Effects of the Po₂ on surfacing activity and food utilization in the air-breathing perch Anabas scandens

Abstract

Fed Anabas seandens surfaced 555 times, swimming 278 m/day in non-aerated walcr (Po₂: 66 rnm Hg)' and 855 limes, travelling 428 m/day in aerated watcr (Po₂: 147 mm Hg). Consumption, assimilation, production and metabolism of either series averaged 22, 18, 5 and 13 mg dry substance/g live fish·day, respeclively. The high Po₂ elevated metabolism, increased surfacing and swimming activities but failed 10 alter food utilization. Culturing A. scandens in aerated waters offers no special advantage. Starved fish in non-aerated and aerated waters surfaced 330 times and swam 164 m/day, expending 1.5 mg/g ·day.