What are the physiological challenges an organism (such as a waterbug) might experience in a freshwater lake of the following conditions: depth of 200 m, water cold (approx 10 degrees celcius on surface), eutrophic, poor visibility, pH approx. 4?
What are the physiological challenges an organism (such as a waterbug) might experience in a freshwater lake of the following conditions: depth of 200 m, water cold (approx 10 degrees Celsius on surface), eutrophic, poor visibility, pH approx. 4?
The key to answering this question is to think about the stresses that these conditions would put on an aquatic insect. These stressors could be things that decrease the organism's ability to capture prey or escape from predators or things that alter the organism's homeostasis. Let's look at each condition separately:
Freshwater: When an organism lives in water osmosis and ion transfer is going to occur between the external environment and the organism's cells, until the two environments are isotonic (same concentration of water and ions inside and out). Most organisms' cells can only operate correctly and/or survive in a limited range of osmolarities. When exposed to external conditions not appropriate to their cells they can do a few things: 1. move, 2. osmoregulate (usually through ionic pumps), 3. become isotonic with the environment and deal with it. To address this question specifically you want to find out the osmotic requirements of the waterbug. It is likely that its cells are isotonic to freshwater and then there would be no osmotic and ionic stress, however if there was a larger ...
In this solution I describe how/why each condition could (depth, temperature, eutrophic level, pH, and visibility) physiologically stresses a waterbug, including definitions of terms and physiological theory.