Deep-Sea Physiological Study

A marine biologist investigated whether deep-sea shrimp (Acanthephyra purpurea) collected from oxygen minimum zones (OMZs) have a higher tolerance to hypoxic conditions compared to those collected from well-oxygenated surface-mixed layers. A matched-pairs design was used, pairing 20 shrimp from OMZs with 20 shrimp of similar mass from surface-mixed layers. The researcher measured the critical oxygen partial pressure ($P_{crit}$ in kPa) of each shrimp, which is the threshold oxygen level below which the shrimp can no longer maintain stable oxygen consumption. It was found that shrimp from OMZs had a significantly lower $P_{crit}$ than those from surface-mixed layers.