The effect of hypoxia on locomotor performance and behaviour during escape in Liza aurata

Abstract

Escape performance was investigated in the golden grey mullet Liza aurata exposed to various levels of oxygen: >85 (i.e. normoxia), 50, 20 and 10 % air saturation. Since the golden grey mullet performed aquatic surface respiration when air saturation approached 15-10 %, escape performance was tested at 10 % air saturation with and without access to the surface (10 % S and 10 % C, respectively). Various locomotor and behavioural variables were measured, such as cumulative distance, maximum swimming speed, acceleration, responsiveness (per cent of responding fish), response latency and directionality. Golden grey mullet showed a decrease in responsiveness when the oxygen level was reduced to 10 % air saturation, whether the surface access was obstructed or not. Hypoxia did not have any effect on the response latency. Cumulative distance and maximum swimming speed over a fixed time were significantly different between normoxic conditions and 10 % C, while no differences were found in maximum acceleration. While the fish's 'C-bend' was mainly directed away from the stimulus in normoxia, the proportion of away and towards 'C-bend' was random when the oxygen was 20 % air saturation. This suggested an impairment of the left-right discrimination at the initiation of the fast start. Hypoxia affected golden grey mullet escape performance mainly through an impairment of responsiveness and directionality, while locomotor performance was affected only in severe hypoxia when the surface was obstructed. The study showed that, in addition to forcing the fish to the surface as shown by previous studies, hypoxia may also reduce fish elusiveness facing a predator by directly impairing its escape performance. # 2005 The Fisheries Society of the British Isles

Effect of temperature and dissolved oxygen on swimming performance in crucian carp

“…Changes in DO showed no significant effect on U fast, which was consistent with previous studies on European sea bass Dicentrarchus labrax and golden grey mullet Liza aurata (Lefrançois et al 2005, Lefrançois & Domenici 2006. The absence of a DO effect on U fast is easily understood because the faststart movement occurs within seconds and is mainly limited by ATP and PCr in muscle tissues, and thus may be largely independent of DO levels.…”

“…U crit ) than the other 2 swimming performances. A depressed U crit under lower temperatures and DO concentrations has been widely documented (Pang et al 2011, Zhao et al 2012; however, little work has been performed on U fast and U cat (Lefrançois et al 2005, Lefrançois & Domenici 2006, Wang et al 2012. Furthermore, no study has investigated the effects of different environmental changes on the different swimming capacities within a single fish species.…”

Physiological tradeoffs may underlie the evolution of hypoxia tolerance and exercise performance in sunfish (Centrarchidae)

“…2A). The limiting effect of hypoxia on aerobic exercise capacity has been documented in many other species (Lefrançois et al, 2005;Dutil et al, 2007), so the relative insensitivity of pumpkinseed and bluegill to hypoxia is somewhat surprising and may help these species to remain active if their environment becomes mildly hypoxic. Largemouth bass were clearly distinguished from other species by having the highest capillarity in the swimming muscle, a feature that should have a strong influence on muscle performance and aerobic capacity (Wagner, 1996;Scott and Milsom, 2006).…”

Preparing for escape: anti-predator posture and fast-start performance in gobies

“…A strong stimulus (SS) consisting of a plastic cylinder (38.3 g, 6.4 cm diameter, 24 cm) was released from 1.23 m above the water surface by switching off an electromagnet, and fell into one of two grey plastic pipes (10.9 cm outer diameter, positioned on either side of the tank, 0.44 m from the tank centre), ending 10 mm above the water surface, to prevent the goby from seeing the stimulus before it made contact with the water surface (Lefrançois et al, 2005). An opening in the pipes allowed the camera to record when the SS hit the water so that escape latency could be measured.…”