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The present study was carried out to determine the antibacterial effect of caprylic acid in the culture system of Artemia franciscana nauplii inoculated with shrimp pathogens Vibrio harveyi and V. parahaemolyticus. To begin with, the antibacterial effect of different concentrations (1, 10 and 100 mM) of caprylic acid against V. harveyi and V. parahaemolyticus was assessed through bacterial growth study. This indicated that at 100 mM concentration, the growth of the pathogens was
completely inhibited within 5 h, whereas, in 1.0 and 10 mM concentrations, effective inhibition was observed with the extension
of time. Subsequently, the influence of pH variation on the growth inhibitory effect of 10 mM caprylic acid against V. harveyi and V. parahaemolyticus at different pH (5–7) was also made through bacterial growth study. At pH 5, the pathogen growth was very less, compared
with pH 6 and 7. The Artemia nauplii (instar II) reared in 10 mM caprylic acid supplemented medium were challenged with V. harveyi and V. parahaemolyticus, and the mortality was recorded at an interval of 6 h up to 60 h. In this study, the mortality of Artemia nauplii reduced to 20.61 and 16.30% in V. parahaemolyticus and V. harveyi challenged groups, respectively. The present results provide evidence for the potential antibacterial activity of caprylic
acid in aquaculture against luminescent vibrios. 相似文献
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Ahmed Barkia Ali Bougatef Rim Nasri Emna Fetoui Rafik Balti Moncef Nasri 《Fish physiology and biochemistry》2010,36(4):893-902
Trypsin from the viscera of Bogue (Boops boops) was purified to homogeneity by precipitation with ammonium sulphate, Sephadex G-100 gel filtration and Mono Q-Sepharose
anion exchange chromatography, with an 8.5-fold increase in specific activity and 36% recovery. The molecular weight of the
purified enzyme was estimated to be 23 kDa by SDS–PAGE and size exclusion chromatography. The purified trypsin appeared as
a single band on native-PAGE and zymography staining. The purified enzyme showed esterase-specific activity on N-α-benzoyl-l-arginine ethyl ester (BAEE) and amidase activity on N-α-benzoyl-dl-arginine-p-nitroanilide (BAPNA). The optimum pH and temperature for the enzyme activity, after 10 min incubation, were pH 9.0 and 55°C,
respectively, using BAPNA as a substrate. The trypsin kinetic constants K
m and k
cat on BAPNA were 0.13 mM and 1.56 s−1, respectively, while the catalytic efficiency k
cat
/K
m was 12 s−1 mM−1. Biochemical characterisation of B. boops trypsin showed that this enzyme can be used as a possible biotechnological tool in the fish processing and food industries. 相似文献
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Zehra Selcuk Serap Ustaoglu Tiril Fikret Alagil Volkan Belen Mustafa Salman Sena Cenesiz Omer Hakan Muglali Feraye Berkay Yagci 《Aquaculture International》2010,18(2):213-221
An experiment was conducted to determine the effects of supplemental dietary l-carnitine, chromium picolinate (Cr-Pic) and their combination on growth performance and serum total protein, cholesterol,
triglyceride and glucose of rainbow trout (Oncorhynchus mykiss). A total of 276 rainbow trout were randomly allocated to four groups. Fish (average initial body weight = 151 ± 1.69 g)
were fed a basal diet without supplemental l-carnitine and chromium picolinate in the control group. The basal diet was supplemented with either 500 mg/kg l-carnitine, 1.6 mg/kg chromium picolinate or 500 mg/kg l-carnitine plus 1.6 mg/kg chromium picolinate for experimental groups 1 (C), 2 (Cr-Pic) and 3 (C + Cr-Pic), respectively.
Fish were fed twice a day to apparent satiation for 58 days. Weight gain, growth rate, feed consumption and feed conversion
ratio (feed/gain) were calculated for the whole period. At the end of the study, six fish were chosen randomly from each tank
to represent the experiment and frozen at −20°C for subsequent dorsal muscle analysis. The results showed no significant differences
in final body weight, weight gain or feed conversion ratio among groups. There were also no significant differences in serum
total protein, cholesterol, triglyceride or glucose concentrations among groups. Significantly higher lipid concentration
of dorsal muscle was observed in experimental groups 1 and 3. In conclusion, supplemental dietary l-carnitine, chromium picolinate and their combination have no beneficial effects on improving growth performance and feed
conversion ratio in rainbow trout. However, dietary l-carnitine slightly increased lipid concentration in dorsal muscle of rainbow trout. 相似文献
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Qing-Kui Wang Cheng-Xun Chen Yong-Jun Guo Hai-Yun Zhao Jing-Feng Sun Shen Ma Ke-Zhi Xing 《Aquaculture International》2011,19(5):945-956
The purpose of this study was to determine the effect of Angelica sinensis polysaccharide (ASP) supplemented in diet on the innate cellular immune response and disease resistance in grouper, Epinephelus malabaricus. Fish were fed diets containing different doses of ASP (0, 500 and 3,000 mg kg−1 diet) for 12 weeks. After 12 week feeding, the respiratory burst activity, phagocytic activity, and leukocytes proliferation
in head kidney were assayed. The functional immunity in terms of cumulative mortality was also assessed by a challenge with
live Edwardsiella tarda. Results showed that the respiratory burst activities in ASP-supplemented groups were increased significantly. The respiratory
burst index was the highest in fish-fed 3000 mg kg−1 diet and the lowest in control. The phagocytic activities in ASP-supplemented groups were significantly higher than that
of control. No significant difference in phagocytic activity was observed between ASP-supplemented groups. ASP stimulated
the head kidney leukocytes proliferation significantly, despite the absence of lipopolysaccharide (LPS) or not. The cumulative
mortalities of fish fed with 3000 mg ASP kg−1 diet were significantly lower than those fed with 500 mg ASP kg−1 diet and control diet after 96 h of challenge. In conclusion, dietary ASP enhanced some cellular immune parameters and disease
resistance against E. tarda in grouper. 相似文献
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The influence of Tribulus terrestris on the activities of testicular enzyme in Poecilia latipinna was assessed in lieu of reproductive manipulation. Different concentrations of (100, 150, 200, 250, and 300 mg) Tribulus terrestris extract and of a control were tested for testicular activity of enzymes in Poecilia latipinna for 2 months. The testis and liver were homogenized separately in 0.1 mol/l potassium phosphate buffer (0.1 mol/l, pH 7.2).
The crude homogenate was centrifuged, and supernatant obtained was used as an enzyme extract for determination of activities.
The activities of testicular functional enzyme ALP, ACP, SDH, LDH, and G6PDH levels were changed to different extent in treated
groups compared with that of the control. The total body weight and testis weight were increased with the Tribulus terrestris-treated fish (Poecilia latipinna). These results suggest that Tribulus terrestris induced the testicular enzyme activity that may aid in the male reproductive functions. It is discernible from the present
study that Tribulus terrestris has the inducing effect on reproductive system of Poecilia latipinna. 相似文献
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Ofelia S. Reyes Marietta N. Duray Corazon B. Santiago Manuele Ricci 《Aquaculture International》2011,19(1):155-164
The free-living nematode, Panagrellus redivivus, was tested as live food for grouper Epinephelus coioides larvae during the first feeding stage. A series of experiments were conducted to determine the acceptability of the free-living
nematodes in grouper larvae at first feeding, the optimum nematode density and the response of the larvae to nutritionally
enriched nematode. All experiments were conducted in 200-L conical tanks filled with 150-L filtered seawater and stocked at
15 larvae L−1. Duration of feeding experiments was up to day 21 (experiment 1) and 14 days (experiment 2 and 3). Brachionus plicatilis and Artemia (experiment 1) and Brachionus plicatilis alone (experiment 2 & 3) was used as the control treatment. Observations indicated that the grouper larvae readily fed on
free-living nematodes as early as 3 days posthatching, the start of exogenous feeding. Optimum feeding density for the larvae
was 75 nematodes ml−1. The enrichment of cod liver oil or sunflower oil influenced the total lipids and n-3 highly unsaturated fatty acids of P. redivivus, which in turn influenced those of the grouper larvae, however, growth and survival of the larvae were not affected (P > 0.05). The results from this investigation showed that the nematode, P. redivivus, can be used as first live food for grouper larvae from the onset of exogenous feeding until they could feed on Artemia nauplii. 相似文献
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Ivan Kurtovic Susan N. Marshall Xin Zhao Benjamin K. Simpson 《Fish physiology and biochemistry》2010,36(4):1041-1060
Lipases were purified from delipidated pyloric ceca powder of two New Zealand-sourced fish, Chinook salmon (Oncorhynchus tshawytscha) and hoki (Macruronus novaezelandiae), by fractional precipitation with polyethylene glycol 1000, followed by affinity chromatography using cholate-Affi-Gel 102,
and gel filtration on Sephacryl S-300 HR. For the first time, in-polyacrylamide gel activity of purified fish lipases against
4-methylumbelliferyl butyrate has been demonstrated. Calcium ions and sodium cholate were absolutely necessary both for lipase
stability in the gel and for optimum activity against caprate and palmitate esters of p-nitrophenol. A single protein band was present in native polyacrylamide gels for both salmon and hoki final enzyme preparations.
Under denaturing conditions, electrophoretic analysis revealed two bands of 79.6 and 54.9 kDa for salmon lipase. It is proposed
that these bands correspond to an uncleaved and a final form of the enzyme. One band of 44.6 kDa was seen for hoki lipase.
pI values of 5.8 ± 0.1 and 5.7 ± 0.1 were obtained for the two salmon lipase forms. The hoki lipase had a pI of 5.8 ± 0.1.
Both lipases had the highest activity at 35°C, were thermally labile, had a pH optimum of 8–8.5, and were more acid stable
compared to other fish lipases studied to date. Both enzymes were inhibited by the organophosphate paraoxon. Chinook salmon
and hoki lipases showed good stability in several water-immiscible solvents. The enzymes had very similar amino acid composition
to mammalian carboxyl ester lipases and one other fish digestive lipase. The salmon enzyme was an overall better catalyst
based on its higher turnover number (3.7 ± 0.3 vs. 0.71 ± 0.05 s−1 for the hoki enzyme) and lower activation energy (2.0 ± 0.4 vs. 7.6 ± 0.8 kcal/mol for the hoki enzyme) for the hydrolysis
of p-nitrophenyl caprate. The salmon and hoki enzymes are homologous with mammalian carboxyl ester lipases. 相似文献
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The ability of an algicidal bacterium Marinobacter salsuginis strain BS2, isolated from shrimp pond water, to reduce shrimp mortality was investigated under laboratory conditions. When
two species of shrimp (Penaeus monodon and Litopenaeus vannamei) (body length 1.5–1.8 cm) were cultured together with the dinoflagellate Noctiluca scintillans, nearly 80 % of the shrimps died within 7 days. However, when bacterial strain BS2 was also added to the culture, N. scintillans was killed within 48 h, and shrimp survival rates on the 7th day improved from 23 to 87 % for both P. monodon and L. vannamei. The bacterium BS2 alone had no effect on shrimp condition. Under conditions of increased dissolved oxygen, the effect of
using BS2 was greater, and shrimp survival rates improved even more dramatically, from 26 to 98 %. These studies provide the
first evidence that the use of killing bacteria, isolated from shrimp culture water, can suppress harmful algal blooms (HABs)
and thus restore the efficiency of shrimp production. The control of HABs in this way in shrimp culture farms would be a major
benefit for shrimp production. 相似文献
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The immediate-early gene (egr-1) expression was used to examine the neuron’s response in telencephalon of goldfish during spatial learning in small space.
Fishes were pre-exposed in the experimental apparatus and trained to pick food from the tray in a rectangular-shaped arena.
The apparatus was divided into identical compartments comprising three gates to provide different spatial tasks. After the
fish learned to pass through the gate one, two more gates were introduced one by one. Fish made more number of attempts and
took longer time (P < 0.05) to pass through the first gate than the gate two or three. This active learning induces the expression of egr-1 in telencephalon as established by western blot analysis. Subsequently, the fish learn quickly to cross the similar type
of second and third gate and make fewer errors with a corresponding decline in the level of egr-1 expression. As the fish learned to pass through all the three gates, third gate was replaced by modified gate three. Interestingly,
the level of egr-1 expression increased again, when the fish exhibit a high exploratory behavior to cross the modified gate three. The present
study shows that egr-1 expression is induced in the telencephalon of goldfish while intensively acquiring geometric spatial information to pass
through the gates. 相似文献
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Jian-He Xu Feng You Wei Sun Bin-Lun Yan Pei-Jun Zhang Bi-Xiang Jing 《Aquaculture International》2008,16(6):623-634
Turbot Scophthalmus maximus exhibits sexually dimorphic growth, with females growing faster and reaching larger adult sizes than males. Thus, development
of techniques for preferentially producing females is necessary to optimize production of these species. In this paper, gynogenetic
diploids of turbot were induced by activating egg development with ultraviolet (UV)-irradiated left-eyed flounder Paralichthys olivaceus sperm combined with cold shock to prevent extrusion of the second polar body. The results of UV irradiation experiments showed
that survival, motility, and duration of activity of P. olivaceus sperm generally decreased with increase in UV dose. The typical Hertwig’s effect was observed after fertilized turbot eggs
with UV-irradiated P. olivaceus sperm and the optimal UV dose for gynogenetic haploid production was 36,000 erg mm−2. At 15°C, appropriate timing of cold shock for retention of the second polar body in turbot eggs was at 6 min after fertilization.
Results of different combinations of two shock temperatures (1 or 3°C) and four shock durations (15, 25, 35 or 45 min) at
6 min after fertilization demonstrated that shock of 25 min at 1°C gave the highest production of diploid gynogens (39.58%
relative to its diploid control). The results of this study reveal that the use of UV-irradiated P. olivaceus sperm for activation of turbot eggs and cold shock for polar body retention is an effective method to produce gynogenetic
offspring. 相似文献
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Sanjoy Banerjee Helena Khatoon Mohamed Shariff Fatimah Md. Yusoff 《Fisheries Science》2010,76(3):481-487
We have investigated the possibility of using a consortium of marine bacterium and periphytic microalgae to improve the water
quality and increase the growth and survival of the shrimp Penaeus monodon in a hatchery system. Three treatments were evaluated for their effect on P. monodon postlarvae (PL) when the culture water was not changed: Bacillus
pumilus alone (B); periphytic microalgae alone (M); B. pumilus + periphytic microalgae (BM). P. monodon PL raised in a tank of unchanged water without bacterium and periphytic microalgae served as the control. The water in tanks
of the M and BM treatments had significantly low levels of total ammonia-nitrogen (TAN) (0.03 and 0.01 mg l−1, respectively) and nitrite-nitrogen (NO2-N) (0.03, 0.01 mg l−1, respectively) than that in the B (TAN 0.80, NO2-N 0.68 mg l−1) and control (TAN 1.11, NO2-N 1.12 mg l−1) tanks. Moreover, PL cultured in tanks M and BM had significantly higher survival and specific growth rates and a significantly
higher resistance to the reverse salinity stress test than those in the B and control tanks. Compared to the control PL, the
PL cultured in the BM tanks had significantly higher levels of protein, lipid, polyunsaturated fatty acids, ecosapentaenoic
acid, and docosahexaenoic acid. The culture water in tanks BM also contained significantly less Vibrio than the control water. Our results illustrate the beneficial effects of a B. pumilus and periphytic microalgae consortium on improving the water quality and the growth and survival of shrimp PL grown in a hatchery
system. 相似文献
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Besides various physiological and biological indices, stress in fish can be expressed directly by changes in their behaviour.
Electrofishing point sampling approach based on CPUE (catch per unit effort) was used to evaluate fish density (escapement)
into the littoral zones of four Czech ponds as a reaction to the occurrence and hunting activities of great cormorant (Phalacrocorax carbo sinensis) flocks. The behaviour of two-year-old common carp (Cyprinus carpio) before and after cormorant arrival was compared. Significant differences (P < 0.001) in CPUE were recorded in fish density before and after cormorant arrival on all of four ponds under study—Žofinsky:
0.04 ± 0.18 and 22.38 ± 26.87 (mean ± SD), Stary Hospodář: 0.05 ± 0.29 and 25.49 ± 25.45, Žebrákov: 0.16 ± 0.57 and 28.58 ± 24.75
and Travičny: 0.03 ± 0.19 and 17.18 ± 18.20, respectively. The evaluation of fish wounding in the CPUE fish samples proved
the proportion of fish injured by cormorant attacks ranging from 3.33 to 18.19% in the ponds under study. 相似文献