Answer:
It depends largely on environment!
Explanation:
External fertilization usually occurs in aquatic environments (fish) where both eggs and sperm are released into the water. After the sperm reaches the egg, fertilization can then take place. Most external fertilization happens during the process of spawning where one or several females release their eggs and the male(s) release sperm in the same area, at the same time. The release of the reproductive material may be triggered by water temperature or the length of daylight. Nearly all fish spawn, as do crustaceans (such as crabs and shrimp), mollusks (such as oysters), squid, and echinoderms (such as sea urchins and sea cucumbers). Pairs of fish that are not broadcast spawners may exhibit courtship behavior. This allows the female to select a particular male. The trigger for egg and sperm release (spawning) causes the egg and sperm to be placed in a small area, enhancing the possibility of fertilization.
When it comes to spawning, where large clutches of eggs will be fertilized at the same time it increases the probability of survival amongst the eggs, only by sheer force of numbers. If fish only fertilized small clutches there would be little to no survivors due to predator's population. Because of predators like Turtles, a lake with little predator's (turtles) will have a higher chance of egg survival rate. On the other hand, Lakes and ponds will have A lower survival rate for egg clutches with more predator's, like turtles.
Hope this helps! let me know in the comments if I need to answer any other parts of this prompt, I would be happy too.
