The Live Bearing Strategy
The live bearing strategy involves the female/male bearing live young, there are two types of live bearers which will be explained in the evaluation of this strategy below. An example of a live bearing species is the seahorse.
A general description of this method-
There are two different types of live bearer's, with ovoviviporous live bearers, the eggs form within the female and are also fertilised internally by the male. The eggs will hatch within the female, and the female will then give birth to live young. With viviparous live bearers, there are no eggs formed and the young receive their food/nutrition through an umbilical cord or from secretions from the female. Live bearers are usually easily bred species'.
Before breeding, the seahorses may "court" for several days, then when they are ready to breed, they will synchronize their movements and may even change colour, they will swim aside each other with their tails linked and will spin around in unison.
Then the male will pump water through his pouch to catch the females attention, and to show her that the pouch is empty, when the female is ready, they will then drift upwards facing each other and will spiral around each other. The female will then deposit her eggs into the male's pouch, and they will sink back down and the female swims away.
Parental protection-
Live bearers do not provide parental protection for their young, seahorses give birth during the night and their young are independent from birth, the male does not look after the brood or protect them in any way. The only parental protection provided, is that the male will carry the brood until they hatch.
Offspring numbers-
The female will deposit up to around 1,500 eggs into the males pouch, although only 100-1,000 of these will survive and be released. The larger number of offspring means that there is a higher chance of success, as around half of the young released will not survive. This is due to predation, and also to the high currents, which means that the brood is swept away from feeding ground and sometimes into extreme temperatures that their bodies cannot survive. Producing more young increases the chances of some of them surviving, meaning that there is a higher chance of increasing the population of the species.
Survival strategy-
Their survival strategy is to produce a larger brood to increase their chances of survival, this means that although some will be eaten and swept away, maybe a small few will survive. They also carry the brood until they hatch, and their brood are born independent, this means that their young can survive on their own from the moment they are released. Increasing their chances of survival, and alloing nature to take its course (survival of the fittest).
Evaluation of the success of this method-
There is a medium chance of success with live bearers, this is due to the fact that they do not provide any parental protection, their young are born independent and so do not receive any guidance or protection from their parents, leaving them vulnerable to predation and starvation.
Genetic diversity-
There is a low amount of genetic diversity with this method, this is due to the fact that the breeding process only involves one pair of seahorses, one female and one male.
Energy costs-
This method involves low energy costs as the male does not provide any paretal protection, he does not need to aid the young in any way. As soon as the brood are released, they will swim away and fend for themselves, whilst the male prepares for the next breeding procedure.
A general description of this method-
There are two different types of live bearer's, with ovoviviporous live bearers, the eggs form within the female and are also fertilised internally by the male. The eggs will hatch within the female, and the female will then give birth to live young. With viviparous live bearers, there are no eggs formed and the young receive their food/nutrition through an umbilical cord or from secretions from the female. Live bearers are usually easily bred species'.
Before breeding, the seahorses may "court" for several days, then when they are ready to breed, they will synchronize their movements and may even change colour, they will swim aside each other with their tails linked and will spin around in unison.
Then the male will pump water through his pouch to catch the females attention, and to show her that the pouch is empty, when the female is ready, they will then drift upwards facing each other and will spiral around each other. The female will then deposit her eggs into the male's pouch, and they will sink back down and the female swims away.
Parental protection-
Live bearers do not provide parental protection for their young, seahorses give birth during the night and their young are independent from birth, the male does not look after the brood or protect them in any way. The only parental protection provided, is that the male will carry the brood until they hatch.
Offspring numbers-
The female will deposit up to around 1,500 eggs into the males pouch, although only 100-1,000 of these will survive and be released. The larger number of offspring means that there is a higher chance of success, as around half of the young released will not survive. This is due to predation, and also to the high currents, which means that the brood is swept away from feeding ground and sometimes into extreme temperatures that their bodies cannot survive. Producing more young increases the chances of some of them surviving, meaning that there is a higher chance of increasing the population of the species.
Survival strategy-
Their survival strategy is to produce a larger brood to increase their chances of survival, this means that although some will be eaten and swept away, maybe a small few will survive. They also carry the brood until they hatch, and their brood are born independent, this means that their young can survive on their own from the moment they are released. Increasing their chances of survival, and alloing nature to take its course (survival of the fittest).
Evaluation of the success of this method-
There is a medium chance of success with live bearers, this is due to the fact that they do not provide any parental protection, their young are born independent and so do not receive any guidance or protection from their parents, leaving them vulnerable to predation and starvation.
Genetic diversity-
There is a low amount of genetic diversity with this method, this is due to the fact that the breeding process only involves one pair of seahorses, one female and one male.
Energy costs-
This method involves low energy costs as the male does not provide any paretal protection, he does not need to aid the young in any way. As soon as the brood are released, they will swim away and fend for themselves, whilst the male prepares for the next breeding procedure.