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1.
Nguyen Tien Thong Max Nielsen Eva Roth Giap Van Nguyen Hans Stubbe Solgaard 《Aquaculture Economics & Management (Blackwell Science)》2013,17(3):400-417
ABSTRACTThis research described in this article aimed to investigate international market potentials for Pangasius catfish (Pangasianodon hypopthalmus). The monthly export data from Vietnam, which accounts for more than 95% of the global export value, in the period 2007 to 2014, were used to estimate a non-linear Inverse Almost Ideal Demand System of the seven market regions. Prices in all markets are found very inflexible, with own-price flexibilities on ?0.200 to ?0.917, or ?0.419 on average, revealing the option of expanding global production and export without inducing a substantial price reduction. Consumers in all markets except Latin America evaluate Pangasius as a necessary good, indicating that the Pangasius industry is relatively little affected by recessions and booms in the world economy. The major markets are substitutes for each other; therefore, if demand at one market region is reduced, the presence of substitution leads suppliers to find other markets. The results reveal that demand provides stable framework conditions for the Pangasius industry. 相似文献
2.
S. Benjamin Scuderi Xuan Chen 《Aquaculture Economics & Management (Blackwell Science)》2018,22(1):112-130
In 2003, the United States adopted anti-dumping tariffs for Vietnamese catfish products entering the country. This study examines how these tariffs have impacted the price relationship between domestically produced and imported catfish products. Cointegration tests confirm a long-run price relationship between domestic and imported catfish, which has persisted despite the anti-dumping tariffs. However, imports are composed of catfish from Vietnam and other countries, with only the former subjected to tariffs. Results from vector error correction models suggest that Vietnamese catfish prices do not significantly influence domestic prices. Conversely, the price of catfish from countries other than Vietnam continues to impact prices received by domestic catfish farmers and processors. The domestic catfish industry is still affected by lower-priced imports from countries other than Vietnam, although some of these may be transshipments that truly originate in Vietnam. This research methodology could be adapted to investigate trade and price interactions among other aquacultured species, which will become increasingly important as global aquaculture expands. 相似文献
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Cynthia Ware Lester H. Khoo Terrence E. Greenway David J. Wise Brian G. Bosworth Mark L. Lawrence Matt J. Griffin 《Journal of the World Aquaculture Society》2018,49(1):197-204
Members of the genus Edwardsiella are important pathogens of cultured and wild fish globally. Recent investigations into the phenotypic and genotypic variation of Edwardsiella tarda have led to the segregation of E. tarda into three distinct taxa: E. tarda, Edwardsiella piscicida, and Edwardsiella anguillarum. In catfish aquaculture in the southeastern USA, E. piscicida has been more commonly associated with disease than E. tarda or E. anguillarum, and recent research has demonstrated E. piscicida to be more pathogenic in channel catfish than E. tarda or E. anguillarum. Anecdotal reports from industry suggest an increased prevalence of E. piscicida associated with the culture of channel (♀) × blue (♂) hybrid catfish. This work investigated the comparative susceptibility of channel catfish, blue catfish, and their hybrid cross to molecularly confirmed isolates of E. tarda, E. piscicida, and E. anguillarum. There was significantly higher mortality in hybrid catfish compared to channel catfish following intracoelomic injection of E. piscicida. To our knowledge, E. piscicida is the first bacterial pathogen to demonstrate increased pathogenicity in hybrid catfish compared to channel catfish. 相似文献
4.
Nguyen M. Duc 《Reviews in Aquaculture》2010,2(2):86-101
Since obtaining membership to the Asia–Pacific Economic Cooperation in 1998, Vietnamese fishery product exports, particularly frozen catfish fillets, to the USA have increased significantly, supported by a bilateral trade agreement (BTA) between the two countries signed in December 2001. With similarities in texture and taste, but of lower price, catfish imports from Vietnam were a concern for US catfish producers. To protect its catfish sector, the US Congress passed a labelling law in November 2002 restricting the use of the word ‘catfish’ to only those fish of the Ictaluridae family, which is farmed popularly in southern states of the USA. Antidumping measures, a trade policy permitted by the World Trade Organization, were also issued by the USA in 2003 leading to tariffs ranging from 44.66% to 63.88% levied on frozen fillet catfish imported from Vietnam. This paper uses selected econometric models to examine the effects of the US laws and policy on prices and trade flows, as a part of a comparative case study of primary production. The models show that the antidumping tariff raised the US domestic price of processed catfish and lowered the Vietnamese export price. The fall in the price of Vietnamese catfish caused by the US tariff raised market demand outside the USA and consequently boosted the Vietnamese export volume of catfish. Empirical models with monthly data from January 1999 to December 2005 examined the effects of the BTA, the US antidumping and the labelling laws on the price and trade flow of frozen catfish fillets. Although the BTA benefited US consumers, the antidumping measures were not favourable to them or to US farmers. The labelling law in reality harmed the US catfish industry. 相似文献
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The historical development, current status and development trends of four internationally traded farmed seafood commodities, tilapia, penaeid shrimp, macrobrachium prawns and catfish in China were reviewed. China is the world's largest producer of tilapia, penaeid shrimp and macrobrachium prawns but, although farming of channel catfish and some indigenous catfish species is well developed, striped catfish failed to become established. In terms of global exports, China ranks first for tilapia and third for shrimp, while macrobrachium prawns and catfish mainly support domestic markets. Endogenous, biological characteristics and market demand explain the different courses of development and the differentiated focus on domestic and international trade. Tilapia and whiteleg shrimp production illustrated rapid growth in both domestic and international markets based on their favourable culture characteristics and well‐developed management systems. Huge production scale and domestic competition have resulted in China attaining a dominant and highly competitive position in the global tilapia market. High value of live freshwater prawns in local markets (and poor processing yield) has limited interest in exports, and local demand is also shifting the emphasis of shrimp production towards domestic markets, and a decline in its international market led to stagnation of channel catfish. Poor tolerance of seasonally low temperatures has restricted tilapia production to south China and completely inhibited the development of striped catfish as a commercial species. Live fish preference and costs of long‐distance transportation have restricted domestic consumption of tilapia. A balance between domestic consumption and export is required to optimise future growth opportunities for the industry. 相似文献
6.
Rhoda Mae C. Simora Shangjia Li Nermeen Y. Abass Jeffery S. Terhune Rex A. Dunham 《Journal of fish diseases》2020,43(12):1553-1562
Cathelicidins are a class of antimicrobial peptides (AMPs) known to possess rapid and direct antimicrobial activities against a variety of microorganisms. Recently identified cathelicidins derived from alligator and sea snake were found to be more effective in inhibiting microbial growth than other AMPs previously characterized. The ability of these two cathelicidins along with the peptides, cecropin and pleurocidin, to protect channel catfish (Ictalurus punctatus, Rafinesque) and hybrid catfish (I. punctatus ♀ × blue catfish, Ictalurus furcatus, Valenciennes ♂) against Edwardsiella ictaluri, one of the most prevalent pathogens affecting commercial catfish industry, was investigated. Cathelicidin-injected fish (50 µg ml−1 fish−1) that were simultaneously challenged with E. ictaluri through bath immersion at a concentration of ~1 × 106 CFU/ml had increased survival rates compared with other peptide treatments and the infected control. Bacterial numbers were also reduced in the liver and kidney of channel catfish and hybrid catfish in the cathelicidin treatments 24 hr post-infection. After 8 days of challenge, serum was collected to determine immune-related parameters such as bactericidal activity, lysozyme, serum protein, albumin and globulin. These immune-related parameters were significantly elevated in fish injected with the two cathelicidins as compared to other peptide treatments. These results indicate that cathelicidins derived from alligator and sea snake can stimulate immunity and enhance the resistance to E. ictaluri infection in channel catfish and hybrid catfish. 相似文献
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A prediction equation for sperm production in blue catfish was developed by a forward step‐wise regression analyses based on five independent factors: body weight, total length, stage of maturation, gonadosomatic index and condition factor of individual mature blue catfish raised in earthen ponds. The stage of gonad maturity and plasma testosterone contributed significantly (P < 0.05) to the prediction equation (Sperm production per unit body weight = 2.51 × maturity ? 0.01 × testosterone ? 5.776, r = 0.62, P < 0.05). The stage of maturity was strongly associated (P < 0.05) with gonadosomatic index and sperm production. Improvements in prediction accuracy are needed to make this model a useful tool to identify higher sperm producing blue catfish to improve the efficiency of channel x blue hybrid catfish embryo production. 相似文献
9.
《海洋渔业》2021,43(03):288-297
In order to study the effects of different sperm densities of Pelteobagrus vachelli on the fertilization rate,hatching rate and emergence rate of hybrid yellow catfish \"Huangyou-1",this paper adopted 8 groups of different sperm densities (1×103-1×106cells·mL-1) to carry out artificial insemination experiments. The fertilized eggs were hatched under the same environmental conditions until the out-of-the-membrane fry developed and started to feed during the parallel swimming period. The hatching water temperature was (27±1) ℃ and each gradient was repeated in three groups.Results showed that when the sperm density increased from 1×103cells·mL-1to 2.5×104cells·mL-1,the fertilization rate,hatching rate and emergence rate all increased significantly (P <0.05); when the sperm density was 5×104cells·mL-1,the fertilization rate reached the maximum value of (88.8±2.0) %; when the sperm density was 2.5×104cells·mL-1,the hatching rate and emergence rate reached the maximum,respectively (83.4±2.8) % and (79.4±4.6)%. In addition,the regression equation was established to determine the relationship between sperm density and fertilization rate,hatching rate and emergence rate. In this experiment,8 different sperm densities (1×103-1×106cells·mL-1) were used to artificially inseminate hybrid yellow catfish,and the optimal sperm density was determined. It is recommended that the sperm density range of 2.5×104-5×104cells·mL-1should be used for artificial insemination in actual production. This density uses less sperm than in actual production,which can effectively protect male gamete resources and reduce the demand for cryopreservation of sperm during artificial seed production. The optimal sperm density selected in this experiment can be used as the best choice in large-scale production of hybrid yellow catfish,and it can also provide certain references for artificial insemination and hybrid breeding of yellow catfish. 相似文献
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Olanrewaju Femi Olagunju;Dadi Kristofersson;Tumi Tómasson;Theódór Kristjánsson; 《Journal of the World Aquaculture Society》2024,55(3):e13058
Since the early 2000s, aquaculture in Nigeria has grown exponentially. African catfish aquaculture was a major contributor to this expansion. However, a fall in output started in 2015, mostly due to challenging economic conditions which affected farmer's profitability. This challenge has been exacerbated by the COVID-19 pandemic. Notwithstanding, some catfish farms remained profitable. This study investigates the profitability strategies that aid farmers' resilience in times of both economic distress and COVID-type shock. Data from 609 randomly sampled farms across the country were verified and included in the study covering 1118 operations for the pre-COVID and COVID periods. Budgetary analysis was done, and stepwise regression was used to identify factors that most contribute to profitability. These factors were ranked by average profit per kilogram and grouped. The profitability during the periods was influenced by factors within the subcategories of scale of operation, experience, targeted markets, ownership, and pond type. Engagement in other agricultural ventures favored profitability during the COVID period. Profitable and non-profitable groups were further characterized based on their technical and financial indicators. Explored strategies for profitability, including the operation scale, marketing tactics, cost-cutting, and innovative production techniques all proved successful during economic distress and the pandemic. 相似文献
12.
Ganesh Kumar Kwamena Quagrainie Carole Engle 《Aquaculture Economics & Management (Blackwell Science)》2013,17(4):252-267
Increased understanding of the factors that influence the frequency of purchase of catfish (Ictalurus punctatus) by U.S. households would provide guidance for catfish marketing programs. A household survey was conducted to analyze consumer preferences and consumption trends of U.S. farm-raised catfish in Birmingham, Memphis, Chicago, Jackson (MS), New Orleans, Baton Rouge, Little Rock, Oklahoma City, Dallas, Houston, and San Antonio. An ordered probit model was developed to examine the variables influencing frequency of catfish purchase. Household respondents in all cities except Jackson, New Orleans, Oklahoma City, and San Antonio were found to be more frequent buyers of catfish products. Respondents who preferred fresh catfish had a greater likelihood of frequent catfish purchase while buyers of frozen catfish were less likely to purchase catfish frequently. Method of preparation and serving had no influence on catfish purchase frequency. Buyers purchasing from supermarket outlets had a higher probability of being more frequent buyers of catfish products than those who purchase from other market outlets. Product origin labels and vacuum-sealed packaging influenced the frequency of catfish purchase. Caucasians and African Americans were found to be more frequent buyers of catfish products while Hispanics were found to be significantly less frequent buyers of catfish products. Married couples had a greater likelihood of purchasing catfish more frequently than unmarried couples. Age of the respondents as well as number of household members had no significant effect on frequency of catfish purchase. The results from this study support the importance of country of origin labeling, supplying high-quality fresh products, and alternative packaging to enhance sales of U.S. farm-raised catfish in supermarkets. 相似文献
13.
Carole Engle Nilima Renukdas Jeonghwan Park Patrick Rees 《Journal Of Applied Aquaculture》2017,29(3-4):245-255
Alternative management strategies will be required to produce hybrid catfish (♂Ictalurus punctatus X ♀Ictalurus furcatus) year-round to provide continuous market supply. Hybrid catfish fingerlings were stocked at 9,880 head/ha singly or in co-culture with sub-marketable (mean weight = 454 ± 16 g) hybrid catfish carried over the winter from a previous year’s multi-size trial. Economic analyses compared cost of production ($/kg of market-size fish produced) and cash flow of single- and multiple-batch production of hybrid catfish for a single- and two-year period. Gross total and marketable yields were significantly greater in the mixed-size treatment as compared to the single-size treatment, in spite of the significantly greater percentage of market-size fish (84%) in the single-size treatment than in the mixed-size treatment (71%). Cost of production ($/kg) was 4% to 10% lower in the multi-size treatment in the single-year analysis, but 18% to 20% lower when the full two-year cycle was assessed. Cash flow and cash flow risk were improved substantially with the multi-size treatment primarily because the overwintered sub-market-size fish from the previous year reached market size three to four months earlier than in the single-size treatment. 相似文献
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The catfish industry (Ictalurus punctatus), the largest segment of aquaculture in the USA, has declined in the number of operations, total yield and sales in recent years. This has led to a call for innovations to improve production efficiency and to lower the cost of production. This paper reviewed the literature on management parameters that affect economically important production parameters under the control of an individual catfish farmer. Stocking density, size of fish at stocking, duration of culture, cropping systems, feeding strategies and aeration were shown to significantly affect the economically important parameters of investment costs, yield and feed conversion ratio. Additional work is needed to quantitatively model the effects of multiple parameters and to develop user‐friendly versions to assist catfish farmers in decision making. 相似文献
16.
Heather A Stewart Brian Bosworth Lora Petrie‐Hanson James A Martin Peter J Allen 《Aquaculture Research》2015,46(10):2407-2417
Climate change is a growing concern for pond culture of catfish, due to possible exacerbation of temperature fluctuations and increased maximum daily temperatures. Because channel catfish (Ictalurus punctatus) have a broad natural distribution from Canada to Mexico, it was hypothesized that natural differences in thermal tolerance and seasonal growth may be attributed to different geographical strains. Furthermore, it was hypothesized that these differences would be observed in hybrid catfish (I. punctatus x [blue catfish] I. furcatus). Chronic thermal tolerance and growth rate were quantified in two geographically distinct strains of channel catfish and a corresponding hybrid catfish from one of these strains with a cross to an industry standard blue catfish strain. In a 6‐week growth experiment, catfish were subjected to daily cycling temperatures of either 27–31°C or 32–36°C, mimicking pond fluctuations. Hybrid catfish had the highest survival at both temperatures, and both strains of channel catfish had greater growth in weight or length at 27–31°C than at 32–36°C. Therefore, these results indicate that physiological performance, in terms of growth, decreases in channel catfish at temperatures greater than 27–31°C regardless of geographical origin of strain, whereas hybrid catfish did not show a decrease in weight under the same temperature conditions. 相似文献
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Imorou Toko Emile D. Fiogbe Patrick Kestemont 《Aquaculture (Amsterdam, Netherlands)》2007,262(1):65-72
African catfish (Clarias gariepinus) (initial body weight: 34.8 ± 4.8 g) and vundu catfish (Heterobranchus longifilis) (initial body weight: 39.1 ± 8.2 g) fingerlings were stocked at densities of 4, 6 or 8 fish m− 3 in traditional fish ponds (whedos) constructed in the floodplain of the Oueme River (South Benin, West Africa), for 70 days from March to June 2005. Fish were fed twice a day with 34% crude protein feed formulated with locally available ingredients. The effects of stocking density were evaluated in growth responses, gross production and body composition. Water quality variables were similar (p > 0.05) in all compartments. Temperature and pH were at the optimum level for fish. Dissolved oxygen ranged from 0.9 to 1.2 mg l− 1 during the experiment and secchi disc transparency was low (< 14 cm). In both species, growth responses increased with the increasing density, significantly in African catfish stocked at density of 8 fish m− 3 compared to the other densities (4 and 6 fish m− 3) but not significantly in vundu catfish. Production data ranged from 3.1 ± 0.5 to 22.8 ± 4.5 t ha− 1 year− 1 in African catfish and from 6.1 ± 1.2 to 15.1 ± 3.1 t ha− 1 year− 1 in vundu catfish. Production increased with increasing stocking densities but only significantly (p < 0.05) between the density of 8 fish m− 3 and the other densities. In both species, carcass fat increased with increasing density (p < 0.05) while carcass protein and moisture decreased (p > 0.05). These results are important because they indicate that, as far as growth rate and production are concerned, African catfish is more profitable than vundu catfish for culture at high density in whedo. 相似文献
19.
Nagaraj Chatakondi Brian C. Peterson Terrence E. Greenway Todd S. Byars David J. Wise 《Journal of the World Aquaculture Society》2018,49(4):686-691
This study evaluated the efficacy of an oral live‐attenuated Edwardsiella ictaluri vaccine against enteric septicemia of catfish (ESC) in channel and hybrid catfish. The vaccine was delivered one time orally by feeding fish a diet coated with an attenuated E. ictaluri isolate at four doses to deliver between 4 × 106 to 3.2 × 107 viable vaccine cells/g wet feed. Thirty‐five days postvaccination, control and vaccinated fish were challenged with virulent E. ictaluri and mortality was examined for 30 d postchallenge. Mortality of nonvaccinated hybrids (85%) and nonvaccinated channel catfish (73%) was similar but significantly greater than all groups of vaccinated fish. In channel catfish, a trend toward increasing mortality with decreasing dose was observed. Mortality of channel catfish vaccinated with the lowest dose (26.6%) was significantly higher than fish vaccinated with the highest dose (14.1%) but similar to fish vaccinated at the intermediate doses (17.5 and 19.4%). In contrast, mortality of four doses of vaccinated hybrid catfish was similar and ranged between 10.4 and 14.0%. The data demonstrate that the attenuated E. ictaluri vaccine at all four doses tested is effective at reducing ESC‐related mortalities in hybrid and channel catfish. 相似文献
20.
Robert G. Nelson Sergio A. Duarte Michael P. Masser 《Aquaculture Economics & Management (Blackwell Science)》2013,17(3-4):171-177
Abstract This study analysed the benefits and costs of three airlift aeration regimes — continuous (24 hr), partial (9 hr/night plus emergencies), and no aeration — for channel catfish in cages. Data from four field studies included four dependent variables based on size at harvest, and six independent variables. Four regression models were fit with a modified Cobb‐Douglas production function in a Seemingly Unrelated Regression system. Yield projections from the production function were then used in a stochastic economic model with prices and variable costs expressed as triangular distributions. Results indicated that none of the aeration methods was preferred to the others by either first‐ or second‐degree stochastic dominance criteria, although partial aeration was the risk‐neutral choice. A power analysis was used to demonstrate that an impractical number of replicates would be needed to detect a difference between partial and continuous aeration that was both economically and statistically significant. 相似文献