The air-breathing striped snakehead Channa striata is an important fish in Asian aquaculture with high market value.
C. striata is typically cultured in simplemud ponds, where it is frequently exposed to severe hypoxia throughout the
growth cycle. Here, the partitioning of oxygen uptake during digestion, and the size of the postprandialmetabolism
(specific dynamic action or SDA), were studied in hypoxic and normoxic snakehead (30 and 150 mm Hg, respectively).
The ventilatory response to hypoxia was investigated separately. When fish were fed 5% of their body
mass as fish fillet, total MO2 increased to 2–2.5 times above the standard metabolic rate. PeakMO2 was significantly
lower in hypoxic fish (253 mg O2 kg−1 h−1) compared to normoxic fish (322 mg O2 kg−1 h−1), and the total
SDA was also significantly lower in hypoxia. These results show that despite C. striata being an air-breather, the
limited aquatic respiration in severe hypoxia impairs its general performance during digestion. These results have
implications for the aquaculture practices of C. striata, and probably other species within this genus, because increased
oxygen availability in the water would be expected to increase their digestion efficiency. Further studies
are needed to understand the underlying mechanisms, and to determine optimal aeration in these aquaculture
ponds.