mosquito larvae can tolerate extremely low dissolved oxygen concentrations, yet cannot survive at temperatures above 25 degrees celcius. how might you aaccoundt for dissolved oxygen concentrations of such a low value at a temperature of 25 degree celcius?
I don't understand how this can be because as the temperature of an area increases, then the concentration of dissolved oxygen increaes.
Nope, dissolved oxygen is highest at low temps. Now you know in the summer fish are at the bottom of rivers and streams.
yes, that is what i meant but i don't understand why the dissolved oxygen concentration would be so low at such a low temperature?
The statement regarding mosquito larvae tolerating low dissolved oxygen concentrations, yet not surviving at temperatures above 25 degrees Celsius, can seem contradictory at first. However, it can be explained by understanding the relationship between temperature and dissolved oxygen concentrations in water.
Generally, as water temperature increases, the solubility of gases, including oxygen, decreases. This means that warmer water can hold less dissolved oxygen compared to colder water. So, your initial understanding that the concentration of dissolved oxygen increases with increasing temperature is not correct.
In the case of mosquito larvae, their ability to tolerate low dissolved oxygen concentrations is an adaptation that allows them to survive in stagnant or oxygen-depleted water sources. They have developed physiological mechanisms to extract the limited available oxygen from the water, even when the dissolved oxygen concentrations are low.
However, as the water temperature exceeds 25 degrees Celsius, the oxygen requirements of the mosquito larvae may outstrip their ability to extract enough oxygen from the water. This can result in hypoxia, a condition where the larvae do not receive enough oxygen to survive, leading to their death.
In summary, the ability of mosquito larvae to tolerate low dissolved oxygen concentrations is an adaptation that allows them to survive in water with limited oxygen. However, their ability to tolerate low oxygen levels is limited by temperature, as higher temperatures reduce the amount of dissolved oxygen that water can hold.
The relationship between temperature and dissolved oxygen concentrations in water can be a bit complex. While it is true that warmer temperatures generally decrease the solubility of oxygen in water, there are other factors at play that can affect the dissolved oxygen levels. In the case of mosquito larvae, their ability to tolerate low dissolved oxygen concentrations, even at a temperature of 25 degrees Celsius, can be explained as follows:
1. Biological Adaptation: Mosquito larvae have evolved specific physiological adaptations that allow them to tolerate low oxygen levels. They have specialized structures called spiracles that enable them to extract oxygen directly from the air, rather than relying solely on dissolved oxygen in water.
2. Breathing Behavior: The mosquito larvae have developed unique behaviors to enhance oxygen acquisition. They possess siphon tubes, which they extend above the water surface to access atmospheric oxygen more efficiently. By doing so, they can compensate for low dissolved oxygen concentrations.
3. Microhabitat Selection: Mosquito larvae have the ability to actively seek out microhabitats within the water body that may have higher dissolved oxygen concentrations. For example, they tend to inhabit shallow or near-surface waters where oxygen levels are generally higher than the deeper regions.
4. Oxygen Production: Another factor to consider is the presence of photosynthetic organisms (such as algae or submerged plants) that use sunlight to produce oxygen via photosynthesis. These organisms can contribute to higher dissolved oxygen concentrations, even in water with warmer temperatures.
While it is true that warmer temperatures generally decrease dissolved oxygen levels, the adaptability and behavior of mosquito larvae allow them to survive in low oxygen conditions by utilizing alternative oxygen sources and selecting suitable microhabitats. It is important to note that this is a general explanation, and specific details may depend on the exact species of mosquito larvae and environmental conditions.