The Egg Scattering Strategy
The egg scattering strategy involves the eggs being fertilised externally, an example of a species of fish that uses the egg scattering strategy is the Koi Carp.
A general description of this method-
Initially, the male chases the female, while doing this he butts and nips around the stomach and vent area. This is to encourage and provoke the female to release/drop eggs. There is no care taken here, and the eggs will just fall wherever the female is swimming, whilst they are falling, the male will spray milt onto the eggs. The fertilised eggs will then fall onto the substrate, into plants, or it will even float to the surface. The female will then encourage other females to release their eggs and this fertilisation period will sometimes occur in groups, the initial female triggering other females to also release their eggs.
Parental protection-
Egg scatterer's provide no parental protection for their young, it is actually extremely common for these species' pf fish to even eat their own brood. Although, it is also common for other fish to eat their brood. Their eggs hatch within a very short period of time (usually around 3 days) which means that they can fend for themselves, so they are not vulnerable for long. This may be seen by some experts as a form of parental protection, although, it seems to me to be more of a survival strategy, to increase population numbers.
Offspring numbers-
Egg scatterer's produce a large number of eggs, they usually produce around 300 eggs, this is to try to increase the broods chances of survival. Due to no parental protection, a larger number of eggs will increase the chances of some of the brood surviving.
Survival strategy-
To increase their brood's chances of survival, egg scatterer's produce a large number of eggs at a low energy cost. They do not provide parental protection, and do not carry their brood, this means that they are saving a lot of energy and can instead, use this to produce more eggs. Their large numbered broods mean that even with predation, and the chance that some of the eggs will not hatch, there is still a chance for some of the brood to survive, increasing the population of the species.
Evaluation of the success of this method-
There is a low chance of success with egg scatterer's, this is due to the fact that most of the eggs will fail to hatch, and to add to this, most of the eggs will be predated on, either by neighbouring fish or even the fish that produced the brood. This means that it is unlikely for many of the brood to survive, making this method hardly successful and meaning that there will only be a slight increase in the population of the species.
Genetic diversity-
There is a high level of genetic diversity with egg scatterer's, this is because more than one male will spray milt onto the falling eggs. This means that each brood will have more than one father, increasing the genetic diversity.
Energy costs-
This strategy uses low energy levels, this is because the fish only need to use their energy to produce eggs/milt. They do not look after or protect their brood meaning their energy levels are preserved.
A general description of this method-
Initially, the male chases the female, while doing this he butts and nips around the stomach and vent area. This is to encourage and provoke the female to release/drop eggs. There is no care taken here, and the eggs will just fall wherever the female is swimming, whilst they are falling, the male will spray milt onto the eggs. The fertilised eggs will then fall onto the substrate, into plants, or it will even float to the surface. The female will then encourage other females to release their eggs and this fertilisation period will sometimes occur in groups, the initial female triggering other females to also release their eggs.
Parental protection-
Egg scatterer's provide no parental protection for their young, it is actually extremely common for these species' pf fish to even eat their own brood. Although, it is also common for other fish to eat their brood. Their eggs hatch within a very short period of time (usually around 3 days) which means that they can fend for themselves, so they are not vulnerable for long. This may be seen by some experts as a form of parental protection, although, it seems to me to be more of a survival strategy, to increase population numbers.
Offspring numbers-
Egg scatterer's produce a large number of eggs, they usually produce around 300 eggs, this is to try to increase the broods chances of survival. Due to no parental protection, a larger number of eggs will increase the chances of some of the brood surviving.
Survival strategy-
To increase their brood's chances of survival, egg scatterer's produce a large number of eggs at a low energy cost. They do not provide parental protection, and do not carry their brood, this means that they are saving a lot of energy and can instead, use this to produce more eggs. Their large numbered broods mean that even with predation, and the chance that some of the eggs will not hatch, there is still a chance for some of the brood to survive, increasing the population of the species.
Evaluation of the success of this method-
There is a low chance of success with egg scatterer's, this is due to the fact that most of the eggs will fail to hatch, and to add to this, most of the eggs will be predated on, either by neighbouring fish or even the fish that produced the brood. This means that it is unlikely for many of the brood to survive, making this method hardly successful and meaning that there will only be a slight increase in the population of the species.
Genetic diversity-
There is a high level of genetic diversity with egg scatterer's, this is because more than one male will spray milt onto the falling eggs. This means that each brood will have more than one father, increasing the genetic diversity.
Energy costs-
This strategy uses low energy levels, this is because the fish only need to use their energy to produce eggs/milt. They do not look after or protect their brood meaning their energy levels are preserved.