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1.
Chinese chive Allium tuberosum oil was studied for its diallyl sulfide content and its antimicrobial activity against Flavobacterium columnare in fish both in vitro and. The oil was found to have a very low concentration of diallyl monosulfide relative to the other
diallyl sulfides (diallyl disulfide, diallyl trisulfide, and diallyl tetrasulfide) identified. In the in vitro study, the
Chinese chive oil had a bacteriocidal effect on all tested strains of F. columnare, with varied minimal inhibitory concentrations. The median lethal dose (LD50) of FC4 for Nile tilapia Oreochromis niloticus was determined to be 3.72 × 103 CFU/fish. In the in vivo trial, no mortality was observed in fish fed fish diets supplemented with 800 mg/kg Chinese chive
oil and 100 mg/kg of oxytetracycline hydrochloride 5 days prior to infection with F. columnare strain 4 at a LD50. These results indicate that Chinese chive oil has the potential to replace antibiotics for controlling fish disease caused
by F. columnare. 相似文献
2.
The effect of aqueous extract of Cratoxylum formosum on innate immune response and disease resistance in tilapia Oreochromis niloticus was investigated. The fish were fed diets containing 0% (control), 0.5% (diet 1), 1% (diet 2), and 1.5% (diet 3) of C. formosum aqueous extract for 30 days. At the end of the experimental period, parameters of innate immune response including phagocytosis
of blood leukocytes, lysozyme activity in plasma, and respiratory bust activity were examined. Feeding the fish with diet
2 and diet 3 for 20 days enhanced phagocytic activity and for 30 days stimulated lysozyme and respiratory burst activities.
Diet 1 increased the phagocytic activity at 30 days, but did not affect the other measured parameters. All parameters were
not significantly changed (P > 0.05) in the control group throughout the experiment. Following 30 days of feeding, fish were infected with S. agalactiae. The cumulative mortalities of bacterial-infected tilapia that were fed diet 1, diet 2, and diet 3 were 56, 12, and 10%,
respectively, compared with 85% in the control group. These results indicate that the aqueous extract of C. formosum may elevate the innate immune response and enhance disease resistance in tilapia. 相似文献
3.
Ana Teresa Gonçalves Masashi Maita Kunihiko Futami Masato Endo Takayuki Katagiri 《Fisheries Science》2011,77(4):633-642
To test the effects of probiotic bacteria against crowding stress, juvenile Nile tilapia Oreochromis niloticus were fed commercial feed supplemented with 1 × 1010 cfu/g pellets of Lactobacillus rhamnosus for 3 weeks. The fish were confined and subjected to crowding for 7 and 14 days after which their physiological condition
was investigated. The administration of probiotic prophylaxis improved growth performance even in the stressed fish. After
7 days of stress exposure, fish receiving probiotic-supplemented feed showed proactive behavior and coping responses to the
stressor, as evidenced by elevated plasma glucose levels and osmolality, stabilized plasma electrolytes, and a higher RNA:DNA
ratio. Fish stressed for 7 days and fed normal commercial diet showed impairment of plasma electrolytes; after 14 days, the
plasma osmolality, electrolytes, glucose, and RNA:DNA ratio decreased, indicating physiological maladaptation to the stressor.
The growth rate was also found to be reduced, suggesting that energy demand exceeded the energy available from metabolism
and dietary uptake. This latter effect was not observed in fish fed the probiotic-supplemented diet. The results suggest that
probiotic bacteria prophylaxis may increase energy availability for metabolic support of the crowding stress response and
improve the stress coping capacity of fish. 相似文献
4.
Suchanit Ngamkala Kunihiko Futami Masato Endo Masashi Maita Takayuki Katagiri 《Fisheries Science》2010,76(5):833-840
The present study histologically examined the effects of glucan-containing and Lactobacillus rhamnosus GG (LGG)-containing diets on intestinal damages inflicted on Nile tilapia by Aeromonas challenges. Tilapia were fed control, glucan, and LGG diets for 2 weeks and were subsequently challenged with Aeromonas. The intestines were then histologically examined at 1, 7, 14, and 21 days post-infection. Mortality following the challenge
was lower for the fish fed the glucan and LGG diets. The intestines of these groups also showed increased inflammatory cell
infiltration and reduced intestinal damage from Aeromonas. Moreover, inflammatory cell infiltration occurred more rapidly in the glucan-fed than in the LGG-fed fish following the
challenge. Before the challenge, the dominant mucous cell was the acid type in all the tests. After the challenge, the main
mucus cell type in the proximal intestine of the glucan-fed fish shifted to AB-PAS double-staining cells, while in the LGG-fed
fish, it remained the acid type throughout the test period, and the number of double-staining cells was smaller than in the
control fish after the challenge. Thus, the different mucous cell and inflammatory cell responses show that glucan and LGG
might have different immunostimulative effects, although they both reduced the intestinal damage following Aeromonas challenges. 相似文献
5.
Marianna Vaz Rodrigues Claire Juliana Francisco Gianmarco S. David Reinaldo José da Silva Maria Fernanda Falcone-Dias João Pessoa Araújo Júnior 《Aquaculture International》2018,26(1):127-138
Francisella noatunensis orientalis is a bacterium that causes emerging bacteriosis in Nile tilapia (Oreochromis niloticus) in many parts of the world, including Brazil. It is a non-motile, Gram-negative, strictly aerobic, facultative intracellular coccobacillus. This species of bacteria is responsible for low to high mortality in fish farms, causing economic losses for fish farmers. This study aimed to detect the presence of F. noatunensis orientalis using qPCR (real-time polymerase chain reaction) and to describe lesions caused by the bacterium in O. niloticus in Brazilian aquaculture. For this purpose, 360 fish from six fish farms (30 per farm) were sampled at two time points (n = 180 per sampling). Necropsies and histopathology were performed for lesion observation, in addition to qPCR and sequencing for detection and identification of Francisella species. Environmental data were collected using a multiparameter sonde YSI EXO2. All measured limnological variables were within the optimum range for cultivation of Nile tilapia. The major lesions present were melanization of the skin, splenomegaly, granulomas, and inflammatory cell responses. The prevalence of francisellosis varied from 0 to 86.66% between time periods and fish farms analyzed, and an outbreak was observed during the second sampling period. This study describes the prevalence of francisellosis in O. niloticus and reports that the lesions found are not exclusively associated with this bacterial disease. 相似文献
6.
In this study, four essential oils—cinnamon oil, leech lime oil, lemongrass oil, and turmeric oil—were examined for their
antimicrobial activities against Streptococcus iniae, a bacterium that is pathogenic in fish, in which it causes streptococcosis. Cinnamon oil was the most potent antimicrobial
agent among these oils, with a minimal inhibitory concentration (MIC) of 40 μg/ml. By using gas chromatography–mass spectrometry
(GC–MS), it was found that the major components of cinnamon oil were cinnamaldehyde (90.24), limonene (2.42%), cinnamyl acetate
(2.03%), linalool (1.16%), and α-terpineol (0.87%). Of these compounds, only cinnamaldehyde exhibited antimicrobial activity
against S. iniae, with an MIC of 20 μg/ml. In an in vivo trial, no mortality was apparent in fish fed on fish diets supplemented with 0.4%
(w/w) of cinnamon oil and with 0.1% (w/w) of oxytetracycline 5 days prior to infection with S. iniae. These results indicate that cinnamon oil had a protective effect on experimental S. iniae infection in tilapia, and thus has the potential to replace the antibiotics used to control this disease. 相似文献
7.
The physiological response of Mozambique and Nile tilapia transferred from fresh to brackish (15 ppt) water was compared during
a one-week time course. Response in the pituitary was measured by the gene expression pattern of prolactin (PRL I), growth
hormone (GH), and calcium-sensing receptor (CaSR), while the response in the gills was measured by the gene expression pattern
of the prolactin receptor (PRL-R), Na+/K+/2Cl− cotransporter (NKCC) and Na+/Cl− cotransporter (NCC), and by activity and expression of Na+/K+-ATPase (NKA). The time-course curves of plasma osmolality levels indicate a rapid elevation 24 h after transfer, which later
decreased and maintained at stable level. PRL I expression decreased in both species, but with stronger response in the Nile
tilapia, while no differences were found in the slightly elevated levels of GH mRNA. The branchial response demonstrated a
faster up-regulation of NKA and NKCC in the Mozambique tilapia, but similar levels after a week, while Nile tilapia had stronger
and constant down-regulation of NCC. The time-course response of the measured osmoregulatory parameters indicate that 24 h
after transfer is a critical time point for brackish-water adaptation. The differences in responses to saltwater challenge
between Mozambique and Nile tilapia shown in this study may be associated with the differences in saltwater tolerance between
these two tilapiine species. 相似文献
8.
Martins ML Vieira FN Jerônimo GT Mouriño JL Dotta G Speck GM Bezerra AJ Pedrotti FS Buglione-Neto CC Pereira G 《Fish physiology and biochemistry》2009,35(1):219-222
This study evaluated the total and differential leukocyte counting and the phagocytic activity in Nile tilapia Oreochromis niloticus experimentally injected with Enterococcus sp. in the swim bladder. Fish were distributed in four treatments in triplicates of non-injected fish, fish injected with
1 ml of sterile saline solution 0.65%, and fish injected with 1 × 103 and 1 × 106 colony-forming units (CFU) of Enterococcus diluted in 1 ml sterile saline. Twenty-four hours after injection, the fish were anesthetized and the blood collected for
white blood cell (WBC) counts, differential counting of WBC, and phagocytic activity of blood leukocytes. The increased numbers
of WBC and lymphocytes were followed by decreased number of monocyte after infection. The percentages of phagocytic activities
in the blood were 55.3 and 55.9%, respectively, in tilapia injected with 1 × 103 and 1 × 106 CFU/ml. 相似文献
9.
Mayra L. González-Félix Francisco J. Castillo-Yañez Víctor M. Ocaño-Higuera Martin Perez-Velazquez Venecia Cota-Moreno José Lozano-Taylor 《Fish physiology and biochemistry》2010,36(3):779-785
A 4 × 3 factorial study was conducted to evaluate the effect of four experimental diets (a control diet and a 0, 50, and 100%
fish meal replacement diet) and the period of time Nile tilapia, Oreochromis niloticus, were fed those diets (0, 20, and 40 days) on the alkaline proteolytic activity of the animals’ digestive tract, as well
as their potential interaction. Significant differences (at P < 0.05) and a significant interaction were observed among dietary treatments for the alkaline proteolytic activity of tilapia
after 40 days of feeding. This study confirmed that, under these experimental conditions, a 50% fish meal replacement formulation
elicited the highest alkaline proteolytic activity in the digestive tract of tilapia, which resulted in the highest final
weight and specific growth rate (SGR), but further research is needed to establish the relative contribution of the alkaline
proteases to the overall proteolytic activity of this omnivorous fish species. 相似文献
10.
Yoshiko Shimahara Yun-Fen Huang Ming-An Tsai Pei-Chi Wang Shih-Chu Chen 《Fisheries Science》2010,76(3):489-494
Largemouth bass Micropterus salmoides were immunized with four different N. seriolae strains—two α-glucosidase-positive (961113, KU040801) and two α-glucosidase-negative (94260, OTTS) strains—along with Freund’s
incomplete adjuvant. After primary immunization (week 0), a booster was administered at weeks 4 and 8. Nonspecific immune
responses to multiple immunizations with the different N. seriolae strains were determined based on serum lysozyme activity and nitroblue tetrazolium (NBT)-positive cells in peripheral blood.
The serum lysozyme activity and NBT-positive cells in peripheral blood were not significantly increased even after the two
booster immunizations. Specific antibody responses against N. seriolae cells were investigated by enzyme-linked immunosorbent assay. At 4 weeks after immunization, all groups immunized with N. seriolae antigens showed significant increases in their specific antibody levels. The sera from fish immunized with different N. seriolae strains exhibited reactivity with N. seriolae sonicated antigens of 28, 30, 36 and 84 kDa by western blot analysis. After two boosters, fish were challenged with live
N. seriolae to assess the vaccine’s efficacy; however, multiple injections of the N. seriolae strains did not reduce mortality, irrespective of the bacterin. 相似文献
11.
The present study develops an experimental procedure aimed to estimate the efficiency of protein digestion in fish by measuring
both gut transit rate and total amount of the main intestinal proteases (trypsin and chymotrypsin). The selected species was
the Nile tilapia (Oreochromis niloticus). Total time for digestion, calculated through the estimation of gut transit rate using differently colored feeds, was 7.15 h.
Mean production of trypsin and chymotrypsin was 15.94 and 24.11 mU in the proximal intestine and much lower (2,39, 4.90 mU)
in the distal intestine. The enzyme efficiency, calculated from the average enzyme activity and time of residence of the digesta
in each intestinal section, points to the major role of proximal intestine in protein digestion for this species. Results
are discussed in relation to the main features characterizing digestion in stomachless fish. 相似文献
12.
Indra Suharman Shuichi Satoh Yutaka Haga Toshio Takeuchi Masato Endo Ikuo Hirono Takashi Aoki 《Fisheries Science》2009,75(4):967-973
The utilization of genetically modified soybean meal (GM SBM) was compared with that of non-GM SBM in Nile tilapia. Four experimental
diets were formulated to include either non-GM or GM SBM at 34 or 48%, respectively. These diets were fed to juvenile Nile
tilapia (49.5 g average weight) for 12 weeks. The uptake of the cauliflower mosaic virus 35S promoter fragment of the GM SBM
in fish muscle was examined at 8th and 12th week. After 12th week, fish were fed the non-GM SBM diets to determine the residual
span of the incorporated promoter fragment. There was no significant difference in specific growth rate or feed efficiency
between GM and non-GM groups at the same inclusion level. A small number of muscles from fish receiving both levels of GM
SBM diet were positive for the promoter fragment. Additionally, the promoter fragment was not detected by the second day after
changing to the non-GM SBM diets. These results indicate that the utilization of GM SBM was similar to that of non-GM SBM
and the promoter fragment was rarely found in fish muscles, suggesting that suitability and safety of GM SBM in Nile tilapia
diet were similar to those of non-GM SBM. 相似文献
13.
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
14.
Bacillus circulans PB7, isolated from the intestine of Catla catla, was evaluated for use as a probiotic supplement in the feeds for the fingerlings of Catla catla. The effect of supplement on the growth performance, feed utilization efficiency, and immune response was evaluated. Catla
fingerlings (ave. wt. 6.48 ± 0.43 g) were fed diets supplemented with 2 × 104 (feed C1), 2 × 105 (feed C2), and 2 × 106 (feed C3) B. circulans PB 7 cells per 100 g feed for 60 days at 5% of the body weight per day in two equal instalments in triplicate treatments.
The control feed (CC) was not supplemented with the B. circulans. All the feeds were isocaloric and isonitrogenous. Fish fed with feed C2 displayed better growth, significantly (P ≤ 0.05) highest RNA/DNA ratio, a lower feed conversion ratio (FCR), and a higher protein efficiency ratio (PER) than the
other experimental diets. Highest carcass protein and lipid was also observed in the fish fed C2 feed compared to the others.
Significantly (P ≤ 0.05), highest protease was recorded in fish fed feed C2 (47.9 ± 0.016) and lowest in fish fed feed C3 (32.10 ± 0.009),
where α-amylase activity did not differ significantly (P ≤ 0.05) beyond the lowest inclusion level. ALP, ACP, GOT, and GPT in the liver of Catla catla were the highest (P ≤ 0.05) in fish fed C2 feed. The highest TSP, albumin, and globulin was observed in fish treated with C2 feed after 60 days
feeding trial, but the lowest glucose level was observed in the same treatment. After the feeding trial, the non-specific
immunity levels and disease resistance of fish were also studied. Phagocytic ratio, phagocytic index, and leucocrit value
were the highest in fish fed feed C2. After the feeding trial, the fish were challenged for 10 days by bath exposure to Aeromonas hydrophila (AH1) (105c.f.u. ml−1 for 1 h, and, after 7 days, 107c.f.u. ml−1 for 1 h). Highest survival percentage was observed in fish fed with feed C2 compared with only 6.66% in the controls, which
indicated the effectiveness of B. circulans PB 7 in reducing disease caused by A. hydrophila. 相似文献
15.
Defeng Zhang Xiaoli Ke Lihui Liu Maixin Lu Cunbin Shi Zhigang Liu 《Aquaculture International》2018,26(3):885-897
Several outbreaks of Streptococcus agalactiae infection of bighead carp (Aristichthys nobilis) were observed in China. The molecular epidemiology and pathogenicity of S. agalactiae in bighead carp and tilapia (Oreochromis sp.) is poorly understood. In the present study, we identified S. agalactiae strains isolated from diseased bighead carp using the API 20 Strep kit and 16S rDNA sequencing and determined whether these strains came from tilapia. Of the 46 identified S. agalactiae strains, 24 strains were successfully isolated from diseased bighead carps, 20 S. agalactiae strains were isolated from tilapia, and two S. agalactiae strains were isolated from tiger frog (Hoplobatrachus chinensis). The results of molecular typing, including multilocus sequence typing, molecular serotyping, surface protein gene detection, and virulence-related gene detection showed that the 44 strains from bighead carp and tilapia were highly similar, whereas different from tiger frog GBS strains. Remarkably, the bighead carp strain Hn1404 showed high virulence in bighead carp and zebrafish. Moreover, this strain was pathogenic to Nile tilapia (Oreochromis niloticus). In addition, comparative genomic analysis showed that isolate Hn1404 had a close relationship with the bighead carp and tilapia S. agalactiae strains. All the analyses of the genetic characteristics of bighead carp and tilapia strains showed that tilapia S. agalactiae strains could be transmitted to other fish species such as bighead carp. 相似文献
16.
Shude Xu Liang Zhang Qingyang Wu Xuebing Liu Shuqi Wang Cuihong You Yuanyou Li 《Aquaculture International》2011,19(5):1007-1018
In order to evaluate the feasibility of dried seaweed Gracilaria lemaneiformis (Bory) as a dietary ingredient for the rabbitfish Siganus canaliculatus (Park), juvenile fish (average weight 15.64 ± 0.15 g) were fed with two isonitrogenous (32% crude protein) and isolipid (8%
lipid) diets for 8 weeks, with one diet incorporating 33% of dried G. lemaneiformis (DGL), which accounted for 6% protein and 17% carbohydrate (DGL-diet), and the other containing no DGL (control diet). After
8 weeks, the growth performance and feed utilization efficiency of fish fed with the DGL-diet were inferior to fish fed with
the control diet, although some non-specific immunity parameters were better in fish fed with the DGL-diet compared with those
of fish fed control diet. Nutritional composition (whole body composition, amino acid, and fatty acid composition in dorsal
muscle) except methionine and tyrosine in muscle showed no differences between the two groups. Furthermore, the survival rate
of fish and apparent digestibility coefficient of diets were the same between the two groups. These results indicated that
incorporation of DGL in diet of S. canaliculatus is feasible, and further studies are recommended to optimize the level of DGL in diet of S. canaliculatus to improve growth performance. 相似文献
17.
Prasad M Kumar A Mishra D Srivastav SK Srivastav AK 《Fish physiology and biochemistry》2011,37(3):505-510
The present study aimed at investigating the effects of Nerium indicum leaf extract on the blood electrolytes of Heteropneustes fossilis for short- and long term. Fish were subjected to Nerium
indicum leaf extract for short term (11.27 mg/L i.e. 0.8 of 96 h LC50) and long term (2.81 mg/L i.e. 0.2 of 96 h LC50). Fish were killed on each time intervals from control and experimental (Nerium
indicum) groups after 24, 48, 72, and 96 h in short-term exposure and after 7, 14, 21, and 28 days in long-term experiment. Blood
samples were analyzed for calcium and inorganic phosphate levels. Acute exposure of Nerium
indicum leaf extract caused a progressive decrease in the serum calcium levels after 48 h in fish H. fossilis, which persists till the close of the experiment (96 h). The serum inorganic phosphate levels remain unaffected till 48 h
in the Nerium
indicum leaf extract–exposed fish. After 72 and 96 h, the levels exhibit a decrease. Chronic Nerium
indicum leaf extract treatment provoked a decrease in serum calcium levels at day 14. This decrease continues till 28 days. The serum
phosphate level of the Nerium
indicum leaf extract–treated fish decreases on day 14 and 21. However, on day 28, the levels become close to the normal values. We
conclude that Nerium indicum leaf extract exposure alters the blood electrolytes of the fish, thus causing physiological disturbances which might affect
seriously the normal vital functions, growth rate, reproduction, and their survival in nature. 相似文献
18.
Jatropha curcas is a multipurpose and drought-resistant shrub or small tree widespread all over the tropics and subtropics. Its seeds are
rich in oil, and the Jatropha kernel meal obtained after oil extraction is rich in protein. However, presence of toxic and
antinutritional constituents restricts its use in fish feed. Jatropha kernel meal was detoxified. Common carp, Cyprinus carpio, fingerlings (15; av. body mass 10.9 ± 0.65 g) were randomly distributed in three groups with five replicates. A 6-week feeding
experiment was conducted in a respirometer system to evaluate the growth performance, nutrient utilisation and energy budget.
Fish were fed isonitrogenous diets (38% crude protein): control diet (C
ontrol group) containing fish meal (FM) protein based protein and two other diets replacing 75% FM protein with detoxified Jatropha
kernel meal (DJKM, J
atropha group) and soybean meal (SBM, S
oybean group). At the end of the experiment, body mass gain, metabolic growth rate, protein efficiency ratio, protein productive
value, energy retention, efficiency of metabolised energy for growth and efficiency of energy retention were determined. These
parameters were high and statistically similar for C
ontrol and J
atropha groups and significantly lower (P < 0.05) for S
oybean group. Whereas a reverse trend was observed for energy expenditure per g protein retained in fish body. No significant differences
were found in heat released, gross energy uptake, metabolised energy intake, metabolisability, energy expenditure, energy
expenditure per g protein fed and apparently unmetabolised energy. Conclusively, common carp–fed plant protein (DJKM and SBM)
and FM protein–based diets exhibited equal average metabolic rate. 相似文献
19.
20.
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