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Bernardo Baldisserotto - One of the best experts on this subject based on the ideXlab platform.

  • effects of water ph and hardness on infection of silver catfish rhamdia quelen Fingerlings by ichthyophthirius multifiliis
    Journal of The World Aquaculture Society, 2011
    Co-Authors: Luciano De Oliveira Garcia, Bernardo Baldisserotto, Alexssandro Geferson Becker, Mauro A Cunha, Carlos Eduardo Copatti, Daiani Kochhann
    Abstract:

    The aim of this study is to determine the effect of (1) different pH levels (5, 6, 7, 8, and 9) with water hardness 20 mg/L CaCO3 and (2) pH 5 and 7 with varying water hardnesses (20, 60, and 120 mg/L CaCO3) on the intensity of infection by Ichthyophthirius multifiliis in Fingerlings of the silver catfish, Rhamdia quelen. In Experiment 1, the lowest and highest mortality rates were observed in Fingerlings exposed to pH 5 and 9, respectively; in Experiment 2, fish kept at pH 5 and 7 with hardness 20 mg/L CaCO3 showed significantly lowest and highest cumulative mortality, respectively, than those maintained in other conditions. The lowest intensity of trophonts/fingerling was observed at pH 5 and hardness 20 mg/L CaCO3 in both experiments. We conclude that infection by I. multifiliis is less severe in silver catfish maintained at pH 5 and hardness 20 mg/L CaCO3. High water hardness led to an increased intensity of trophonts and decreased survival in silver catfish kept at pH 5, but decreased intensity of trophonts and improved survival when the fish were kept at pH 7.

  • efficacy of different salt nacl concentrations in the treatment of ichthyophthirius multifiliis infected silver catfish rhamdia quelen Fingerlings
    Journal of Applied Aquaculture, 2003
    Co-Authors: Denise Dos Santos Miron, Lenise Vargas Flores Da Silva, Jaqueline Ineu Golombieski, Bernardo Baldisserotto
    Abstract:

    ABSTRACT The objective of this study was to evaluate different salt concentrations in the treatment of Ichthyophthirius multifiliis. Silver catfish, Rhamdia quelen, Fingerlings infected with I. multifiliis were submitted to four sodium chloride concentrations (g/L): 0,1,2, and 4 for 23 days. In a second experiment, Fingerlings were maintained with 4 g/L salt, but for 45 days. Treatments with 2 and 4 g/L salt significantly increased fingerling survival compared with 0 and 1 g/L, and survival was significantly correlated with salt concentrations. In the second experiment, fish maintained at 4 g/L salt showed a gradual reduction of “white spots” and survival was 100%. Therefore, salt offers an alternative for treatment of silver catfish Fingerlings infected with I. multifiliis.

  • transport of silver catfish rhamdia quelen Fingerlings at different times load densities and temperatures
    Aquaculture, 2003
    Co-Authors: Jaqueline Ineu Golombieski, Lenise Vargas Flores Da Silva, Bernardo Baldisserotto, J H S Da Silva
    Abstract:

    Abstract Silver catfish (Rhamdia quelen) Fingerlings (5–10 cm) were caught from a fish culture pond and placed in a tank for stomach emptying for 24 h. Fingerlings were then weighed and placed in plastic bags (5 l) with 1.5 l water and oxygen, which were kept at temperatures of 15, 20, and 25 °C. The load densities tested were 50, 67, 87, and 168 g l−1. When bags were opened after 6, 12, or 24 h, mortality, dissolved oxygen, pH, total ammonia, non-ionized ammonia, total hardness, nitrite, total alkalinity, and carbon dioxide levels were determined. There was fingerling mortality only at the load density of 168 g l−1 after 24 h of transport at 20 and 25 °C, suggesting that mortality increased with temperature and time of transport. The dissolved oxygen levels in the water were reduced throughout 24 h of transport in the load density of 168 g l−1 at 20 and 25 °C, but remained unchanged at the other load densities. The pH decreased significantly at all load densities and temperatures throughout 24 h. Total alkalinity, total ammonia, and carbon dioxide levels increased significantly up to 24 h of transport in all treatments. Non-ionized ammonia and nitrite levels were below 0.02 and 0.06 mg l−1, respectively. Total hardness ranged from 20 to 48 mg l−1 CaCO3. The best temperature for transporting Fingerlings of this species in plastic bags is 15 °C, because up to 24 h there was no significant mortality even at the load density of 168 g l−1, dissolved oxygen levels were still high, and total ammonia and carbon dioxide presented the lowest increase. Transport at 25 °C and a load density of 168 g l−1 must not exceed 6 h due to the high levels of ammonia and carbon dioxide and low dissolved oxygen levels in the water.

Jaqueline Ineu Golombieski - One of the best experts on this subject based on the ideXlab platform.

  • efficacy of different salt nacl concentrations in the treatment of ichthyophthirius multifiliis infected silver catfish rhamdia quelen Fingerlings
    Journal of Applied Aquaculture, 2003
    Co-Authors: Denise Dos Santos Miron, Lenise Vargas Flores Da Silva, Jaqueline Ineu Golombieski, Bernardo Baldisserotto
    Abstract:

    ABSTRACT The objective of this study was to evaluate different salt concentrations in the treatment of Ichthyophthirius multifiliis. Silver catfish, Rhamdia quelen, Fingerlings infected with I. multifiliis were submitted to four sodium chloride concentrations (g/L): 0,1,2, and 4 for 23 days. In a second experiment, Fingerlings were maintained with 4 g/L salt, but for 45 days. Treatments with 2 and 4 g/L salt significantly increased fingerling survival compared with 0 and 1 g/L, and survival was significantly correlated with salt concentrations. In the second experiment, fish maintained at 4 g/L salt showed a gradual reduction of “white spots” and survival was 100%. Therefore, salt offers an alternative for treatment of silver catfish Fingerlings infected with I. multifiliis.

  • transport of silver catfish rhamdia quelen Fingerlings at different times load densities and temperatures
    Aquaculture, 2003
    Co-Authors: Jaqueline Ineu Golombieski, Lenise Vargas Flores Da Silva, Bernardo Baldisserotto, J H S Da Silva
    Abstract:

    Abstract Silver catfish (Rhamdia quelen) Fingerlings (5–10 cm) were caught from a fish culture pond and placed in a tank for stomach emptying for 24 h. Fingerlings were then weighed and placed in plastic bags (5 l) with 1.5 l water and oxygen, which were kept at temperatures of 15, 20, and 25 °C. The load densities tested were 50, 67, 87, and 168 g l−1. When bags were opened after 6, 12, or 24 h, mortality, dissolved oxygen, pH, total ammonia, non-ionized ammonia, total hardness, nitrite, total alkalinity, and carbon dioxide levels were determined. There was fingerling mortality only at the load density of 168 g l−1 after 24 h of transport at 20 and 25 °C, suggesting that mortality increased with temperature and time of transport. The dissolved oxygen levels in the water were reduced throughout 24 h of transport in the load density of 168 g l−1 at 20 and 25 °C, but remained unchanged at the other load densities. The pH decreased significantly at all load densities and temperatures throughout 24 h. Total alkalinity, total ammonia, and carbon dioxide levels increased significantly up to 24 h of transport in all treatments. Non-ionized ammonia and nitrite levels were below 0.02 and 0.06 mg l−1, respectively. Total hardness ranged from 20 to 48 mg l−1 CaCO3. The best temperature for transporting Fingerlings of this species in plastic bags is 15 °C, because up to 24 h there was no significant mortality even at the load density of 168 g l−1, dissolved oxygen levels were still high, and total ammonia and carbon dioxide presented the lowest increase. Transport at 25 °C and a load density of 168 g l−1 must not exceed 6 h due to the high levels of ammonia and carbon dioxide and low dissolved oxygen levels in the water.

J H S Da Silva - One of the best experts on this subject based on the ideXlab platform.

  • transport of silver catfish rhamdia quelen Fingerlings at different times load densities and temperatures
    Aquaculture, 2003
    Co-Authors: Jaqueline Ineu Golombieski, Lenise Vargas Flores Da Silva, Bernardo Baldisserotto, J H S Da Silva
    Abstract:

    Abstract Silver catfish (Rhamdia quelen) Fingerlings (5–10 cm) were caught from a fish culture pond and placed in a tank for stomach emptying for 24 h. Fingerlings were then weighed and placed in plastic bags (5 l) with 1.5 l water and oxygen, which were kept at temperatures of 15, 20, and 25 °C. The load densities tested were 50, 67, 87, and 168 g l−1. When bags were opened after 6, 12, or 24 h, mortality, dissolved oxygen, pH, total ammonia, non-ionized ammonia, total hardness, nitrite, total alkalinity, and carbon dioxide levels were determined. There was fingerling mortality only at the load density of 168 g l−1 after 24 h of transport at 20 and 25 °C, suggesting that mortality increased with temperature and time of transport. The dissolved oxygen levels in the water were reduced throughout 24 h of transport in the load density of 168 g l−1 at 20 and 25 °C, but remained unchanged at the other load densities. The pH decreased significantly at all load densities and temperatures throughout 24 h. Total alkalinity, total ammonia, and carbon dioxide levels increased significantly up to 24 h of transport in all treatments. Non-ionized ammonia and nitrite levels were below 0.02 and 0.06 mg l−1, respectively. Total hardness ranged from 20 to 48 mg l−1 CaCO3. The best temperature for transporting Fingerlings of this species in plastic bags is 15 °C, because up to 24 h there was no significant mortality even at the load density of 168 g l−1, dissolved oxygen levels were still high, and total ammonia and carbon dioxide presented the lowest increase. Transport at 25 °C and a load density of 168 g l−1 must not exceed 6 h due to the high levels of ammonia and carbon dioxide and low dissolved oxygen levels in the water.

Lenise Vargas Flores Da Silva - One of the best experts on this subject based on the ideXlab platform.

  • efficacy of different salt nacl concentrations in the treatment of ichthyophthirius multifiliis infected silver catfish rhamdia quelen Fingerlings
    Journal of Applied Aquaculture, 2003
    Co-Authors: Denise Dos Santos Miron, Lenise Vargas Flores Da Silva, Jaqueline Ineu Golombieski, Bernardo Baldisserotto
    Abstract:

    ABSTRACT The objective of this study was to evaluate different salt concentrations in the treatment of Ichthyophthirius multifiliis. Silver catfish, Rhamdia quelen, Fingerlings infected with I. multifiliis were submitted to four sodium chloride concentrations (g/L): 0,1,2, and 4 for 23 days. In a second experiment, Fingerlings were maintained with 4 g/L salt, but for 45 days. Treatments with 2 and 4 g/L salt significantly increased fingerling survival compared with 0 and 1 g/L, and survival was significantly correlated with salt concentrations. In the second experiment, fish maintained at 4 g/L salt showed a gradual reduction of “white spots” and survival was 100%. Therefore, salt offers an alternative for treatment of silver catfish Fingerlings infected with I. multifiliis.

  • transport of silver catfish rhamdia quelen Fingerlings at different times load densities and temperatures
    Aquaculture, 2003
    Co-Authors: Jaqueline Ineu Golombieski, Lenise Vargas Flores Da Silva, Bernardo Baldisserotto, J H S Da Silva
    Abstract:

    Abstract Silver catfish (Rhamdia quelen) Fingerlings (5–10 cm) were caught from a fish culture pond and placed in a tank for stomach emptying for 24 h. Fingerlings were then weighed and placed in plastic bags (5 l) with 1.5 l water and oxygen, which were kept at temperatures of 15, 20, and 25 °C. The load densities tested were 50, 67, 87, and 168 g l−1. When bags were opened after 6, 12, or 24 h, mortality, dissolved oxygen, pH, total ammonia, non-ionized ammonia, total hardness, nitrite, total alkalinity, and carbon dioxide levels were determined. There was fingerling mortality only at the load density of 168 g l−1 after 24 h of transport at 20 and 25 °C, suggesting that mortality increased with temperature and time of transport. The dissolved oxygen levels in the water were reduced throughout 24 h of transport in the load density of 168 g l−1 at 20 and 25 °C, but remained unchanged at the other load densities. The pH decreased significantly at all load densities and temperatures throughout 24 h. Total alkalinity, total ammonia, and carbon dioxide levels increased significantly up to 24 h of transport in all treatments. Non-ionized ammonia and nitrite levels were below 0.02 and 0.06 mg l−1, respectively. Total hardness ranged from 20 to 48 mg l−1 CaCO3. The best temperature for transporting Fingerlings of this species in plastic bags is 15 °C, because up to 24 h there was no significant mortality even at the load density of 168 g l−1, dissolved oxygen levels were still high, and total ammonia and carbon dioxide presented the lowest increase. Transport at 25 °C and a load density of 168 g l−1 must not exceed 6 h due to the high levels of ammonia and carbon dioxide and low dissolved oxygen levels in the water.

Carole R. Engle - One of the best experts on this subject based on the ideXlab platform.

  • a comparative analysis of the economic risk of hybrid striped bass fingerling production in ponds and indoor tanks
    North American Journal of Aquaculture, 2012
    Co-Authors: Carole R. Engle, Pratikshya Sapkota
    Abstract:

    Abstract A risk analysis was conducted to compare the economic risk of producing hybrid striped bass (♀ white bass Morone chrysops × ♂ striped bass M. saxatilis) Fingerlings in ponds and indoor tanks. Cost budgets developed previously for three pond sizes (0.4, 1.2, and 2.4 ha) and three tank sizes (945, 2,457, and 5,670 L) for each of six scales of production (50,000, 100,000, 250,000, 500,000, 1,000,000, and 2,000,000 Fingerlings/year) were used as the initial starting point for the development of a spreadsheet-based risk analysis. Probability distributions and cumulative frequency distributions of break-even prices above total costs were calculated for each scenario. Pond production was less risky than tank production, and larger pond sizes had lower risk. Survival rates contributed the most to the economic risk of hybrid striped bass fingerling production. Research is needed to improve survival rates for hybrid striped bass fingerling production in ponds. Received December 9, 2011; accepted April 9, 2012

  • The Effect of Hybrid Catfish Fingerling Prices on the Relative Profitability of Hybrid Channel Catfish
    Journal of the World Aquaculture Society, 2011
    Co-Authors: Ganesh Kumar, Carole R. Engle
    Abstract:

    Previous studies have indicated that the price premium charged for hybrid catfish Fingerlings may be a significant factor in the adoption and profitability of hybrid catfish production. An enterprise budgeting simulation analysis was developed to compare costs, risk, and effect of hybrid fingerling costs. Feed, fingerling, and total costs ($/ha and $/kg) were highest for hybrid catfish production, intermediate for NWAC-103, and lowest for normal channel catfish production. Net returns were highest for hybrid catfish production, but breakeven prices were also highest. Risk analysis showed that downside risk (risk of losing money) was higher for hybrid production for all farm sizes. Risk-averse farmers would not select hybrid catfish at the mean fingerling values used in the analysis. However, at hybrid fingerling prices less than $0.0081/cm, hybrid catfish production was superior in profitability and breakeven cost of production. Thus, for hybrid catfish production to be preferred economically to normal channel catfish, the price premium for hybrid catfish Fingerlings can be no more than 84% ($0.0037/cm) above that of normal channel catfish Fingerlings and 57% ($0.0025/cm) above that of NWAC-103 fingerling prices.

  • THE ECONOMIC TRADE-OFFS BETWEEN STOCKING Fingerlings AND STOCKERS: A MIXED INTEGER MULTI-STAGE PROGRAMMING APPROACH
    Aquaculture Economics & Management, 2010
    Co-Authors: Carole R. Engle, Ganesh Kumar, David Bouras
    Abstract:

    This paper addresses the economic trade-offs associated with stocking varying sizes of Fingerlings and stockers either purchased or produced on farm in catfish growout. A mixed integer-programming model of catfish growout was developed that included seven fingerling, six stocker, and eight foodfish production activities as well as options to purchase and sell Fingerlings, stockers, and foodfish. Results showed that profits are maximized on farms of 102 ha and larger by adopting a three-phase production system that includes a stocker phase. On farms smaller than 102 ha, profits are maximized by understocking 17.5-cm Fingerlings in multiple-batch. The choice of stocking Fingerlings or stockers depended on the efficiency of the stocker production phase; at stocker FCRs of 2.4 or above or survivals less than 40%, stocking Fingerlings in multiple-batch was more profitable than the three-phase system with stockers. Additional research is needed to develop farm-level datasets of the variability in key stocker pr...

  • OPTIMAL SIZE OF FINGERLING TO UNDERSTOCK IN CATFISH GROW-OUT PONDS: AN APPLICATION OF A MULTI-PERIOD INTEGER PROGRAMMING MODEL
    Aquaculture Economics & Management, 2007
    Co-Authors: David Bouras, Carole R. Engle
    Abstract:

    This article developed a multi-period linear programming model to identify the optimal size of fingerling to understock to maximize multi-period returns on a catfish grow-out farm. Grow-out production alternatives included understocking three different sizes (7.6 cm, 12.7 cm, and 17.8 cm) of Fingerlings in multiple-batch production at 15,000 Fingerlings per hectare. Fingerlings were produced either with or without thinning at different stocking densities. Results showed that the optimal size of fingerling to understock was 12.7 cm. On-farm production of Fingerlings was optimal across all farm sizes but the fingerling production technique selected varied with farm size. Models of larger farm sizes indicated that it is optimal to thin Fingerlings, while for smaller farm sizes, producing Fingerlings without thinning was optimal. When farm size was treated as an endogenous variable in the farmer's profit-maximizing decisions, the optimal size of a catfish farm was 404 water-ha. Sensitivity analyses suggested ...

  • The Effect of On‐Farm Production of Various Sizes of Stocker Caffish Ictalurus punctatus on Farm Profitability.
    Journal of the World Aquaculture Society, 2007
    Co-Authors: Steeve Pomerleau, Carole R. Engle
    Abstract:

    — The effect of on-farm production of various sizes of stocker catfish Ictalurus punctatus on farm profitability was compared to profitability of understocking Fingerlings directly into multiple-batch growout production. Vat-graded catfish averaging 9 × 2 g (10 cm total length) and 27× 8 g (15 cm total length) were stocked into eight 0.1-ha ponds at 100,000 fingerlingdha. Fish were fed once daily to apparent satiation and harvested 210 d after stocking. There were no significant differences (P < 0.10) in yield, feed conversion ratio (FCR), and survival across treatments. Mean gross yield (× SD) was 9,469 × 852 kg/ha and 8,846 × 2,099 kg/ha; net yield averaged 8,531× 885 and 6,374 × 2,189 kg/ha; FCR averaged 1.8 × 0.1 and 2.4 × 0.7, and survival averaged 38 × 7% and 26 ×11% for the 10-cm and 15-m fingerling stocking treatments, respectively. While experimental survival was low, varying survival rates of stockers in the economic analysis did not affect selection of the most profitable stocking strategies. The 15-cm hgerlings reached a size significantly larger (361× 81 g or 32.8 × 2.2 cm) than the 10-cm Fingerlings (255 × 28 g or 29.6 × 1.4 cm) (P < 0.07). Whole-farm budgets were developed based on three sizes of farm (65, 130, and 260 ha) and eight production strategies involving the purchase of different sizes of Fingerlings for either understocking growout ponds (6,12, or 37-g Fingerlings) or to grow into stockers (114,135, 176, 255, or 361 9). Purchasing 37-g advanced Fingerlings for multiple-batch production was the most profitable strategy for the three sizes of farm. The second most important profit-maximizing strategy for larger farm sizes was single-batch production with 255-g stockers produced on-farm, but purchasing 12-g Fingerlings to stock into multiple-batch production was the second most profitable strategy for the smallest farm. Sensitivity analysis indicated that the results were robust to variation in survival, prices, and other production characteristics. Risk analysis indicated that purchasing 37-g advanced Fingerlings for multiple-batch production was associated with the lowest levels of economic risk for growout production.