The lower limit of oxyregulation (Pcrit) at different temperatures in the brown shrimp (Crangon crangon).
In the marine environment low oxygen levels (hypoxia) and even complete oxygen depletion (anoxia) are not uncommon phenomena. Many marine animals are oxyregulators, which means that they are able to maintain constant oxygen consumption in spite of decreasing oxygen levels in the surrounding water. However, below a certain oxygen level they cant keep the oxygen consumption constant and they switch to oxyconformity, which means that the rate of oxygen consumption becomes proportional to the oxygen level of the surrounding water (see below). The oxygen level at which an oxyregulator shifts to oxyconformity is called the critical oxygen tension (Pcrit). The Pcrit must, however, not be considered a constant value, because it can be affected by a lot of factors. The most prominent of these factors are temperature and salinity. Therefore, the effect of hypoxia on the Pcrit will depend on the temperature and salinity at which it occurs. As a consequence an oxyregulators physiological ability to keep constant oxygen consumption and thereby normal activity (and behavior) will not only be dependent on the degree of hypoxia but also on the temperature and salinity. This highlights that the effect of hypoxia on marine animals is not only a matter of the severity of the hypoxia.
|Anvendte metoder:||Intermittent respirometry|
|Keywords:||Hypoxia, oxygen consumption, temperature, salinity, marine invertebrates, marine invertebrates|