Re: How does temperature affect the heartrate of Daphnia?

Hi Khalika:

Many biological rates increase exponentially with temperature (as do many chemical reactions). It has long been known for metabolic rates that a ten degree increase in temperature results in approximately a doubling of rates. This is called the van't Hoff rule, after the Dutch chemist Jacobus Henricus van't Hoff.

The Q10 approximation is expressed mathematically as:
Q₁₀ = (K₁/K₂)^{10/(t₁-t₂)}
Where K₁ and K₂ are the rates at temperatures t₁ and t₂.
Most metabolic rates have a Q₁₀ somewhere between 2 and 3 (a doubling or tripling with an increase in temperature of 10 degrees).

You can see more about daphnia Q₁₀'s and daphnia heartrates by checking out the results of these searches at google.com

Hope that helps,
Rob Campbell, MAD Scientist