Influence of ambient oxygen on the swimming performance of goldfish and rainbow trout

1968 ◽  
Vol 46 (4) ◽  
pp. 647-653 ◽  
Author(s):  
Methil Narayanan Kutty

The influence of ambient oxygen concentrations on sustained swimming effort (less than four body lengths (L.)/second, fish approximately 20 cm long) was tested in goldfish acclimated to two levels of ambient oxygen, 95 and 15% air saturation, and in rainbow trout acclimated to 95% air saturation only. The acclimations and tests were done at 20 °C in the case of goldfish and 15 °C in the case of rainbow trout. Experiments were done in Blažka's activity apparatus.The swimming effort of goldfish acclimated to air saturation declined from 3 L./sec at about 2 p.p.m. of ambient oxygen to 1 L./sec at about 1 p.p.m.The swimming effort of rainbow trout acclimated to air saturation declined sharply from 4 L./sec at about 2.5 p.p.m. to 1 L./sec at 2 p.p.m. of oxygen.Goldfish acclimated to 15% air saturation were tested in two separate groups, namely those left overnight in the activity chamber and those tested within 7 hours after they were handled; results from both these groups did not show any marked difference from each other or from those of goldfish acclimated to high oxygen.Since acclimation to low oxygen does not indicate any change in the swimming effort–ambient oxygen relation in goldfish, it is possible that the oxygen response studied is mediated through a behavioral mechanism which does not involve those physiological aspects of respiratory metabolism which are influenced by acclimation to low oxygen.

1968 ◽  
Vol 25 (8) ◽  
pp. 1689-1728 ◽  
Author(s):  
Methil Narayan Kutty

The respiratory quotients (R.Q.) of goldfish and rainbow trout were measured at 20 and 15 C respectively under spontaneous and forced activity. In goldfish spontaneously active and acclimated to air saturation the R.Q. was 1.02 in ambient oxygen above 50% air saturation and rose to 1.94 below 25% air saturation. Rainbow trout under similar conditions displayed respective R.Q.'s of 0.96 and 1.4. The latter R.Q. could be sustained only for a short time. In both species the metabolic rate dropped at oxygen concentrations below 50% air saturation but spontaneous activity remained high. Goldfish acclimated to 15% air saturation displayed the same R.Q. as unacclimated fish and thus did not display any increase in anaerobic capacity. When forced to swim steadily in water above 50% air saturation both species showed an initial anaerobic phase. This phase was less marked in the rainbow trout and was followed by an aerobic steady state except that at low swimming speeds the goldfish appeared to continuously derive some energy anaerobically. At oxygen concentrations below 50% air saturation the R.Q. of goldfish increased with decreasing concentration during steady swimming. At the single level of steady swimming effort at which comparisons were made, the R.Q. of goldfish did not change with acclimation to 15% air saturation but the rate of oxygen consumption fell to about 50% of the value before acclimation. The rainbow trout was not acclimated to low oxygen for any test.


1961 ◽  
Vol 38 (2) ◽  
pp. 447-455
Author(s):  
R. LLOYD

1. A given reduction in the dissolved oxygen concentration of the water from the air-saturation value to a lower level increases the toxicity to rainbow trout of zinc, lead and copper salts, and of a mixture of monohydric phenols, to about the same extent. 2. The effect of a reduced oxygen concentration on the toxicity of ammonia solutions is greater than that found for the other four poisons; the extra increase can be accounted for by a theoretical calculation of the difference between the pH value of the bulk of the solution and that at the gill surface. 3. An hypothesis is presented to account for the effect of low oxygen concentrations on the toxicity of poisons to fish. It assumes that a given toxic effect is produced by a specified concentration of poison at the gill surface, and suggests that this concentration is governed not only by the concentration of poison in the bulk of the solution but also by the velocity of respiratory flow.


1939 ◽  
Vol 16 (3) ◽  
pp. 363-373 ◽  
Author(s):  
C. A. WINGFIELD

1. The oxygen consumption of normal and gill-less nymphs of the mayflies Baetis sp., Cloeon dipterum and Ephemera vulgata has been measured at various oxygen concentrations. 2. It has been found that over the complete range of oxygen concentrations studied, the tracheal gills do not aid oxygen consumption in Baetis sp. In Cloeon dipterum, at all oxygen concentrations tested, no gaseous exchange takes place through the gills; at low oxygen concentrations, however, the gills function as an accessory respiratory mechanism in ventilating the respiratory surface of the body and so aid oxygen consumption. In Ephemera Vulgata the gills aid oxygen consumption even at high oxygen concentrations. In this species the gills may function both as true respiratory organs and as a ventilating mechanism. 3. It is shown that the differences in gill function can be related to the oxygen content of the habitat of each species.


1996 ◽  
Vol 62 (7) ◽  
pp. 2427-2434 ◽  
Author(s):  
J Krooneman ◽  
E B Wieringa ◽  
E R Moore ◽  
J Gerritse ◽  
R A Prins ◽  
...  

2016 ◽  
Vol 13 (6) ◽  
pp. 1977-1989 ◽  
Author(s):  
Helena Hauss ◽  
Svenja Christiansen ◽  
Florian Schütte ◽  
Rainer Kiko ◽  
Miryam Edvam Lima ◽  
...  

Abstract. The eastern tropical North Atlantic (ETNA) features a mesopelagic oxygen minimum zone (OMZ) at approximately 300–600 m depth. Here, oxygen concentrations rarely fall below 40 µmol O2 kg−1, but are expected to decline under future projections of global warming. The recent discovery of mesoscale eddies that harbour a shallow suboxic (< 5 µmol O2 kg−1) OMZ just below the mixed layer could serve to identify zooplankton groups that may be negatively or positively affected by ongoing ocean deoxygenation. In spring 2014, a detailed survey of a suboxic anticyclonic modewater eddy (ACME) was carried out near the Cape Verde Ocean Observatory (CVOO), combining acoustic and optical profiling methods with stratified multinet hauls and hydrography. The multinet data revealed that the eddy was characterized by an approximately 1.5-fold increase in total area-integrated zooplankton abundance. At nighttime, when a large proportion of acoustic scatterers is ascending into the upper 150 m, a drastic reduction in mean volume backscattering (Sv) at 75 kHz (shipboard acoustic Doppler current profiler, ADCP) within the shallow OMZ of the eddy was evident compared to the nighttime distribution outside the eddy. Acoustic scatterers avoided the depth range between approximately 85 to 120 m, where oxygen concentrations were lower than approximately 20 µmol O2 kg−1, indicating habitat compression to the oxygenated surface layer. This observation is confirmed by time series observations of a moored ADCP (upward looking, 300 kHz) during an ACME transit at the CVOO mooring in 2010. Nevertheless, part of the diurnal vertical migration (DVM) from the surface layer to the mesopelagic continued through the shallow OMZ. Based upon vertically stratified multinet hauls, Underwater Vision Profiler (UVP5) and ADCP data, four strategies followed by zooplankton in response to in response to the eddy OMZ have been identified: (i) shallow OMZ avoidance and compression at the surface (e.g. most calanoid copepods, euphausiids); (ii) migration to the shallow OMZ core during daytime, but paying O2 debt at the surface at nighttime (e.g. siphonophores, Oncaea spp., eucalanoid copepods); (iii) residing in the shallow OMZ day and night (e.g. ostracods, polychaetes); and (iv) DVM through the shallow OMZ from deeper oxygenated depths to the surface and back. For strategy (i), (ii) and (iv), compression of the habitable volume in the surface may increase prey–predator encounter rates, rendering zooplankton and micronekton more vulnerable to predation and potentially making the eddy surface a foraging hotspot for higher trophic levels. With respect to long-term effects of ocean deoxygenation, we expect avoidance of the mesopelagic OMZ to set in if oxygen levels decline below approximately 20 µmol O2 kg−1. This may result in a positive feedback on the OMZ oxygen consumption rates, since zooplankton and micronekton respiration within the OMZ as well as active flux of dissolved and particulate organic matter into the OMZ will decline.


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