Effects of silver carp and small indigenous species on pond ecology and carp polycultures in Bangladesh

A sustainable semi-intensive pond aquaculture technology including major carp species as cash-crop and small indigenous fish species (SIS) as food for the farmers' families is being optimized in Bangladesh. The inclusion of silver carp (Hypophthalmichthys molitrix), a cheap large species affordable by poor farmers, is now being considered. As part of a study on the effects of this filter feeder on polycultures including the large carps rohu (Labeo rohita), catla (Catla catla) and common carp (Cyprinus carpio) and the SIS punti (Puntius sophore) and mola (Amblypharyngodon mola), an experiment was carried out to test the effects of silver carp and of each SIS species on the growth, survival and yield of the large and small fish and on pond ecology.The ecology of the ponds was dominated by changes in time, strongly related to the development of a surface plankton scum at the beginning of the culture season and weather conditions. The surface scum increased decomposition processes and decreased algal development in the water body, promoted photosynthesis and ammonium release and reduced nitrification. Over those effects, the presence of silver carp in the ponds decreased algal biomass through grazing and promoted nitrification providing and resuspending particles in the water column. These effects were also produced by mola, but were evident only in the absence of silver carp. Punti stirring on the pond bottom increased nutrient flow from the sediments into the water column and promoted nitrification, but were also evident only in the absence of silver carp.The addition of 10 silver carp over the 99 large carps stocked in the 100 m² fishponds did not affect punti and mola reproduction in the ponds, negatively affected rohu and catla growth and yield by about 20-25% but not their survival, did not affect common carp performance, reduced punti harvested biomass by 10%, reduced mola performance by about 50%, and silver carp's own biomass increased total yield and total income in about 20% each. The addition of 250 mola or punti to the large carp polycultures did not affect the performance of any of the large carps. The decreased income from selling the more expensive large carps was more than compensated by that obtained from silver carp, which increased total income by 13-24% as compared to the corresponding treatments without silver carp. This allows the option to the farmer of selling part of the silver carp to complete the cash income that would have been obtained from large carps only if silver carp would not be stocked, and consume the rest with the family.     

Balancing protein ingredients in carp feeds to limit dischargeof phosphorus and nitrogen into water bodies

ABSTRACT:   Through a series of experiments, it has been demonstrated successfullythat an appropriate choice of ingredients is primary for achievinga reduction in phosphorus (P) and nitrogen (N) loading from carpculture. In this final study, four multi-ingredient diets were examined.In addition to the basal ingredients (fish meal 15%, corngluten meal 8%, defatted soybean meal 10%, blood meal3–5%), three of the test diets (PF, MM, and SP)contained 6% each of either poultry feather meal, meatmeal or soy protein concentrate, respectively, and the fourth diet(PMS) had each of the three aforementioned ingredients includedat 3%. These diets had crude protein < 35%,digestible energy > 3.5 kcal/g,available P between 0.65 and 0.66% and total P rangingfrom 1.26 to 1.36%. The diets were fed to juvenile carpduring a 12-week feeding trial. The highest growth was obtained forfish fed the MM diet. The absorption and retention rates of P werehigher for the PF diet, whereas these values for N did not showtreatment-related differences. The total discharges per ton fish productionwere estimated to range between 7.8 and 9.2 kg for P andbetween 39.1 and 40.7 kg for N. These were lower than thefigures for Lake Kasumigaura, a main carp culture site, indicatingthat proper balancing of protein ingredients aids in efficientlylowering emissions from aquaculture.     

不同投喂频率下草鱼对5种非粮蛋白源利用效率的比较

采用双因素正交试验(3ｘ5)评估了草鱼在3种投喂频率下对豆粕(美国)、乙醇梭菌蛋白、黄粉虫、小球藻、棉籽蛋白粉的利用效率。以5种原料为单一蛋白源配制5种等氮等能饲料,在池塘网箱(1mｘ1.5mｘ1.5m)中,分别以投喂频率(2次/d、3次/d和4次/d)投喂初始体质量~80g的草鱼8周,考察草鱼的生长性能,全鱼和肌肉营养成分以及血清生化指标。研究结果表明：黄粉虫试验组(2次/d)草鱼表现出最低的生长性能;豆粕(4次/d)和乙醇梭菌蛋白(3次/d和4次/d)试验组草鱼表现出最高的生长性能;投喂频率与蛋白源对草鱼的末重,饲料系数,蛋白质效率和增重率有交互作用(P＜0.05)。除小球藻试验组,各试验组草鱼的终末体质量和蛋白质效率随着投喂频率的增加而增加。不考虑蛋白源,投喂频率为4次/d的草鱼生长性能显著高于2次/d。 不考虑投喂频率,黄粉虫和棉籽浓缩蛋白组的增重率和蛋白质效率显著低于豆粕、乙醇梭菌蛋白和小球藻三组(P＜0.05),饲料系数则表现出相反的趋势(P＜0.05)。不同的投喂频率下,五种蛋白源对草鱼的形体指标(肝体比、脏体比、肥满度)和全鱼和肌肉的基础营养成分均无显著影响(P＞0.05)。投喂频率对草鱼血清的碱性磷酸酶和葡萄糖有显著影响(P＜0.05),投喂2次/d的碱性磷酸酶的活性显著高于投喂3次/d和投喂4次/d(P＜0.05),投喂4次/d试验鱼的葡萄糖含量显著高于投喂2次/d和3次/d(P＜0.05)。黄粉虫试验组草鱼血清中的谷丙转氨酶和谷草转氨酶活性显著高于豆粕组和小球藻组(P＜0.05)。本试验条件下,以生长性能为评价指标,草鱼适宜的投喂频率为3~4次/d,草鱼对五种蛋白源饲料的利用能力为：乙醇梭菌蛋白=豆粕=小球藻>棉籽浓缩蛋白>黄粉虫。     

Growth and condition of marron Cherax tenuimanus fed pelleted diets of different stability

Six groups of 0 + marron Cherax tenuimanus were reared on commercial marron diets based on two different fish meals in a study lasting 4 months. Both diets were prepared in a stable and an unstable pelleted form. Matron fed with koi carp or salmon diet and unfed were used as reference groups. Matron were reared communally in tanks (5 m⁻²) and individually in an intensive crayfish culture system (ICCS, 25 m⁻²). Marron were fed at the rate of 6.5% of their body weight per week. Groups fed with stable diets showed larger weight increment at moult, shorter intermoult period, and higher specific growth rate than groups fed with similar unstable diets. Stable matron diets resulted in faster growth than fish diets. There were no differences in hepatopancreatic indices of marron fed with stable diets or similar unstable diets in the ICCS. The condition of hepatopancreata of marron reared in communal tanks were better than those of marron reared in the ICCS on a similar diet. Results indicate that marron production can be improved using stable pelleted diets in both intensive and semi-intensive culture.     

Introduction and present status of exotic carp in Africa

This paper presents a review of all introductions of various carp species: Common carp, Cyprinus carpio (L.), but also major Chinese and Indian carp into Africa. The historical background of the present situation of carp culture is provided for 16 African countries. This contribution shows that, despite important efforts at aquaculture and fisheries development, carp production remains at a very low level except in Egypt. Various consequences of carp introductions are also discussed.     

Effect of fish size and temperature on the utilization of different protein sources in two catfish species

Two sets of feeding trial were conducted to determine the effect of size and temperature on the utilization of different protein sources in two catfish species. In both the experiments, the fish were fed to apparent satiation daily at 08.00 and 18.00 hours, and faecal matter collected through slow siphoning. The first experiment was designed to study the effect of fish size on apparent digestibility coefficients for plant and animal proteins in the African catfish, Clarias gariepinus (Burchell, 1822). Three size classes (105–109 g; 780–830 g; 1250– 1300 g) of fish were stocked in triplicate sets of 600‐L plastic pools fitted with a flow‐through system (2 L min^?1). Within each size class, the apparent digestibility coefficient (ADC) for protein varied significantly with the source and quality of protein used. Soybean meal and fishmeal protein were utilized with greater efficiency, whereas rice bran protein was least digestible. An increase in ADC protein was apparent with increase in fish size for high protein sources such as soybean meal, full‐fat soybean, laboratory‐prepared fishmeal, steam‐cooked brown fishmeal and dried fish. ADC protein for other ingredients decreased with increase in size. In the second experiment, the influence of varying temperature on ADC for protein was determined in the catfish, Heteropneustes fossilis (Bloch) (6–8 g). Triplicate groups of 25 fish were kept at three different ambient temperatures (18, 28 and 38 °C), in 70‐L polyvinyl indoor flow‐through (1–1.5 L min^?1) circular tanks (water volume = 55 L). The trend in utilization of protein from different sources remained similar at the three temperatures. For each ingredient, digestibility values obtained at 18 °C were significantly lower than those obtained at 28 °C and 38 °C. Optimal protein utilization in H. fossilis was measured at 28 °C.     

Growth and survival response of Penaeus stylirostris (Stimpson) to fertilization, pelleted feed and stocking density in earthen ponds

Abstract. Growth and survival response of Penaeus stylirostris (Stimpson) to fertilization, pelleted feeding and stocking density were analysed for the conditions prevailing on the Baja California peninsula (Mexico). Three 0·25-ha earthen ponds were longitudinally divided in half with mesh structures. One half received inorganic fertilization (trial F) and the other supplementary feeding using a pelletized ration (trial PF). The initial stocking rates were approximately 5, 10 and 15 PL5/m² in both trials. After 210 days, final mean weights ranged from 15·0 to 5·3g and survival from 48·6 to 17·8%. Growth and survival were analysed by means of a reparameterization of the von Bertalanffy's growth model and the exponential mortality equation. Results indicated that: (1) final mean weight was dependent on density in both trials ( P < 0·01) although growth rate was only affected in trial PF ( P < 0·01); (2) pelleted feeding produced both greater final mean weight and increased growth rate at densities higher than 5 PL/m² ( P < 0·005); (3) the ratio tail weight/total weight was influenced by density in trial F ( P < 0·015); (4) the mortality equation served to explain differences in survival to a limited extent. An increase in growth rate after 170 days occurring at the intermediate density in trial PF was attributed to an increase in mortality, which allowed the remaining individuals to attain larger sizes. Further research to increase biomass yields should focus on the optimization of pond depth, the supply of vigorous post-larvae and on the possible influences of seasonal variations of planktonic communities of the lagoons on the productivity of ponds.     

Growth performance,haematology, antioxidant status,immune response and histology of common carp (Cyprinus carpio L.) fed biofloc grown on different carbon sources

A 10 weeks trial was performed to investigate how different carbon sources (sugar beet molasses: SBM+BFT, sugar: S+BFT, corn starch: CS+BFT) along with control affect welfare status of common carp (Cyprinus carpio L.) fingerlings in biofloc‐based tanks. Three hundred healthy fingerlings (22.5 ± 0.2 g) were randomly distributed in 12 tanks (70 L) at a density of 8.02 kg/m³ (25 fish/tank). The fish in BFT treatments fed only 75% feeding rate of control. At the end of the experiment no differences were seen between the groups in case of growth performance, but the fish reared in CS+BFT had a significant lower food conversion ratio compared with the others (p < .05). Different carbon sources did not affect on haematological parameters (p > .05). Total serum protein and antibody concentration differed in treatments, and the highest values were found in S+BFT and CS+BFT treatments (p < .05). No significant differences were observed in case of lysozyme, superoxide dismutase and complement activity in treatments (p > .05), whereas the fish in BFT treatments showed a significant higher total antioxidant capacity and lower glutathione peroxidase than the control (p < .05). Different carbon sources resulted in no change in goblet and kupffer cells in intestine and liver respectively. The highest relative percentage survival was obtained in the CS+BFT and S+BFT (50%) in comparison with SBM+BFT (20%) treatment. The results obtained in this experiment, suggest that corn starch improves immune response, diseases resistance and histology of digestive and respiratory systems in carp fingerlings when used as a carbon source in zero water exchange system.     

Growth response of the siluroid, Heteropneustes fossilis bloch,fed pelleted feed

Growth response and survival of catfish, Heteropneustes fossilis, fed compounded pelleted diet have been studied. It was observed that the fish accepts and thrives well on pelleted feed, with 100% survival. The conversion factor of the feed over a 6-week feeding trial was found to be 1.8, corresponding to gross growth efficiency of 0.56. The study suggests that cost-effective raw materials could be used for compounding nutritive feed for this species.     

Reassessment of phosphorus and nitrogen discharge from commercial carp feeds

ABSTRACT:   The present study, one in a series to clarify the phosphorus (P) and nitrogen (N) loading from carp culture, evaluated four commercial diets. The total and available P in these diets varied from 1.57 to 1.86% and from 0.38 to 0.87%, respectively. The control diet, selected based on an earlier experiment, contained 1.40% total P and 0.68% available P. The 7-week feeding trial was performed with juvenile carp. Superior feed gain ratio was obtained for the control diet (1.00) and it varied from 1.19 to 1.56 among the commercial diet groups. Similarly, the control diet showed higher rates of P absorption (43.8%) and retention (33.1%) than the rest (absorption: 18.1–40.9%; retention: 10.7–18.7%). Total P loading (kg/t production) was 10.0 for the control group but ranged from 19.1 to 25.0 among the commercial diet groups. Nitrogen absorption was not markedly different; however, fluctuations in retention resulted in N loading (kg/t production) that ranged between 47.1 and 66.3 among the commercial diets, higher than the 34.8 obtained for the control diet. The available P in the commercial diets rarely matched the requirement level, thereby negatively affecting the waste loading. The superior performance of the control diet underscores the fact that effective formulations help in keeping emission levels low.     

Growth and immune response of Chinese mitten crab (Eriocheir sinensis) fed diets containing different lipid sources

A 10‐week feeding trial was conducted to evaluate the effects of dietary lipid sources on the growth and immune responses of Chinese mitten crab Eriocheir sinensis. Six isonitrogenous and isoenergetic diets were formulated with fish oil (FO), linseed oil (LO), soybean oil (SO), rapeseed oil (RO), coconut oil (CO) and beef tallow (BT) as the sources of lipid with five replicates each. Thirty crabs (2.35 ± 0.14 g) were stocked into each tank and fed twice daily. Weight gain and specific growth rate of crab fed the FO diet were significantly lower than those fed other diets (P < 0.05), except for crabs fed LO diet (P < 0.05). Crab fed the SO diet weighed more than those fed FO diets (P < 0.05). Serum superoxide dismutase and malondialdehyde of crab fed the FO diet were significantly higher than in other groups (P < 0.05). Crab fed the FO diet had the highest activities of serum phenoloxidase, acid phosphatase, alkaline phosphatase and lysozyme (P < 0.05). The fatty acid composition in the liver of crab reflected the change in test diets. Our results indicate that the use of dietary vegetable or animal oils can achieve similar growth performance to the use of dietary FO in Chinese mitten crab, but non‐FOs may impair crab immunity. Soybean oil is recommended as a suitable replacer for FO in Chinese mitten crab diet.     

Apparent digestibility coefficient of protein sources for carp, Cyprinus carpio L.

The digestibility of various diet components as protein sources for common carp, Cyprinus carpio L., at 500–800 g was studied by using an inert marker in the feed and collecting the faeces by stripping. Protein in fish meal (83.8%) and soybean meal (69.8%) were significantly more digestible than that of poultry meal (47.2%). Energy digestibility tests gave the following results: fish meal 93.4%, soybean meal 74.7% and poultry meal 63.9%. It was evident that the ability of carp to digest proteins is very high, and that they can utilize proteins as the main component of their diet.     

Growth, feed efficiency and slaughter quality of salmon, Salmo salar L., given feeds with different ratios of carbohydrate and protein

The effects of using increasing levels of carbohydrate to replace protein in diets for Atlantic salmon were studied in a long-term, semicommercial-scale experiment in sea cages, using wheat and corn starch as carbohydrate sources. The fish were fed extruded diets containing 24 g and 602 g kg^?1, 98 g and 521 g kg^?1, 165 g and 454 g kg^?1, 230 g and 384 g kg^?1 of carbohydrate and protein, respectively. The contents of lipid were kept constant at 280 g kg^?1. The experiment lasted for 9 months until the fish had reached about 4 kg. All groups showed good growth in the experimental period. Feed efficiency decreased and feed intake increased linearly with increased level of carbohydrate in the diet. Digestibility of dry matter and energy were seriously decreased with increased carbohydrate level in the diets. This was mainly due to decreased digestibility of carbohydrate, but also to decreased digestibility of lipid. The digestibility of protein or amino acids was not affected by diet. Higher levels of carbohydrate resulted in increased storage of energy as lipid in fillet and abdominal fat. Red coloration showed an optimum at 98 g kg^?1 carbohydrate in the diets. No differences in maturation were found between diets. Overall, based on feed efficiency, growth and slaughter quality, the optimum level of carbohydrate in the diet for Atlantic salmon in sea water is found to be approximately 100 g kg^?1 dry matter.     

Development of a pelleted feed for juvenile tropical spiny lobster (Panulirus ornatus): response to dietary protein and lipid

Critical to the development of a cost‐effective feed for the tropical spiny lobster Panulirus ornatus is knowledge of its response to the protein and lipid (or energy) content of the feed. An experiment of 12 weeks duration was carried out to examine growth responses of juvenile lobsters to pelleted diets that provided six crude protein (CP) levels [320–600 g kg^?1 dry matter (DM)] and two lipid levels (nominally 60 and 100 g kg^?1 DM). Lobsters (mean initial weight of 1.8 g) were held in groups of nine or 10 animals in 24 × 350 L tanks, fed twice daily at a restricted level, and maintained at 28 °C. Maximal growth responses occurred at dietary CP contents of 474 g kg^?1 for the 60 g kg^?1 lipid series and 533 g kg^?1 for the 100 g kg^?1 lipid series. A second experiment, of 4 weeks duration, compared two dietary treatments: a mixture of two of the best diets from the first experiment, and a commercial shrimp (Penaeus japonicus) feed. Lobsters were held under the same experimental conditions as in the first experiment, but were fed to excess twice daily. Their growth was significantly greater (P < 0.05) on the shrimp feed (0.68 g week^?1) than on the laboratory‐pelleted diets used in the main study (0.32 g week^?1). The results indicate that the optimal dietary protein and lipid content of the diet for P. ornatus is about 530 and 100 g kg^?1, respectively.     

两种碳源对草鱼养殖水质、藻类和微生物群落的影响

为研究淀粉及其与乙酸钠的复合物(淀粉乙酸钠质量比为19∶1)两种碳源对草鱼养殖水体水质、藻类和微生物群落调控作用的差异,在为期60 d的试验中,每周向养殖水体添加一次碳源,添加量为当日水体氨氮含量的20倍,监测分析水体理化指标、藻类和微生物群落参数。结果显示:(1)试验期内,淀粉组(GS)和淀粉乙酸钠组(GSA)养殖水体氨氮保持在0.25 mg/L左右,总氮、总磷和叶绿素a均逐步升高,而透明度和碳氮比逐步下降,同次样品两试验组间水体理化指标差异不显著。(2)试验期内,GS组和GSA组藻类数量逐步上升,中后期显著高于前期,同次样品两试验组间藻类数量差异不显著,但GSA组藻类种类数和多样性稍高于GS组。(3)GS组微生物活性、碳源利用能力同比略高于GSA组,且微生物群落多样性在试验末期差异显著。结果表明,淀粉碳源中复合少量乙酸钠可改变藻类和微生物结构功能,可作为池塘养殖水体藻类和微生物群落结构功能定向调控碳源。     

饲料蛋白质水平对俄罗斯鲟幼鲟生长的影响

设计 5种不同粗蛋白质水平的饲料 ,分别投喂平均体重约为 4 2 9g的俄罗斯鲟幼鲟 ,试验时间 4 0天。结果表明 ,幼鲟对饲料中粗蛋白质的最适需要量为 4 2 %。当饲料粗蛋白质水平低于 4 2 %时 ,随着饲料中粗蛋白质水平的增加 ,幼鲟的生长速度和饲料转换率都显著增加。当饲料中粗蛋白质水平达到和超过 4 2 %时 ,随着饲料粗蛋白质水平的增加 ,幼鲟的生长速度和饲料转换率没有明显变化。     

Effects of manures and pelleted feeds on survival,growth, and yield of Penaeus stylirostris and Penaeus vannamei in Panama

Brackishwater ponds on the Pacific coast of Panama were stocked at 5/m² with wild-caught postlarval shrimp (0.05 g). Species composition at stocking was 56% Panaeus vannamei, 33% P. stylirostris and 11% P. occidentalis. Experimental treatments were: chicken manure (4500 kg/ha dry weight), cow manure (4500 kg/ha), 25% protein pelleted feed (790 kg/ha) and control (which received no nutrient input). Water was exchanged 5–10% daily throughout the 120-day production period during the 1982 rainy season. Average shrimp yields at harvest, by treatment, were: chicken manure, 262 kg/ha; cow manure, 218 kg/ha; feed, 386 kg/ha; and the control, 160 kg/ha. Average survival for each treatment was 50%, 76%, 58% and 77%, respectively. All P. occidentalis died during the production period. Survival was not significantly different among treatments (P > 0.05). Average weights or shrimp at harvest were 8.72g, 7.32 g, 12.07 g, and 5.98 g, respectively, for the treatments. Manures and feed significantly increased yield over the control (P < 0.002). Feed significantly increased yield over that of the manures (P < 0.0001), while yield for manures did not differ (P > 0.05). A partial budget analysis indicated that a net income for the feed treatment was higher than for chicken manure or cow manure treatments.     

Growth and feed efficiency of Octopus vulgaris fed on dry pelleted

The purpose of this study was to evaluate the effect of two dry extruded diets on growth and nutritional composition of digestive gland (DG) and muscle of Octopus vulgaris. Both artificial diets (FMK and 3FMK) were composed of gelatin, maltodextrin, yolk, fish and krill meal. The 3FMK diet contained more fishmeal (3×) than the FMK diet. These diets were compared with a control frozen diet consisting of golden grey mullet (Liza aurata) and crab (Liocarcinus depurator). The 3FMK diet promoted higher intakes and feed efficiency than FMK diet, resulting in larger growths (296 respect to 158 g in 42 days; 0.81% vs. 0.78% body weight/day). There was significantly lower moisture, protein and ash content in digestive glands of animals fed pellets (P < 0.05). No significant differences were observed on nutritional composition of muscle among the three groups. Even though the results were still below those of the control group (increase of 1258 g), the good performance in terms of acceptance and growth showed that this extruded diet can be the starting point to develop a commercial feed for this species.     

大伙房水库鲢鳙的生长及生长模型_

根据灰色系统理论，建立了拟合鱼类生长的灰色动态生长模型，并应用这一模型和一般ＶＢＧＦ及特殊ＶＢＧＦ拟合了大伙房水库鲢鳙的体长生长和体重生长。这三个模型拟合鲢的体长生长的残差平方和分别产７．７７、８．５６、１８１５．９，拟合链的体重生长的残差平方和分别是０．０７、０．１５、５３．８８，拟合鳙的体长生长的残差平方和分别是２．４７、５．４９、２２９５．３，拟合鳙的体重生长的残差平方和分别为１．０５、０．     

鱼菜共生模式中不同鱼类肠道微生物群落结构的比较

为研究鱼菜共生模式下不同鱼类肠道微生物的菌落结构,采用宏基因组学测序技术和生物信息学分析手段,构建了草鱼(Ctenopharyngodon idellus)、鲫(Carassius auratus)、鲢(Hypophthalmichthys molitrix)和鳙(Aristichthys nobilis)4种鲤科鱼类的肠道内含物等12个样品的16S rDNA测序克隆文库,分析了这4种鲤科鱼类肠道微生物的菌落组成和多样性。结果表明,鱼菜共生模式下不同鲤科鱼类肠道内含物微生物优势菌落的组成十分相似(P0.05,Kruskal-Wallis),优势微生物菌群均是鲸杆菌属(Cetobacterium)和梭状芽孢杆菌属(Clostridium)、拟杆菌属(Bacteroides)和芽孢杆菌属(Bacillus)等, 其中鲸杆菌属和梭状芽孢杆菌属含量最丰富,且主要在非优势菌属之间具有显著差异(P0.05,Kruskal-Wallis),研究结果还表明食性不是造成不同食性鲤科鱼类肠道微生物菌落差异的唯一决定性因素。