things we asked ourselves was: why do salmon lay eggs outside the body?
This is because they are fertilized outside of the body and are highly sensitive to temperature changes and external factors. Female salmon, for instance, will lay anywhere from 1,500 eggs to about 10,000 at one time. Among these eggs, only around 10 will successfully spawn salmon.
Salmon aren’t the only fish that will attack salmon eggs! This is why salmon eggs make great bait for many different species of fish. Here are the most common species that will also attack salmon eggs.
How does fertilization occur in salmon?
Male salmon release white milt. The milt contains millions of sperm. Salmon gametes mixing. (GA image) Fertilization occurs as the salmon eggs and milt mix. The fertilized egg then settles into the redd (just below grade so that the flow of the stream does not move the fertilized egg).