Weight and width relationship of freshwater prawn (Macrobrachium rosenbergii)

It has been shown that there is no significant difference (P < 0·05) in the weight = f (width) and orbit length = f (width) relationships of commercially produced male and female Macrobrachium rosenbergii in Hawaii. A regression equation of the form ? = (A 1 X 7 B) 1 ? has been shown to adequately describe the above relationships. In particularWeight = 0·01278 1 (width) 7 2·5189, R 7 2 = 0·978Orbit length = 0·1828 1 (width) 7 0·77685, R 7 2 = 0.996This relationship allows the development of a simple mechanical prawn size sorter.     

Chemical and Thermal Properties of Freshwater Prawn (Macrobrachium rosenbergii) Meat

Chemical compositions and thermal properties of cultured freshwater prawn meat (FPM) were studied. FPM contained 83.2% protein (dry basis), 62.7% of which was myofibrillar protein. Pepsin-soluble collagen (PSC) and insoluble collagen (ISC) contents were 0.63 and 0.32%, respectively. Both collagens were similar to type V collagen from porcine placenta. Glutamic acid/glutamine, arginine, aspartic acid/?asparagine, and lysine were abundant amino acids in FPM. Glycine, proline, hydroxyproline, and aspartic acid/?asparagine were predominant in both collagens. FPM exhibited thermal transition temperatures (T_max) of 48.3 and 64.7°C, whereas T_max of PSC and ISC were 43.0 and 46.0°C, respectively. Textural changes in FPM during post-mortem storage on ice are plausibly dependent upon its compositional and thermal properties.     

Effect of nucleotide on growth, immune responses and resistance of Macrobrachium rosenbergii (De Man) to Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV) and Aeromonas hydrophila infection

A 60-day feeding trial was conducted to evaluate the effect of dietary nucleotide on growth, survival, immunity and resistance to white muscle disease and Aeromonas hydrophila infection in freshwater prawn (Macrobrachium rosenbergii). The nucleotide was supplemented at 0, 1.5, 2.25 and 3.0 g/kg diet. The test diets were fed for 60 days in triplicate groups of prawns, which had initial weight of 0.27 g. At the end of the feeding trial, growth was recorded and non-specific immune parameters, such as, prophenol oxidase activity, superoxide anion production, total haemocyte count and total serum protein, were studied in haemolymph samples. Phenol oxidase activity and superoxide anion production were significantly (P < 0.05) higher in prawns fed nucleotide-based diets. Total haemocyte count and haemolymph were higher (P < 0.05) in prawns fed nucleotide-based diets. The relative per cent survival of prawn after the challenge test against white muscle disease was significantly (P < 0.05) higher in prawn fed nucleotide-incorporated diets. However, there was no effect of nucleotide supplementation on growth and survival of prawn.     

Serum constituents of the Malaysian prawn (Macrobrachium rosenbergii) and pink shrimp (Penaeus marginatus)

Baseline serum values of newly captured Malaysian prawns (Macrobrachium rosenbergii) and pink shrimp (Penaeus marginatus) were determined by Sequential Multiple AutoAnalysis. Both of these species have considerable potential for commercial captive culture.Sex differences in serum constituent levels were found within species. Female pink shrimp had higher serum glucose levels than the males. Malaysian prawn males had higher cholesterol levels than females, and the latter had higher levels or activities of urea nitrogen, creatinine and lactic dehydrogenase.Pink shrimp held under laboratory conditions for 10 days had higher levels or activities of serum glucose and alkaline phosphatase and lower levels or activities of serum inorganic phosphorus, total protein, lactic dehydrogenase and glumatic-oxaloacetic transaminase than pink shrimp sampled immediately after capture.     

Current status and prospects of farming the giant river prawn ( Macrobrachium rosenbergii) and the oriental river prawn ( Macrobrachium nipponense) in China

The current status of the farming of Macrobrachium species in China is presented, including the scale of production and with an emphasis on its farming technology. The problems faced and research needed for the further development of freshwater prawn farming of China is also reviewed. Finally, this paper discusses the prospects and future expansion in this sector of national aquaculture.     

罗氏沼虾越冬新技术

罗氏沼虾为热带淡水虾,抗寒能力差。１７—１８℃活动减弱,摄食减少,１４℃以下持续几天就会冻死。罗氏沼虾收获季节成虾大量上市,易造成货多价跌,而干塘捕虾售完后易造成货缺价扬现象。因此,罗氏沼虾的越冬对丰富水产品市场,提高渔业经济效益具有十分重要的意义。...     

Embryonic development of Ganga river prawn Macrobrachium gangeticum (Bate)

Macrobrachium gangeticum (Bate) are commercially valuable prawns that are broadly distributed in the Ganga river that flows from northern to eastern India. We studied embryonic development from cleavage (blastomeres), segmentation, formation of optic vesicle, eye pigment development to larva formation, as these data are largely unknown in this species. We conducted this study using mature M. gangeticum broodstock placed in freshwater tanks. Just after spawning, females were kept in separate aerated tanks, where fecundity was estimated from the total number of eggs. Thereafter, egg samples from berried females were used to study their embryonic stages. The correlation coefficient between size and prawn weight, egg weight, egg number, body weight and egg mass of different sizes of prawns was analysed. Our results show that an increase in prawn size led to an increase in egg weight and egg number while decreases in body weight:egg mass ratio was noticed. Further results indicate that an increase in prawn weight had a positive impact on egg weight and egg number. The embryo development stages were used in this study as a tool to evaluate the development process of the prawn in a hatchery environment.     

人工诱导罗氏沼虾同步产卵与卵巢组织学研究

运用保幼激素类似物－ＺＲ５１５诱导罗氏沼虾同步产卵进行了生产性规模试验，每性雌虾体钙点滴４０μｌＪＨＡ－ＺＲ５１５，通过体表渗稼促进卵巢成熟和产卵。药物处理后１６－１７天，产卵率为４１．８１％，较常规生产的自然产卵率提高５０．２３％。罗氏沼虾卵巢生物学和组织滂研究表明，性成熟后的任何发育阶段，卵巢中均存在由卵原细胞组成的生发带和卵黄发生卵母细胞。     

Fecundity changes in Macrobrachium rosenbergii (de Man) during egg incubation

Abstract. For a study of the fecundity of Macrobrachium rosenbergii , a total of 117 berried females were sampled from ponds. Fecundity was found to vary from 1216 to 89747 eggs for prawns measuring 9.0cm to 15.8cm total length and weighing 6.22 to 45.80g. The relationship between fecundity (EN) and total length (TL) was found to be EN = 0.001876 TL^6.3617.
The average egg number/g total body weight for prawns having orange, yellow and grey eggs was 1132.7 ± 484.1,766.4 ± 524.3 and 745.5 ± 487.2, respectively, a decrease of 32.3% when orange eggs became yellow and 34.3% when they turned grey. This decrease was probably due to unfertilized eggs dropping off and some eggs being eaten by the brooders during the incubation period.
Egg numbers/g egg weight were found to be 11360.1 ± 1642.1,10715.7 ± 2725.3 and 8634.0 ± 1892.3 for orange, yellow and grey eggs, respectively. When compared to orange eggs, yellow eggs were slightly heavier (6%), but grey eggs were significantly heavier by 31.6%. The increase in the weight of the grey eggs can be explained by the elongation of fully formed organs and appendages by about 17 days post fertilization.     

青虾池塘养殖试验

青虾又名河虾,学名日本沼虾,主要分布在我国和日本,无论在南方还是北方都能很好地生长和繁殖,青虾是经济价值较高又普遍受市场欢迎的名特优水产品,不仅肉味鲜美无腥无刺,而且营养丰富。青虾的养殖在我国具有悠久的历史,但多以粗放粗养为主,产量低、效益差。为促进我市渔业产业结构调整,     

青虾苗自繁自育技术

青虾生长速度快,养殖成本低,市场需求量大,销售季节长,生产效益好,是水产养殖的优质品种之一。目前池塘养虾,每1／15hm^2产量可达100kg以上,生产效益可观。自繁自育苗种,是搞好养虾生产,获得较好经济效益的基础,现将青虾苗自繁自育技术介绍如下：     

Effect of ammonia-N on growth and feeding of juvenile Macrobrachium rosenbergii (De-Man)

Survival rate, growth and feed intake were determined for late juveniles (4.31 ± 0.18 g) of river prawn Macrobrachium rosenbergii in freshwater with total ammonia‐N (NH₃‐N+NH₄‐N) concentrations of 0.015 (control), 0.5, 1.0 and 1.5 mg L⁻¹ for 60 days at pH 7.53 ± 0.04 and temperature 24.0 ± 2.5°C. Survival rate was significantly (P<0.05) lower (54 ± 4.2–70 ± 5.4%) for total ammonia concentrations from 0.5 to 1.5 mg L⁻¹ [0.0139–0.0419 mg L⁻¹ of unionized ammonia (NH₃)]. Growth (0.026–0.030 g day⁻¹ range) of the prawns did not differ for the different NH₃ levels but were significantly (P<0.05) lower compared with control (0.056 g day⁻¹). Feed intake rates also diminished significantly (P<0.05) from 77.60 ± 2.45% at control (0.015 mg L⁻¹ NH₃‐N) to 48.69 ± 2.13% at 1.5 mg L⁻¹ NH₃‐N (0.0419 mg L⁻¹ of unionized NH₃).     

Allozyme variation in riverine and lacustrine populations of Macrobrachium nipponense (de Haan)

Abstract. Allozyme variation at 32 protein genetic loci was studied in four populations of Macrobrachium nipponense (de Haan) from two contrasting habitats, wholly freshwater lacustrine sites and brackish water riverine areas from different parts of Asia (Hong Kong, Canton, Wuhan, Japan). The average values of observed heterozygosity were 7·45% for lacustrine and 12·30% for riverine sites, the percentage of polymorphic loci (0·99) was 32·5%. The freshwater/lacustrine populations had lower estimates of genetic variability than the river/brackish water populations. The average genetic similarity and genetic distance (Nei's) were 0·92 and 0·084 respectively. The results were compared with those of the only other study on this species. The implications of these results for this species are discussed.     

青虾的暂养与活体运输技术

青虾 ,又名河虾 ,学名叫日本沼虾 (Macro brachiumnipponense) ,隶属节肢动物门、甲壳纲、长臂虾科、沼虾属 ,是淡水虾中最重要的一类 ,也是我国产量最大的淡水虾。青虾在我国分布很广 ,江苏、上海、浙江、福建、江西、四川、广东、湖北等省市均有分布 ,它广泛生活于淡水湖泊、     

Monoculture of Indian freshwater prawn,Macrobrachium malcolmsonii (Milne Edwards)

The paper describes the growth and production performance of the Indian freshwater prawn, Macrobrachium malcolmsonii, in a monoculture system. At a moderate stocking density of 60 000 ha, survival of prawns ranged from 44.2 to 57.2%. Wide size variation was noted, with only 27.9–36.1% of the prawns attaining market size. Males grew faster than females, with average lengths and weights of 136–152 mm, 44–63 g and 124–135 mm, 31–38 g, respectively, recorded during multiple harvests in a 390-day growout period. By adopting a continuous culture system with periodic harvesting, total production of M. malcolmsonii reached 534.2–690.4 kg/ha with a 475.3–605.4 kg/ha marketable yield in 390 days.     

Live transportation of Macrobrachium rosenbergii (De Man) in chilled sawdust

Three cooling rates of 1.26±0.09°C h^?1 within 8 h (slow, T₁), 2.52±0.18°C h^?1 within 4 h (moderate, T₂) and 5.04±0.36°C h^?1 within 2 h (fast, T₃) were tested to cold‐anaesthetize farm raised Macrobrachium rosenbergii (De Man) (45–52 g) in each case from 25°C down to 15±1°C in a refrigerated chilling tank, provided with aeration. The cold‐anaesthetized prawns subjected to each chilling rate were packed in an insulated cardboard box (triplicate) between two layers of moist and chilled (2–3°C) sawdust, and kept inside a chilled storage cabinet at 15±1°C, for set durations of 6, 9, 12, 15 and 18 h. Survival was determined by revitalizing the prawns in aerated water with an initial temperature of 20°C, which was raised to 29±1°C within 3 h. The experiment was repeated using berried females acclimated to brackishwater of 12 g L^?1 salinity and the percentage survival recorded after live storage for durations ranging from 6 to 24 h at intervals of 3 h. Statistically valid safe durations for obtaining 100% survival of the cold anaesthetized and live stored prawns were determined using probit analysis at the three chilling rates tested, and were found to be 7.39, 6.98 and 4.54 h in the case of adult prawns, and 7.87, 8.17 and 6.43 h for berried females for T₁, T₂ and T₃ respectively. For practical purposes, the durations that yielded 95% survival rates were computed to be 16.47, 12.14 and 8.35 h in the case of adult prawns and 18.49, 19.02 and 11.11 h for berried females for T₁, T₂, and T₃ respectively. The berried prawns revitalized after live storage were incubated in tanks and the zoea larvae reared up to postlarvae (PL‐5), and compared against a control. No significant difference was found in larval hatch fecundity, survival rate and the production of PL L^?1 between the treatment and control, indicating that the method of cold anaesthetization and live storage of berried prawns could be used for successful transportation of broodstock.     

罗氏沼虾与青虾轮养技术

罗氏沼虾具有食性杂、生长快、产量高的优势 ,但是不耐低温 ,在我国江淮流域 ,虾池的利用实际只有半年时间 (5～ 1 0月 )。青虾适温范围广 ,生长快。它具有繁殖力强、肉味鲜美、经济价值高的特点。为了提高池塘的养殖效益 ,在实际生产过程中 ,可以通过增大放养规格 ,加强饲养管理 ,来缩短罗氏沼虾生长周期(1 0 0天以内 )。另一方面采取二级放养的措施 ,来延长青虾生长时间 ,从而实现罗氏沼虾、青虾的二茬轮养。下面就我们 1 999年开展的这一试验做一初步总结。1　条件和方法1 1　试验池 :为马鞍山市前庄水产良种场2 2 #、2 3#成虾池 ,面积…