Gene Expression in Black Tiger Prawns Following Intramuscular Injection of β-gal Plasmid     

Z.H. Sulaiman  R.H. Ming Chan  P.M. Simanjuntak 《Aquaculture International》1999,7(5):333-340

Gene expression in black tiger prawns (Penaeus monodon) was studied following intra-muscular injection of CMVGal plasmid into the second abdominal segment. We used an in situ staining technique to detect -gal expression in one- and three-month-old injected prawns. We found that only one of the three-month-old prawns expressed the marker gene (2 days after injection), and the site of expression was confined to the sixth abdominal segment away from the injection site. We repeated the experiment on a new batch of three-month-old prawns, but using fluorometric determination technique. This time we found that -gal expression was detected (6/42) at the site of injection after 2, 7, and 14 days. In two other test samples, transgene expression was detected in the sixth abdominal segment only, further confirming the possibility of injected DNA dispersal. The results of the study also suggest that direct gene transfer is a feasible technique in black tiger prawns.  相似文献   

Dominant sources of dietary carbon and nitrogen for shrimp reared in extensive rice-shrimp ponds   总被引：1，自引：0，他引：1  

Michele A Burford  Nigel P Preston  Truong Hoang Minh  Tran Thi Tuyet Hoa  Stuart E Bunn  & Vanessa M Fry 《Aquaculture Research》2004,35(2):194-203

Stable isotope analysis was used to determine the sources of dietary nitrogen (N) and carbon (C) for shrimp during the rearing phase in extensive rice‐shrimp ponds in My Xuyen and Gia Rai districts, Vietnam. Farm‐made feed was added as a food source in shrimp ponds in My Xuyen district, and based on stable isotope analyses, was generally a poor dietary source. The commercial formulated feed used in Gia Rai also appeared to contribute little directly to the nutritional needs of the shrimp. In contrast, the natural biota in all ponds appeared to contribute substantially. In particular, biota from beam trawls and benthic organic matter were the most likely sources of nutrition in My Xuyen ponds, while benthic organic matter was the main source in Gia Rai ponds. δ¹⁵N ratios in the natural biota in My Xuyen farms decreased over the growing season, suggesting increased N fixation in the case of the benthic organic matter reaching values as low as 1‰. This suggests N‐limitation in the ponds and that natural biota become increasingly dependent on N fixed by algae and/or other microorganisms. There is the potential to promote the growth of the plankton and hence, the other natural biota, by the judicious addition of fertilizer.  相似文献   

Treatment of shrimp farm effluent with omnivorous finfish and artificial substrates   总被引：1，自引：0，他引：1  

Dirk Erler  Peter Pollard  Peter Duncan  & Wayne Knibb 《Aquaculture Research》2004,35(9):816-827

Long‐term environmental sustainability and community acceptance of the shrimp farming industry in Australia requires on‐going development of efficient cost‐effective effluent treatment options. In this study, we aimed to evaluate the effectiveness of a shrimp farm treatment system containing finfish and vertical artificial substrates (VAS). This was achieved by (1) quantifying the individual and collective effects of grey mullet (Mugil cephalus L.) and VASs on water and sediment quality, and (2) comparing the retention of N in treatment systems with and without the presence of finfish (M. cephalus and the siganid Siganus nebulosus (Quoy & Gaimard)), where light was selectively removed. Artificial substrates were found to significantly improve the settlement of particulate material, regardless of the presence of finfish. Mullet actively resuspended settled solids and reduced the production of nitrate when artificial substrates were absent. However, appreciable nitrification was observed when mullet were present together with artificial substrates. The total quantity of N retained by the mullet was found to be 1.8– 2.4% of the incoming pond effluent N. It was estimated that only 21% of the pond effluent N was available for mullet consumption. When S. nebulosus was added, total finfish N retention increased from 1.8% to 3.9%, N retention by mullet also improved (78±16 to 132±21‐mg N day^?1 before and after siganid addition respectively). Presence of filamentous macroalgae (Enteromorpha spp.) was found to improve the removal of N from pond effluent relative to treatments where light was excluded. Denitrification was also a significant sink for N (up to 24% N removed). Despite the absence of algal productivity and greater availability of nitrate, denitrification was not higher in treatments where light was excluded. Mullet were found to have no effect on the rates of denitrification but significantly reduced macroalgal growth on the surface of the water. When mullet were absent, excessive macroalgal growth led to reduced dissolved oxygen concentrations and nitrification. This study concludes that the culture of mullet alone in shrimp farm effluent treatment systems does not result in significant retention of N but can contribute to the control of macroalgal biomass. To improve N retention and removal, further work should focus on polyculturing a range of species and also on improving denitrification.  相似文献   

日本对虾活虾冬季运输技术研究     

宫春光  李凤臣  苏利 《水产科学》2006,25(6):310-311

研究了日本对虾在不同运输方式、装运密度、运输时间下的运输成活率。结果表明:无水运输日本对虾密度在33.3 kg/m2时,3 h以内的运输成活率均在95%以上;无水充氧运输日本对虾密度在33.3 kg/m2时,13 h以内的运输成活率均在90%以上。  相似文献   

Trypsin enzyme activity during larval development of Litopenaeus vannamei (Boone) fed on live feeds   总被引：1，自引：0，他引：1  

A C Puello-Cruz  R S Sangha  D A Jones  & L Le Vay 《Aquaculture Research》2002,33(5):333-338

Larval stages of the Pacific white shrimp, Litopenaeus vannamei (Boone) were fed standard live diets of mixed microalgae from the first to the third protozoea (PZ1 to PZ3), followed by Artemia nauplii until post‐larvae 1 (PL1). Trypsin enzyme activity for each larval stage was determined using N‐α‐p‐toluenesulphonyl‐l ‐arginine methyl ester (TAME) as a substrate. Results were expressed as enzyme content to assess ontogenetic changes during larval development. Tissue trypsin content (IU µg^?1 DW for each larval stage) was significantly highest at the PZ1 stage and declined through subsequent stages to PL1. This contrasts with previously observed patterns of trypsin development in Litopenaeus setiferus (Linnaeus) and other penaeid genera, which exhibit a peak in trypsin activity at the third protozoea/first mysis (PZ3/M1) larval stage. Litopenaeus vannamei larvae transferred to a diet of Artemia at the beginning of the second protozoea (PZ2) stage were significantly heavier on reaching the first mysis stage (M1) than those fed algae, while survival was not significantly different between treatments. At both PZ2 and PZ3 stages, trypsin content in larvae feeding on Artemia was significantly lower than in those feeding on algae. The rapid decline in trypsin content from PZ1 and the flexible enzyme response from PZ2 suggest that L. vannamei is physiologically adapted to transfer to a more carnivorous diet during the mid‐protozoeal stages.  相似文献   

On-farm evaluation of three different hatchery sources of Pacific white shrimp (Litopenaeus vannamei) cultured in on-levee tanks in low-salinity waters of west Alabama     

Luke A. Roy  David Teichert-Coddington  Sunni Dahl  Benjamin H. Beck  Craig A. Shoemaker  Gregory N. Whitis 《Journal Of Applied Aquaculture》2020,32(3):193-204

ABSTRACT

Shrimp farmers in Alabama who produce the Pacific white shrimp, Litopenaeus vannamei, have recently reported abnormally low survival at harvest. Farmers have hypothesized that this phenomenon may be due to disease, toxic algae, shrimp source, or reduced shrimp robustness in later stages of production. To compare performance of shrimp from different sources, postlarvae were obtained from three different hatcheries and stocked on the same day in on-levee tank systems (TS) on two farms (Farm 1-TS; Farm 2-TS1; Farm 2-TS2). Following 104 days of culture on Farm 2-TS1 and Farm 2-TS2, there were no differences in survival (72.8%–91.2%) or final weight (19.8–24.6 g). At Farm 1-TS following 107 days of culture, there were differences in survival from shrimp sourced from one hatchery (40.5%) compared to the other two hatcheries (61.0%–69.8%). Results demonstrated acceptable growth performance and survival from all hatchery sources.  相似文献   

Effects of partial and complete replacement of freshwater shrimp meal (Caridinea niloticus Roux) with a mixture of plant protein sources on growth performance of Nile tilapia (Oreochromis niloticus L.) in fertilized ponds     

David M Liti  Herwig Waidbacher  Michael Straif  Raphael K Mbaluka  Jonathan M Munguti  & Mark M Kyenze 《Aquaculture Research》2006,37(5):477-483

Despite the well‐documented herbivorous food habits, commercial feeds for production of Oreochromis niloticus usually contain between 7% and 15% animal protein. However, animal protein feedstuffs are expensive, hence the need to search for cost‐effective alternatives in plant‐protein sources. Such alternatives are probably more effective in semi‐intensive systems where natural pond food forms part of the diet. This study evaluated the performance of O. niloticus after feeding diets in which fresh shrimp meal (SM) was gradually replaced by a mixture of plant‐protein sources in fertilized ponds. Three isonitronegenous (24% crude protein) diets containing 12 (control), 6% and 0% SM were fed to three groups of O. niloticus in four replicates per group for 250 days. Fish were fed daily at 2% body weight and sampled monthly to monitor growth and make feed adjustments. Growth, yields, survival and feed conversion ratio were not significantly different (P>0.05) among treatments. Growth of males was double that of females, while the sex ratio was skewed towards females. Although complete substitution of SM by plant protein did not affect the growth of tilapia, production cost was reduced by 36%. In conclusion, animal protein is not required in diets for production of O. niloticus in fertilized ponds.  相似文献   

对虾白黑斑病的病原病因研究   总被引：2，自引：0，他引：2  

蔡生力 《水产学报》1996,20(4):325-331

对虾白黑斑病是养殖中国对虾的常见病，曾被怀疑是细菌性疾病，本试验通过对病虾肝胰腺、血液和病灶组织的细菌分离，对正常虾用白黑斑虾的细菌注射感染等一系列试验发现：细菌或其它生物性病原与对虾白黑斑病并无直接关系。  相似文献   

Dietary folic acid requirement determined for grass shrimp, Penaeus monodon     

Shi-Yen Shiau  Shih-Ying Huang 《Aquaculture (Amsterdam, Netherlands)》2001,200(3-4):339-347

A feeding trial was conducted to determine the dietary folic acid requirement of juvenile grass shrimp, Penaeus monodon. Purified basal diets were formulated using vitamin-free casein as the protein source. Graded levels (0, 1, 2, 5, 10, 15, 30, and 60 mg folic acid/kg diet) of folic acid were added to the basal diet, resulting in eight dietary treatments in the experiment. Each diet was fed to three replicate groups of shrimp initially averaging 0.79±0.01 g for 8 weeks. Shrimp fed diets supplemented with 2 mg folic acid/kg diet had greater (P<0.05) weight gain and hepatopancreatic folic acid concentrations than shrimp fed the unsupplemented control diet. Feed efficiency (FE) was highest in shrimp fed the diets supplemented with 2 mg folic acid/kg diet, followed by the groups fed 1 mg/kg, then the control group. Hepatosomatic index (HSI) was highest in shrimp fed the control diet, followed by 1 mg folic acid/kg and lowest in shrimp fed diets supplemented with 2 mg folic acid/kg. Weight gain percentage, hepatopancreatic folic acid concentration and hepatosomatic index of the shrimp analyzed by broken-line regression indicated that the adequate dietary folic acid concentration in growing P. monodon is 1.9–2.1 mg/kg diet.  相似文献   

长毛对虾幼体的食性   总被引：3，自引：0，他引：3  

陈柏云  易建生 《水产学报》1991,15(3):218-227

本文采用11种单细胞藻类、3种动物、2种人工饵料，分别喂养不同发育期的长毛对虾幼体，从其变态速度和存活率，比较各种饵料的效果．并对幼体口器与食性关系、溞状幼体死亡率与食性转化关系，以及人工投饵与生态系育苗相结合的问题作了初步探讨。  相似文献