How does temperature affect the temperature of organisms within the water and their rate of growth and reproduction?

Most organisms that live in water will have the same temperature within their bodies as the temperature of the water that surrounds them.

Aquatic organisms have adapted over time to survive and reproduce best within a narrow range of temperatures.  In general, as temperature increases an organism's activity and growth rate increase. Associated with this increased activity is an increased need for oxygen.

Reproductive systems are very sensitive to temperature and, as a result, organisms tend to reproduce best at a particular time of year.  Reproduction of organisms tends to change with the seasons and, therefore, is directly related to the temperature of an organism's environment.