A methodological evaluation of the determination of critical oxygen threshold in an estuarine teleost
One measure of hypoxia tolerance is the critical oxygen threshold, P crit , which is the point where standard metabolism can no longer be maintained through aerobic processes. Traditionally, P crit was determined using closed respirometry, whereby the fish's respiration naturally lowered O 2 ....
| Published in: | Biology Open |
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| Main Authors: | , |
| Format: | Text |
| Language: | English |
| Published: |
The Company of Biologists Ltd
2019
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| Subjects: | |
| Online Access: | http://bio.biologists.org/cgi/content/short/8/11/bio045310 https://doi.org/10.1242/bio.045310 |
| Summary: | One measure of hypoxia tolerance is the critical oxygen threshold, P crit , which is the point where standard metabolism can no longer be maintained through aerobic processes. Traditionally, P crit was determined using closed respirometry, whereby the fish's respiration naturally lowered O 2 . More recently, intermittent flow techniques have been adopted, where N 2 is used to displace O 2 , which ostensibly reduces end-product build-up. This study used a paired design on the marine teleost, red drum. P crit is comparable between closed (4.6±0.2 kPa; mean±s.e.m.) and intermittent flow (4.4±0.2 kPa; mean±s.e.m.) respirometry. pCO 2 , ammonia and pH changes within the chamber were measured prior to the onset of P crit and at the end of a typical P crit trial and revealed changes in water chemistry in both closed and intermittent flow. P crit values were similar in both methods of hypoxia induction regardless of subsequent water chemistry changes that occurred in both methods. |
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