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1.
K. LORENZEN 《Fisheries Management and Ecology》1995,2(1):61-73
Abstract The population dynamics of culture-based fisheries are studied by means of a mathematical model, which incorporates explicit sub-models for density-dependent individual growth and size-dependent mortality. The model applies to populations of carps, i.e. common carp, Chinese carps, and Indian major carps, and coregonids.
The effects on production of stocking density and size of seed fish, fishing mortality, and size at harvesting are studied in a model population of carp. Management implications of the modelling results are emphasized. An adaptive approach to management, involving judicious experimentation with stocking and harvesting regimes, is proposed to gain information on the dynamics of actual fisheries, and to optimize their production. 相似文献
The effects on production of stocking density and size of seed fish, fishing mortality, and size at harvesting are studied in a model population of carp. Management implications of the modelling results are emphasized. An adaptive approach to management, involving judicious experimentation with stocking and harvesting regimes, is proposed to gain information on the dynamics of actual fisheries, and to optimize their production. 相似文献
2.
为评估长江江苏段鳙(Aristichthys nobilis)增殖放流效果,本研究基于微卫星标记的亲子鉴定技术,选用 10对扩增效果稳定的微卫星荧光标记引物,结合毛细管电泳对江苏省内良种场 563 尾鳙亲鱼和长江江苏段 687 尾回捕鳙进行基因分型,并对位点多态性及亲子鉴定结果进行了分析。结果表明,各位点等位基因介于 19~55 之间,其观测杂合度为 0.530~0.909(平均值为 0.748),期望杂合度为 0.818~0.929 (平均值为 0.882),多态性信息含量为0.797~0.924 (平均值为 0.871);Cervus3.0 模拟结果显示,当双亲未知且置信度为 95%时, 10 个微卫星位点的累积非亲权排除率为 99.996%。亲子鉴定结果发现,所有回捕鳙中有 42 尾与亲本之间存在亲子关系,被确认来源于鳙增殖放流群体,并由此推算此次评估亲本的放流子代对长江江苏段野生群体的贡献率为 6.11%。结果显示该研究进行的鳙亲子鉴定技术可为长江鳙增殖放流效果评估工作提供可靠的数据支撑,为长江渔业资源管理提供参考资料。 相似文献
3.
The topography, general ecology, present status and potential for growth and development of the commercial fisheries of the Ganga River System are discussed. Based on studies over about two decades, the evidence gathered shows that the fishery of yesteryear no longer exists. The major carp population has suffered a decline in the post-1961 period, especially in the upper stretches. The average annual yield rate from the Ganga is estimated to have fallen from 52.0 kg/ha in the period 1958–1961 to 50.3 kg/ha, while that of major carps has declined from 16.6 kg/ha to 13.3 kg/ha. The recent fall in quality as well as production of spawn from 3350 million in the nineteensixties to 2595 million in the nineteenseventies is weighed against existing stock-recruitment theories. Causative factors for the decline are analysed and the major carp seed production potential of the system is shown to be much higher than the present level. The decline in the major carp stocks and spawn abundance is attributed to large scale juvenile and spawner exploitation and to habitat degradation brought about by increased water abstraction and regulation, and pollution. The problems impeding development are discussed and management strategies suggested. 相似文献
4.
水晶彩鲫、红鲫、锦鲤、荷包红鲤杂交子代的生长和体色研究 总被引：10，自引：0，他引：10
利用人工授精的方法,进行水晶彩鲫、红鲫、锦鲤和荷包红鲤的相互杂交试验,测定各个杂交组合子代的成活率、生长速度和体色分离比例。结果表明：4种鱼能够相互杂交受精,孵出鱼苗。孵化率锦鲤自交最低为46．4％,其它组合为70％～80％;杂交鱼苗经28d的人工饲养,水晶彩鲫与荷包红鲤、锦鲤的正、反杂交,同其它杂交组合比较有明显的差别,其生长速度慢,个体之间差异大,成活率低;杂交子代的体型分为3类：鲫鱼型、鲤鱼型和鲤鲫型。鳞片反光组织(虹彩细胞或鸟粪素细胞)为2类：完全型、缺失型。体色分离复杂多样,水晶彩鲫与红鲫杂交是水晶彩鲫,红鲫与锦鲤、荷包红鲤杂交是青灰色鲤鲫杂种,水晶彩鲫与锦鲤、荷包红鲤杂交都会出现水晶彩色和青灰色鲤鲫杂种。 相似文献
5.
用１ｍ３网箱于库湾进行松浦镜鲤（散鳞镜鲤♀×德国镜鲤♂）与野鲤，建鲤网箱养殖试验。野鲤４个网箱，平均每箱为５３１尾，平均个体重１１０．９３ｇ；建鲤２个箱一箱放４５０尾，另一箱放４４９尾，平均个体重７３．４５ｇ；松浦镜鲤１个网箱放５７８尾，平均个体重４９．５０ｇ，经１３７天饲养群体净重野鲤为７８．８ｋｇ／箱，建鲤为６０．８ｋｇ／箱，松浦镜鲤为１０６．９ｋｇ／箱，瞬时体重增长率野鲤为０．７７８；建鲤为１．１２６；松浦镜鲤为１．３３６。从群体产量及个体生长速度松浦镜鲤都高于野鲤和建鲤。 相似文献
6.
Md Abdul Wahab Sk Ahmad‐Al‐Nahid Nesar Ahmed Mohammad M Haque Mahmudul Karim 《Aquaculture Research》2012,43(7):970-983
Giant river prawn (Macrobrachium rosenbergii) farming plays an important role in the economy of Bangladesh. Presently, it is cultured in around 50 000 ha area with total annual production of 23 240 t. Traditional extensive prawn farming has been expanding over the last three decades through the introduction and adoption of improved culture systems, such as culture of prawn‐carps, prawn‐shrimp‐fish and prawn‐fish‐rice as concurrent and rotational systems. Efforts for the development of improved techniques on broodstock management, seed production and rearing and grow‐out of prawn have been made over the last decade. The outcomes are low‐cost feed for broodstock, production of post‐larvae in net cages (hapa), all‐male prawn culture, periphyton based prawn‐tilapia culture, C/N based prawn culture, organic prawn farming, prawn‐mola culture and prawn‐carp‐mola polyculture. Despite the development of culture technologies, a number of challenges for sustainable development of prawn farming need to be overcome to realize the potentials of this promising sector. Good aquaculture practises at all levels and application of measures for quality control and food safety would ensure sustainable development of prawn farming in Bangladesh. 相似文献
7.
The effects of introduction of common carp, Cyprinus carpio (L.). in polyculture with major Indian carps and silver carp were studied in fertilized and fed earthen ponds in Mymensingh, Bangladesh. Bottom-dwelling common carp were found to exert an influence on the quality and quantity of planktonic food organisms. The presence of common carp significantly increased (P < 0.05) the growth of other carps including the bottom-feeder mrigal. Cirrhinus mrigala (Hamilton). A significantly higher fish yield (P < 0.05) was observed in the fish ponds containing common carp when the combined yields of all species in three treatments were compared. 相似文献
8.
《Journal Of Applied Aquaculture》2013,25(3-4):251-282
ABSTRACT Asian aquaculture has been contributing in great measure to the global fish basket. The Indian subcontinent, with a rich biodiversity of fish species, has emerged as an important aquaculture country, particularly in the freshwater environment. Carps form the mainstay of culture practices in the country, supported by a strong traditional knowledge base and scientific input in various aspects of biology, environment, nutrition, and health management. New species and culture systems, integration with other farming systems, use of organic material as nutrient inputs, and depuration measures in waste-fed culture systems are being considered for enhancing aquaculture productivity. This article presents the status of grow-out production of carps in India and traces the growth of the practices over the decades as well as the potential of the sector. 相似文献
9.
A year‐long grow‐out carp polyculture trial was conducted in nine earthen ponds to study the growth performance of Kuria labeo (Labeo gonius) with the different major carps such as catla (Catla catla), silver carp (Hypophthalmichthys molitrix), rohu (Labeo rohita) and mrigal (Cirrhinus mrigala). Suitable water quality parameters were maintained in ponds through intermittent liming, manuring and fertilization. Three different species combinations of carps were evaluated using silver carp and catla as the common species and varying other carp components as rohu–Kuria labeo, mrigal–Kuria labeo and rohu–mrigal in the three treatments. The ponds were stocked at a combined density of 7500 fingerlings ha?1. Silver carp and catla showed similar growth performances in all the three combinations, suggesting that other carps in the combination do not have any differential influence on their growth. Kuria labeo was compatible with rohu, while competition was observed with mrigal. Although growth performance of Kuria labeo was inferior to that of mrigal, better compatibility of Kuria labeo with rohu helped this combination to yield a biomass equivalent to the mrigal–rohu combination, suggesting feasibility to use Kuria labeo as an alternative species to mrigal in the major carp polyculture system without compromising the total biomass yield. 相似文献
10.
ABSTRACT: The annual reproductive cycle, including the first maturity of ovarian development and plasma levels of testosterone (T) and estradiol-17β (E2), was examined in female Japanese catfish Silurus asotus reared under natural conditions. In addition, the possible period that final oocyte maturation and ovulation can be induced by human chorionic gonadotropin (hCG) injection were investigated. Results showed that female Japanese catfish matured 1 year after hatching under reared conditions. The beginning of vitellogenesis was in March and ovarian development and plasma T and E2 levels peaked in June. Thereafter, the gonadosomatic index gradually decreased to October and regression of oocytes at the tertiary yolk globule stage was observed. Female Japanese catfish could be induced to final oocyte maturation and ovulation by hCG treatment during the period from June to September. In addition, the fertilization rates were relatively high and stable during this period. These results suggest that yearling female Japanese catfish can be used as brood stock for seed production. This is the first study to investigate the annual reproductive cycle in Japanese catfish. These data will provide useful information regarding brood stock management and seed production. 相似文献
11.
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. 相似文献
12.
分析长江下游原良种场鳙(Aristichthys nobilis)亲本和后备亲本的遗传多样性和遗传结构,评估鳙育种群体的种质资源现状,可为鳙的种质资源管理和活体资源库建设提供科学的参考依据。本研究利用已发表的10对SSR荧光引物结合毛细管电泳技术,对7个亲本群体和1个后备亲本群体共638份DNA进行基因分型。主要应用GenAlEx 6.501、Cervus 3.0和Structure 2.3.4等软件进行遗传多样性参数计算和群体遗传结构分析。结果表明,8个群体总体遗传多样性水平较高,但存在一定程度的近亲繁殖风险。其平均等位基因数(N_a)为14.83±1.45,观测杂合度(H_o)和期望杂合度(H_e)分别为0.76±0.05、0.82±0.02,Shannon's信息指数(I)为2.08±0.09,近交系数(F)为0.08±0.05。各亲本群体之间遗传多样性水平存在差异,后备亲本遗传多样性水平最高。鳙的贝叶斯群体遗传结构分析图(Structure)与主坐标分析(PCoA)结果具有一致性,将所有样本划分为两个类群,大部分亲本群体之间并无明显的遗传分化,而后备亲本和亲本之间则表现明显的遗传分化。分子方差分析(AMOVA)显示,11%的遗传变异来自群体间,群体间的遗传分化处于中等水平,而89%的遗传变异来自群体内。本研究探究了鳙亲本和后备亲本的遗传差异性,对野生原种引进和保护提供了建议,以期为构建健康负责的增殖放流种苗繁育体系提供理论支持和数据参考。 相似文献
13.
Technical efficiency of carp production in India: a stochastic frontier production function analysis 总被引：1，自引：0，他引：1
This paper aims to examine the levels and determinants of technical efficiency in carp pond culture in India. The stochastic production frontier technique involving the model for technical inefficiency effects is applied separately to samples of semi‐intensive/intensive and extensive carp producers interviewed during 1994–95. The results showed significant technical inefficiencies in carp production in India, especially among extensive farms. The mean technical efficiencies for semi‐intensive/intensive and extensive sample farms were estimated to be 0.805 and 0.658 respectively. By operating at full technical efficiency levels, the semi‐intensive/intensive farms could, on average, increase their production from about 3.4 Mt ha?1 to 4.1 Mt ha?1. Likewise, the extensive farms could increase their production from 1.3 Mt ha?1 to 1.9 Mt ha?1. Much of these efficiency gains would come from improvement in the adoption of recommended fish, water and feed management and monitoring practices. Besides expanding production area, the results indicated several other possibilities for increasing carp production in India by increasing yields per hectare, such as: (1) increased intensification of carp culture (i.e. moving from extensive to semi‐intensive or intensive systems); (2) improvement in technical efficiency at the farm level; and (3) technological progress. However, the realization of these potentials will depend on continuous efforts by the government in ensuring an adequate supply of inputs, technology transfer and development and adequate provision of research, extension and credit services in aquaculture. 相似文献
14.
15.
Abstract
Fanners employing crude human chorionic gonadotropin (Sumach, Infar India Ltd.) for inducing breeding of major carps, in India have claimed that it also promotes growth. The present study was undertaken in order to confirm this and its potential statics pure HCG (Sigma Chemicals Ltd), wherein two experiments were conducted in a recirculatory system. In the first experiment of 84 days duration, 10 mg/kg diet Sumach induced significantly higher growth, but not 20mg/kg diet. Both doses of pure HCG tried (1 and 2 mg/kg diet) were ineffective. In the second experiment, growth produced by 5 mg/kg diet pure HCG and 10 mg/kg diet Sumach were comparable and significantly higher than the rest after 42 days, indicating higher potential of pure HCG. The findings are significant as they reveal that a protein hormone like HCG is capable of growth promotion in carp when administered orally 相似文献
Fanners employing crude human chorionic gonadotropin (Sumach, Infar India Ltd.) for inducing breeding of major carps, in India have claimed that it also promotes growth. The present study was undertaken in order to confirm this and its potential statics pure HCG (Sigma Chemicals Ltd), wherein two experiments were conducted in a recirculatory system. In the first experiment of 84 days duration, 10 mg/kg diet Sumach induced significantly higher growth, but not 20mg/kg diet. Both doses of pure HCG tried (1 and 2 mg/kg diet) were ineffective. In the second experiment, growth produced by 5 mg/kg diet pure HCG and 10 mg/kg diet Sumach were comparable and significantly higher than the rest after 42 days, indicating higher potential of pure HCG. The findings are significant as they reveal that a protein hormone like HCG is capable of growth promotion in carp when administered orally 相似文献
16.
17.
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 under farm conditions to test the effects of silver carp and of each SIS species on the growth, survival and yield of the large and small species and on pond ecology.The experiment was performed in 38 farmers' fishponds of different sizes, from 220 m2 to 1200 m2. The results show that the larger the fish pond the better rohu performance, the larger punti fry weight and the lower punti fry harvested biomass. Pond size did not affect other fish species. The addition of 250 mola and/or punti per 100 m2 fishponds affected rohu and catla and did not affect common and silver carps. The addition of mola alone reduced rohu's parameters by 15%. The addition of SIS in the three combinations tested (250 mola, 250 punti, 125 of each species) reduced catla's parameters by 20-24%. Punti fry were larger when both SIS were stocked and punti fry biomass was larger when only punti were present. Total mola harvested biomass and yield were larger when the entire SIS stocked were only mola.The addition of 10 silver carp over the 99 large carps stocked per 100 m2 fishponds negatively affected rohu and catla growth and yield by about 15-21% and 45-50% respectively but not their survival, did not affect common carp performance, did not affect punti and mola reproduction in the ponds, reduced punti yields by 25%, reduced mola performance by about 35%, and silver carp own biomass increased total yield and total income in about 12% each. These effects are explained and discussed considering fish interactions through the food web. The decreased income from selling the more expensive large carps is more than compensated by that obtained from silver carp, which allows the option to the farmer to sell 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. 相似文献
18.
Theeffect of pig dung, as pond manure [at 18 and 36 tha–1 yr–1] and as fish feed ingredient[replacing traditional diet composed of solvent extracted rice bran and mustardcake (1:1) at 25, 50, 75 and 100% levels], was observed on water quality, pondproductivity and survival and growth of carp in polyculture system during winter(12–18 °C) and summer (18–36 °C)months. The studies on water quality parameters viz pH, dissolved oxygen andalkalinity revealed that pig dung even at higher levels (both as manure and /oras feed ingredient) did not deteriorate the quality of water, as all the waterparameters remained within the optimum ranges required for carps. The nutrient(phosphates and nitrates) status of water was significantly better in pondsreceiving pig dung as pond manure at 36 tha–1 yr–1. Pond productivity in terms ofplankton production (phyto and zooplankton) was also significantly higher innutrient rich water (36 tha–1 yr–1) both during winter andsummer. Further, in all the ponds (including control) phytoplankton levels weresignificantly higher during winter and zooplankton was higher during summer. Thestudies revealed 100% survival of all the fish species in all the treatments.During winter, the growth of carp was higher in treatments where pig dung wasused as feed ingredient (at 25% level), whereas during summer growth was higherwhere pig dung was used either as pond manure and/or as feed ingredient (athigher levels). Further, among carps, the growth of Indian major carps vizCatla catla, Labeo rohita and Cirrhinamrigala was higher during summer and that of exotic carps vizCyprinus carpio and Ctenophayrengodonidella was higher during winter. 相似文献
19.
Investigation of fat content in market common carp (Cyprinus carpio) flesh during the growing season
Effects of supplemental feeding with cereals (rye, triticale, maize and the unsupplemental control group) on fat content in flesh of 3‐year‐old common carp (Cyprinus carpio) were the subject of study carried out at four ponds (Czech Republic, Central Europe) during the growing season. The main result was that supplemental feeding with cereals to the same energetic level was associated with varying growth and fat content in the flesh of common carp. At the end of the experiment, the stock of fish supplementally fed with maize was found to have the highest fat content (112.7 ± 15.6 g kg?1), while the lowest value of fat content was found in the control group (56.8 ± 9.4 g kg?1). The carps supplementally fed with rye were found to have a higher fat content (90.1 ± 19.0) than those supplementally fed with triticale (84.3 ± 15.7 g kg?1). Established average fat content values (except for maize) were at the level that indicate a high sensory quality of carp flesh during the whole growing season. 相似文献
20.
大坝的建设阻隔了鱼类的洄游通道,鱼类通过水电站水轮机下行或误入水轮机流道有可能被流道内复杂的结构及水动力特性损伤,甚至致死。为优化水轮机流道结构及水动力特性,降低流道内鱼类的损伤概率,需明确鱼类对水轮机流道内水动力特性的响应关系,特别是河道内主要鱼种对反击式水轮机流道内压力突变的响应关系。本文以长江半洄游性鱼类四大家鱼幼鱼为研究对象,采用透明高压舱及真空泵组成的实验装置模拟轴流式水轮机流道压力变化过程对四种家鱼幼鱼的影响。实验得出,生活于河流中表层的鲢鱼和鳙鱼较生活于河流中底层青鱼和草鱼的对负压及压力梯度具有较强的敏感性;四种家鱼幼鱼均受损伤的低压阈值为20kPa;压力最低值及压力变化梯度是决定家鱼幼鱼是否受到损伤及损伤程度的关键因子。结果可以为我国长江流域上水电站水轮机的结构优化和生态运行提供技术支撑。 相似文献