Friday, July 20, 2012

Respiration Nation

One of our goals for this summer is to measure the respiration rates of a variety of stream invertebrates in the Hengill area.  These respiration estimates will contribute to the calculation of threshold elemental ratios (TERs) which are the elemental ratios of food resources at which consumer growth limitation switches from one element to another.  TERs provide a more quantitative index of the chemical imbalance between a consumer and its food than arithmetic differences between consumer body and resource elemental composition.

For the past couple of weeks, Amanda and I (Team Respiration) have been been practically running the respirometer non-stop.  In doing so, we've generated some 'breathtaking data' (I'm sorry, it had to be said).   The figure to the left shows the respiration rate of the freshwater snail, Radix peregra, at four different temperatures.  Clearly, respiration rate increases with body size.  Temperature also has an effect on respiration rate, with increased rates at higher temperatures for a given body size.  I guess this is not surprising.  However, we are excited that the respirometer is actually working and producing great results!

Until next time,

Dan

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