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1.
A study of factors limiting crab densities in closed blue crab Callinectes sapidus shedding systems was conducted using scaled down experimental units. Nitrification beds, activated carbon, dolomite and plants were used to maintain water quality. Nitrite (NO2N) was found to be the most critical toxic element accumulating in the system as a result of the nitrification process. Concentrations of approximately 20 mg liter?1 NO2N and above caused increased mortality in intermolt crabs. Mortality in molting crabs was observed at concentrations as little as 2 mg liter?1 NO2N. Dissolved oxygen (DO) was identified as the factor limiting the efficiency of the nitrification beds. As DO concentrations decreased, the rate of nitrification slowed, apparently causing nitrification to be inhibited at the nitrite to nitrate conversion step. As nitrite concentrations increased, high mortalities resulted, further increasing the loading in the systems and depressing DO concentrations, due to the high BOD exerted by the dead crabs. Elevated crab populations were maintained in the systems when aeration and flow increases were supplied to the nitrification beds.  相似文献   

2.
Effects of density and water change frequency on food intake and conversion as well as surfacing activity were studied in an obligate air-breathing fish, Channa striatus. An increase in density and decrease in water change frequency resulted in significant (i) reduction in food consumption, (ii) decline in rate and efficiency of conversion, and (iii) increase in surfacing frequency. These adverse effects are due to the accumulation of CO2 and ammonia and to a decline in the partial pressure of oxygen (pO2). The critical levels of CO2 and ammonia for C. striatus are 8.2 and 0.92 mg/l respectively; above these levels the frequency of surfacing to obtain atmospheric oxygen and/or to release CO2 increased remarkably. pO2 acts not as an independent factor but adds to the toxic effects of the metabolites.  相似文献   

3.
The mudskipper Scartelaos gigas is expected to experience repeated severe hypoxia in its environment. Hence, we conducted experiments on the oxygen consumption rate (OCR) and OCR rhythm of S.?gigas at low graded dissolved oxygen (DO) levels, without access to atmospheric air, to estimate its tolerance to hypoxia. A dominant circadian OCR rhythm was observed at the control DO level of 6.96?C7.78?mg?O2/l. This rhythm was unchanged until 2.06?mg?O2/l, even though the amplitude of the peak was somewhat diminished at 2.06?C2.87?mg?O2/l. The OCR rhythm amplitude was greatly diminished and the rhythm period was also greatly changed at 1.23?C2.05?mg?O2/l. Nevertheless, the mean OCR (0.11?ml?O2/g WW/h) at 1.23?C2.05?mg O2/l was similar to that of control (0.12?ml O2/g?WW/h). Thus, the weakness and period change of the OCR rhythm kept the metabolic rate level similar to control. These results suggest that S.?gigas does not have normal metabolic activity at 1.23?C2.05?mg O2/l but barely manages to endure this DO level as a pre-emergency state. This species could be inhibited under a longer maintenance period at DO level of 1.23?C2.05?mg?O2/l or still lower. It can be concluded that S.?gigas is quite tolerant to low DO environment and may have a specific strategy for such tolerance.  相似文献   

4.
Summer stratification often leads to large areas of hypolimnetic hypoxia in lakes and reservoirs. These areas of hypoxia alter fish behaviours and distributions as well as restrict access to valuable prey resources, yet few studies have examined foraging behaviour of fish in response to low dissolved oxygen (DO) concentrations. We observed foraging behaviour of juvenile largemouth bass, Micropterus salmoides, in response to varying DO concentrations in tanks that simulated a stratified lake water column during the summer: 28°C oxygenated epilimnion, 15°C deoxygenated hypolimnion. Compared with saturated concentrations (8.0–9.0 mg/L), hypolimnetic oxygen concentrations of 3.0 mg/L and 1.5 mg/L resulted in a drastic decrease in prey consumption, handling efficiency and time spent below the thermocline mainly due to avoidance behaviour of hypoxic conditions. However, we found at high hypolimnetic prey densities, individual fish were more willing to venture into reduced oxygen concentrations. Several unique behaviours including transporting prey above the oxycline for consumption, aquatic surface respiration and gill flaring were employed by largemouth bass foraging in low oxygen environments. Reduced hypolimnetic oxygen concentrations may influence and alter feeding strategies, especially for fish that rely on benthic prey resources.  相似文献   

5.
Nitrite was about 55 times more toxic to milkfish juveniles in fresh water than in 16% brackish water: the 48-h median lethal concentrations were 12 mg NO2N/l (95% confidence limit=7.4–19.6) and 675 mg NO2N/l (95% confidence limit = 435.8–1,045.4) respectively. Methemoglobin levels were higher for a given concentration of nitrite in milkfish kept in fresh water than in the brackish water. Methemoglobin decreased to a normal level within 24–26 hours of the removal of nitrite.  相似文献   

6.
We studied the physiological status of juvenile turbot (Scophthalmus maximus L.) under severe hypoxia (1 and 2 mg/L dissolved oxygen, DO), hypoxia (3 and 5 mg/L DO), hyperoxia (11 and 14 mg/L DO) and normoxia (7 mg/L DO, control) conditions. The respiratory rates, haematology parameters, acid–base balance status and gill structure were analysed to find the effects of different DO concentration on turbot. Fish mortality was only observed under severe hypoxia conditions. Severe hypoxia caused an increase in respiratory rates and red blood cell counts, as well as an increase in haemoglobin and haematocrit levels in the fish. In fish exposed to hypoxia conditions, the respiratory rate increased overall as the DO concentration decreased. Lower pCO2 and HCO3? levels led to a high blood pH, while the pO2 remained stable. In hyperoxia groups, respiratory rate decreased as the DO concentration increased. The levels of pCO2 and HCO3? significantly increased (P < 0.05), while the pO2 level and blood pH did not change obviously. The gill structure was damaged after prolonged exposure to hyperoxia, but no obvious damage was found in hypoxia groups. The fish that survived the hypoxia or hyperoxia treatment were able to restore the structural integrity of the gills after 14 days' recovery. The results suggest that juvenile turbots can tolerate a wide range of DO concentrations. However, even mild hyperoxia condition (11 mg/L DO), which is widely used in fish culture, has adverse effects on juvenile turbot physiology.  相似文献   

7.
Consecutive failure of the improved extensive shrimp farming system has deterred the economy of some coastal areas in Vietnam. To investigate pond physico‐chemical characteristics, a monitoring scheme was performed in the Cai Nuoc district of Southern Vietnam. Results show that the system was not optimal for shrimps. While ponds were not contaminated by organic loadings or major nutrients (N, P) and salinity and pH were most optimal for shrimp, more than 37% of dissolved oxygen (DO) measurements were lower than recommended. In the early morning hours, DO measurements were even much lower (0.84–2.20 mg L?1). Sulphate (SO42?) concentrations were most within the acceptable range. Total suspended solids (TSS) were above the acceptable limit (<50 mg L?1). Iron, alkalinity and hydrogen sulphide were also higher than recommended. Pond sediment was anaerobic (redox potential ?422 to ?105 mV) and contained high amounts of organic matter (9.84–21.96%). Lethal DO levels, high TSS and anoxic sediment are the drawbacks in this system. Suggested measures to improve pond conditions are (1) allowing sedimentation before filling culture ponds, (2) covering dikes, (3) including no‐culture breaks between shrimp crops, (4) drying pond bottom, (5) removing sediment and (6) controlling pond's vegetation.  相似文献   

8.
The objective of this study was to determinate the lethal concentration of dissolved oxygen (DO) over 96 hours of exposure (LC50–96h) for diploid and triploid jundia Rhamdia quelen juveniles. Diploid and triploid fish weighing approximately 4 g were subjected to DO concentrations varying between 0.4 and 1.3 mg O2 L?1; water temperature was maintained at 27?°C and pH at 6.3. The LC50–96h for diploids of Rhamdia quelen was 0.535 mg O2 L?1, while the value obtained for triploids was 6% greater. These results demonstrated that triploids of Rhamdia quelen juveniles have greater sensitivity to hypoxia compared to diploids.  相似文献   

9.
The pollution loading from Øxna Bruk, a trout farm with an annual fish production of 200–250 tons, and the influence on the water quality of River Figgjo, a mediumsized watercourse, was studied. The feed used was dry pellets. The loadings were estimated to be 0.3–0.8 g N/kg fish.24h; 0.05 g P/kg fish.24h; and 1.6–4.6 g O/kg fish.24 h as BOD7 (biochemical oxygen demand, 7 days). As a result of the fish farming activities, moderate chemical alterations were registered in the river downstream of the farm at low river flow: decreased oxygen concentration (÷ 1 mg/l) and increased concentrations of total-N (+ 0.2 mg N/l), NH3 + NH4+ (+ 0.1 mg N/l), total-P (+ 0.03 mg P/l) and ortho-P (+ 0.02 mg P/l). Compared with the receiving water, BOD7 increased maximally 1 mg O/l downstream of the farm. The salmonid stocks in the river were not affected by the effluents from the trout farm.  相似文献   

10.
A variety of parameters associated with breathing and feeding of silver carp were measured in response to declines in dissolved oxygen (DO) levels when the fish were fed microalgae Padorina morum (PM group) and Chlorella ellipsoidea (CE group), respectively, to explore the relationship between breathing and feeding while filtering microalgae particles at different DO levels. The results indicated that (i) respiratory frequency (fR) of the fish in CE group were higher significantly than those in PM group at DO levels of 0.98–7.49 mg/L (P < 0.05); respiratory stroke volume (VS.R), gill ventilation (VG) and VG/VO2 the fish in two groups began to increase sharply while DO levels declined to below 4.04 mg/L (P < 0.05); oxygen extraction efficiency (EO2) of the fish in two groups increased significantly with decline of DO levels from 7.49 mg/L to 0.98 mg/L (P < 0.05); (ii) the infiltration rate (FR) and filtering efficiency (E) of the fish in two groups began to decrease significantly while DO levels declined to below 4.04 mg/L (P < 0.05); clearance rate (CR) of fish in PM group was sixfold higher than that in CE group at DO levels of 0.98–7.49 mg/L (P < 0.05). In addition, antifiltering response appeared at DO levels of 2.21 mg/L and 0.98 mg/L in both groups. This study indicated that ‘filtration effect’ is dominant when the fish filter algae particles larger than its gill raker gaps, while the ‘food sinking effect’ is dominant when the fish filter algae particles smaller than its gill raker gaps.  相似文献   

11.
《Aquacultural Engineering》2008,38(3):234-251
Convenient, economical, and reduced labor fish harvest and transfer systems are required to realize operating cost savings that can be achieved with the use of much larger and deeper circular culture tanks. To achieve these goals, we developed a new technology for transferring fish based on their avoidance behavior to elevated concentrations of dissolved carbon dioxide (CO2). We observed this behavioral response during controlled, replicated experiments that showed dissolved CO2 concentrations of 60–120 mg/L induced rainbow trout (Oncorhynchus mykiss) to swim out of their 11 m3 “growout” tank, through a transfer pipe carrying a flow with ≤23 mg/L dissolved CO2, into a second 11 m3 “harvest” tank. The research was conducted using separate groups of rainbow trout held at commercially relevant densities (40–60 kg/m3). The average weight of fish ranged from 0.15 to 1.3 kg during the various trials. In all trials that used a constant flow of low CO2 water (≤23 mg/L) entering the growout tank from the harvest tank, approximately 80–90% of the fish swam from the growout tank, through the transfer pipe, and into the harvest tank after the CO2 concentration in the growout tank had exceeded 60 mg/L. The fish that remained in the growout tank stayed within the area of relatively low CO2 water at the entrance of the transfer pipe. However, the rate of fish transfer from the growout tank to the harvest tank was more than doubled when the diameter of the transfer pipe was increased from 203 to 406 mm. To consistently achieve fish transfer efficiencies of 99%, water flow rate through the fish transfer pipe had to be reduced to 10–20% of the original flow just before the conclusion of each trial. Reducing the flow of relatively low CO2 water near the end of each fish transfer event, restricted the zone of relatively low CO2 water about the entrance of the fish transfer pipe, and provided the stimulus for all but a few remaining fish to swim out of the growout tank. Results indicate that the CO2 avoidance technique can provide a convenient, efficient, more economical, and reduced labor approach for fish transfer, especially in applications using large and well mixed circular culture tanks.  相似文献   

12.
为明确刺参养殖池塘中微孔增氧的效果以及增氧管的布设间距、增氧时间对水体溶氧的影响,研究测定了在夏季刺参养殖池塘一个增氧周期内(每天23:00—7:00增氧8 h,7 d一个周期)水体中溶氧(DO)、亚硝酸盐氮(NO_2~--N)、COD的变化。结果显示:连续充气增氧的8 h内DO持续增加,增氧2 h上升速率缓慢,增氧2~6 h上升速率迅速提高,增氧6~8 h上升速率下降,连续充气8 h能够显著改变夜间溶氧降低现象;增氧7 d时间内,NO_2~--N和COD持续下降,分别由0.025 mg/L下降到0.014 mg/L、18.46 mg/L下降到14.15 mg/L。对充氧管道不同距离处DO的测定结果表明,距离增氧管1~2 m处DO较高,3~4 m处缓慢下降,与1~2 m处差异不显著(P0.05),DO保持在5.22 mg/L左右,距离5 m以上时DO下降速度较快,与1~2 m处差异显著(P0.05)。研究表明:微孔增氧可以明显增加水体DO,减少COD、NO_2~--N;微孔增氧机充氧时间6~8 h效果较好;微孔增氧管之间的布设距离在6~8 m可以实现高效增氧。  相似文献   

13.
Bioassays in static water (mean ± SD; temperature, 20–22 C; pH, 8.2–8.4; alkalinity, 205 ± 10 mg/L CaCO3; total hardness, 220 ± 10 mg/L CaCO3) were used to determine median lethal concentrations (LC50) of un-ionized ammonia (NH3-N) for striped bass Moronc saxatilis and hybrid striped bass M. saxatilis × M. chrysops. The 96 h LC50 for striped bass was 1.01 ± 0.24 mg/L NH3-N3 and was significantly higher than the LC50 for hybrid striped bass (0.64 ± 0.05 mg/L NH3-N). The effects of sublethal ammonia were evaluated after fish were exposed for 96 h to 0.0, 0.25, or 0.5 mg/L NH3-N or to additional exposure to oxygen depleted water (about 2.0 mg O2/L). Plasma ammonia of striped hass did not change as sublethal ammonia increased, but exposure to oxygen depletion caused a decrease in plasma ammonia. In contrast, plasma ammonia of hybrid striped bass increased as environmental ammonia increased, and increased further after exposure to oxygen depletion. Plasma cortisol levels of striped bass were significantly higher and more variable than cortisol levels of hybrid striped bass; additional exposure to oxygen depletion increased this variability, but these responses may be due to the stress of handling and confinement. Mean differences also existed between species for hemoglobin and hematocrit, while differences in variability occurred for osmolality and oxygen depletion rates. Striped bass tolerated ammonia better than hybrid striped bass but were more susceptible than hybrid striped bass to the additional stress of oxygen depletion. Most changes in physiological characteristics were relatively independent of environmental ammonia, but they were affected by oxygen depletion challenge.  相似文献   

14.
Two commercial shrimp farms in south Texas were evaluated for influent and effluent water quality from June to October 1994. The intensive farm, Taiwan Shrimp Village Association (TSV) had an average annual yield of 4630 kg ha?1 while the semi‐intensive farm, Harlingen Shrimp Farm (HSF), had a yield of 1777 kg ha?1. The study had three objectives: (1) to compare influent and effluent water from the intensive and semi‐intensive shrimp farms, (2) to show which effluent water‐quality indicators exceeded allowable limits, (3) to indicate inherent problems in farms operated with water exchange and summarize how findings from this study led to changes in farms' management that limited potential negative impact on receiving streams. Water samples were collected and analysed twice a week for the TSV farm and once a week for the HSF farm. Samples were analysed for dissolved oxygen (DO), salinity, pH, ammonia‐nitrogen (NH3‐N), nitrite‐nitrogen (NO2‐N), nitrate‐nitrogen (NO3‐N), total phosphorus (TP), total reactive phosphorus (TRP), five‐day carbonaceous biochemical oxygen demand (cBOD5), total suspended solids (TSS) and settleable solids (SettSols). Most of the effluent constituents showed fluctuations throughout the sampling period often related to harvest activity. Effluent pH at TSV was lower than influent values but within the regulatory requirements set by Texas Commission of Environmental Quality (TCEQ), formerly known as Texas Natural Resource Conservation Commission (TNRCC). HSF effluent pH values were higher than its influent, but still within TCEQ limits. Effluent DO mean levels were generally below the regulatory daily mean requirement, with values at TSV often below those for influent. Effluent nutrient concentrations and net loads were generally higher at the intensive shrimp farm, with NH3‐N mean concentrations above the daily mean set by the TCEQ on several occasions. Effluent TSS concentrations were higher than influent for both farms, with daily mean values above the TCEQ limit. The two farms presented similar TSS concentrations despite their different stocking densities. However, TSS total net load and net load per hectare were higher at the intensive farm. The semi‐intensive farm presented higher cBOD5 concentrations and net loads despite its lower stocking density, with daily mean values above the TCEQ limit. The cBOD5 net load at TSV presented negative values indicating higher load at the influent than at the effluent. Analyses showed no evidence of self‐pollution between influent and effluent at the two farms. The high feed conversion ratio (FCR) values (2.3 and 2.7 for the intensive and the semi‐intensive farm respectively) suggest that better feed management is needed to reduce nutrient and solid net loads release from the two farms. The data obtained from this study resulted in several modifications in design and management of the two farms that reduced the potential negative impact on receiving streams. A brief summary of the improvement in selected effluent water‐quality indicators at the intensive shrimp farm is provided.  相似文献   

15.
We describe a computer-operated recirculating respirometer system (ca. 140 L water) with six respirometer chambers and a reference chamber (L × W × H: 26 cm × 12 cm × 20 cm; volume 6.24 L) that simulates diurnal dissolved oxygen (DO) fluctuations normally occur in aquaculture ponds. A gas-mixing device, “Digamat” proportionately dissolves gaseous nitrogen and oxygen (and if desired, carbon dioxide) in water to achieve DO levels from 1.0 to 40.0 kPa (0.3–14.0 mg L?1) at different temperatures. A series of computer-operated valves sequentially allow water from respirometer chambers to a single oxygen probe to measure DO concentration. Oxygen consumptions of fish as the differences in DO concentrations between respirometer and reference chamber are used to calculate different metabolic rates (standard, routine, and active), and critical (P c) and recovery (P r) oxygen tensions of individually reared unfed and fed fish. An experiment was conducted to evaluate the ability of the system to measure metabolic parameters for individually reared Nile tilapia (Oreochromis niloticus L.) at three temperatures (low: 22.5, optimum: 27.5 and high: 33.5 °C). The fed fish had significantly higher P c and P r values at optimum and high temperatures than unfed fish. At low and high temperatures, both fed and unfed fish had higher P c and P r than at optimum temperature. The standard metabolic rate was significantly higher at higher temperatures (44.9, 51.7, and 77.7 mg O2 kg?0.8 h?1 at 22.5, 27.5, and 33.5 °C, respectively).  相似文献   

16.
Previous research and experience has linked elevated dissolved carbon dioxide (CO2) to reduced growth performance, poor feed conversion, and a variety of health issues in farm-raised fish, including Atlantic salmon Salmo salar. Supplemental control measures in water recirculation aquaculture systems (RAS) to reduce CO2 accumulation, however, such as increased water pumping to decrease tank hydraulic retention time, can represent significant costs for operators. We exposed post-smolt S0 Atlantic salmon (197 ± 2 g, 423 days post-hatch) to either high (20 ± 1 mg/L) or low (8 ± <1 mg/L) dissolved CO2 in six replicated freshwater RAS for 384 days to investigate differences in performance and health as the salmon were grown to harvest size. All RAS were operated at moderate water exchange rates (1.0% of the total recirculating flow), a 24-h photoperiod was provided, fish were fed to satiation, and densities were maintained between 40 and 80 kg/m3. Over the study period, dissolved oxygen was kept at saturation, mean water temperature was 14.1 ± 0.1 °C, and alkalinity averaged 237 mg/L as CaCO3. At study’s end, no significant differences in fish weight (high CO2 mean weight = 2879 ± 35 g; low CO2 mean weight = 2896 ± 12 g), feed conversion ratio (1.14 ± 0.12 vs. 1.22 ± 0.13, respectively), or thermal growth coefficient (1.45 ± 0.01 vs. 1.46 ± 0.01, respectively), were observed. No significant differences in survival (high CO2 mean survival = 99.1 ± 0.4%; low CO2 mean survival = 98.9 ± 0.3%) or culls due to saprolegniasis (3.5 ± 1% vs. 3.0 ± 1%, respectively) were determined, and no nephrocalcinosis was observed through histopathological evaluation. Blood gas and chemistry evaluation revealed higher pCO2, bicarbonate, and total CO2, and lower chloride and glucose, in the high CO2 cohort. Molecular analyses of gill enzyme regulation showed significantly higher expression of Na+/K+ ATPase α1a in high CO2 fish at 3-weeks post-challenge, indicating physiological adaptation to the higher CO2 environment without any noticeable long-term impacts on health or performance. Overall, the results of this study suggest that, at 237 mg/L as CaCO3 mean alkalinity, post-smolt Atlantic salmon can be raised in freshwater RAS to harvest size with up to 20 mg/L CO2 without significantly impacting fish health and performance.  相似文献   

17.
During a 1-year operation of a warm water recycling system (salinity about 8‰) sufficient water quality was maintained under high stocking density conditions using Tilapia and the European eel as potential candidates for intensive farming. The final fish: water ratio was 1 : 23 (or 43.5 g fish per 1 water) for the whole experimental culture unit. The total water volume of the system was about 5 m3. The water treatment unit held 52% of the total volume, whereby 46% was available for fish culture. Combined biological (trickling filter with Hydropack-foil) and chemical (ozonation) water treatment proved to be useful to meet water quality requirements under these rearing conditions. After an initial conditioning period of the biofilter, BOD varied from 4.5 to 6.0 mg O2/l, ammonium levels were maintained at less than 1 mg/l and nitrite concentrations averaged 1 mg/l. The average efficiency (oxidation rate) of the biofilter for NH4+-and NO2?-oxidation was 31% and 13.2%, respectively. The pH was stabilized slightly above 7.0 when a denitrification unit was connected to the system. Nitrate concentration of the system levelled of between 200 and 400 mg/l and was regulated by the addition of an electron donator (first glucose solution, then methanol) to the denitrification unit; the elimination rate averaged 50% with a maximum of 98%. High nitrite levels were avoided by ozone treatment of the recycled water. The accumulation of low-biodegradable substances was also successfully counteracted by ozonation. Fish growth rates of about 30% per month at high stocking densiteis were reached for Tilapia at a fish: water ratio of 1 : 4.6 (217 g fish per 1 water), indicating that a combination of biological water treatment and ozonation supports intensive fish culture in a closed aquaculture system.  相似文献   

18.
Dissolved oxygen concentration (DO), water temperature and wind speed were monitored overnight at prawn (Macrobrachium rosenbergii) ponds of Amorient Aquafarm Inc. (Kahuku, Oahu) and at Brigham Young University-Hawaii (Laie, Oahu) from June to November 1985. A new model, the whole pond respiration-diffusion (WPRD) model, was developed to predict pond DO at dawn. The two components comprising the model were whole pond respiration and diffusion. Model inputs included a measurement of pond DO and water temperature at dusk, another DO and temperature measurement made several hours after the dusk measurement, and an estimate of the average wind speed for the night. For a lag of 3 h between the dusk and second DO measurement, the mean absolute deviation of the predicted dawn DO from the observed dawn DO was 0·40 mg O2 liter−1 (standard error of mean = 0·8 mg O2 liter−1), based on 40 verification trials. The WPRD model performed equally well for both calm nights (wind speed < 0·3 m s−1) and for relatively windy nights (wind speed > 7 m s−1).  相似文献   

19.
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20.
Transportation of yellowtail kingfish (Seriola lalandi Valenciennes) juveniles from hatchery to on‐growing operations in New Zealand exposes the fish to significantly elevated carbon dioxide (CO2) concentrations. Experiments were undertaken to assess metabolic and haematological stress responses after a 5‐h period of hypercapnia, followed by recovery in normocapnia. Mortality was low (0.5%) and secondary stress indices (blood glucose, blood lactate, muscle pH and muscle lactate) remained largely unchanged during a simulated transportation and recovery, despite juveniles being exposed to CO2 concentrations as high as 75 mg CO2 L?1 (38 mm Hg partial pressure). There was some haematological disturbance midway through simulated transports, where water was maintained at fixed CO2 concentrations of 8 and 50 mg CO2 L?1 (4 and 26 mm Hg respectively). Persistent erythrocyte swelling continued during transport at 50 mg CO2 L?1, whereas at 8 mg CO2 L?1, haematological variables had returned to control levels. There was no mortality recorded for any of the treatments, and haematological variables were restored to pre‐manipulation levels after 31 h. The results indicated that juvenile yellowtail kingfish have a robust physiology and can cope with the stressors imposed by acute exposure to moderate to high levels of CO2 associated with live transport.  相似文献   

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