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1.
Vu Nam Son Nguyen Thanh Phuong Tran Ngoc Hai Amararatne Yakupitiyage 《Aquaculture International》2011,19(3):555-566
Production management of intensive prawn farming strongly differs between dry and wet season in terms of availability and
quality of prawn seeds and water quality. Secondary data implied that prawn seed batches from the market had a total pathogen
infection rate of 53%, predominantly caused by 37% white spot syndrome virus (WSSV), 19% monodon baculovirus (MBV) and 4%
yellow head virus (YHV). Pathogen-free seed batches averaged to 52% during the dry season compared to the wet season (42%).
Survey revealed average stocking density of 17 PL m−2 with a survival rate of 55%, a crop yield of 2,470 kg ha−1 crop−1 and a net income of 6,768 USD ha−1 crop−1. Average production cost amounted to 3.4 USD kg−1, and feed cost accounted for 58% of the production cost. Technical efficiency with respect to prawn yield and survival rate
was higher during the dry season than the wet season. The probability of yield loss was 15.6 times higher in the wet than
in the dry season. A positive net income can be generated for farms operating in the dry season using new ponds and performing
pathogen laboratory tests on prawn seeds before stocking. 相似文献
2.
White spot syndrome (WSS) is considered as a great threat to commercial farming of the tiger shrimp (Penaeus monodon). The causal agent of WSS is a DNA virus called white spot syndrome virus (WSSV). The prevalence of this dreadful virus infection
has been studied in five randomly selected hatcheries located in the Cox’s Bazar district of Bangladesh. Both one-step and
nested polymerase chain reaction (PCR) involving two pairs of primers, namely, 146F1/146R1 and 146F2/146R2, amplifying the
1447 bp and 941 bp fragments, respectively, were conducted to detect the WSSV. Out of 60 randomly collected shrimps, 12 (20%)
were found to be positive by one-step PCR, while 18 (30%) were found to be positive by nested PCR. The nested PCR was found
to be much more sensitive than the one-step PCR. The shrimp specimens showing clinical signs of WSS were positive for WSSV
by both one-step and nested PCR. Some of the apparently healthy samples were also found to be positive for WSSV by nested
PCR. Among the two primer-pairs, the inner pair amplifying the 941 bp fragment was more sensitive than the outer primer pair
amplifying the 1447 bp fragment when used in one-step PCR. 相似文献
3.
应用PCR和RT-PCR技术对4种对虾病毒的检测 总被引：5，自引：3，他引：5
探讨了应用PCR和RT－PCR技术对4种主要的对虾病毒进行检测的方法。同时使用该方法检测了对虾天然饵料－－卤虫中的4种对虾病毒。结果显示，含病毒核酸的阳性对照样品分别扩增出了大小为824bp,705bp,260bp和216bp的预期产物，但未能从卤虫样品中检测到此4种病毒的存在。本文报道的病毒检测方法具有快速、灵敏、准确的特点，可以用于进出口贸易中对活体或冰冻对虾，虾苗，对虾饵料等进行相关对虾病毒的检疫，也为制定我国对虾病毒检疫检验规范提供了技术参考。 相似文献
4.
Circe E. Badillo-Salas Enrique Valenzuela-Espinoza Marco A. González-Gómez Griselda Pares-Sierra Francisco Ley-Lou Zaul Garcia-Esquivel 《Aquaculture International》2009,17(2):173-186
Two trials were carried out in the laboratory in order to assess the effect of microparticulated feed (F) and live (Thalassiosira pseudonana, M) diets on the growth of recently set (396 ± 13 μm shell height) and 2 mm Crassostrea gigas postlarvae. Different proportions of M and F (100:0, 75:25, 50:50; 25:75, 0:100) were delivered in a single dose of 3 h d−1 in trial 1. Dietary M:F proportions of 100:0, 50:50, and 0:100 were delivered as a single pulse of 8 h d−1 (P1) or two pulses of 4 h−1 (P2) in trial 2. Maximal daily M ration was 296 cells μl−1 d−1 (trial 1), 150 M cells μl−1 d−1 (trial 2), or their equivalent F dry weight. Shell height (SH), dry (DW), and organic weight (AFDW) were evaluated weekly.
Oysters from trial 1 significantly increased their size after 28 days, and exhibited no significant dietary differences in
terms of DW (1.21 ± 0.15 to 2.01 ± 0.28 mg) or AFDW (0.091 ± 0.022 to 0.166 ± 0.029 mg). Newly set postlarvae (trial 2) also
exhibited significant growth after 25 days. No dietary differences were observed in trial 2, yet P2 oysters attained significantly
higher shell heights (825–912 μm) than P1 oysters (730–766 μm) after 25 d. Pulse effects were marginally not significant in
terms of AFDW and growth rate. Together, these findings showed that balanced microfeeds have a practical potential for the
culture of early C. gigas postlarvae, when they are delivered in pulse-feeding schemes 相似文献
5.
B. T. Nga R. Roijackers T. T. Nghia V. N. Ut M. Scheffer 《Aquaculture International》2006,14(5):467-477
We studied the effects of different concentrations of decomposing Rhizophora apiculata leaves and their leachates on larvae of the shrimp Penaeus monodon under laboratory conditions. Shrimp mortality was highly dependent on the concentration of oxygen in the water, which in turn was strongly correlated to the amount of decomposing leaves in the same water. Shrimps died after 5 min when placed in water containing the highest concentration of mangrove leachates (15 g l−1) tested in our experiments. Shrimp survival and biomass decreased significantly when the shrimp were cultured at the relatively higher concentrations of leaves and leachates (10 and 15 g l−1); in contrast, moderate amounts of leaves or their leachates (2.5–5 g l−1) had positive effects on shrimps. The survival and biomass of shrimps cultured with plastic leaves was lower than those of shrimps cultured with mangrove leaves, indicating that food derived from mangrove leaves contributed to a higher shrimp survival and biomass. These results have important implications for the culture of shrimps in extensive mangrove-shrimp systems. While litter may promote shrimp production, high leaf concentrations may have negative effects due to the drop in the oxygen concentration. Water circulation may help to prevent low oxygen conditions and reduce local accumulations of mangrove leaves. 相似文献
6.
Jae Seong Lee Yong-Tae Kim Kyung-Hoon Shin Jung-Ho Hyun Sook-Yang Kim 《Aquaculture International》2011,19(5):931-944
To assess the impact of aquaculture activities, we measured the primary production, total sediment oxygen consumption, and
benthic nutrient flux at two aquaculture farms (sea squirt and oyster) and one reference site. The estimated primary production
in the water column ranged from 19–169 mmol C m−2 d−1. Total sediment oxygen consumption rates ranged from 58 to 328 mmol m−2 d−1, 1.1 to 40 mmol m−2 d−1 for nitrogen, 0.17 to 3.0 mmol m−2 d−1 for phosphate, and 7.3 to 74 mmol m−2 d−1 for silicate. The average total sediment oxygen consumption at the longline farms was >2.5 times higher than the reference
site. Nitrate was significantly removed by denitrification at the longline farms in July and September and ranged from −5.4
to −0.09 mmol m−2 d−1, which is higher than for other coastal sediments. The benthic fluxes of nitrogen and phosphate at longline farms were up
to 16 and six times higher than at the reference site, respectively. The average nitrogen requirements of the primary producers
were 9.3 mmol m−2 d−1 at the sea squirt farm, 7.0 mmol m−2 d−1 at the oyster farm, and 13.5 mmol m−2 d−1 at the reference site, corresponding to 88, 316, and 27.2% of the nitrogen supplied by benthic fluxes, respectively. Our
results suggest that benthic nutrient fluxes at longline farms are a major nutrient source for primary production in coastal
waters. 相似文献
7.
Bacillus subtilis isolated from the intestine of Cirrhinus mrigala (Hamilton) was incorporated into the rearing water of Poecilia reticulata (Peters), Poecilia sphenops (Valenciennes), Xiphophorus helleri (Heckel) and Xiphophorus maculatus (Gunther) at four different concentrations (5 × 108 cells ml−1, 5 × 107 cells ml−1, 5 × 106 cells ml−1 and 5 × 105 cells ml−1) and its effect on fish growth performance and survival, water quality parameters and bacterial population of water were
assessed. The results showed that the addition of bacterial cells in the rearing water resulted in greater survival and a
faster growth rate and, hence, greater length and weight increments of the livebearers. The use of a bioaugmentor in the rearing
water of the livebearing fishes resulted in significantly lower (P < 0.05) concentrations of dissolved organic matter and total ammonium nitrogen. The counts of motile aeromonads and total
coliforms recorded in the water of bioaugmented tanks were also lower than that in the control tank. Bioaugmentation between
106 and 108 cells ml−1 in the rearing water is sufficient in establishing a bioaugmentor and the use of a higher concentration of bacterial cells
did not always lead to significantly better results. 相似文献
8.
The effect of prebiotic xylooligosaccharides (XOS) on the growth performance and digestive enzyme activities of the allogynogenetic
crucian carp, Carassius auratus gibelio, was investigated. XOS was added to fish basal semi-purified diets at three concentrations by dry feed weight: diet 1, 50 mg kg−1; diet 2, 100 mg kg−1; diet 3, 200 mg kg−1, respectively. Twelve aquaria (n = 20) with three replicates for each treatment group (diets 1–3) and control treated without XOS were used. Weights of all
collected carp from each aquarium were determined at the initial phase and at the end of the experiment, and the carp survival
was also determined by counting the individuals in each aquarium. After 45 days, there were significant differences (P < 0.05) in the relative gain rate (RGR), and daily weight gain (DWG) of diets 1–3 were compared with the control. However,
the survival rate was not affected (P > 0.05) by the dietary treatments. For enzymatic analysis, dissection produced a crude mixture of intestine and hepatopancreas
of each segment to measure. The protease activity in the intestine and hepatopancreas content of fish in diet 2 (487.37 ± 20.58 U g−1 and 20.52 ± 1.93 U g−1) were significantly different (P < 0.05) from that in the control (428.13 ± 23.26 U g−1 and 12.81 ± 1.52 U g−1) and diet 3 (428.00 ± 23.78 U g−1 and 14.04 ± 1.59 U g−1). Amylase activity in the intestine was significantly higher for diet 2 compared to diet 1 and the control. As for amylase
in the hepatopancreas, assays showed higher activity in diet 2 (P < 0.05) compared to the rest. 相似文献
9.
为查明黄头病毒(Yellow Head Virus,YHV)在我国的存在和变异情况,本研究采用世界动物卫生组织(OIE)《水生动物诊断手册》中YHV套式RT-PCR检测方法对2012-2014年采集的299份样品进行了YHV监测,并对部分YHV阳性样品基因进行了克隆测序及系统发育分析.流行病学调查显示,299份样品中YHV的阳性率为11％,我国养殖的中国明对虾、凡纳滨对虾、日本囊对虾以及罗氏沼虾的部分样品中均检出了YHV,中国明对虾和罗氏沼虾是本次调查中新发现的YHV自然宿主,而且YHV在中国明对虾中的检出率最高.对6份较强阳性样品YHV基因组ORF1b内1002 bp的分型片段进行克隆测序和序列分析,序列比对结果显示,阳性样品的YHV与国外报道的YHV的6个基因型相似度为81.0％-90.5％;系统发育分析显示,6份阳性样品归于同一分支,但与已知YHV的6个基因型均不在同一分支内,其与YHV基因1型(YHV-1)亲缘关系较近.对阳性样品YHV基因组ORF3内编码gp116蛋白的一段序列进行克隆测序,得出其序列长度为509 bp,与YHV-1a的545 bp、YHV-1b的383 bp和YHV-2(即鳃联病毒GAV)的476 bp均不同;依据该片段构建的系统发育树显示,6份阳性样品归于同一分支,与YHV已知的6个基因型不同,与YHV-1亲缘关系较近,且与YHV-1a相似度大于YHV-1b.对其中两份样品的ORF2序列进行比对显示,两份样品序列相似性为99.8％,蛋白序列完全相同,与YHV-1的序列相似度为85.9％,与YHV-2相似性为80.9％.样品调查结果对增补YHV的宿主范围有重要意义;YHV核酸检测和序列比对结果表明,感染我国养殖对虾的YHV为一种新的致病株型. 相似文献
10.
Immune responses by dietary supplement with Astragalus polysaccharides in the Pacific white shrimp,Litopenaeus vannamei 
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下载免费PDF全文 Two experiments were conducted to investigate the immune‐enhancing effect of dietary supplement with Astragalus polysaccharides (APS) on the Pacific white shrimp, Litopenaeus vannamei. In experiment 1, the optimal APS dose was determined based on the immune responses of shrimps fed APS diet for 30 days. In experiment 2, the effect of APS supplementation on immune response of shrimp suffering white spot syndrome virus (WSSV) challenge was determined. Results showed that the total haemocyte count and phagocytic activity in shrimps fed APS diets significantly (p < .05) increased in comparison with those fed the basal diet. Dietary supplement with APS markedly (p < .05) increased the activity of phenoloxidase (PO), total superoxide dismutase (SOD), lysozyme (LZM), acid phosphatase and alkaline phosphatase in shrimp hemolymph, but decreased the maleic dialdehyde (MDA) content. Significantly higher (p < .05) activity on PO, SOD and LZM and lower (p < .05) MDA content have also been found in shrimps suffering WSSV challenge. Therefore, APS could be used as a safe and effective feed additive in shrimp aquaculture, and the optimal dose of APS for the Pacific white shrimp was suggested to be 0.2 g/kg based on our results. 相似文献
11.
Teleost fish lack the enzyme for endogenous synthesis of ascorbic acid (AA), an essential micronutrient for fish. The aim
of this study was to examine the effect of higher levels of dietary vitamin C on growth, nutritional quality, and immunomodulation
in the Indian major carp, rohu (Labeo rohita). Four groups of L. rohita were fed experimental diets containing either no vitamin C (control) or supplemented with vitamin C at 500 mg kg−1 (Exp-1), 1000 mg kg−1 (Exp-2), or 1500 mg kg−1 (Exp-3) for 60 days. Growth parameters (NWG, ADG, and SGR), serological parameters (TSP, TSA, TSG, and A:G), haematological
parameters (TLC, TEC, Hct, MCV, and MCH), and different non-specific immunological parameters (PR, PI, respiratory burst activity,
and bactericidal activity) were evaluated during the experimental trial. Fish fed a vitamin C-supplemented diet showed higher
specific growth rate (SGR) up to 1000 mg kg−1 compared with control fish. Different haematological and serological parameters along with non-specific immune parameters
were influenced by vitamin C supplementation. Among the non-specific immune parameters phagocytic activity (PR and PI) and
respiratory burst activity (NBT cells) were significantly (P ≤ 0.05) enhanced by increasing doses of vitamin C supplementation. Higher levels of dietary vitamin C significantly (P ≤ 0.05) enhanced protection against Aeromonas hydrophila (AH1) infection compared with controls. Results from this study help to establish the beneficial effect of vitamin C on growth
and immunmodulation in rohu (L. rohita). 相似文献
12.
S Dutta S Biswas K Mukherjee U Chakrabarty A Mallik N Mandal 《Journal of fish diseases》2014,37(5):471-480
White spot disease (WSD) caused by white spot syndrome virus (WSSV) creates severe epizootics in shrimp aquaculture industry worldwide. Despite several efforts, no such permanent remedy was yet developed. Selective breeding using DNA markers would be a cost‐effective strategy for long‐term solution of this problem. In the present investigation, out of 30 random primers, only one primer produced a statistically significant (P < 0.01) randomly amplified polymorphic DNA (RAPD) marker of 502 bp, which provided a good discrimination between disease resistant and disease susceptible populations of Penaeus monodon from three geographical locations along the East coast of India. Because RAPD markers are dominant, a sequence characterized amplified region (SCAR) marker was developed by cloning and sequencing of 502 bp RAPD fragment, which generates a single 457 bp DNA fragment after PCR amplification only in the disease resistant shrimps. Challenge experiment was also conducted to validate this 457 bp SCAR marker, and the results suggested that the WSSV loads were 2.25 × 103 fold higher in disease susceptible than that in disease resistant shrimps using real‐time PCR. Therefore, this 457 bp DNA SCAR marker will be very valuable towards the development of disease‐free shrimp aquaculture industry. 相似文献
13.
Y. Durmaz M. Donato M. Monteiro L. Gouveia M. L. Nunes T. Gama Pereira Ş. Gökpınar N. M. Bandarra 《Aquaculture International》2009,17(4):391-399
Diacronema vlkianum was grown in polyethylene bags at two different temperatures (18 and 26°C) in the laboratory. The biochemical composition
level decreased when the temperature increased from 18 to 26°C. The maximum cell number at 18°C was 11.9 × 106 cells ml−1, while maximum cell number at 26°C was 1.6 × 106 cells ml−1. The maximum level of α-tocopherol was 257.7 ± 21.6 μg g−1 dry weight (DW) at 18°C. The highest total carotenoids and chlorophylls were 6.5 mg g−1 DW and 4.3 mg g−1 DW, respectively, and the main pigments were determined as astaxanthin and lutein. Polyunsaturated fatty acids were found
to be the predominant group, reaching 39.5% of the total fatty acids at 18°C. This comprised 20:5(n − 3) as the main polyunsaturated
fatty acids (20.4%, at 18°C) followed by 22:6(n − 3) (4.8%, at 18°C). The results suggest that D. vlkianum can be successfully used as feed in shellfish hatcheries or aquaculture hatcheries, either as a substitute or in association
with other microalgae, when this algae is cultured at 18°C. 相似文献
14.
15.
Guojian Jiang 《Aquaculture Research》2010,41(9):1322-1330
The defence ability of Fenneropenaeus chinensis and Marsupenaeus japonicus against the intrusion of the white spot syndrome virus (WSSV) was compared after injecting WSSV intramuscularly by recording cumulative mortality, diagnosing the virus and examining variations in immunological parameters including the total haemocyte counts (THCs), phagocytic percentage (PP), plasma protein concentration (PPC), phenoloxidase (PO) and nitric oxide synthase (NOS) activity. The results showed that the variations in the immunological parameters of F. chinensis and M. japonicus showed similar trends. The THCs of the two species decreased significantly postchallenge of WSSV. The virus was detected at 78 h in M. japonicus and at 42 h in F. chinensis after infection, which was in correlation with the accumulative mortality, and the variations in PO, PP, NOS and PPC in the two species. All shrimps of F. chinensis in the mortality experiment died within 66 h, much more quickly than M. japonicus, whose cumulative mortality reached 100% after 198 h. In conclusion, the immune system of M. japonicus has a stronger resistant ability to antagonize and endure the invasion of WSSV than that of F. chinensis. 相似文献
16.
White spot syndrome virus (WSSV) is a pathogenic and threatening virus in shrimp culture for which there is no effective control strategy. Finding antiviral lead compounds for the development of anti-WSSV drugs is urgent and necessary; in this study, esculin from 12 monomeric compounds exhibited an excellent anti-WSSV activity. The results showed that esculin increased the survival rate of WSSV-infected shrimps by 59% and reduced the virus copy number in vivo over 90% at 100 μM. In the pre-treatment and post-treatment experiments, esculin could prevent and treat WSSV infection. Compared with the control group, the virus copy number decreased by 30% after 6 h of esculin pre-incubation with WSSV particles and inhibited horizontal transmission of WSSV to a certain extent. Considering that the antiviral activity of esculin was stable in the aquacultural water for 2 days, we evaluated the dosing pattern of continuous medication changes. Obviously, the survival rate of WSSV-infected shrimps was 0% at 108 h when no esculin exchange was made, while at 120 h the survival rate was over 40% at continuous medicine changes. In addition, esculin significantly increased the expression of antimicrobial peptides and thus improved the ability of shrimp to resist WSSV. Overall, our findings suggest that esculin has the potential to be developed into an anti-WSSV medicine. 相似文献
17.
18.
Satisfying nutrient requirement of corals is still a major constraint for maintaining corals in marine aquariums. Corals are
polytrophic in nature. Heterotrophic feeding on zooplankton is one of the corals’ strategies to overcome nutrient deficiency.
Artemia salina nauplii are commonly used as biocarriers for many fish larvae in aquaculture and can also serve as a biocarrier for coral
in aquariums, provided coral acceptability, optimal feeding rate, and digestibility of the nauplii are well understood. Feeding
rate and digestibility of coral fed on A. salina nauplii at 100, 2,000, 4,000, 6,000, and 10,000 ind. l−1 under light and dark conditions was assessed in this study. The maximum feeding rates of Galaxea fascicularis under light and dark conditions was 113.6 ind. polyp−1 h−1 and 76.9 ind. polyp−1 h−1, respectively. The daily feeding rates of G. fascicularis varies and depends on nauplii density. Light plays an important role in coral feeding. Nevertheless, the quantity of A. salina nauplii consumed by the coral under light and dark conditions was not significantly different (P > 0.05). A. salina nauplii are well accepted by G. fascicularis. Complete nauplii digestion was observed after 180 min. Digestibility of A. salina nauplii by G. fascicularis was positively correlated with digestion time. 相似文献
19.
A multiplex PCR kit for simultaneous detection of white spot syndrome virus (WSSV) and hepatopancreatic parvovirus (HPV) was developed and field testing was conducted. A 604‐bp target sequence was selected from the vp28 gene of WSSV. A primer set was developed to amplify a 338‐bp DNA fragment at the junction of the NS2 and NS1 protein genes of HPV after alignment of eight sequences from different strains. Another internal positive control primer set produced a 139‐bp PCR fragment from the β‐actin gene by alignment of this gene from Litopenaeus vannamei, Fenneropenaeus chinensis and Penaeus monodon. The detection limits, tested using purified plasmids, for WSSV and HPV were 21.4 and 19.0 copies respectively. The optimum ratio for HPV, WSSV and β‐actin was 3:1:1, with an optimum annealing temperature of 57°C. Field test of the multiplex PCR with 170 L. vannamei individuals from 17 aquaculture farms showed 41.8% coinfection with WSSV and HPV, and 40.0% and 3.5% single infection with WSSV and HPV respectively. No virus‐free shrimp farm was found. Ten wild catch F. chinensis individuals showed 60% coinfection, and 40% were infected with HPV. 相似文献
20.
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