Showing papers on "Polyculture published in 2007"
TL;DR: The successful linking of human nutrition and fisheries to address micronutrient deficiencies has relevance for other countries with rich fisheries resources, such as Cambodia and countries in the Lake Victoria region of Africa.
Abstract: Background. Fish and fisheries are important for the livelihoods, food, and income of the rural population in Bangladesh. Increased rice production and changing agricultural patterns have resulted in a large decline in inland fisheries. Implementation of carp pond polyculture has been very successful, whereas little focus has been given to the commonly consumed small indigenous fish species, some of which are rich in vitamin A and minerals, such as calcium, iron, and zinc, and are an integral part of the rural diet. Objective. The overall objective of the research and capacity-building activities described in this paper is to increase the production, accessibility, and intake of nutrient-dense small indigenous fish species, in particular mola (Amblypharyngodon mola), in order to combat micronutrient deficiencies. The large contribution from small indigenous fish species to recommended intakes of vitamin A and calcium and the perception that mola is good for or protects the eyes have been well documented. Methods. An integrated approach was conducted jointly by Bangladeshi and Danish institutions, linking human nutrition and fisheries. Activities included foodconsumption surveys, laboratory analyses of commonly consumed fish species, production trials of carp–mola pond polyculture, teaching, training, and dissemination of the results. Results. No decline in carp production and thus in income was found with the inclusion of mola, and increased intake of mola has the potential to combat micronutrient deficiencies. Teaching and training of graduates and field staff have led to increased awareness of the role of small indigenous fish species for good nutrition and resulted in the promotion of carp–mola pond polyculture and research in small indigenous fish species. The decline in accessibility, increase in price, and decrease in intake of small indigenous fish species by the rural poor, as well as the increased intake of silver carp (Hypophthalmichthys molitrix), the most commonly cultured fish species, which is poor in micronutrients and not preferred for consumption, are being addressed, and some measures taken by inland fisheries management have been discussed. Conclusions. The successful linking of human nutrition and fisheries to address micronutrient deficiencies has relevance for other countries with rich fisheries resources, such as Cambodia and countries in the Lake Victoria region of Africa.
119 citations
TL;DR: Results clearly indicate that A. mollis is an ideal candidate for polyculture with green-lipped mussel farms and at the highest densities appeared to be constrained by food limitation.
115 citations
TL;DR: The effects of intercropping via competition on crop yields, pest, and natural enemy efficacy were studied in the Brassica oleracea L. italica system.
Abstract: The effects of intercropping via competition on crop yields, pest (cabbage aphid Brevicoryne brassicae (L.)) abundance, and natural enemy efficacy were studied in the Brassica oleracea L. var. italica system. 2 From May to December 2004, insect populations and yield parameters were monitored in summer and autumn in broccoli monoculture and polyculture systems with or without competition from Brassica spp. (mustard), or Fagopyrum esculentum Moench (buckwheat), with addition of organic (compost) or synthetic fertilizer. 3 Competition from buckwheat and mustard intercrops did not influence pest density on broccoli; rather, aphid pressure decreased and natural enemies of cabbage aphid were enhanced in intercropping treatments, but this varied with the intercropped plant and season (summer vs. autumn). 4 In compost-fertilized broccoli systems, seasonal parasitization rates of B. brassicae by Diaeretiella rapae (M'Intosh) increased along with the expected lower aphid pressure compared with synthetically fertilized plants.
69 citations
TL;DR: The study revealed the relative advantage of using periphytic substrates in carp polyculture systems with kalbasu as a component species.
64 citations
TL;DR: Yields and mean weight of prawns in monoculture and polyculture were significantly different, and total yield in polyculture was 3,720 kg/ha showing an increase over the production separately obtained in prawn and fish monocculture.
Abstract: .— Tilapia and freshwater prawn production in Puerto Rico for monoculture and polyculture systems were compared. The experiment consisted of three treatments with three replicates each. The stocking rates for the prawn monoculture, fish monoculture and polyculture treatments were respectively: 7 prawns/m2, 1 tilapia/M2, and 7 prawns with 1 tilapia/ m2. The mean stocking size for tilapia and prawn were respectively, 7–8 g and 1–1.3 g. After 145 d of culture, yields and mean weight of tilapia in monoculture and polyculture system were not significantly different. Total yields were 2,942 and 2,769 kg/ha, respectively. Mean weights were 348 g in monoculture and 331 g in polyculture. Yields and mean weight of prawns in monoculture and polyculture were significantly different. Total yields were 1,367 and 951 kg/ha, respectively. Mean weights were 55 g in monoculture and 31 g in polyculture. Total yield in polyculture was 3,720 kg/ha showing an increase over the production separately obtained in prawn and fish monoculture.
49 citations
TL;DR: The electivity indices indicated that there were low dietary overlaps between tilapia and prawn, and survival rates in ponds with bamboo substrate were higher than in the control ponds without substrates.
48 citations
TL;DR: It is suggested that DDGS provides economical growth intilapia when fed as a direct feed and that polyculture of tilapia may improve overall pond efficiency in freshwater prawn production ponds, even at temperate latitudes.
Abstract: .— A 12-wk feeding trial was conducted in cages with juvenile Nile tilapia Oreochromis niloticus to evaluate distillers grains with solubles (DDGS) as a direct feed, the effects of pelleting on its utilization, and the compatibility of caged tilapia and prawns in polyculture. Nine 1.0-m3 cages were stocked with 200 juvenile (26 ± 0.9 g) tilapia. Cages were suspended in a 0.2-ha pond stocked with juvenile freshwater prawns Macrobrachium rosenbergii at 40,000/ha. Three replicate cages were randomly assigned to each dietary treatment. In one dietary treatment DDGS was fed as an unpelleted loose grain ration (26% protein). In a second dietary treatment fish were fed DDGS that had been steam-pelleted (23% protein). Fish in a third dietary treatment were fed a commercial catfish diet (31% protein) for comparison. After 12 wk, individual weight, individual length, and specific growth rate were significantly higher (P 0.05) among treatments (>95%). Although growth was increased in fish fed the commercial diet, their cost of production (<0.66/kg gain) was significantly higher (P < 0.05) than in fish fed unpelleted and pelleted DDGS (<0.26/ kg gain and <0.37/kg gain, respectively). The costs of gain in fish fed unpelleted DDGS was significantly lower (P < 0.05) than in fish fed the pelleted DDGS. Prawn production was 1,449 kg/ha and addition of tilapia in polyculture increased total pond productivity approximately 81 %. These data suggest that DDGS provides economical growth in tilapia when fed as a direct feed and that polyculture of tilapia may improve overall pond efficiency in freshwater prawn production ponds, even at temperate latitudes.
46 citations
TL;DR: The present research investigated the effect of stocking density on pond production of Nile tilapia and prawn and individual weight gain oftilapia were lower, and survival of tilapias and prawes and individual Weight gain of tilapsis were lower.
Abstract: The present research investigated the effect of stocking density on pond (75 m2, depth 1.2 m) production of Nile tilapia (Oreochromis niloticus) and freshwater prawn (Macrobrachium rosenbergii) stocked at a fixed 3:1 tilapia:prawn ratio. Three stocking densities were tried in triplicate: 20 000 ha?1 (treatment TP-20), 30 000 ha?1 (TP-30) and 40 000 ha?1 (TP-40). The ponds were provided with bamboo as substrate for periphyton development. Bamboo poles (mean diameter 5.5 cm and 5.0 poles m?2) were posted vertically into pond bottoms, resulting in 60% additional substrate area in each pond. On average, 43 genera of algae and 17 genera of zooplankton were identified from pond water, whereas 42 genera of algae and six genera of microfauna were attached to bamboo substrates. No differences were observed between treatments in the ash-free dry matter (AFDM), chlorophyll a and phaeophytin a content of periphyton (P>0.05). Survival of tilapia and prawn and individual weight gain of tilapia were lower (P
38 citations
TL;DR: Data indicate that a caged tilapia/freshwater prawn polyculture system may provide pH control while maximizing pond resources in temperate areas.
Abstract: The effects of different densities of caged Nile tilapia, Oreochromis niloticus, on water quality, phytoplankton populations, prawn, and total pond production were evaluated in freshwater prawn, Macrobrachium rosenbergii, production ponds. The experiment consisted of three treatments with three 0.04-ha replicates each. All ponds were stocked with graded, nursed juvenile prawn (0.9 ± 0.6 g) at 69,000/ha. Control (CTL) ponds contained only prawns. Low-density polyculture (LDP) ponds also contained two cages (1 m3; 100 fish/cage) of monosex male tilapia (115.6 ± 22 g), and high-density polyculture (HDP) ponds had four cages. Total culture period was 106 d for tilapia and 114 d for prawn. Overall mean afternoon pH level was significantly lower (P ≤ 0.05) in polyculture ponds than in CTL ponds but did not differ (P > 0.05) between LDP and HDP. Phytoplankton biovolume was reduced in polyculture treatments. Tilapia in the LDP treatment had significantly higher (P ≤ 0.05) harvest weights than in the HDP treatment. Prawn weights were higher (P ≤ 0.05) in polyculture than prawn monoculture. These data indicate that a caged tilapia/freshwater prawn polyculture system may provide pH control while maximizing pond resources in temperate areas.
38 citations
TL;DR: Bivalves, such as green and brown mussels, and oyster, could be used as an alternative species for polyculture with shrimp to control disease due to luminous bacteria.
01 Jan 2007
TL;DR: The positive effects on survival and production of tilapia of additional prawn stocking indicated mixed culture of these two species is promising and options for further optimization should be explored.
Abstract: In recent years, the concept of periphyton-based aquaculture has been tested and applied in aquaculture. Positive effects of substrate addition for periphyton development included increasing the food supply and providing shelter for culture animals. The aim of this project was to develop a low-cost culture technology for resource-poor farmers in South-East Asia. The technology is an extension of traditional brush-park fisheries in which bacteria, protozoa, fungi, phytoplankton, zooplankton, benthic organisms and a range of other invertebrates colonized the substrates installed in rivers and lakes, attracting many fishes. These microbial communities are an excellent food for fishes or crustaceans. The effects of the addition of substrates to ponds to stimulate periphyton development have been studied intensively, but for tilapia-prawn polyculture the methodology still had to be optimized. This thesis focused on the effects of substrate and artificial feed addition on the overall nutrient dynamics, growth, production and economics of tilapia-prawn polyculture. A stepwise approach was followed. The first step was to quantify the effects of substrate and prawn addition to tilapia ponds on total productivity and to quantify the contribution of substrates to tilapia and prawn production. In the second step, the best tilapia :prawn stocking ratio for periphyton ponds was determined . The third step was to optimize the stocking density in periphyton ponds while using the previously determined best stocking ratio. In the fourth step, the optimized tilapia-prawn polyculture package was compared to a traditional (fertilizer, no feed, no substrate), a fed traditional and a periphyton-based fed production systems in terms of total fish production and economic benefits. The final step combined all data from the previous experiments into a multivariate analysis looking at the relationships between production and pond ecology related parameters. In the first study, a considerable overlap was found between the feeding niches of tilapias and prawns (Chapter 2). Substrate addition improved the food conversion ratio in tilapia ponds by 32%, while stocking of prawns resulted in an additional 12% improvement. On average, substrate addition resulted in a 40% higher net yield of tilapia in monoculture and 56% in tilapia-prawn polyculture. The individual weight gain of tilapia increased by 30% due to addition of substrates in both mono- and polyculture ponds. Substrate addition resulted in 9% higher survival and 45% higher tilapia production while prawn survival increased 75% and production 127%. The highest total yield (2445 kg ha -1 tilapia and 141 kg ha -1 prawn) over a 145 days culture period was recorded in periphyton-based tilapia-prawn polyculture ponds. The positive effects on survival and production of tilapia of additional prawn stocking indicated mixed culture of these two species is promising and options for further optimization should be explored. In Chapter 3, the tilapia :prawn stocking ratio in the periphyton-based production system was optimized. The survival of tilapia was higher in polyculture whereas that of prawn was higher in monoculture. The periphyton biomass decreased with increased stocking density of tilapia, indicating the preferential feeding of tilapia on periphyton. The highest production (1,623 kg tilapia and 30 kg prawn ha -1 ) was recorded in the combination of 75% tilapia and 25% prawn at a total density of 20,000 ha -1 . The cost benefit analysis revealed that the monoculture of tilapia and addition of prawn to the tilapia ponds at any ratio were profitable. Chapter 4 explored the optimum stocking density of tilapia and prawn in periphyton-based polyculture ponds. Total stocking densities of 20,000, 30,000 and 40,000 individual ha -1 were tested. Periphyton biomass on the substrates increased during the first 2 months of culture and then decreased for all stocking densities. Survivals of tilapia and freshwater prawn were higher at low and medium (83-86% for tilapia and 51-57% for prawn) stocking densities than at high (78% for tilapia and 39% for prawn) stocking density. The combined net yield of tilapia and freshwater prawn were higher at medium (2,372 kg ha -1 ) and high (2,303 kg ha -1 ) than at low (1,641 kg ha -1 ) stocking density. The net profit margin was highest (69%) at medium (30,000 ha -1 ) and lowest (44%) at high (40,000 ha -1 ) stocking density. Chapter 5, compared tilapia-prawn production in non-fed periphyton-based ponds with traditional (fertilizer, no feed, no substrate), fed traditional and periphyton-based fed ponds. The food conversion ratio (FCR) of tilapia was 13% lower in periphyton-based fed ponds than in fed traditional ponds. Both substrate and feed addition influenced tilapia harvesting weight but not prawn harvesting weight. Survival, final weight gain and net yield of both tilapia and prawn were highest in periphyton-based fed ponds and lowest in traditional ones. The absence of significant differences in survival, harvesting weight and net yield of both tilapia and prawn between periphyton-based and feed driven ponds indicate that periphyton is a good alternative to supplemental feeding. The combined net yield was 59% higher in periphyton-based fed ponds, 48% in fed traditional and 47% in non-fed periphyton-based ponds compared to traditional ponds. The net profit margin was similar between fed traditional and non-fed periphyton-based ponds. Interestingly, although the contribution of prawn to the total production in quantity, as compared to tilapia, was very low (4-7%), it contributed 22-32% to the total sales value. Therefore, even at low density, freshwater prawns contributed an important fraction of farming revenue in tilapia-prawn periphyton-based ponds. In Chapter 6, all water quality, periphyton and fish production data from the previous four experiments were merged into a single dataset and re-analysed using multivariate statistics, to gain deeper insights into the functioning of the ecosystem. The objective was to explore the effects of tilapia and prawn density, presence of substrates for periphyton growth and supplemental feed on the water quality in tilapia-prawn polyculture ponds. The main sources of water quality variability were due to photosynthesis, nutrient uptake, respiration and decomposition. Substrates for periphyton development resulted in a more favorable environment for the cultured organisms and provided an extra source of food for culture animals. The positive effects on the overall pond ecology supported the conclusions from the previous studies that tilapia :prawn polyculture in periphyton-based ponds is a reliable production system that improves farming benefits considerably. In the final discussion (Chapter 7), the applicability of this new technology was reviewed, giving attention to developmental aspects and contemplating ideas for future research.
TL;DR: Irrespective of species combination with silver barb as a component species, similar total biomass production in treatments revealed the feasibility of its incorporation into the Indian major carp-based polyculture practice without affecting the total yield.
Abstract: The compatibility and growth performance of silver barb Puntius gonionotus (Barbonymous gonionotus) with the three Indian major carps, i.e., Catla catla, Labeo rohita and Cirrhinus mrigala, were assessed in a 10-month carp polyculture trial. Treatments T-1, T-2, T-3 and T-4 were stocked with three of the above four carp species, with an absence of silver barb, mrigal, rohu and catla, respectively, while all four species were stocked in treatment T-5. The treatments were stocked at 6000 fingerlings ha−1, with an equal species ratio maintained in each treatment. Incorporation of silver barb into the polyculture system neither affected the survival of any carp irrespective of species combination nor yielded significant changes in biomass production among treatments, except for the one without catla, where it was significantly low. The study revealed a higher extent of competition between silver barb and rohu, perceptible from the lower growth of one in the presence of the other. Although a certain level of competition of silver barb with mrigal was evident, competition with catla was not perceptible. Irrespective of species combination with silver barb as a component species, similar total biomass production in treatments revealed the feasibility of its incorporation into the Indian major carp-based polyculture practice without affecting the total yield.
TL;DR: It is suggested that provision of additional substrate for the enhancement of periphyton production has a greater importance in growth enhancement of Nile tilapia and pearlspot when stocked at the densities used in this study.
Abstract: Growth performance of Nile tilapia, Oreochromis niloticus, and pearlspot, Etroplus suratensis, under polyculture was studied in inland saline groundwater ponds. Three treatments (1–3) each in replicate of two were maintained: In Treatment 1 (substrate ponds), bamboo poles as additional substrate were provided for the development of periphyton, while in Treatment 2 (fed ponds), no additional substrate was provided; however, the fish were fed on supplementary diet (40% CP). Treatment 3 served as control, where neither the fish were fed on any supplementary diet, nor any substrate provided in the ponds. Irrespective of the treatment (duration 90 days), ponds were fertilized with cow-dung at 7,500 kg/ha/year. Results revealed significantly (P < 0.05) higher fish growth in Treatment 1 due to the provision of additional substrate compared with diet (39%) and control (102%) ponds. The exponential value of “n” for both the fish species was higher (n = 3.2) in ponds provided with additional substrate than...
Journal Article•
TL;DR: Factors affecting polyculture of sea urchin with sea cucumber including optimal ratio of sea iurchin to sea cucumbers were discussed.
Abstract: Sea urchin(Strongylocentrotus intermedius)juveniles weighing(17±07)g were stocked into 24 plastic tanks of each 45 cm×31 cm×30 cm at a rate of 10,20 and 30 individuals per tank and polycultured with juvenile sea cucumber(Apostichopus japonicus Selenka)averaging(18±05)g in body weight at water temperature of 130～230 ℃ for 151 daysThe sea urchin were ad libtum fed kelp(Laminaria japonica) and the sea cucumber unfedSpecific grow rate and survival were found to increase by 2846%,286%;3399%,1035% and 2552%,2313% in the sea urchin polycutured with sea cucumber at a rate of 10,20 and 30 individuals per tank,respectivelyThere was 150%,799% and 185% lower feed conversion ratio in polyculture than in monoculture for each stocking density of sea urchinIn polyculture water,ammonia-N level was registered low and constant,and high dissolved oxygen level was observedThe density of sea urchin showed no significant influence on approximate composition of sea cucumber(P005)Factors affecting polyculture of sea urchin with sea cucumber including optimal ratio of sea urchin to sea cucumber were discussed
Patent•
18 Apr 2007
TL;DR: A composite forage for green shrimp and river crabs is described in this article, using 18 raw materials including wheat flour, fish powder, soybean cake, fish oil, choline chloride, etc.
Abstract: A composite forage for green shrimp and river crab is prepared from 18 raw materials including wheat flour, fish powder, soybean cake, fish oil, choline chloride, etc.
TL;DR: A typology of brackish-water pond farming systems is constructed using multivariate methods (principal components analysis, cluster analysis), and implications for technical efficiency estimation and comparative study of economic indicators are discussed.
Abstract: Aquaculture in the Philippines is long-established but has witnessed rapid technical change in the last 20 years with the introduction of hatchery technology and commercial feed mills changing the production possibilities for a fishpond operator. To understand the sector, a typology of brackish-water pond farming systems is constructed using multivariate methods (principal components analysis, cluster analysis). Eight input variables across all major factors of production are used in the analysis, gathered from a net sample of 136 farms in two regions in 2003. Three latent variables are described, accounting for 58% of variance in the original data: specialization; land vs. labor intensity; and feeding intensity. Five clusters (farm types) are subsequently described: extensive polyculture (40% of sample); semi-intensive prawn-oriented polyculture (11%); low-input labor-intensive farms (27%); very large, extensive milkfish-oriented farms (8%); and semi-intensive milkfish monoculture farms (14%). Implicatio...
01 Jan 2007
TL;DR: In this paper, one-year old river puffers were stocked to four earthen ponds of in surface area as followings: polyculture LvP, L. vannamei and Fenneropenaeus chinensis.
Abstract: Shrimp culture in Korea had been rapidly developed during 1990's and the production of farmed shrimp reached 3,268 mt from 2,605 ha in 2001. However the shrimp production decreased to 2,368 mt in 2004 because of the mass mortality due to outbreak of white spot syndrome virus (WSSV). WSSV which is one of the most serious threats associated with cultured shrimp around the world has given the economic damages to shrimp culture industry every year since it was found from the shrimp ponds in the west coast of the South Korea in 1993. Various polyculture technologies of shrimp with shellfish, finfish or seaweeds have been implemented to reduce economic damages by mass mortalities of shrimp. Among them, the polyculture of shrimp with carnivorous fish can suppress or delay the viral outbreak of shrimp ponds because the fish may selectively eat the moribund shrimps infected by virus. To determine the selective predatory effect of river puffer Takifugu obscures on WSSV infected shrimp, postlarvae of Litopenaeus vannamei and Fenneropenaeus chinensis. One-year old river puffers were stocked to four earthen ponds of in surface area as followings: polyculture LvP, L. vannamei ()+puffer (); control Lv, L. vannamei (); polyculture FcP, F. chinensis ()+puffer (); control Fc, F. chinensis (). Ponds of control Fc and polyculture FcP had mass mortalities by WSSV outbreak on the and days of culture respectively. The shrimps of polyculture LvP and control Lv were harvested on the . Shrimp survival rates of polyculture LvP and control Lv were 32.4% and 18.2% respectively and shrimp productivity of polyculture LvP was 69.2% higher than that of control Lv. Concentration of nutrients (TAN, , ) was maintained within optimal ranges for shrimp growth although that of polyculture ponds showed at least two times higher than that of control ponds. The results suggest that polyculture of L. vannamei with river puffer is higher than monoculture in survival rate and productivity. In addition, F. chinensis should be carefully cultured because this species shows much higher susceptibility to WSSV than L. vannamei.
01 Jan 2007
TL;DR: The functional and trophic analyses shown that epigeics organisms mainly detritivores dominated in forage and polyculture, while the endogeics and geophagous were most abundant in pasture, which could indicate different functional strategies in the systems.
Abstract: The response of the soil macrofauna to the application of diverse agroecological methods or to the conversion of grassland into agroecosystem is poorly known in Cuba. The objective of this research was to characterize the macrofauna in grasslands with a combination of cattle raising and crop sowing. Three areas were studied: a pasture, a pasture covered with trees (forage) and a polyculture, the last two with different agroecological managements. The three systems are placed in Cangrejeras, Havana, Cuba. The macrofauna was assessed from January 2002 to March 2003 and the soil samples were collected according to the TSBF Methodology. Three phyla, six classes, 16 orders, 36 families, 47 genus and 22 determined species formed the edaphic communities. The functional and trophic analyses shown that epigeics organisms mainly detritivores dominated in forage and polyculture, while the endogeics and geophagous were most abundant in pasture. These facts could indicate different functional strategies in the systems. Taxonomic richness, diversity and evenness index as well as the communities density and biomass had the highest values in the forage and the polyculture, the lowest were obtained in the pasture. According to the results, the agroecological practices studied help to develop the edaphic macroinvertebrates communities.
TL;DR: There was significant reduction in the counts of those groups of biogeochemical cycling bacteria (AB, PMB, NB, CDB An, Vibrio sp.) which mostly belong to the Gram-negative group which indicates the possibility of exploiting carp–prawn polyculture as an associative system for reducing the gram-negative water borne enteropathogenic bacteria that causes epidemiological problems.
TL;DR: The overall conclusion of the present experiment showed that under such stocking rate and production system, introduction of catfish at the rate of 13% of total Tilapia stocked has not only eliminated 70% oftotal tilapia recruitment but also enhanced total pond production of marketable size fish in both of the polyculture treatments.
Abstract: he present experiment was conducted in twelve earthen ponds 2100-m 2 at WorldFish Center research facility at Abbassa, Egypt, to assess the efficiency of African catfish (Clarias gariepinus) in controlling unwanted Nile tilapia (Oreochrmis niloticus) reproduction in grow out and to evaluate the performance of tilapia in polyculture system with catfish under low-input production system. Mixed sex tilapia fry (averaging 0.15 g total body weight) stocked at the rate of 2 fish/m 2 and African catfish fingerlings (223 g) were introduced two month later at stocking rates of 7 and 13% of tilapia into T2 and T3 respectively in addition to T1 which had no African catfish introduced to it. Ponds were fertilized weekly using chicken letter at the rate of 500 kg/ha. Water quality parameters were monitored weekly for measuring DO concentration, temperature, Secchi disk, pH and NH4. Also monthly water samples were taken for measuring pH, alkalinity, TAN, NO3, NO2 available phosphorus, chlorophyll a, and total hardness. Statistical analysis of the obtained fish production data at the end of the thirty-week experimental period, showed that catfish significantly (P< .05) reduced the biomass of recovered tilapia reproduction to 14.9 and 8 % fry as percentage of the total fish yield in T2 and T3, respectively as compared to 26.6% obtained in T1. Tilapia production in polyculture with catfish was significantly lower than tilapia monoculture while, on the other hand, total fish production was significantly (P< .05) higher in the case of both of the two polyculture treatments compared to the tilapia only treatment. The overall conclusion of the present experiment showed that under such stocking rate and production system, introduction of catfish at the rate of 13% of total Tilapia stocked has not only eliminated 70% of total Tilapia recruitment but also enhanced total pond production of marketable size fish in both of the polyculture treatments. T
24 Aug 2007
TL;DR: Fish from monoculture and polyculture systems showed over twice the weight gain, lower food consumption, better food conversion rate, bigger standard length and group uniformity than the fish maintained in aquariums, while the aquarium system showed lower survival than monocculture.
Abstract: Culture systems for freshwater angelfish (Pterophyllum scalare). The present study aimed to compare three production systems for freshwater angelfish: intensive indoor aquarium, semi-intensive greenhoused earth pond (monoculture) and greenhoused earth pond in polyculture with Amazon River prawn. Two stock densities were also tested: 1.6 and 3.2 fish 10 L. The experimental design was entirely randomized, in a 3x2 factorial scheme, with four replicates. ANOVA and Tukey’s test were used (α = 0.05). Fish from monoculture and polyculture systems showed over twice the weight gain, lower food consumption, better food conversion rate, bigger standard length and group uniformity than the fish maintained in aquariums. The aquarium system showed lower survival than monoculture. The stock density increase reduced the weight gain, standard length and body condition in all culture systems. The interaction analysis for biomass was statistical significance, showing no difference between the densities inside aquarium and increasing with density within mono and polyculture ponds. In polyculture, mean final weight and survival of Amazon river prawns were 1.66 g e 84.4%, respectively. Due to better growth results, density of 1.6 fish 10 L is better than 3.2 fish 10 L. Freshwater angelfish can be produced better in hapas on monocultured or polycultured semi-intensive compared to indoor aquariums system.
TL;DR: Study of the utilization of energy in the three tropical ponds, which were fertilized with vermicompost, cow dung and diammonium phosphate, revealed that herbivores were more efficient in utilizing energy than were autotrophs.
Abstract: The energy budget patterns of three tropical ecosystems in which the polyculture of fish was practised were studied. The rates of organic production of the three tropical ponds over two annual cycles were evaluated. Study of the utilization of energy in the three ponds, which were fertilized with vermicompost, cow dung and diammonium phosphate, revealed that herbivores were more efficient in utilizing energy than were autotrophs. The available energy in these systems was supplied by autochthonous sources. Silver carp was found to be the most efficient organism in converting energy in the grazer food chain in the ponds. The efficiency of the system in regard to fish production was 0.052, 0.049, and 0.051%, respectively, of the total available solar radiation. Organisms in various trophic levels were all characterized by energy changes in the studied ponds, forming the food webs contained in them.
DOI•
01 Jan 2007
TL;DR: The Strength, Weaknesses, Opportunities and Threats (SWOT) analysis identifies the factors of the external strategy, such as the opportunity and threat, while the Factors of the internal strategy show that the traditional tiger shrimp cultivation in ponds in Pinrang regency needs to be developed and protected against diseases and against demands of improvement of the shrimp quality produced by the shrimp importing countries.
Abstract: The cultivation of tiger shrimp as an export commodity is a prospective business. The Pinrang regency in South Sulawesi, as the central producer of tiger shrimp, yields 4,447 tons, 3,823 tons, 3,290 tons, and 3,079 tons of shrimp respectively in the years of 2000 to 2003 from a pond of 15,735 hectare, with a labor of 17,541 shrimp farmers. The system of cultivation is mostly traditional (approximately 99.7%) using the polyculture and monoculture systems. The study aimed (1) to analyze the business feasibility of tiger shrimp in ponds in the traditional way, using both polyculture and monoculture systems, (2) to analyze the problems faced by traditional farmers of tiger shrimp in ponds. The results of the study were based on the method of income analysis and Benefit Cost (B/C) ratio on ten shrimp farmers using the polyculture system, and on five others using the monoculture system, which showed that it was a feasible business (B/C ratio was greater than 1). The analysis showed that the productivity of the monoculture system was higher than that of the polyculture. As a comparison, the monoculture system produced an average of 567 kg/hectare/year, and made a profit around IDR 15.489.000/hectare/year compared to the polyculture system which produced 197 kg/hectare/year, or equal to the average profit at approximately IDR 4.365.000/hectare/year. Based on the analysis of rentability, only 60% of the total sampling showed a rentability value greater than the interest rate in 2003, which was 7%. The analysis of the survival rate of the monoculture system showed a better average of the survival rate of 33.94% compared to 19.13% of the polyculture system. From these analysis it can be concluded that the higher the survival rate of tiger shrimp (above 10,000 pieces/hectare/season), the higher the production and income. The Strength, Weaknesses, Opportunities and Threats (SWOT) analysis identifies the factors of the external strategy, such as the opportunity and threat, while the factors of the internal strategy show that the traditional tiger shrimp cultivation in ponds in Pinrang regency needs to be developed and protected against diseases and against demands of improvement of the shrimp quality produced by the shrimp importing countries.
01 Jan 2007
TL;DR: The results showed that puffer tends to selectively prey on virus infected shrimps among infected and non-infected ones in a limited space with although there is difference in predatory rate with age and density of animals.
Abstract: White spot syndrome virus (WSSV) which is the most serious threat to cultured shrimp around the world has given enormous economic damages to shrimp culture industry every year since it was found from the shrimp ponds in the west coast of the South Korea in 1993. WSSV has strong infectivity as well as virulence and it can be rapidly transmitted among shrimps in ponds by cannibalism of infected ones. Polyculture of shrimps with carnivorous fish has been applied in commercial shrimp farms to suppress or delay the viral outbreak because the fish may selectively eat the moribund shrimps infected by virus. To determine the selective predatory effect of a carnivorous fish, river puffer Takifugu obscurus on white shrimp Litopenaeus vannamei, polyculture trials in laboratory scale of WSSV-infected and non-infected shrimps with river puffer were conducted in concrete round tanks of 28.26 m 2 in surface area as followings: 1) juvenile shrimps (B. W. 0.62 g) with 5 months old puffer (B. W. 11.60 g) cultured for 8 days, and 2) sub-adult shrimps (B. W. 6.84 g) with 16 months old puffer (B. W. 85.82 g) cultured for 5 days in order to know the effects according to size difference of cultured animals. In polyculture of juvenile shrimp with 5 months old puffer, survival rates of infected and non-infected shrimps were 46.0% and 89.1% respectively and in that of sub-adult shrimp with 16 months old puffer those were4% and 48% respectively. The results showed that puffer tends to selectively prey on virus infected shrimps among infected and non-infected ones in a limited space with although there is difference in predatory rate with age and density of animals. Regardless of different densities and ages of animals as well as health condition of shrimps, however, there were low differences in daily biomass of shrimp consumed per kg body weight of puffer. This finding suggests that puffer preys on healthy shrimps when moribund shrimps were not sufficient. Therefore, farmers should consider the total biomass of puffer as well as density and stocking time when they stock puffer into shrimp ponds for polyculture.
Patent•
28 Mar 2007
TL;DR: In this paper, a method for mixed-raising crabs and clams is described, which is characterized by that in every ma of water surface in which 1000 breeding clams are being bred 5-8 kg of juvenile crabs can be bred.
Abstract: The present invention relates to a method fox mixed-raising crab and clam. It is characterized by that in every ma of water surface in which 1000 breeding clams are being bred 5-8 kg of juvenile crabs can be bred. Besides, said invention adopts special-purpose bag for raising breeding clams, every bag can hold 3-4 breeding clams, and regularly adds food and changes fresh water, and regularly spread quicklime powder so as to attain the goal for mixed-raising clams and crabs.
01 Jan 2007
01 Jan 2007-The International Journal of Environmental, Cultural, Economic, and Social Sustainability: Annual Review
TL;DR: In this article, a series of experiments were conducted to compare different inorganic and organic fertilizers to improve production of Macrobrachium rosenbergii and to make a decision support program in an artificial sustainable aquaculture-agriculture system.
Abstract: There are many research activities to improve sustainable aquaculture and agriculture production in the wide world. Sustainable aquaculture is referred to as production of aquatic commodities through farming activities with social, economic and environmental sustainability.
A series of experiments were conducted to compare different inorganic and organic fertilizers to improve production of Macrobrachium rosenbergii and to make a decision support program in an artificial sustainable aquaculture-agriculture system. Simply, nutrient wastes from culture tanks were used to fertilize hydroponics or terrestrial plants production via irrigation water. The sustainability and success functioning of the whole system were involved to manage and optimize the use of supplemented minerals, diet and desirable environment for each compartment (prawn, plant and microorganisms).The first experiment was made to evaluate the tolerance of M. rosenbergii in different levels of inorganic fertilizer (EC) formulated in nutrient film technique (NFT) vegetable production system. Results of the first experiment indicated that desirable growth rate of M. rosenbergii was obtained using 0.1 to 0.5EC of supplemental liquid fertilizer. High concentration of potassium (117-177 mg l-1), ammonia (0.72-1.05 mg l-1) and copper (0.04-0.06 mg l-1) inhibited the growth rate of M. rosenbergii in integrated culture system.
The second experiment was carried out to assess the effects of different nutrient and stocking density on different population of M. rosenbergii in polyculture system. A different range of inorganic and organic fertilizer was used in the polyculture of plant and freshwater prawn species. Overall results indicated that essential concentration of nutrients, source and M. rosenbergii stocking density have played a major role in the effectiveness of suitable range of minerals in integrated production system. The results also demonstrated that 0.5 EC liquid inorganic fertilizer was not suitable to provide optimum nutrients and chicken manure is still an important fertilizer even in indoor integrated culture system.
Finally, a comparative study was conducted to evaluate the optimum level of chicken manure and formulated inorganic nutrients in an artificial integrated culture system. The results indicated that high density culture of M. rosenbergii juveniles (380-400 individual m-2) in fiberglass tanks is possible by the installation of artificial substrate and controlling of nutrient concentration in system. Moreover the addition of aeration tank significantly improved the quality of water (DO and pH) and freshwater prawn growth (1343.0 g/tank) in recirculated polyculture system. The application of 70 g m-3 chicken manure alone encouraged growth of benthic and periphyton algae in culture tanks. The overall observation illustrated the desirable combination of supplemental liquid fertilizer and chicken manure is essential to obtain best growth for each compartment in sustainable polyculture system.
A visual expert program (IAAS) was adopted to improve managing and develop technical operation in an artificial integrated culture system. The operation of the polyculture system required the specific knowledge, developing and application of computer systems to excellent operation, control of water quality variables, dissolved nutrients and feed to avoid the production of toxic substance and increase self efficiency and sustainability of the culture system. The accuracy of IAAS expert program was evaluated by polynomial and linear regression techniques through additional experiment. The comparison of results (yield and survival) in expert and real culture system represents higher variation of survival, prawn and plant yields in abnormal culture system. Moreover the evaluation processes demonstrated succeed performance of IAAS expert program in prediction results of optimized integrated culture system (with low variation). In aquaculture, the success estimation of production depends largely on the state of physical and chemical parameters which define optimal culture conditions.