FIG 1.

Rates of N₂O emission from the shrimp Litopenaeus vannamei and its dissected guts incubated in filtered rearing water at 28°C. Complete animals were incubated under oxic conditions, dissected complete guts (i.e., gut contents plus gut wall) were incubated under oxic and anoxic conditions, and gut walls were incubated under anoxic conditions. Complete guts were also incubated under anoxic conditions with 10% acetylene (C₂H₂), which inhibits the last step of denitrification; the resulting N₂O production indicates total denitrification. Means ± standard deviations are shown (n = 4 to 15). Treatments that share the same letter are not significantly different (see the text for details on statistics).