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1.
A combination of radio telemetry and electrofishing was used to assess seasonal feeding activity and habitat utilisation of common carp (Cyprinus carpio) in a large (130 ha) semi-intensive aquaculture pond receiving supplementary feed. While telemetry indicated no difference in fish habitat utilisation by size, age or sample year, all fish showed a strong preference for the supplementary feed area (SFA) during the feeding period, electrofishing indicating a 15× higher fish concentration. Despite this, not all of the feed provided was eaten immediately. Carp activity was more evenly spread over the pond in summer/autumn and more concentrated at the SFA in spring. There was a significant shift to deeper waters in winter. Diet analysis indicated a high preponderance of cereal in SFA fish, with natural food (mainly zooplankton) dominant at natural feeding areas. The proportion of ‘emergency’ food (e.g. detritus) was similar in both areas, as was the index of gut fullness. Our results confirm that concentrated and repeated supplementary feeding in one area results in aggregation of carp, potentially leading to uneven population growth and flesh quality and reduced water quality from turbidity and increased nutrient input. As an alternative, we suggest spreading less supplemental feed over a greater area at wider time intervals. This would ensure (a) full utilisation of feed, reducing costs and increasing water quality, and (b) more homogenous fish distribution, ensuring more efficient use of natural food, reduced turbidity, more homogenous size/weight distribution and improved product quality.  相似文献   

2.
The semi-intensive system of carp farming is dominant in inland aquaculture. Although it appears to be simple, this system has a whole range of options, from those based on traditional rearing methods with use of plants from the region where the fish are reared to production based on the use of high-quality concentrated feeds. In this paper, we conduct a comparative analysis of the effect of using cereal grains as opposed to compound feed (pelleted and extruded) on the quantity of fish produced, flesh quality, histological changes in the digestive tract, water quality, and structure of the biocoenosis in the pond ecosystem. When the fish are fed cereal grains, production ranges from 500 to 1500 kg/ha, while using compound feed gives production that is twice as great. The proportions of protein and water are higher and that of lipids lower in flesh of common carp reared on compound feed in relation to fish fed cereal grains. Use of extruded feed gives better content of n-3 polyunsaturated fatty acids and a better n-3/n-6 ratio than when pelleted feed and cereal grains are used. Comparison of water quality in carp ponds under conditions of using various types of feed indicates that there are no significant differences. Although it was expected that feed with a higher percentage of proteins would cause disturbances in the aquatic ecosystem, their continual incorporation into the cycling of matter in the water contributes to maintenance of ecological equilibrium and even indirectly promotes growth of the common carp.  相似文献   

3.
A four‐and‐a‐half months study was conducted in nine earthen ponds to evaluate the addition of different supplemental feeds as a management tool for enhancing natural food availability and common carp growth, while maintaining optimal water quality in the semi‐intensive system. Three supplemental feeds were used: commercial extruded and pelleted feed with 25% protein and 7% fat and cereals. The type of supplemental feed did not influence water quality, except hardness, but significantly affected abundance of cyanobacteria, natural food availability and common carp growth. The use of pelleted feed was related to the lowest abundance of cyanobacteria in the ponds. For the two groups of large zooplankton, Cladocera and Copepoda, abundances were higher in the ponds with pelleted feed compared with the ponds where cereals and extruded feed were used. The abundance of benthic macroinvertebrates in the treatment with pelleted feed was three times higher than in the other two treatments. The results of this study indicate that pelleted feed can help farmers not only as a source of nutrients for carp growth but also indirectly as a management tool for maintaining ecological stability and control of cyanobacterial bloom in ponds.  相似文献   

4.
Abstract. Interactions between fish species as to their effect on the zooplankton populations in the ponds were studied in ten ponds of 0–1 ha each. The ponds were stocked with bottom-feeding fish: common carp, Cyprinus carpio L., and male hybrid tilapia Oreochromis niloticus L. ×O. aureus (Steindachner), and a filter feeder: silver carp, Hypophthalmichtys molitrix (Valenciennes), at varying proportions. A Principal Component Analysis of the data showed that the fish combination present in the pond accounted for 30% of the overall variability, through the first two components. The first zooplanktonic component (ZC1) can be considered as expressing community structure, showing high zooplankton diversity on one pole and low diversity on the other. The second component (ZC2) is related to the time of appearance of certain zooplankton groups. The most striking differences occurred between ponds with and without silver carp. The presence of the other bottom-feeding fish caused a reduction of zooplankton diversity, but not so pronounced as that of silver carp. The interactions among silver carp, zooplanktonic trophic groups and algal size are discussed. It is concluded that the effect of silver carp on the zooplanktonic community is a compound one, which includes both direct predation and depletion of their food resources.  相似文献   

5.
The role of offering a commercial pelleted diet has been characterized as both an expensive organic fertilizer and as a selected food item for larval hybrid striped bass (palmetto), Morone saxatilis × Morone chrysops, culture operations. In this study, we examined the effects of providing a commercial diet on fish production and zooplankton dynamics during phase I culture in plastic‐lined ponds. We also sought to estimate relative dietary contribution of a commercial fish feed relative to natural pond biota using stable isotope tissue analysis. Palmetto bass were stocked into six 0.04‐ha plastic‐lined ponds at a rate of 125,000/ha. During the 31‐d culture period, ponds were fertilized with alfalfa pellets at a rate of 112 kg/ha/wk. At 14 d post‐stock (dps), Silver Cup Trout Fry diet was offered at a rate of 13.6 kg/ha/d and fertilization was discontinued in three ponds. Although mean final fish length was significantly greater within the fed treatment, no other production parameters were found to be different (P < 0.1). Following feed application, copepod concentrations within the fed ponds were greater in magnitude by 24 dps. Through stable isotope tissue analysis, we found a significant enrichment in both 13C and 15ν of fish, zooplankton, and Chironomidae larvae within the fed ponds (P < 0.10). Using a three‐source mixing model, the mean (±SE) percent composition of feed in the fish's isotopic signature increased from 5% ±2 to 20% ±6 within 16 d. Although fish production was not greatly affected through the addition of a commercial fish feed, enriched 13C and 15ν of fish tissue indicate that palmetto bass fingerlings increasingly utilized the prepared diets over time. However, based on the isotopic values of fish and potential food sources, it can be estimated that natural pond biota likely accounted for up to 80% of nutrient assimilation in the hybrid striped bass.  相似文献   

6.
Four 20m3 cages stocked with 120 bighead carp x silver carp hybrids per cage were placed in each of four ponds varying in trophic status from mesotrophic to hypereutophic. Fish were cultured, without feeding, from 13 March to 1 Octorber 1987. Fish in the mesotrophic pond survived but lost weight (-0.37 g/fish/d). The mesotrophic pond produced insufficient food to sustain fish growth. Maximum fish growth rate occured in the two eutotrophic ponds (6.61vand 7/04 g/fish/d). Fish growth in the hypereutrophic pond was about one-half (3.64 g/fish/d) that in the two eutrophic ponds. Guy analysis of fish in the hypereutrophic pond revealed consumption of larger quantities (P < 0.05) of colonial blue-green algae that were apparently poorly digested and less (P < 0.05) zooplankton (primarily cladocerans) than was found in fish from the eutrophic ponds.  相似文献   

7.
The effect of supplementation of fish diets with phosphorus was studied both in tank and pond experiments. In the tank experiments phosphorus (6.5% di-calcium or mono-calcium phosphates) was added to three diets: two containing fish meal as the main protein ingredient and the third containing algal meal to replace it. Feeding common carp in tanks with these diets significantly increased fish growth rate (P < 0.05) over fish fed the same diets without phosphorus supplementation. In the pond experiments phosphorus was added to a fish meal diet in two different compounds: mono- and di-calcium phosphates (at 1% of the feed). The diets were fed to fish in a polyculture system for two consecutive culture cycles. Due to supplementation with phosphate, growth rate of tilapia (Sarotherodon aureus) increased in both culture cycles. The growth rate of common carp fed phosphorus-supplemented diets increased over the control only in the first cycle, when fish were large and the standing crop of carp exceeded 1.8 ton/ha. At lower standing crops the natural food seems to supply adequate amounts of phosphorus. Silver carp were not affected by phosphorus supplementation, probably because they consume very little supplementary feed. Total yield for the entire season (kg/ha) was significantly higher in ponds where fish were fed a phosphorus-supplemented diet. Di-calcium phosphate, which is soluble only in weak acids, seems to be more efficient than the water-soluble mono-calcium phosphate in affecting the growth of common carp even though this fish lacks a gastric acid secretion.  相似文献   

8.
The effects of introducing common carp (CC) and of adding artificial feed to fertilized rohu ponds on water quality and nutrient accumulation efficiency were studied. All ponds were stocked with 15 000 rohu ha?1. Treatments included ponds with rohu alone, rohu plus 5000 common carp ha?1 and rohu plus 10 000 CC ha?1. A comparison was also made between supplementally fed and non‐fed ponds. The overall highest nitrogen (N) and phosphorus (P) concentrations were observed in ponds with 5000 CC ha?1, followed by ponds with 10 000 and 0 CC ha?1. The largest fractions of N and P inputs accumulating in fish, phytoplankton and zooplankton were observed in ponds with 5000 CC ha?1, followed by ponds with 10 000 CC ha?1 and subsequently ponds without CC. Relatively more nutrients accumulated in benthic organisms in ponds without than in ponds with CC. A smaller fraction of the nutrient input was retained in fish, plankton and benthic organisms in ponds without CC compared with ponds with CC. Compared with 5000 CC ha?1, stocking 10 000 CC ha?1 can be considered as overstocking, because this leads to lower fish production and relatively less nutrients retained in plankton and benthic organisms.  相似文献   

9.
This paper reviews state-of-the-art techniques for culture of larval common carp, Cyprinus carpio, silver carp, Hypophthalmichthys molitrix, bighead carp, H. nobilis, and grass carp, Crenopharyngodon idella. Water temperature, food, and predation are important factors influencing larval survival and growth. Lower and upper lethal temperatures range from 3 to 44°C. Optimum growth temperatures range from 38 to 40°C. Lethal and optimum temperatures vary with acclimation temperature, fish age, and development stage of fish. Water temperatures are close to optimum for larval culture in tropical regions but are often too low in temperate climates. Intensive culture in temperature-controlled systems is important in temperate climates. The first food eaten by larvae in ponds consists mainly of protozoa, rotifers, and copepod nauplii. As fhe larvae grow, they quickly shift to larger food items, including cladocera and insect larvae. Management practices to enhance natural food development in earthen ponds include bottom drying, soil preparation, liming, fertilization, and agricultural crop cultivation. The development of food organisms in freshly filled ponds follows a pattern of succession. For best results, a pond should be stocked at the stage of succession when the size relationship between fish larvae (predators) and zooplankton (prey) is proper. A common practice is to stock larvae 3-7 days after filling. If ponds are filled too long before larvae are stocked, food relationships between fish and invertebrates can be reversed. Predator control includes biological, chemical, physical, and mechanical methods. Although great progress has been made in the development of dry starter diets, prepared feeds are not yet available for successful large-scale production. This problem is usually overcome by starting larvae with live food or with a mixture of live food and dry feed and by shifting larvae to dry diets as they grow. Live food either is collected from zooplankton ponds or is produced in intensive culture conditions. Systems for larval culture can range from ponds to intensive culture with water recirculation systems. Choice of the best system depends on the local climate, technical, and socio-economic conditions.  相似文献   

10.
Sustainable development of common carp Cyprinus carpio pond fisheries in Europe postulates their multifunctional use, integrating exploitation of aquaculture resources with recreational services and maintenance of high levels of local biodiversity. Age classes of farmed carp are grown separately and pond ecosystems may be differently affected by different ontogenetic stages of fish. To examine these relationships, a study was conducted on spring and summer diet of carp, invertebrate abundance and community structure, and water quality characteristics in ponds stocked with three carp age classes in SE Poland. With the exception of young-of-the-year fish in spring, benthic dipterans prevailed in the diets of all carp age classes and their consumption increased from spring to summer. Zooplankton featured in the diet of carp only in spring. Medium- and large-sized cladocerans predominated among microcrustaceans found in the guts of one- and two-year-old carp. Consequently, in summer, total biomass of medium- and large-sized cladoceran grazers was substantially lower in ponds stocked with older-age fish than in ponds used for production of 1-summer-old fingerlings. The relatively sparse submerged vegetation cover and low water transparency in ponds with older fish stocks compared to ponds with young-of-the-year carp indicate a transition to a turbid water state mediated by a trophic cascade mechanism in the presence of older-age fish. Densities of water-column macroinvertebrates decreased with the age of carp in the ponds. These results suggest that non-aquaculture use of carp ponds should be diversified according to their environmental quality. Fingerling rearing ponds are more suitable for environmentally friendly multifunctional use than ponds with older stocks.  相似文献   

11.
Raising ducks on fish ponds (fish-duck culture) on a commercial scale is a new practice in Egypt, therefore, a study was undertaken to evaluate this practice from production, carcass composition and economic viewpoints.Five earthern ponds were used in the non-integrated system (no ducks) whereas four earthen ponds, in which each pond was supplied with 125 Pecking ducks per 0.42 ha, were used for the Integrated system. In both systems, each pond was stocked with four species of fish (common carp Cyprinus carpio, silver carp Hypophthalmichthys molitrix, Grey mullet Mugil cephalus and tilapias Oreochromis niloticusand O. aureus) at the same densities.There were no differences in temperature or pH in any of the ponds but dissolved oxygen levels were lower in integrated ponds concomitant with increasing levels of ammonia, phosphate and nitrate. Water in integrated ponds was richer in natural productivity (phytoplankton and zooplankton) either in species or density when compared with those variables in non-integrated ponds.Fish species reared in integrated ponds exhibited better body weight, food conversion and protein efficiency ratios compared with those of fish species in the non-integrated ponds. Fish yield per 0.42 ha produced from the integrated ponds was significantly higher than that obtained from non-integrated ones. Also, body composition of fish species was affected by the type of farming. Carcass crude protein of grey mullet, silver carp and tilapia was improved in the integrated system. The data on return on sales, return on costs, return on equity, pay-back period and break-even point showed that the integrated system was more profitable than the non-integrated system.  相似文献   

12.
In 1977 and 1978, two fish ponds at the Dor Aquaculture Experiment Station were integrated with duck production. Each pond's area was 400 m2 and they were stocked with a polyculture of common carp, Tilapia, silver carp and grass carp (White Amur). The ducks were fed with prepared, nutritionally balanced feed, while the fish had to get by with the ducks' droppings plus the feed dropped directly from the ducks' beaks into the ponds. The ducks' performance on the ponds was superior to their ‘land’ control in growth rate, feed efficiency, viability and cleanness of feathers and skin. The average daily gain of the fish was 38.5 kg ha?1, not significantly different from ponds receiving similar mixtures of dry poultry manure plus supplementary feeds.Our experimental results provide necessary empirical support to the conclusion that the system is very efficient and its use should be expanded in warm water aquaculture.  相似文献   

13.
Split ponds are recently developed pond‐based aquaculture systems that allow intensification of catfish aquaculture. Successful industry‐wide adoption of newly developing technologies like split‐pond systems will depend upon their productivity and cost efficiencies. Costs and production performance of the following three split‐pond design scenarios were monitored in Arkansas and Mississippi: (1) research design developed at the Thad Cochran National Warmwater Aquaculture Center, Stoneville, Mississippi; (2) waterwheel design tested on commercial catfish ponds; and (3) screw‐pump design tested on commercial catfish ponds. An economic engineering approach using standard enterprise budget analysis was used to develop estimates of breakeven prices (BEPs) ($/kg) for producing foodsize hybrid catfish (♂Ictalurus furcatus × ♀Ictalurus punctatus) for each scenario. Estimates of BEPs of hybrid catfish raised in split ponds ranged from $1.72 to $2.05/kg. The cost of catfish production in split ponds was sensitive to yield, fish prices, and feed prices. Annual net cash flows from both commercial split‐pond systems were high and sufficient to make the investment profitable in the long run. Feed price, feed conversion ratio, and yield contributed the most to downside risk of split ponds.  相似文献   

14.
In carnivorous fish species, zooplankton is one of the main food items in the early life stages and some fish species continue feeding on such food items further along the life stages even in the farming environment. In this study, the intake of natural food items was assessed in juvenile pirarucu Arapaima gigas reared in earthen ponds. Juvenile pirarucu (12.2 ± 4.32 g and 12.1 ± 1.13 cm) were stocked in fertilized earthen ponds (240 m²). For the analysis of the fish stomach content and plankton in the pond water, the fish and pond water were sampled weekly for 75 days and biweekly until the fish reached a mean weight of 750 g. Although artificial feed was used, pirarucu also ingested the natural food available in the pond water. Among the zooplankton, pirarucu demonstrated feeding preference for cladocerans despite the abundance of rotifers and copepods. Cladocerans were present in more than 80% of the stomach contents of fish up to 300 g and in 65%, 45% and 17% of fish of 301–500 g, 501–700 g and 701–900 g respectively. Copepods were present only in fish up to 500 g at low abundance. High ingestion of insects and plant material was observed in the stomach content of fish of all size classes. The results demonstrate that juvenile pirarucu ingest natural food available in the farming pond and suggests that the adoption of pond fertilization practices may have positive effects on fish growth performance.  相似文献   

15.
Just like other domesticated animals, common carp (Cyprinus carpio) are able to learn where food can easily be obtained. As a result, carp in semi-intensive polyculture ponds could conceivably restrict their main activity centres to supplemental feeding sites, leading to lowered exploitation of natural food resources (zooplankton and macrozoobenthos) and localised degradation of environmental conditions. At two semi-intensive ponds in southern Moravia (Czech Republic), areas around feeding sites displayed significantly reduced oxygen concentration and saturation (mainly p < 0.001). Likewise, temperature, pH and transparency also decreased significantly at feeding sites (mainly p < 0.05), while turbidity increased. While there was no significant difference in zooplankton biovolume at feeding and non-feeding sites, zoobenthos density and biomass were significantly lower at feeding sites (mainly p < 0.01). The feeding behaviour of carp, therefore, led to significant changes in both abiotic and biotic conditions at supplemental feeding sites.  相似文献   

16.
The effect of different farming systems (cage, pond) upon digestive enzyme activities of Nile tilapia was evaluated. Juvenile Nile tilapia (87.61 ± 1.52 g) were simultaneously cultured in pond and cage systems during 90 days. Cages used nutritional biphasic plan (35 and 32 % crude protein—CP feeds) and ponds used nutritional triphasic plan (35, 32 and 28 % CP feeds). Biometric measurements were monthly performed for adjustments in feeding regimes and removal of intestine tissues to evaluate the performance of enzyme activities. Total proteolytic, amylase and lipase activities were not statistically different between the treatments throughout the periods analyzed (31, 63 and 94 days of culture). However, trypsin and chymotrypsin activities were higher with 31 and 63 days of culture in fish from pond system, suggesting that natural food may have influenced these activities. A positive correlation was observed between the recommended concentration of essential amino acids for Nile tilapia and specific aminopeptidases activity in fish cage system. Substrate–SDS–PAGE revealed 12 active proteolytic bands in both systems. However, integrated density (ID) values were higher in the bands of ponds. Specimens of either cage or pond exhibited five bands of amylolytic activity. Fish from cage and pond systems showed the highest values of ID within 31 days of cultivation. In this study, the complexity of digestive functions could be verified for animals maintained under commercial conditions. Some of the assessed enzymes may show adaptations of their activities and/or expression that allow the fish to achieve a more efficient nutrient assimilation.  相似文献   

17.
This work is a continuation of the studies conducted in the ponds of the Fish and Aquaculture Research Station, Dor, in 1975 concerning the components of fish feed under conditions of polyculture, with additional food and intensive fertilization.A study was made of the food eaten by the silver carp, Hypophthalmichthys molitrix (Val.), grown with or without supplementary food in ponds that had previously been used for storage of fish fed on pellets (ponds Types 1 and 3), or which had been kept dry for various periods of time (ponds Types 2 and 4).The special pattern of its gills, which are adapted to retain suspended organisms and particles of sizes less than 20 μm, enables the silver carp to filter enormous quantities of phytoplankton and organic particles.A comparative study was made of the trophic relations existing between Hypophthalmichthys molitrix (Val.), Cyprinus carpio (L.) and Tilapia aurea Steindachner, which were the principal species in the polyculture system, and of the influence of the type of pond used on the growth of the fish.  相似文献   

18.
Supplemental cereal feeding (maize, wheat and triticale compared with a control group with natural food only) and its effect on fatty acid (FA) expression in the flesh during long-lasting storage of common carp (Cyprinus carpio) was investigated. The fish were cultured in earthen ponds in the Trebon region (Czech Republic). The content of fatty acid was investigated in the flesh of carp during 8 months of long-lasting storage without additional feeding. Sixty common carp in their third year of life were used for the analyses. The weight of the fish (marketable fish) ranged from 1,358 g to 2,221 g. Polyunsaturated fatty acid (PUFA, n–3) content and composition in fish flesh were determined by gas chromatography (VARIAN 3300). Supplemental cereals caused lower levels of PUFAs and n–3 PUFAs in fish fat. The content of these fatty acids did not decrease, even during 8 months of fish storage. The average percentage of PUFAs in total fat from edible parts was: for maize 13.7% ± 1.58%, for wheat 11.6% ± 1.17% and for triticale 10.7% ± 1.00%. The percentage of n–3 PUFA for maize was 2.5% ± 0.36%, for wheat 3.38% ± 0.44% and for triticale 3.1% ± 0.39%.  相似文献   

19.
The experiments on the intensive–extensive system were carried out between 2008 and 2010 in three ponds (area 310 m2, depth 1 m) serving as extensive units, where cages were placed as an intensive units (volume 10 m3) one in each pond. In the intensive units, African catfish (Clarias gariepinus) was cultured and fed with pellet whilst common carp (Cyprinus carpio) was stocked in each extensive unit and raised without any artificial feeding. Three different setups of extensive ponds were tested: the additional artificial plastic substrate for periphyton development equalled to 0, 100 and 200 % of the pond surface area (PP0 %, PP100 % and PP200 %) at feed loading level of 1.2, 1.9 and 2.8 gN m?2 day?1 in 2008, 2009 and 2010, respectively. The additional net fish yields in the extensive unit were 2.8–6.5 t ha?1 in PP0 %, 5.1–8.1 t ha?1 in PP100 % and 2.1–4.3 t ha?1 in PP200 %. The nitrogen recovery in the additional fish yields of extensive ponds, expressed as the percentage of feed load, was 5.6–6.1, 6.8–10 and 2.1–6.1 % in the treatments PP0 %, PP100 % and PP200 %, respectively. The combined fish production resulted in higher protein utilisation by 22–26 %; even this ratio can be increased by 33–45 % with periphyton application.  相似文献   

20.
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   

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