Koi Carp
The Koi Carp is known as an egg scatterer. The female fish will produce hundreds of eggs inside her and when she is ready to deposit these eggs the will swim to the top of the water whilst a few males will nudge her abdomen which aids the eggs coming out. once the eggs have come out the male Koi will spray milt over the unfertilized eggs to fertilize them as they fall to the bottom. With this method of fertilization it leads to their being a big genetic diversity which means they have a good immune system and is why goldfish are some of the hardest fish to kill. There is no species variation as each species of Koi has the same breeding technique. Once the eggs have been fertilized there is no parental protection involved and the eggs are now on their own to hatch.
The Koi Carp will produce thousands off eggs when breeding as it is their survival strategy as it means the more eggs produced the more will survive. They do this because the survival rate of these eggs are low as other fish including other goldfish will eat the eggs produced by the female as they fall to the bottom but the eggs will also be eaten once fertilized at the bottom of the floor by any fish that comes across them which means the success rate is pretty low especially in the wild.
Commercial breeders will take the female out of the water and keep her wet with a damp towel and they will take the eggs out themselves and put them in a bowl and once all the eggs have been extracted the female will be put back and the male will then spray milt over the eggs. the now fertilized eggs will be put into a tank so that they are safe and so that none will be eaten.
This is a video of some koi breeding :
The Koi Carp will produce thousands off eggs when breeding as it is their survival strategy as it means the more eggs produced the more will survive. They do this because the survival rate of these eggs are low as other fish including other goldfish will eat the eggs produced by the female as they fall to the bottom but the eggs will also be eaten once fertilized at the bottom of the floor by any fish that comes across them which means the success rate is pretty low especially in the wild.
Commercial breeders will take the female out of the water and keep her wet with a damp towel and they will take the eggs out themselves and put them in a bowl and once all the eggs have been extracted the female will be put back and the male will then spray milt over the eggs. the now fertilized eggs will be put into a tank so that they are safe and so that none will be eaten.
This is a video of some koi breeding :
Advantages
The advantages of this method for the Koi Carp is that their babies will have a high genetic diversity. Also due to the Koi producing thousands of eggs it means some will survive. This method also has a low energy cost which is good for the female as it means she doesn't have to concentrate on both hers and their survival. The eggs that are fertilized and reach the bottom and haven't been eaten will hatch within 3 days meaning that once again more will hopefully survive.
Disadvantages
The disadvantages to this method is that when you look at the amount of eggs produced there is not a lot that actually survive compared to the other breeding methods where most of all the eggs will survive.
Compared to the other two methods Mouth brooders and oviparous fish the advantage of the fish scatterer is that not a lot of energy is used up when breeding and that there is a big genetic diversity in all the fish. However these fry don't get protected by the parent and therefore the success rate for this breeding technique is low unlike both the mouth brooder and oviparous breeders who will protect their fry for a better chance of success. the advantages for this fish using this breeding method is that it doesn't take up a lot of energy.
The advantages of this method for the Koi Carp is that their babies will have a high genetic diversity. Also due to the Koi producing thousands of eggs it means some will survive. This method also has a low energy cost which is good for the female as it means she doesn't have to concentrate on both hers and their survival. The eggs that are fertilized and reach the bottom and haven't been eaten will hatch within 3 days meaning that once again more will hopefully survive.
Disadvantages
The disadvantages to this method is that when you look at the amount of eggs produced there is not a lot that actually survive compared to the other breeding methods where most of all the eggs will survive.
Compared to the other two methods Mouth brooders and oviparous fish the advantage of the fish scatterer is that not a lot of energy is used up when breeding and that there is a big genetic diversity in all the fish. However these fry don't get protected by the parent and therefore the success rate for this breeding technique is low unlike both the mouth brooder and oviparous breeders who will protect their fry for a better chance of success. the advantages for this fish using this breeding method is that it doesn't take up a lot of energy.