Swimming performance, oxygen consumption and excess post‐exercise oxygen consumption in adult transgenic and ocean‐ranched coho salmon

Abstract

Routine oxygen consumption (Mo2) was 35% higher in 1 day starved and 21% higher in 4 day starved adult transgenic coho salmon Oncorhynchus kisutch relative to end of migration ocean‐ranched coho salmon. Critical swimming speed (Ucrit) and Mo2 at Ucrit (Mo2max) were significantly lower in 4 day starved transgenic coho salmon (1·25 BL s−1; 8·79 mg O2 kg−1 min−1) compared to ocean‐ranched coho salmon (1·60 BL s−1; 9·87 mg O2 kg−1 min−1). Transgenic fish swam energetically less efficiently than ocean‐ranched fish, as indicated by a poorer swimming economy at Ucrit (Mo2max). Although Mo2max was lower in transgenic coho salmon, the excess post‐exercise oxygen consumption (EPOC) measured during the first 20 min of recovery was significantly larger in transgenic coho salmon (44·1 mg O2 kg−1) compared with ocean‐ranched coho salmon (34·2 mg O2 kg−1), which had a faster rate of recovery.