Assessment of requirement values for essential amino acids in the prawn, Marsupenaeus japonicus (Bate)

The requirements of juvenile prawn, Marsupenaeus japonicus (Bate), 0.79 g initial body weight, for essential amino acids (EAA) were evaluated based on the daily increase of each EAA in the whole body when the prawn was maintained on a diet with a high nutritive value (a casein‐squid protein‐based diet). The quantities of each EAA needed daily for growth and maintenance of prawn are conceived to correspond to the daily requirements of this prawn species for EAA. Therefore, these requirement values of respective EAA should be supplied from dietary proteins. To determine these values, protein and amino acids of the whole body of the prawn were quantified before and after feeding experiments, and the quantities of respective EAA needed to meet the requirements were estimated based on the EAA profile of the whole body protein of prawn. As a result, the contents of EAA in dietary proteins (%) needed to meet the requirements of the prawn for EAA were assessed to be: threonine (2.3), methionine (1.3), valine (2.4), isoleucine (2.3), leucine (3.4), phenylalanine (2.6), lysine (3.2), histidine (1.1), arginine (2.9) and tryptophan (0.6), respectively, when the prawn are fed 50% protein diet with 90% protein digestibility at a ration size of 2% (% of body weight).     

Expression of a recombinant crustacean hyperglycemic hormone of the kuruma prawn Penaeus japonicus in methylotrophic yeast Pichia pastoris

ABSTRACT:   Until now, six crustacean hyperglycemic hormones (CHH) designated Pej-SGP-I, -II, -III, -V, -VI and -VII have been characterized in the kuruma prawn Penaeus japonicus . All CHH consist of 72 amino acid residues and have an amidated carboxyl (C)-terminus. In the present study, we expressed Pej-SGP-III in methylotrophic yeast Pichia pastoris in order to obtain a large quantity of recombinant CHH possessing biological activity. A cDNA encoding Pej-SGP-III that had been previously cloned was processed by polymerase chain reaction (PCR) and the resulting product was ligated into an expression vector. Pichia pastoris was transformed with this vector after which a recombinant Pej-SGP-III was expressed having an additional amino acid residue (glycine) at the C-terminus (rPej-SGP-III-Gly), a form considered to be a putative precursor of this hormone. rPej-SGP-III-Gly secreted into the culture medium was purified by reversed-phase HPLC, and amidated using a peptidylglycine alpha-amidating enzyme. The amidated rPej-SGP-III (rPej-SGP-III) showed hyperglycemic activity in in vivo bioassay almost comparable to that of the natural Pej-SGP-III. rPej-SGP-III thus obtained will be a useful tool not only for its physiological study but also for the determination of its 3-D structure.     

日本对虾杆状核病毒性传染病诊断技术

本文提出了分别用暗视野显微技术和透射电子显微技术快速确诊日本对虾杆状核病毒性传染病的方法。在暗视野显微镜下观察到的血淋巴中的病毒粒子大小约为0.5μm;胃表层上皮被病毒感染的细胞核明显地呈白色均质小体,直径10～15μm,球形或椭圆形,坏死细胞被囊化为棕色小块(约20～50μm)。病虾血淋巴和胃经负染制样在透射电子显微镜下观察病毒颗粒大小为400×150nm;核衣壳大小为390×85nm。     

Evaluation of cholesterol additions to a soyabean meal-based diet for juvenile Pacific white shrimp, Penaeus vannamei (Boone), in an outdoor growth trial

Cholesterol is considered a required nutrient for penaeid shrimps, but an optimal level has not been defined. A 68-day grow-out trial was conducted in 1300-L outdoor tanks in Hawaii, USA, to determine the cholesterol level required in a soyabean meal-based diet for juvenile Pacific white shrimp, Penaeus vannamei (Boone). Test feeds were prepared by adding six cholesterol levels (1.0-10.2 g kg^?1, as-fed basis) to a standard diet high in plant-protein meals, starch and flour. These feeds were provided to the shrimp three times daily. Harvest weights and weekly growth increments varied significantly among diets. The 2.3 g kg^?1 and 4.2 g kg^?1 cholesterol diets yielded better growth than the 1.0 g kg^?1 and 10.2 g kg^?1 diets. Survival and feed conversion ratios did not vary significantly among diets. Significant dietary cholesterol effects on growth of P. vannamei in conditions resembling commercial grow-out indicate that its inclusion in practical diets at more accurately defined levels is necessary. Optimal cholesterol levels for juvenile shrimp may be lower than those now utilized, and may vary relative to the contribution of free sterols from natural foods in shrimp ponds.     

Evaluation of various diets for the optimum growth and survival of larvae of the penaeid prawn Penaeus japonicus Bate

Four types of food were tested to determine their effects on the growth and survival of larvae of the penaeid shrimp Penaeus japonicus Bate. The food types were live cells of Candida utilis (yeast), freeze-dried Candida utilis, microparticulate diet, and microencapsulated diet (commercial product). The diatom Chaetoceros gracilis was fed to larvae as a control. Two sets of experiments were carried out; the first was run in outdoor 1.5 ton tanks, and the second in indoor 1.2 ton tanks. In the outdoor experiment, the best survival and growth from nauplius to postlarva stage were obtained using microparticulate diet. During the first week of culture, freeze-dried Candida utilis resulted in the highest growth and survival among examined diets, but both factors dropped dramatically after the mysis stage. In the indoor experiment, the best growth and survival were obtained using live cells of Candida utilis from nauplius stage to end of mysis stage followed by brine shrimp. Tested diets were analysed for their contents of crude protein, total lipids, total carbohydrates, amino acid profiles and fatty acid contents.     

Dietary phosphatidylcholine requirements in larval and postlarval Penaeus japonicus Bate

Three nutritional experiments were carried out to investigate the effect of dietary phosphatidylcholine (PC) on the growth (length, weight and metamorphosis) and survival (rearing and stress) of larval and postlarval Penaeus japonicus Bate. Purified soybean phosphatidylcholine (SPC, 95% purity), hen egg-PC (EPC, 94% purity), and de-oiled soybean lecithin (DSL, PC 23% purity) were used as sources of dietary PC. The results indicated that optimal metamorphosis in larval P. japonicus was obtained at levels of 15–30 g kg^?1 of dietary SPC. Feeding trials with postlarval P. japonicus showed that low levels of dietary SPC (15 g kg^?1) were more beneficial than higher levels of SPC (30 g kg^?1) or DSL (65 g kg^?1), although early postlarvae (<3 mg dry weight) presented a higher requirement for PC than later stages. Shrimp fed the 150 g kg^?1 PC-supplemented diets exhibited significantly better resistance to salinity stress than those fed a PC-deficient diet. A high level of dietary soybean lecithin (65 g kg^?1 DSL), providing 15 g kg^?1 of dietary PC, was no more effective for young postlarvae of P. japonicus than 15 g kg^?1 of purified PC alone, which suggested that the other phospholipids (mainly phosphatidylethanolamine and phosphatidylinositol) in the soybean lecithin are not required for postlarval shrimp, at least when there is already an adequate source of PC.     

刺参与日本对虾池塘高效混养技术

刺参夏眠期间正是日本对虾生长的大好季节,将刺参和日本对虾混养,在7月份放养虾苗,严格控制养殖池内的杂鱼虾等,就可大大提高日本对虾和刺参的成活率,利用此二者在饵料和空间的互补性,可显著提高虾池的利用率和经济效益。     

Effect of high water temperature on the survival, moulting and food consumption of Penaeus (Marsupenaeus) japonicus (Bate, 1888)

The kuruma shrimp, Penaeus (Marsupenaeus) japonicus (Bate, 1888), is a valuable aquaculture species in Queensland, Australia. The shrimp is supplied live to the Japanese market and must survive emersed transport for up to 36 h. In-transit mortality after harvest from high water temperatures (> 30 °C) has been reported by the industry, and a knowledge of the effects of high water temperature may provide important information for producers on grow-out management, timing of production and farm location. Experiments were conducted to determine the effect of high water temperature on survival, moulting and food consumption in P. japonicus. Replicated groups of 15.6 ± 0.2 g shrimp were acclimated and exposed to five temperatures, between 28 and 36 °C, for up to 28 days. Mortality was highest at 36 °C and equally lowest between 28 °C and 32 °C. Intermoult period was not significantly different for temperatures between 28 and 32 °C (19.8–15.5 days) but was significantly greater above 32 °C (27.4 days at 34 °C and > 104 days at 36 °C). There was evidence of moulting synchrony at 28 °C. Mean daily food consumption was highest at 32 °C at 2.34% of body weight, but decreased to 1.56% at 28 °C and 1.33% at 36 °C. Over the range of water temperatures examined, survival, moulting rate and food consumption were highest at 32 °C.     

缢蛏与对虾无公害生态养殖技术研究

改造66．7hm^2对虾养殖池塘,放养规格6000粒／kg的缢蛏苗种6250kg,日本对虾苗种1200万尾（2茬）,当年共收获缢蛏（规格6．67cm）270100kg,对吓124400kg,实现产值537．39万元,利税369．67万元。     

北方地区日本对育苗技术的探讨

针对我国北方地区日本对虾育苗生产存在的问题,对亲虾利用率,幼体引进,幼体培育等有技术进步全全面探讨,专家鉴定认为,硒成果达国内领先水平。     

日本对虾仔虾培育试验

用无节幼体培育仔虾,采用的对虾幼体饵料有中肋骨条藻、卤虫无节幼体及台湾产的人工配合饵料,并注意饵料的配合使用及消毒工作;为维持水质稳定,整个培育期间不换水,加大布气石的密度（３．６个／ｍ２）。在３００ｍ３水体中,一茬育出仔虾２２１８万尾,成活率为６６．２％,取得了良好的经济效益。     

弧菌疫苗对斑节对虾和日本对虾免疫预防的作用

尝试使用免疫学的方法来防治对虾弧菌病。将病原副溶血弧菌制成福尔马林灭活疫苗,在实验条件下分别以浸泡、口服和注射等方式接种于斑节对虾和日本对虾,结果发现,在一定的范围内,对虾的免疫保护率随疫苗浓度的增加而升高。在注射接种的方式中,斑节对虾在１９＾９、１０＾８、１０＾７ｃｅｌｌｓ．ｍＬ＾－１的疫苗剂量下的保护力分别为４０％、５０％和４０％,浸泡组（疫苗浓度分别为１０＾８ｃｅｌｌｓ．ｍＬ＾－１、１０＾７     

日本对虾血清凝集素及其免疫作用的初步研究

用日本对虾（Penaeus japonicus)亲虾的血清与11株弧菌和7种脊椎动物的红细胞进行凝集反应实验，其中，溶藻弧菌HW283的凝集效价最高，达4096，而产气弧菌和海蛹弧菌的凝集效价最低，仅为8；与红细胞的凝集结果显示，对虾血清与大白鼠，小白鼠，豚鼠的红细胞反应较强，与鸡、人、山羊、兔的红细胞反应较弱，表明日本对虾血清中存在自然凝集素，养成期的日本对虾经弧菌菌苗免疫后，对该致病菌株的抵抗力获得提高，病原感染组，对照组和菌苗免疫组的对虾血清分析对豚鼠，大白鼠和小白鼠红细胞的凝集强度皆为感染组＞对照组＞免疫组。     

日本对虾对镉冒集能力的研究

研究了日本对虾摄食镉含量不同的饲料,其可食部位与不可食部位对饲料中镉的富集能力。研究结果表明,镉主要富集于日本对虾不可食部位,可食部位与不可食部位对镉的富集趋势基本一致,均随着镉浓度的上升而增大,且不可食部位对镉的最高富集量明显高于可食部位。     

浙北地区利用冬闲虾塘饲养日本对虾的试验

利用饲养南美白对虾的冬闲虾塘 ,采取精养模式养一茬日本对虾 ,可提高围塘养殖的综合效益。本试验的放养密度为 2× 10 4余尾 / 6 6 7m2 ,单产 38.5kg/ 6 6 7m2 ,成活率 2 3.3%。盐度控制在 17以上     

Inheritance mode of microsatellite DNA markers and their use for kinship estimation in kuruma prawn Penaeus japonicus

The allelic inheritance mode of microsatellite DNA markers was examined using seven copulated wild females and their offspring. Five microsatellite loci, CSPJ002 *, CSPJ010 *, CSPJ012 *, CSPJ014 *, and CSPJ015 *, were used in the study. At almost all family/locus combinations, one sire was determined and distributions of genotypes in offspring were consistent with the Mendelian segregation ratio. Distributions of genotypes were consistent with the ratio after assuming a null allele at some loci. Consequently, the alleles of CSPJ002 * and CSPJ012 * were inherited following the Mendelian inheritance mode in every family; however, the null allele was expected in CSPJ010 *, CSPJ014 *, and CSPJ015 * in some families. Thus, these loci should be used carefully in population genetic analysis, but siblings could be detected in the dendrograms based on unweighted pair-group method using arithmetic averages (UPMGA).     

Relatedness structure estimated by microsatellites DNA and mitochondrial DNA polymerase chain reaction–restriction fragment length polymorphisms analyses in the wild population of kuruma prawn Penaeus japonicus

ABSTRACT: The genetic structure and variability of four wild populations of kuruma prawn in Japan were examined by estimating relatedness among individuals. The relatedness was estimated by five microsatellites (MS) DNA markers. Examination of relatedness showed that individuals were related significantly in Kumamoto and Kagoshima. In Kagoshima, some individuals showed full-sib level of relatedness. The analysis of mitochondrial (mt)DNA polymerase chain reaction–restriction fragment length polymorphisms (PCR-RFLP) was also performed, showing that the closely related individuals in Kagoshima tended to share a common haplotype. It is, therefore, supposed that there are many kins in Kumamoto and Kagoshima. However, the heterozygosities and allelic and genotypic frequencies in MS-DNA analysis were not significantly different among the localities. Moreover, the haplotype distributions of mtDNA in Kumamoto and Kagoshima were significantly different from other localities. Thus, it is suggested that no spatial differentiations occurred due to the geographic or historical effects between the localities and that there is the possibility of a mixture of hatchery populations in Kumamoto and Kagoshima.     

Development of a Bacterial Denitrification Filter for Sand-Based Recirculating Saltwater,Penaeus japonicus Shrimp Culture Systems

Abstract

This study investigated the ability of a simple bacterial denitrification filter (BDF) to reduce nitrate levels in experimental low-intensity recirculating broodstock tanks. These broodstock tanks are equipped with a sand-substrate system which provided the dual purpose of habitat and nitrification filter. The BDF was constructed of 50-mm PVC pipe, filled with 50% gravel and 50% crushed pipi shell. The BDF was designed to be easily fitted to individual tanks (assisting biosecurity) and to operate with minimal management.

There were 3 treatments, each with 3 replicates: control tanks with no BDF; tanks with BDFs receiving 0.605 g C/day as glucose (Low C); and tanks with BDFs receiving 1.512 g C/day as glucose (High C). Kuruma shrimp, Penaeus japonicuswere maintained in all tanks at a density of 185 g/m² (avg. weight of 8.02±2.4 g), and no water was exchanged for the duration of the experiment. In the control tanks, nitrate increased at about 1 mg/L/day until 38 days when it peaked at 38.9 mg/L. Nitrate levels in control tanks decreased slightly (i.e., by up to 2.5 mg/L) from 38 days to 50 days when the experiment was concluded. In the Low C treatments, nitrate increased at a similar rate at first; however, it peaked at 24 days (18 mg/L) and then gradually reduced to 12 mg/L after 50 days. In the High C treatments, nitrate also peaked at 18 mg/L after 24 days, but then decreased to zero by 50 days.

Sand-substrate in the High C treatment tanks was anoxic by the end of the experiment (black beneath the surface, with redox potential < –100 mV). However, in the control and Low C treatments, where nitrate levels were above 10 mg/L, the substrate remained in good condition (no black sediment, and redox potential –10 to 50 mV).

These results demonstrate that a simply-designed and operated BDF, together with an appropriate nitrification system, can effectively maintain nitrate below 20 mg/L, removing the need for water exchange and improving biosecurity. The BDF operation should be limited to allow nitrate to be maintained at about 10 mg/L, to help maintain oxidized conditions in the sediment.     

日本对虾与菲律宾蛤仔混养技术的研究

本文报道了日本对虾与菲律宾蛤仔混养的技术措施,结果表明:试验池投入产出比为1:3.7,经济效益显著。