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1.
Growth, production and economic analysis was performed for the polyculture of juveniles spotted babylon, Babylonia areolata, and milkfish, Chanos chanos, to marketable sizes using a large‐scale production of earthen ponds in Thailand. The analysis was based on actual cost and production data from a pilot commercial‐scale farm. A total farm area of 0.8 ha was comprised of 0.3 ha grow‐out earthen ponds, a 0.4 ha seawater reservoir, and a 0.08 ha accommodation and office. Each pond was stocked with spotted babylon juveniles of 0.3 g initial body weight at a density of 200 snails m?2, and they were harvested at a 7‐month period, at an average body weight of 4.6 g for a total yield per production cycle of spotted babylon and milkfish of 9875 and 6875 kg ha?1 respectively. Based on farm data and harvest data used in this study, initial investment requirement was estimated to be $4837. The ownership cost and operating cost per production cycle were $2241 and $18 501 respectively. Total cost per production cycle was $20 742. The cost of producing spotted babylon marketable sizes in this grow‐out farm design was $6.56 kg?1. The enterprise budgets based on the price of spotted babylon at a farm gate in 2003 of $9.00 kg?1 results in gross return, net return, return to capital and management, and return on investment of $31 190, $10 448, $12 689 and 2.62 respectively. Milkfish was not calculated for any returns because they were less than marketable sizes.  相似文献   

2.
Juvenile spotted babylon (Babylonia areolata) and sea bass (Lates calcarifer) were cultured in 11.5‐m3 indoor rearing tanks supplied with flow‐through of ambient natural sea water over a 120‐day experiment. Each species, stocked at the following densities for the following treatments, was tested with three replicates per treatment: 5000 B. areolata per tank (Treatment 1); 200 L. calcarifer per tank (Treatment 2); and 5000 B. areolata plus 200 L. calcarifer per tank (Treatment 3),. The average growth (length and weight), feed conversion ratio and total production of spotted babylon and sea bass from Treatment 3 were not significantly different from those of Treatment 1 and 2 (P > 0.05). Average survival rates for both spotted babylon and sea bass exceeded 95% for all treatments.  相似文献   

3.
The effects of feeding regimes on the growth, survival and feed conversion of hatchery-reared juvenile spotted babylon Babylonia areolata (Link) were assessed. Six continuous and discontinuous feeding regimes were fed at satiation to triplicate groups of snails in 200-L flowthrough (3.0 L h–1) indoor rectangular tanks for 180 days. Shell length growth rates of juvenile B. areolata did not differ significantly (P > 0.05) between the various feeding treatments. Body weight gain and feed conversion of snails were not significantly different between various feeding treatments, nor were there significant differences in mean survival between any of the feeding treatments.  相似文献   

4.
Hatchery reared juvenile spotted babylon, Babylonia areolata, were raised in canvas rearing tanks at four stocking densities (100, 200, 300 and 400 ind. m–2) in flow-through and recirculating seawater systems until they reached the marketable sizes of 100–140 snails/kg. At all stocking densities, final increments in mean length and weight of snails held in flow-through systems were higher than those in recirculating systems, there was a significant effect (p < 0.05) of culture system on final length and weight. Mean (±SE) survival of snails held at 100 ind. m–2 in the flow-through system was 100.0 ± 0.1% but was not significantly higher than survival in any other treatment (p > 0.05). Mean survival of snails held in the recirculating system was not significantly lower than at any stocking density in the flow-through system (p > 0.05).  相似文献   

5.
Growth and water quality for growing-out of juvenile spotted Babylon, Babylonia areolata, were determined at three water-exchange regimes of 7-, 15- and 30-day intervals in large-scale operation of earthen ponds over a 5-month period. Results showed that growth was significantly different among the water-exchange treatments (P < 0.05). The higher body weight gains and shell length increments were observed in snails held at water exchange of 7- and 15-day intervals when compared with those held at water exchange of 30-day intervals. At the end of the experiment, average body weight gains were 4.22, 3.73 and 2.77 g for snails held in water-exchange treatments of 7-, 15- and 30-day intervals, respectively, and 16.63, 15.04 and 13.78 mm for those of shell length increments, respectively, The average final survivals were 83.60, 80.90 and 74.20% for snails held in water-exchange treatments of 7-, 15- and 30-day intervals, respectively. Seawater temperature, salinity, pH, dissolved oxygen, nitrite–nitrogen and ammonia–nitrogen had gradually changed throughout the culture period for all water-exchange treatments. With one exception, the total alkalinity showed the greatest changes during the culture period for all water-exchange treatments ranging from 58.67–97.50 mg/l.  相似文献   

6.
A 120-day feeding trial was conducted to determine growth, feeding efficiency, and biochemical composition of juvenile spotted babylon Babylonia areolata (initial mean weight of 1.48 ± 0.06 g) fed on conventional trash fish and a formulated moist diet in a flow-through grow-out system. The snails readily accepted the formulated moist diet and showed good growth and survival during the trial. There were no significant differences in specific growth rate, feeding efficiency, and survival between the snails fed on trash fish or the formulated moist diet. At the end of the experiment, biochemical analysis of the snail flesh showed significant differences in flesh quality, with the snails fed on trash fish having a significantly higher crude protein compared to those fed on the formulated diet, but there was little difference in crude lipid content. Whole body tissue of snails fed on trash fish had significantly higher total amino acid, essential amino acid, and non-essential amino acid levels compared to those fed the formulated diet. This study showed that the formulated moist diet can be readily used for B. areolata growout for maximizing growth, survival, and feeding efficiency; however, further research is needed to improve the flesh quality particularly amino acid and fatty acid levels before its suitability for B. areolata is assured.  相似文献   

7.
The growth and survival of juvenile spotted babylon, Babylonia areolata , were determined at five stocking densities (100, 200, 300, 400 and 500 snails m−2) and three water exchange regimes (7-, 15- and 21-day intervals) in experimental earthen ponds over a 6-month experimental period. The results showed that the growth of spotted babylons was not significantly different among any density treatments ( P <0.05). At the end of the experiment, the average growth rates in body weights were 0.59, 0.59, 0.58, 0.42 and 0.41 g month−1 respectively. Growth was significantly different among the different water-exchange treatments ( P <0.05). The higher body-weight gains were observed in snails held at water exchanges of 7- and 15-day intervals, when compared with those held at water exchange of 30-day intervals. At the end of the experiment, average body-weight gains were 4.22, 3.67 and 2.68 g for snails held in water-exchange treatments of 7-, 15- and 30-day intervals respectively. This study recommended that stocking densities ≤300 snails m−2 and water exchange of 7–15-day intervals are suitable for cultured B. areolata juveniles in earthen pond.  相似文献   

8.
Cellular and humoral effectors are imperative for the innate defense mechanisms of invertebrates, including the spotted babylon snail Babylonia areolata, a marine gastropod belonging to the family Buccinidae. In this study, we have investigated the influence of body size [5–8 g (small), 10–12 g (medium) and 15–17 g (large)], and culture waters of varied quality [natural seawater, low salinity, low alkalinity, high total ammonia nitrogen (TAN) and artificial seawater] on some hemato-immunological parameters [total hemocytic counts (THC), hemolymphatic glucose, total protein concentration, phenoloxidase (PO), agglutinating and lysozyme activity] of the snail. Growth performance measures and survival of test snails were also evaluated after rearing them in culture water of varied quality. Body size did not influence most parameters assessed, except that the lysozyme and PO activities of medium and large-size snails were higher than those of the small-size snails. Sub-optimal culture water quality affected hemato-immunological factors, growth and/or survival of the spotted babylon snail. Seawater with low salinity, low alkalinity and a high TAN level caused decreased THC, hemolymphatic glucose, and PO activity; increased lysozyme activity; and clearly retarded growth of the snail. The snails held in artificial seawater could not survive after 4 weeks, suggesting the lack of certain essential factors necessary for their survival.  相似文献   

9.
Holothuria scabra (sandfish) and Babylonia areolata were trialed in two large‐scale co‐culture experiments. Experiment 1 assessed co‐culture in 4 × 400 m2 earthen ponds where Babylonia were cultured in a central pen at a density of 400 individuals/m2 with sandfish occupying the remaining pond space at 1.1 individuals/m2. Sandfish grew from 18.20 ± 6.67 g to 119.03 ± 17.74 g in 92 days and Babylonia (fed trash fish in both experiments) grew from 0.90 ± 0.38 g to 4.93 ± 1.44 g, but Babylonia growth was not increased in co‐culture compared to monoculture. Water and sediment quality varied between co‐culture and monoculture ponds. Neither showed clear improvement due to sandfish culture. Experiment 2 compared non‐segregated sandfish‐Babylonia co‐culture with Babylonia monoculture in 20 m2 concrete raceways. Sandfish were cultured at 2 individuals/m2 and Babylonia at 300 individuals/m2. Sandfish grew up to 1.91 g.day?1 with 100% survival. Babylonia weight gain was significantly greater in co‐culture raceways (3.35 ± 0.64 g over 61 days), which was double that of Babylonia in monoculture. Substrate total N was reduced by 20% in co‐culture compared with monoculture (p = .032). This provisional study of commercial scale sandfish‐Babylonia co‐culture demonstrates culture compatibility, providing a basis for further system development.  相似文献   

10.
This article examines the economic considerations involved in the production of spotted babylon (Babylonia areolata) in Thailand. A financial analysis of the construction and operating costs of a pilot commercial production of spotted babylon of marketable sizes is provided, based upon proven practical techniques and production data for a flow‐through growout system. The investment required for a spotted babylon growout hatchery producing 990 kg per year is estimated to be US$4528.8. The annual cost of operating such a hatchery is estimated to be US$4624.1. The cost of producing 990 kg of marketable‐size spotted bablyon with a survival rate of 95% is estimated to be US$4.91 per kg of snails produced. Cash flow analysis showed that a constant selling price of US$5.8 kg?1 results in positive cash flow by year 4. The proposed enterprise is marginally feasible if cost can be considerably reduced by targeting production and integrating hatchery and growout operations.  相似文献   

11.
This study was undertaken to evaluate the use of brewers yeast and nucleotides as a growth promoter and to provide vibriosis resistance for the juveniles of gastropod spotted babylon (Babylonia areolata). Juvenile spotted babylon (0.3 g initial weight) were randomly distributed at a density of 50 snails in 45-L aquaria and fed a basic diet (40% crude protein) containing two incremental levels of 1 and 2% brewers yeast and nucleotides singularly for 4 months. After the feeding trial, snails from each treatment were challenged by pathogenic bacteria Vibrio alginolyticus given by intramuscular injection and kept under observation for 5 days to record clinical signs and daily mortality rates. Results indicated that the snails fed with diets supplemented with brewers yeast or nucleotides exhibited significantly greater growth than those fed the basic diet (P < 0.05) and significantly better food conversion ratios compared to snails fed the basic diet (P < 0.05). These results indicated that dietary supplementation of brewers yeast or nucleotides, at least at the tested dosages, enhanced spotted babylon growth. Supplementing the diet with 1% brewers yeast promises to provide appropriate resistance to V. alginolyticus.  相似文献   

12.
Growth, survival and shell normality of hatchery reared juvenile Babylonia areolata were examined at four water exchange regimes of 0, 15, 30 and 60 day intervals in a recirculating seawater system over a 120 day experimental period. Higher body weight gains and shell length increments were observed in snails held at water exchange of 15 day intervals, especially when compared with those held at water exchange of 60 and 0 day intervals (P < 0.05). Water exchange affected the final survival of B. areolata. At the end of the experiment, final survival rates were 65.47 ± 0.66%, 87.48 ± 0.67%, 86.34 ± 0.92% and 78.50 ± 3.26% for snails held in the water exchange treatments of 0, 15, 30, and 60 day intervals, respectively, and those of shell abnormality were 97.65 ± 1.04%, 93.09 ± 2.34%, 97.08 ± 1.18% and 96.71 ± 1.84%, respectively. The present study concluded that water exchange regimes of the recirculating system influenced growth, survival, shell normality and water quality of the recirculating culture system for this species.  相似文献   

13.
Juvenile prawns (Macrobrachium rosenbergii) were stocked at 37,050/ha and golden shiner (Noremigonus crysoleucas) fry at 321,100/ha into 16 earthen ponds at Rockefeller Wildlife Refuge, Grand Chenier, Louisiana. Four replicated treatments were tested: fed prawn monoculture, fed shiner monoculture, fed prawn and fed shiner polyculture, and unfed prawn fed shiner polyculture. The study lasted 149 days. There were no significant differences in growth between prawns fed in monoculture and prawns fed in polyculture (P > 0.05). However, fed prawns grew significantly larger (P < 0.05) than unfed prawns. Prawn survival in all treatments combined averaged 63%. Survival was significantly higher (P < 0.05) for fed prawns than for unfed prawns. Prawn yields averaged 533 kg/ha, when all treatments were combined. Yield was significantly higher (P < 0.05) for prawns grown with shiners and for prawns that received supplemental feed. Growth was significantly higher (P < 0.05) for shiners grown with fed prawns than for shiners grown with unfed prawns. Shiner survival averaged 33% and was significantly higher (P < 0.05) in monoculture than in polyculture. Yield for all ponds averaged 392 kg/ha, with no significant differences between treatments (P > 0.05).  相似文献   

14.
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.  相似文献   

15.
This study was conducted to determine the feasibility of using seaweeds as biofilters in a hatchery scale recirculating aquaculture system for juvenile spotted babylons (Babylonia areolata). Two seaweeds Gracilaria salicornia and Caulerpa lentillifera were used with three initial biomass levels of each species (280, 560 and 840 g wet weight m−3). Spotted babylon with an average initial shell length of 1.32 ± 0.01 cm and body weight of 0.37 ± 0.01 g was used with a stocking density of 300 snails m−2. The experiment was carried out in triplicate over a period of 120 days. Results showed that seawater quality (water temperature, conductivity, salinity, pH, dissolved oxygen and total suspended solids) gradually changed with no significant differences between treatments throughout the experimental period, except alkalinity, total ammonia nitrogen, nitrite–nitrogen, nitrate–nitrogen and phosphate. Growth rates in weight and shell length of the spotted babylon cultured in all seaweed treatments used were not significantly different between seaweeds and density treatments, but significant differences in final survival rate of the spotted babylon were found between seaweed and density treatments. Growth rate and biomass gain of C. lentillifera were significantly higher than those of G. salicornia for all stocking density treatments. This study shows that Gracilaria salicornia and Caulerpa lentillifera can be used as biofilters for regulating water quality in a recirculating culture system for spotted babylons.  相似文献   

16.
In this study, we evaluated the production potential of the polyculture of Freshwater Angelfish (Pterophyllum scalare, Cichlidae) and Pacific white shrimp (Litopenaeus vannamei). Two experimental trials were set up. The first trial entailed the use of a randomized design to investigate three treatments options: angelfish monoculture, shrimp monoculture, and fish and shrimp polyculture in 12 experimental 15 m2 ponds. In the second trial, we investigated two treatments (polyculture of caged fish and uncaged fish) in 10 experimental units. In trial 1, polyculture negatively affected fish growth and survival. However, fish did not affect shrimp growth and the greatest profit was achieved in polyculture. In trial 2, caging fish improve the growth of both fish and shrimp. An economic analysis showed the greatest profit and benefit cost ratio for caged fish compared with uncaged fish. We conclude that growing P. scalare and L. vannamei together is a better strategy than shrimp monoculture in low‐salinity water. The use of caged fish in such a polyculture operation would enhance productivity and profitability.  相似文献   

17.
A feeding experiment was conducted to determine the effects of dietary calcium and phosphorus, and the interaction between calcium and phosphorus, on the growth of juvenile spotted babylon, Babylonia areolata, cultured in a recirculating culture system. Nine isonitrogenous experimental diets supplemented with three levels of calcium (1, 4, and 7%) for each of three levels of phosphorus (1, 3, and 5%) were prepared using fish meal, squid meal, and shrimp meal as the main protein sources. Juveniles with an initial average body weight of 0.59 ± 0.09 g were fed to satiation once daily with one of the nine diets for 180 days. Absolute and specific growth rates were calculated for both shell length and whole wet body weight. Results showed that dietary calcium and phosphorus supplementation significantly affected the growth of juvenile spotted babylon (P < 0.05), but not survival and feed-conversion ratio. The specific growth rate in shell length (SGRL) ranged from 0.32 to 0.39% day−1. No significant difference among phosphorus levels and no significant interaction between calcium and phosphorus in SGRL of the spotted babylon (P > 0.05) was found, but significant differences were observed among calcium levels, irrespective of phosphorus levels (P < 0.05). For 1 and 7% supplemental calcium, the spotted babylon had significantly higher SGRL than those fed diets supplemented with 4% calcium. However, the specific growth rate in body weight (SGRW) ranged from 0.91 to 1.19% day−1 with no significant difference among calcium and phosphorus levels and no significant interaction between calcium and phosphorus (P > 0.05). Survival and feed-conversion ratio were not significantly affected by dietary calcium and phosphorus levels with ranges from 91.00 to 95.00% and 2.43 to 2.76, respectively. At the end of the experiment, shell abnormality of B. areolata was found for all feeding trials.  相似文献   

18.
Studies were conducted to determine the effect of stocking size and density of prawns in polyculture.
In one experiment, postlarval prawns (av. wt. 0.02 g) were stocked in six 0.02 ha earthen ponds at 35,00O/ha. Two ponds were stocked with tilapia fry (av. wt. 0.14 g) and two were stocked with tilapia fingerlings (av. wt. 30.1 g), each at 10,000/ha. Two control ponds had no tilapia. Tilipia stocking size had no effect on prawn growth. Mean weight of prawns after 70 days of culture ranged from a low of 4.5 g when cultured with tilapia fingerlings to a high of 6.6 when cultured in monoculture. Prawn survival was adversely affected by tilapia fry. Average prawn survival in tilapia fry ponds was 65% compared to 75% and 91%, respectively, in tilapia fingerling and monoculture ponds.
In a second experiment, postlarval prawns were stocked in nine 0.02 ha earthen ponds at 40,000/ ha. Six ponds were stocked with 30 g tilapia fingerlings, three at 5,000/ha and three at 15,000/ha. Three control ponds received prawns only. After 100 days of culture, prawn weight ranged from an average of 15.9 g in monoculture ponds to 11.5 g in polyculture ponds. Survival was highest (93.8%) in low density polyculture ponds. Survival was lowest (85.6%) in prawn monoculture ponds. Tilapia reproduction had a negative impact on shrimp production.  相似文献   

19.
To compare the effect of polyculture against conventional monoculture on ornamental carp production, investigations on food selection and growth performance of koi carp (K), Cyprinus carpio L. and goldfish (G), Carassius auratus (L.) were conducted in a 11‐week rearing experiment in two monoculture (100% K and 100% G) and five polyculture (90% K–10% G, 70% K–30% G, 50% K–50% G, 30% K–70% G and 10% K–90% G) conditions in tropical ponds. There were three replicates for each treatment. Environmental conditions and food availability were similar in all the treatments. Ivlev's electivity index showed that both fish species avoided phytoplankton and preferred cladocerans to other zooplankton groups (copepods and rotifers) in monotypic conditions. However, in the polyculture treatments, the positive electivity of goldfish towards cladocerans reduced significantly (P<0.05), while the percentage of copepods, rotifers and phytoplankton in the gut content increased. No significant differences in weight gain, specific growth rate and deformities were recorded at harvest for koi carp between the different treatments (P>0.05). Even the survival rate of koi carp recorded above 90% in all the treatments. However, the goldfish recorded significantly better weight gain, specific growth rate and survival in monoculture (100% G), compared with the polyculture treatments (P<0.05). Goldfish deformities were lowest (P<0.05) in the monoculture treatment (2.42%). The number of marketable fish above a set size limit of 4 g total weight was significantly higher in the two monoculture treatments, compared with the five polyculture treatments (P<0.05). Keeping in view of the dietary similarities of koi carp and goldfish, and the aggressive nature of koi carp in polyculture, it is suggested to refrain from polyculture of goldfish and koi carp until further documentations relating to optimum stocking density and management of polyculture of ornamental carps are available.  相似文献   

20.
To determine a suitable culture environment to maximize growth and survival, the hatchery‐reared juvenile spotted babylon, Babylonia areolata, were held in plastic rearing tanks at four calcium carbonate additions of 0, 100 and 300 g tonne?1, and four water exchange regimes of 0‐, 15‐, 30‐ and 60‐day intervals in a recirculating grow‐out system for 120 days. The results clearly showed that growth was greatest between water exchange regimes of 15‐ and 30‐day intervals and all calcium carbonate additions, with water exchange regimes of 0‐ and 60‐day intervals resulting in poor growth. Final survival was highest between water exchange regimes of 15‐ and 30‐day intervals, and all calcium carbonate additions, with water exchange regimes of 0‐day intervals and all calcium carbonate additions resulting in high mortalities. This study showed that water exchange regimes had a stronger influence on the growth of juvenile B. areolata than calcium carbonate additions. It is recommended that B. areolata juveniles be maintained within the water exchange regimes range of 15–30‐day intervals and at calcium carbonate additions between 0 and 500 g tonne?1, providing optimum conditions for production of this species in a recirculating grow‐out system.  相似文献   

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