关于动物繁殖的策略.pptVIP

Reproduction strategies of prawn cod killer whale GROUP1 DEFINITION reproductive strategy - the way in which a species allocates or budgets energy to produce viable offspring. Energy is diverted into actual offspring and into parental care. Food and temperature conditions have effect on the reproductive strategy CATEGORY r-strategy :The energy may be invested a multitude of offspring that receive little or no parental care, K-strategy: or invested in a few, large offspring that require considerable parental care Although some organisms are primarily r- or K-strategists, the majority of organisms fall between these two extremes and may display traits considered characteristic of both ends of the r/K spectrum. Other classification of reproduction There are two modes of reproduction: asexual. sexual Cod Murray Cod reach sexual maturity between 4 and 6 years of age. Female Murray Cod, upon first reaching sexual maturity, will have egg counts of around 10,000. Very large female Murray Cod can have egg counts as high as 80,000 - 90,000. The male remains to guard the eggs during incubation, which takes 6-10 days (depending on water temperature), and to guard the hatched larvae for a further week or so until they disperse. r-strategy sexual Killer whale Females become sexually mature when they reach about 4.6 to 4.9 m (15–16 ft.), at about 6 to 10 years. Males become sexually mature when they reach about 5.5 to 6.1 m (18–20 ft.), at about 10 to 13 years. Killer whales are polygamous: they mate with several partners. K-strategy sexual prawn The male inject sperm into water and female inject the eggs into the water, sperm-egg binding. That sexual reproduction. a female can lay 4 to 5 times, each time the number of eggs from 100,000 to 1,000,000. However, due to marine environment and climate change or the sudden mass mortality of inadequate food supply r-strategy sexual * * * *