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1.
Cyanobacterium Spirulina (Arthrospira) platensis is a commercial product with high content of protein and other nutritional elements, serving as a source of nutrients for food, feed and pharmaceutical industry. Generally, CO2 gas bubbling method is a common method to supply carbon source for algae culture. However, in commercial situation where the CO2 supply is limited, alternative bicarbonate could be utilized as a substitute carbon source in Spirulina cultivation. In this study, the optimum culture method of ammonium bicarbonate supplementation in open raceway pond as carbon source was firstly investigated to avoid the inhibition effect of ammonium bicarbonate. The optimal conditions estimated by experimental results for S. platensis cultivation were set as following: (1) the addition of ammonium bicarbonate at each time must be <2.0 mmol L?1; (2) the addition rate of ammonium bicarbonate is in the range of 10–20 g m?2 day?1. Then, S. platensis were cultured in eight 800 m2 raceway ponds with fed‐batch addition of ammonium bicarbonate combined with sodium bicarbonate as carbon source. The results illustrated that ammonium bicarbonate addition not only did not show any adverse impact on productivity, chlorophyll and carotenoid content of S. platensis, but also significantly increased the protein content of S. platensis. With ammonium bicarbonate supplementation as carbon source in alkaliphilic Spirulina mass culture, the carbon utilization efficiency was dramatically increased to approximately 70% from 38.89%, and the carbon cost was reduced by approximately 57%. Therefore, ammonium bicarbonate can be applied as supplement of carbon source for alkaliphilic Spirulina culture.  相似文献   

2.
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   

3.
A feeding trial on yellow tail cichlid Pseudotropheus acei (Regan 1922) was undertaken to asses the effect of dietary Spirulina meal as a natural carotenoid source. Four experimental diets were formulated to progressively replace 0% (C), 2.5% (SP2.5), 5% (SP5) and 10% (SP10) of fish meal weight. Ten fish per tank (initial weight 3.75?±?0.02?g) were randomly distributed into twelve 80?l fiberglass tanks connected to a closed recirculation system (temperature 26.7?±?0.06°C). The diets were tested in triplicate for 12?weeks. The specific growth rate of fish fed all Spirulina diets were significantly higher compared to diet C. Feed intake (FI) tended to increase with dietary Spirulina level, and fish fed diet SP10 had significantly higher FI values compared to diet C. No significant differences in feed conversion ratio were observed among these groups. Although the protein efficiency ratio of fish fed diet C was lower than that of all Spirulina diets, no significant differences were observed among these groups (P?>?0.05). The total egg production and hatching rate (%) of eggs derived from all fish fed with Spirulina diets was significantly higher compared those from fish fed diet C. The yellow and blue coloration of yellow tail cichlid fed the diet containing Spirulina meal was enhanced and inclusion of dietary Spirulina meal was elevated carotenoids in skin. Results of the present study indicated that Spirulina meal has the potential to enhance the growth, reproductive performance and coloration on yellow tail cichlid.  相似文献   

4.
The effect of feeding Spirulina platensis on the growth, carcass composition, organoleptic quality, digestive enzyme activity and digestibility of common carp, Cyprinus carpio L., was studied through a culture trial lasting 120 days. Four experimental diets were employed by replacing fish meal protein from the standard diet at 25%, 50%, 75% and 100% through the incorporation of Spirulina. Another diet with Spirulina as the sole source of protein was also used. The final weight gain, specific growth rate, food conversion ratio and protein efficiency ratio of common carp were not affected by Spirulina supplementation. However, the diet with Spirulina as the sole source of protein resulted in better net protein retention. The muscle RNA:DNA ratio of fish fed Spirulina diets was higher than that of fish fed control diet. There was no significant difference in carcass moisture and protein content in the fish fed Spirulina diets as compared to fish-meal-based control diet. The carcass ash and fat contents were positively and negatively correlated with dietary Spirulina level, respectively. Organoleptic evaluation revealed no effect of Spirulina feeding on the quality of both raw and cooked fish. The gut digestive enzyme activity did not show any definite trend with respect to Spirulina supplementation. Spirulina improved the protein digestibility of the diets.  相似文献   

5.
Several studies investigated the usage of spirulina (Arthrospira platensis) in aquaculture as a functional dietary additive or plant proteins replacers; however, more efforts still needed to test its nano form inclusion in aquafeed. In this study, Nile tilapia (Oreochromis niloticus) fed dietary spirulina (A. platensis) nanoparticles (SNP) at 0 (control), 0.1, 1 and 10 g/kg diet while the fifth diet was mixed with 10 g/kg of the normal form of A. platensis as a positive control. The final weight (FW), weight gain (WG) and feed conversion ratio of fish fed SNP at 10 g/kg displayed improved values comparing with the other groups (p < 0.05). Further, fish fed 1 g SNP had higher FW and WG than the control and 0.1 g SNP and 10 g normal A. platensis. The incorporation of SNP at 1 and 10 g/kg in Nile tilapia diets significantly (p < 0.05) enhanced total protein, albumin, globulin, lowered the values of serum glucose and activities of ALT and AST compared with control and spirulina groups. The SOD, CAT, GPx, lysozyme and respiratory burst activities were meaningfully promoted (p < 0.05) in fish received 1 and 10 g/kg diet concerning the control and spirulina groups. Nile tilapia challenged with Aeromonas hydrophila showed congestion of the kidney, liver and spleen tissues while SNP alleviated the inflammation induced by A. hydrophila. Different levels of SNP-incorporated group showed lower cumulative mortality than the other groups. In conclusion, the obtained results illustrated that spirulina in nano form is recommended to enhance Nile tilapia well-being.  相似文献   

6.
The aim of this study was to evaluate the effects of Bacillus subtilis and Bacillus licheniformis on growth, gut microbiota, and digestive enzyme activities of Artemia urmiana. Three diets containing 102 (T1), 104 (T2), 106 (T3) CFU of probiotics/g feed, and a control diet (C) without probiotic were used through a completely randomized design (treatments with triplicates). Twelve plastic tanks with the capacity of 60- l and density of 20 nauplii/ml were used and the trial continued for 15?days. Results showed that probiotics significantly increased the total length of A. urmiana (P?<?0.05). Although the total aerobic gastrointestinal bacteria count showed no significant differences among the treatments, the total Bacillus count significantly increased in experiments (P?<?0.05). The ratio of TCBS to total aerobic bacteria count was significantly lower in T1 (0.31?±?0.05), T2 (0.27?±?0.15), and T3 (0.25?±?0.05) compared to the control (0.76?±?0.34) (P?<?0.05). The probiotics were able to increase the protease and amylase activities (P?<?0.05). No significant effect on lipase activity. The study determined T2 and T3 as the most effective treatments for improving growth, bacterial flora, and digestive enzyme activities. As less probiotic needed in T2, using 104 bacteria per g diet is recommended for rearing Artemia up to the maturity stage.  相似文献   

7.
Respiration of Cherax tenuimanus (marron) was compared with that of Cherax albidus (yabbie) from measurements in 20 closed system tests (respiration induced oxygen depletion) at ? 25° C. Comparisons were made from the point of inflexion (maximum rate of respiration) of the reversed, asymmetrical, S-shaped oxygen—time curves described by the Richard's equation. Yabbies attained the maximum respiration rate at a lower oxygen concentration (4.0–4.5 mg/l) than marron (5.0–6.0 mg/l). The species did not differ in maximum respiration rate (0.000176 mg/g min?1) which fell within the range of previous estimates for yabbies. The coefficient for respiratory dependence on body weight was 0.788.A further 25 bioassays on groups of 5 marron were performed at constant, low, oxygen levels and 20°C. The 24-hour LC50 of 7.25% of oxygen saturation approximated the incipient lethal, low oxygen level for marron. The survival time of yabbies for an LC50 of 4.9% oxygen was 45 hours compared with 14 hours for marron.  相似文献   

8.
The fertilization of carp ponds as an important intensification means has been utilized in Europe since the first half of the 19th century, but even in most intensive fertilization the concentration of nitrogen (N) hardly exceeds 2 mg/l and of phosphorus (P), 0.5 mg/l.Polycultural carp growing using intensive mineral fertilization (weekly and every 3 days) has been experimented in the Freshwater Fishery Research Station in Plovdiv in the 1971–1972 period.The greatest zooplankton and benthos biomass and the greatest fish growth per ha water area are obtained with 3-day mineral fertilization with ammonium nitrate, 708 kg/ha and superphosphate, 395 kg per hectar. The average monthly water temperature in the experimental ponds during the vegetation period (June–September) fluctuates between 21.5 and 24.7°C. The oxygen dissolved (O2) during the day hours changes within the average of 4.9–7.6 ml/l and the aeration is normal for the carp ponds (4.0–8.1 mg O2/l). The highest average seasonal zooplankton biomass in mixed fertilization (mineral and organic) is 2.437 g/m3. The zooplankton is represented by the following variaties: Rotatoria — Brachionus calyciflorus; Copepoda — Acanthocyclops vernalis and Cladocera — Moina rectirostric. The benthos consists of: chironomid larvae (family Chironomidae, Diptera) and Oligochaetae. The highest average seasonal biomass of the benthos is established with three-day mineral fertilization, 1.472 g/m2. The total fish growth with three-day fertilization is 300 kg/ha higher than in the control ponds (without fertilization). The best fishery results have been achieved with three-day fertilization giving a total growth of the fish of 2 730 kg/ha and a food coefficient of 2.8.  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.
Although water hyacinth is an adventive aquatic plant that threatens the Japanese ecosystem, its high growth rate may be a benefit in terms of its potential as a raw material for the production of bioethanol. In our study, water hyacinth was saccharified with 3?% (v/v) sulfuric acid and subjected to cellulase treatments to determine optimum bioethanol production conditions. The original saccharified solution yielded both glucose at 5.3?±?0.2?g/l and reducing sugars at 9.7?±?0.1?g/l. Concentration of the saccharified solution under vacuum at 70?°C yielded both glucose at 21.5?±?2.9?g/l and reducing sugars at 33.3?±?2.1?g/l. An aquatic yeast Saccharomyces cerevisiae TY2 produced ethanol at 9.6?±?1.1?g/l from the concentrated saccharified solution. In comparison, Ogawa et al. (Afr J Microbiol Res 2:110?C113, 2008) reported that this yeast produced 0.90?g/l and that the production of bioethanol was about 11.2-fold lower than that obtained in our study. These results suggest that refinement of the saccharification process and application of the selected yeast could improve the efficiency of obtaining bioethanol from the water hyacinth.  相似文献   

11.
Five herbs such as Acalypha indica, Hygrophila spinosa, Picrorhiza kurooa, Tinospora cordifolia and Zingiber officinale were selected to screen for the in vitro immunostimulant activity against the shrimp pathogen Vibrio harveyi using different organic polar and non-polar solvents. After initial screening, the best extract of the five herbs was mixed thoroughly in equal proportion and made it an artificial immunostimulant diets (ISD) such as ISD-1(500), ISD-2 (1,000), ISD-3 (1,500) and ISD-4 (2,000) mg?kg?1. The control diet was prepared without adding immunostimulant herbal extracts. The Indian white shrimp, Fenneropenaeus indicus having the weight of 8.0?±?1.0?g, were fed with the above diets for 60?days. After the completion of feeding trail, they were challenged with V. harveyi at the rate of 107CFU/ml and found out the cumulative mortality, growth parameters, haematological and immunological parameters. The weight gain and specific growth rate were significantly (P?<?0.05) increased from the control group to experimental group. The immunostimulant active principles helped to decrease the coagulation time and improved the total haemocyte count (THC), phagocytosis, phenol oxidase (PO) activity, haemagglutinin activity and bacterial clearance.  相似文献   

12.
The growth of juvenile channel catfish (Ictalurus punctatus) was reduced in a linear manner during a 31 day growth trial when exposed to concentrations of ammcnia ranging from 48 to 989 μg/l NH3N (0.31 to 5.71 mg/l NH+4N). On a wet weight basis, growth was reduced by 50% at 517 μg/l NH3N and the no growth occured at 967 μg/l. The no growth level was 60% of 96-h LC50 value. Mortality was increased significantly at 989 μg/l NH3N and above. The sublethal effects of ammonia may depend, in part, on the concentrations of NH4+ and and Na+ in solution.  相似文献   

13.
This investigation examines the influence of implants containing 11-ketotestosterone (11KT), 17-estradiol (E2), and 3,5,3-triiodo-l-thyronine (T3) on astaxanthin metabolism in sexually immature individually tagged Arctic charr. The fish (initial average weight 427 g) were maintained in freshwater for 40 days, and weekly implanted intraperitoneally with oil-based injections containing either 11 KT, E2 or T3 at levels of 0.1, 1.0 and 0.1 mg (100 g body weight (BW))–1, respectively. The control fish were given the oil medium alone (0.2 ml 100 g BW–1). The diet contained ca. 50 mg astaxanthin kg–1. Carotenoid composition was monitored in plasma, fillet, liver and skin, and 11 KT, E2 and testosterone (T) levels in plasma. All hormone treatments reduced plasma T compared to the control. E2-treated fish had a higher (p<0.05) hepatosomatic index (HSI) than the other treatments. Hormone treatment did not influence gonadosomatic index (GSI). T3 administration induced a silvery skin appearance. The fillet and plasma carotenoid content decreased during the experiment. 11 KT implantation reduced astaxanthin and idoxanthin concentrations of plasma and fillets, and increased the amount in liver and skin, compared to the other treatments. The relative proportion of astaxanthin to idoxanthin was higher in the control fish and T3 implanted fish, than in fish implanted with 11 KT or E2 (p<0.05). Fish treated with E2 had the highest skin carotenoid concentration. Male fish had significantly higher carotenoid content in plasma, fillet and skin than female fish. This study reveals that sex hormones affect carotenoid metabolism and partitioning among body compartments of Arctic charr, effects differently displayed by the sexes.  相似文献   

14.
The aim of the present study was to evaluate the effect of acute stress and cortisol injection on oocyte final maturation process in female Nile tilapia (Oreochromis niloticus). Handling followed by a prophylactic treatment (0.3?mL?L?1 H2O2, 5?g?L?1 NaCl solution during 30?min) and an environmental change (transfer from a 2?m3 fibreglass square tank to 50?L aquaria) were used as acute stressors and compared to a single cortisol injection (0.5 or 5?mg?kg?1 body weight). For both acute stress and cortisol injection (0.5?mg?kg?1 body weight), serum cortisol level was significantly increased from 2.3 to 134.1?ng?mL?1 1?h post-stress/injection and returned to a resting basal value 24?h after the stress/injection. In fish injected with 5?mg?kg?1 body weight cortisol, mean serum cortisol level reached a peak up to 2500?ng?mL?1 1?h after injection. 63?% of the females (mean body weight: 242?±?4?g) submitted to the acute stress ovulated within 72?h after the stress. In the same way, cortisol injection (5?mg?kg?1 body weight) at the 10th day of the maturation cycle led to a twofold reduction of the time before ovulation compared to vehicle injected control fish. Relative and total fecundity were significantly decreased in females submitted to an acute stress or cortisol injected at 5?mg?kg?1 body weight, but not fertilization or hatching rates. In conclusion, acute stress and cortisol induction exert both positive and negative effects on the final reproductive process in O. niloticus, and cortisol is the endocrine mediator causing these changes.  相似文献   

15.
A technique for the intensive rearing of Artemia salina larvae (Branchiopoda) of 1 – 4 mm using the blue-green algae, Spirulina maxima (Cyanophycea) in dry powder form is described. Experimentation was carried out in a small volume (20 l) and techniques were simplified whenever possible to enable minimal handling (i.e. water is not renewed). The system is therefore easily applicable to medium and large volumes. The production requirements of Artemia salina for larval aquaculture at Centre Océanologique de Bretagne have been fulfilled by this technique since 1974 in 450-l volumes. Growth and survival rates have been satisfactory to date.Up to a certain threshold and within a given age group, the amount of food introduced influences mean population size. Under optimal conditions it is possible to rear larvae of 1 mm in 2 days, 2 mm in 4 days and 3.75 mm in 6 days. The minimal food supplies required to obtain these figures are respectively 600 mg, 1 800 mg and 4 300 mg of Spirulina powder for 10 000 larvae at the ages of 2, 4 and 6 days. These rapid growth rates are achieved by overfeeding the larvae, which results in a reduction in the size of the installations and in time demanded for culture maintenance. The use of an optimal feeding regime gives a growth rate very close to the maximum and diminishes production costs only slightly.Consequently, an optimal larval concentration per unit volume is the most economically feasible choice for a production unit. The maximum larval concentration which gave good growth and survival rates was established for an average food quantity (3 200 mg/10 000 larvae). Larval densities may reach 13 to 14 2-day-old larvae (1 mm), five 4-day-old larvae (2 mm) and two 6-day-old larvae (3.75 mm) per ml of water. To regulate the concentration of Artemia, fixed volumes of the culture are removed regularly, thus considerably increasing the production of a given tank. The weekly production of a 450-l tank is approximately 75 g of dry matter.  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.
Hemolymph osmolality, ion concentration, acid–base balance, and immune parameters in Macrobrachium rosenbergii (15–20 g) were measured after 8 days of exposure to 0–0.3 mg l−1 trichlorfon. A significant depression in hemolymph osmolality and Cl−1 contents were observed with exposure to 0.3 mg l−1 trichlorfon. Similarly, hemolymph pH, HCO3−, and TCO2 decreased significantly when prawns were exposed to concentration of greater than 0.2, 0.1, and 0.1 mg l−1 trichlorfon, respectively. A notable increase in the hemolymph pCO2 was observed with 0.3 mg l−1 trichlorfon. However, no significant differences in hemolymph oxyhemocyanin or protein levels were observed among prawns with 0–0.3 mg l−1 trichlorfon. These findings may have resulted from histological changes in the respiratory epithelium and/or the inhibitory action of the nervous system of respiration. Phenoloxidase activity in the hemocytes of prawns decreased significantly with exposure to greater than 0.2 mg l−1 trichlorfon. This indicates that trichlorfon reduces the immune ability of M. rosenbergii.  相似文献   

18.
Pseudomonas piscicida, Aeromonas formicans and Flavobacteria sp. were involved in aggregation of hatchery reared Penaeus stylirostris larvae. Aggregation was experimentally reproduced with pure cultures of these organisms at densities of 104 cells per ml. Adding at least 3 μg/ml gentamycin, 10 μg/ml nalidixic acid, 0.1 μg/ml acridine or Cutrine Plus®1 into test suspensions prevented aggregation of the shrimp larvae.  相似文献   

19.
The secretion of vitellogenin (Vg) in kuruma prawn, Penaeus japonicus, by 17α-hydroxy-progesterone was investigated under tank-culture conditions. A significant (P<0.1) increase in Vg concentration in the sera (9.6-fold over initial value) was observed after 48 h in early vitellogenic prawns injected with 17α-hydroxy-progesterone (0.01 μg/g body weight) compared to control I (no injection, 3.0-fold over initial value) and control II (0.1 μl pure ethanol/g body weight, 2.4-fold over initial value). These results indicate that 17α-hydroxy-progesterone stimulates Vg synthesis and/or release into the haemolymph in prawns.  相似文献   

20.
This study investigates the effect of high dissolved oxygen concentrations (DO) on sterlet Acipenser ruthenus maturation. Two groups, each comprising 246 individuals of 8-month-old juvenile sterlets, were reared for 37 months under high DO (group H, mean DO of 11.2 mg/L) or normal DO (group C, mean DO of 7.3 mg/L). Significant differences in body weight were observed between group H (638.7?±?191.9 g) and group C (572.2?±?151.9 g) in 12 months (P?<?0.05). Growth until 12 months occurred at a specific growth rate of 0.6%/day for group H and at 0.5%/day for group C. The food conversion rate of groups H and C was 5.2 and 5.8, respectively. The gonadosomatic index of group H was 3.1?±?1.1 for females and 3.1?±?9.7 for males, and showed no significant difference with group C (3.0?±?0.7 for females and 2.8?±?8.9 for males, P?>?0.05) in 24 months. Significant differences in follicle diameter in mature females were also observed. Group H included 68 mature females, with an average follicle diameter of 2318.0?±?175.3 µm, whereas group C included 56 mature females, with a smaller average follicle diameter of 2152.3?±?287.0 µm (P?<?0.001). However, the polarization index in group H (0.194?±?0.049) was higher than that in group C (0.178?±?0.042) (P?<?0.05). These results suggest that, for sterlet, rearing conditions with high DO can affect growth of both the body and follicle diameter of fish compared to normal rearing conditions.  相似文献   

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