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Ictalurus punctatus (channel catfish)
Abstract
This datasheet on Ictalurus punctatus covers Identity, Overview, Associated Diseases, Pests or Pathogens, Distribution, Dispersal, Diagnosis, Biology & Ecology, Environmental Requirements, Natural Enemies, Impacts, Uses, Prevention/Control, Management, Genetics and Breeding, Economics, Further Information.
... Previous studies have failed to find any acute thermal tolerance differences between Channel Catfish strains (Hart 1952;Allen and Strawn 1968;Cheetham et al. 1976;Reutter and Herdendorf 1976;Bennett et al. 1998). However, these studies either did not directly compare strains, used different heating rates, or varied in methodology or were limited in inference by small sample sizes. ...
Critical thermal maxima have been used extensively to provide physiologically and ecologically valuable reference points that identify early signs of thermal stress. In catfish pond culture, daily temperature maxima up to 36°C and daily fluctuations of as much as 6°C are observed. These extreme conditions will probably be exacerbated by the effects of global climate change. Channel Catfish Ictalurus punctatus have a broad natural distribution from southern Canada to northern Mexico. If regional genetic differences could cause strains with a southern distribution to have greater thermal tolerance than strains with a northern distribution, and consequently a greater critical thermal maximum, then hybrid catfish (Channel Catfish × Blue Catfish I. furcatus) strains might be expected to have greater critical thermal maxima than their respective Channel Catfish strains because Blue Catfish have a more southern range of distribution. To examine this, we quantified differences of acute thermal tolerance in two geographically distinct strains of Channel Catfish and their hybrid crosses with an industry standard strain of Blue Catfish. The catfish were subjected to water temperature increases of 2.0 ± 0.1°C · h−1 until they lost equilibrium. Standard length, which ranged from 162 to 320 mm, had a significant effect on survival, survival being greater in larger fish. The critical thermal maximum ranged from 38.6°C to 40.3°C. Southern Channel Catfish tolerated higher temperatures than northern Channel Catfish did, and both strains of Channel Catfish tolerated higher temperatures than their hybrid catfish strains did. This study indicates that geographically distinct catfish strains differ in acute thermal tolerance and suggests heritability for this trait, as evidenced by similar responses in Channel Catfish and their corresponding hybrid crosses with Blue Catfish.
The culture of African catfish, Clarias gariepinus, is constrained by the high mortality of fry, occasioning a shortage of high-quality seeds for stocking by farmers. Asia, a continent with many success stories for aquaculture, leads in farmed production of some catfishes, a diverse group of 37 different families. Globally, the culture of catfishes ranks fifth in global farmed finfish production. Globally, Vietnam leads in the production and export of farmed striped catfish, Pangasianodon hypophthalmus, with 1,400,000 tonnes produced annually from about 7,000 hectares. Similarly, China farmed the non-native Channel catfish, Ictalurus punctatus, into the major crop, with a current annual production of 250,000 tonnes. On the contrary, C. gariepinus, the main farmed catfish species in Africa, records low annual yields, with 240,000 tonnes for the whole continent. This paper explores the factors behind the high production of P. hypophthalmus and I. punctatus in Vietnam and China, respectively, and draws lessons for C. gariepinus farmers in Africa. Specifically, the use of differentiated hatchery and nursery husbandry practices was critical in boosting seed production, quantity, availability, and distribution for expanding the culture of P. hypophthalmus in Vietnam. Improvement of fish species through well-designed genetic improvement programs helped China substantially increase production of I. punctatus. For both species, intensive fish production, as well as the adoption and implementation of suitable policies, increased seed production from hatcheries in both countries. These are discussed as some of the factors that spurred catfish production in the two Asian countries. We argue that if these are adopted by farmers in Africa, they could help improve the production of farmed C. gariepinus on the continent for food and nutrition security as well as generation of livelihood for local communities.
The study of animal function is organized more or less under three heads, which in everyday language are, as applied to a machine, what it can do, how it works, and what makes it go. Insofar as fields of study can be classified in biology these divisions of the subject are ordinarily considered to be autecology, physiology, and biochemistry, with a great deal of individual taste governing the label any particular worker may choose for himself. The chapter discusses what fish can do in relation to their environment and therefore largely autecology. The chapter focuses on the action of the environment on metabolism and the effects of this action on the activity of the organism.
Effects of high summer temperatures on Channel Catfish Ictalurus punctatus are poorly understood, particularly for thermal regimes that mimic pond aquaculture conditions. Therefore, this study examined the effects of three cycling upper-range temperature regimes (23–27°C, 27–31°C, and 31–35°C) characteristic of aquaculture environments in the Mississippi Delta. Feed conversion ratio, feed consumption, specific growth rate, activity levels, survival, and overall growth in terms of wet weight and TL were measured in fingerling channel catfish over an 8-week period in a flow-through, multiple-tank system. Specific growth rate, feed consumption, TL, and wet weight of fish increased significantly in the 27–31°C treatment in contrast to the 23–27°C and 31–35°C treatments. Feed conversion ratio was lowest in the 27–31°C treatment, whereas activity levels were highest in the 31–35°C treatment. Survival significantly decreased for catfish in the warmest treatment compared with catfish in the coolest treatment. These results indicate that high temperatures decrease growth in Channel Catfish, largely due to reduced food consumption and feed conversion and increased levels of activity. Therefore, increases in temperatures, such as from climate change, present challenges to the culture and management of Channel Catfish.Received April 30, 2012; accepted September 12, 2012
Most channel catfish are grown in hypertrophic ponds that are extremely dynamic environments with respect to spatial and temporal variation in water quality. Many of these water quality parameters have direct and indirect effects on fish physiology, thereby affecting growth, and survival. This chapter discusses physiological responses of channel catfish to this dynamic environment. The chapter presents the important factors that affect catfish metabolism, growth, and survival, with specific emphasis on identification of those factors that are within and beyond management control to improve catfish production in ponds. In general, channel catfish are tolerant of poor water quality. Indeed, the tolerance of channel catfish to a broad range of water quality is one of the key attributes of the fish as a candidate for aquaculture. In particular, channel catfish are tolerant of repeated episodes of low dissolved oxygen concentration. Recovery from exposure to various stressors associated with routine culture in ponds is rapid. Temperature is the most important water quality variable from the standpoint of catfish metabolism, growth, gonadal maturation, and immunocompetence.
Rates of acclimation and the response to fluctuating low temperatures of juvenile striped mullet Mugil cephalus (L.) have been described in terms of changes in heat resistance over a period of time. Fish changed from 25.5 to 27 or 29° C were acclimated within seven days. Acclimation to 23 or 15° C required a maximum of 11 days. Thermal responses to fluctuating low temperatures were lower than responses to constant temperature levels. Cyclic variations in heat resistance were present in all experimental and control tests.
1.1.|A 1°C increase in constant acclimation temperature over a range of 6.5 to 33.1°C increased the critical thermal maximum (CTM) by 0.47°C for both starved and satiated hybrid bass; however, the CTM of starved fish averaged 0.35°C lower than satiated fish.2.2.|If the mean daily temperature was at least 24°C, diel oscillating temperatures of ±4°C amplitude increased the CTM.3.3.|With a mean daily temperature of 20°C, oscillating temperatures had no effect on the CTM for satiated fish and the CTM for starved fish was reduced.4.4.|Photoperiod had no discernible effect on CTM.
Understanding farm-level efficiencies of resource use is critical in comparisons of the sustainability of aquaculture production systems. We developed a set of practical resource-use efficiency metrics to calculate and compare resource-use efficiency with resource-cost efficiency across major species and production systems in US aquaculture. Results showed that no one production system used all resources most efficiently. Intensive pond production of channel catfish Ictalurus punctatus demonstrated the greatest efficiency in the use of water, energy, labor, management, and capital resources, while RAS production was most efficient in terms of land and feed use. Among the wide array of pond scenarios examined, more intensive scenarios generally were more efficient in terms of several metrics, but economic sustainability also depends upon business models that effectively meet differing demand requirements of customers. Thus, less intensive production systems were economically sustainable in areas with relatively abundant land and water resources available at lower cost. Labor efficiencies varied widely across scenarios analyzed. Given increasing concerns related to the availability of labor for aquaculture farming in the USA, greater attention to the efficiency of labor on farms is warranted. The metrics used were aligned with common farm management tools (e.g. enterprise budgets) that allow for ease of use by farms and researchers to assess effects on comparative resource-use efficiencies of new farming practices and technologies under development.
The threat posed by invasive non-native species worldwide requires a global approach to identify which introduced species are likely to pose an elevated risk of impact to native species and ecosystems. To inform policy, stakeholders and management decisions on global threats to aquatic ecosystems, 195 assessors representing 120 risk assessment areas across all six inhabited continents screened 819 non-native species from 15 groups of aquatic organisms (freshwater, brackish, marine plants and animals) using the Aquatic Species Invasiveness Screening Kit. This multi-lingual decision-support tool for risk screening of aquatic organisms provides assessors with risk scores for a species under current and future climate change conditions that, following a statistically based calibration, permits the accurate classification of species into high-, medium- and low-risk categories under current and predicted climate conditions. The 1,730 screenings undertaken encompassed wide geographical areas (regions, political entities, parts thereof, water bodies, river basins, lake drainage basins, and marine regions), which permitted thresholds to be identified for almost all aquatic organismal groups screened as well as for tropical, temperate, and continental climate classes and for tropical and temperate marine ecoregions. In total, 33 species were identified as posing a ‘very high risk’ of being or becoming invasive in the study areas, and the scores of several of these species under current climate increased under future climate conditions, primarily due to their wide thermal tolerances. The risk thresholds determined for taxonomic groups and climate zones provide a basis against which area-specific or climate-based calibrated thresholds may be interpreted. In turn, the risk rankings help decision-makers identify which species require an immediate ‘rapid’ management action (e.g. eradication, control) to avoid or mitigate adverse impacts, which require a full risk assessment, and which are to be restricted or banned with regard to importation and/or sale as ornamental or aquarium/fishery enhancement.
The North American channel catfish Ictalurus punctatus has been introduced to several locations in Europe but has received little or no scientific study despite its invasive attributes, including prolific reproduction, tolerance to a wide range of conditions, opportunistic feeding, at least partial ‘predator release’, and some evidence of environmental impacts (e.g. disease transmission). To assess the species’ potential invasiveness and the likely risks to native species and ecosystems in Europe, available literature from both North America and Europe was reviewed and used to carry out risk screenings of the species for the risk assessment areas, North and South Italy, using the Aquatic Invasiveness Screening Kit (AS-ISK), which was followed by a more detailed evaluation (for both North America and Europe) of the species’ potential impacts using the Environmental Impact Classification of Alien Taxa (EICAT) assessment protocol. The AS-ISK score indicated that channel catfish to pose a high risk of being invasive in both North and South Italy, with EICAT scores indicating “Major” impacts for both North America and Europe, at high and medium confidence levels, respectively. The present results emphasise the urgent need to carry out in-depth studies on introduced populations of this species to understand better its invasive potential so as to inform management decisions on the appropriate control or eradication measures for invaded water bodies.
Substantial economic losses of farmed catfish to fish-eating birds such as the double-crested cormorant, Phalacrocorax auritus, continue to be reported on U.S. catfish farms. An economic analysis was conducted of the on-farm effects of both the increased expenditures to scare fish-eating birds from catfish farms and of the value of the catfish that were consumed by cormorants. A survey was conducted of U.S. catfish farmers in the Delta region of Mississippi and Arkansas, to obtain farm-level data on expenditures to scare birds. Estimations of the lost revenue from catfish consumed by cormorants were developed from a concurrent study on cormorant distribution, abundance, and diet in the region. The economic effects of bird predation in terms of both fish consumption and management costs were evaluated across three farm sizes and nine catfish production practices. Catfish farmers spent on average 394/ha to scare birds, making bird-scaring costs one of the top five costs of raising catfish. The greatest cost components of scaring birds were manpower (39% of all bird-scaring costs) and the variable and fixed costs of trucks used to scare birds (34% of all bird-scaring costs). Losses were greater on hybrid than channel catfish fingerling ponds. Industry-wide, the value of catfish losses averaged 25.8–64.7 million (ranging
from 92.6 million). Profitability improved by
4% to 23% across the farm size/production strategies analyzed
upon removal of the economic effects from bird predation,
with greater effects occurring on smaller-scale
farms. One-third of the farm size and production scenarios
analyzed changed from being unprofitable to showing a
profit in the absence of such negative economic effects
associated with bird depredation. Overall, the combined
effects of increased farm expenditures to scare birds from
farms and the value of the catfish lost to predation by cormorants
caused substantial negative economic effects on
catfish farms.
Compares economics across production systems of ponds, raceways, RAS, including efficiencies of use of labor and capital
Economics of U.S. catfish farming practices
Fish‐eating birds prey and scavenge on catfish ponds with outbreaks of an emergent, atypical Aeromonas hydrophila (AAH) and may play a critical role in the pond‐to‐pond spread of AAH. The objectives of this study were to: (a) determine if great egrets that consumed AAH‐infected fish shed enough AAH in their feces to cause a disease outbreak and (b) determine the environmental factor(s) and animal vector(s) associated with epidemic AAH dissemination. Three experimental catfish ponds within an aviary facility were stocked with naïve channel catfish fingerlings. Individually housed egrets were fed catfish fingerlings injected with AAH (treatment, Ponds 1 and 3) or uninfected catfish (control, Pond 2) and then placed in their ponds. Ponds 1 and 2 had no detectable fish mortality, whereas in Pond 3, mortality occurred on Days 15–29. Beginning on Day 15, AAH was recovered from fish, pond water, chironomids, aquatic invertebrates, snails, and mud from Pond 3. Egrets can transfer viable AAH between ponds, resulting in AAH colonization of invertebrates and fish mortality. This information is critical to understand the risk factors and epidemiology associated with the spread of AAH between catfish ponds and farms to develop best management practices for ponds before and after an AAH mortality event.
The US catfish industry has shown increasing trends toward intensification of production as a means of achieving cost efficiencies on farms. Previous studies depicted the potential for cost efficiencies in alternative technologies such as split‐pond systems, intensively aerated ponds, and in‐pond raceway systems. This study provides an economic comparison of these systems under a uniform set of economic assumptions using a standard enterprise budget analysis. Cost of production of hybrid catfish raised in these systems ranged from 2.91/kg, the highest cost being that of in‐pond raceways and the lowest from split ponds. Positive annual net cash flows from split‐pond systems and intensively aerated ponds were sufficient to make the investment profitable. Cumulative effects of high investment cost (high annual fixed costs), poor survival, and lower yields from the in‐pond raceway systems made it economically infeasible. However, the feed conversion ratio (FCR) was the best among these technologies. Risk analysis showed stochastic dominance of intensively aerated ponds and split‐pond systems over in‐pond raceway systems. Variations in catfish price, yield, and FCR were the major contributors to economic risk. Implementing combinations of intensively aerated ponds and split‐pond systems should be viewed as a strategy to respond to production and market needs.
Technology adoption has played a key role in the global development and increase in agricultural productivity. However, the decision to adopt a new technology on farms is complex. While the factors that drive the adoption of new technologies have been well studied in agriculture, less attention has been paid to drivers of technology adoption in aquaculture. Aquacultural technologies have developed and advanced rapidly in recent decades, but not all technologies have been adopted readily by farmers. This review paper summarizes some of the critical factors that influence aquaculture technology adoption decisions such as: (1) method of information transfer, (2) characteristics of the technology, (3) farm characteristics, (4) economic factors, and (5) sociodemographic and institutional factors. Fish farmers have tended to adopt technologies that are perceived to be more advantageous than others in terms of productivity, cost efficiency, and ease of management. Price of aquaculture products and profit expectations from business ventures were key economic factors influencing adoption decisions. Given the wide array of species, production practices, and global nature of aquaculture, the intensity and the extent of adoption of technologies depend on the nature of the industry in which they are adopted and their economic, social, political, and regulatory environments.
Introductions of aquatic organisms into Japan are controlled only on the basis of the Convention on International Trade in Endangered Species (CITES) of Wild Fauna and Flora and the quarantine acts. Up to 1986 more than 120 exotic species have been introduced, of which only 36 were made prior to 1945. Introductions are classified into four basic categories. In this paper of those in two categories, (i) species which have spread widely over Japan and are self reproducing, and (ii) those which have been maintained for generations through artificial propagation or in confined natural waters are dealt with.
Aeromonas hydrophila is a gram-negative, rod-shaped, facultative, anaerobic bacterium that is ubiquitous in freshwater and slightly brackish aquatic environments and infects fish, humans, reptiles, and birds. Recent severe outbreaks of disease in commercial channel catfish (Ictalurus punctatus) aquaculture ponds have been associated with a highly virulent A. hydrophila strain (VAH), which is genetically distinct from less-virulent strains. The epidemiology of this disease has not been determined. Given that A. hydrophila infects birds, we hypothesized that fish-eating birds may serve as a reservoir for VAH and spread the pathogen by flying to uninfected ponds. Great Egrets (Ardea alba) were used in this transmission model because these wading birds frequently prey on farmed catfish. Great Egrets that were fed VAH-infected catfish shed VAH in feces demonstrating their potential to spread VAH.
Turkey's natural river systems have been anthropogenically altered in the past century. Native fish communities of river systems have come under increasing pressure from water engineering projects, pollution, overfishing and the movements of alien fish species. Introduction of alien fishes is one of the main threats to the survival and genetic integrity of native fishes around the world. In Turkey, alien freshwater fish are continuing to increase in number of species, abundance, and distribution. The present paper reviews fish stocking studies in Turkey's reservoirs.
Distribution records (historical, contemporary) for native and non-native freshwater fish species from 105 hydrographic basin areas were compiled and analysed in order to develop a nation-wide inventory (including transboundary river basins). Overall, 162 species, including diadromous and euryhaline, with documented occurrence records in freshwaters, and taxa of unclarified taxonomic status, are accommodated in the distributional compilation. An annotated checklist summarises the confirmed ichthyofauna of Greek freshwaters (161 species); a provisional supplementary list contains species recorded in brackish waters (55 species). In comparison to the last published (1991) checklist of freshwater fish of Greece, the present checklist shows an increase in species number of 53% (56 species). This increase has resulted mainly from taxonomic re-evaluations of existing taxa on the basis of new information and adoption of a new systematic concept. The current trend, as reflected in recent ichthyological publications, is towards abandonment of the biological species concept (BSC) and adoption of the phylogenetic species concept (PSC) for the delineation of species boundaries. The practical implications of the change in species concept on biodiversity conservation and watershed management are discussed. An overview of the composition and characteristics of the freshwater fish fauna of Greece is provided, especially with regard to the native and introduced status of species, and the spatial patterns of species richness and endemism. This systematic inventory may assist in efforts to develop nation-wide surface water bioassessment tools within the demands of the Water Framework Directive (WFD); it may further promote biodiversity conservation and biologically-orientated fishery management approaches.
HADJINIKOLOVA, L., T. HUBENOVA and A. ZAIKOV, 2010. Status and development tendencies of freshwater aquaculture production in Bulgaria. Bulg. J. Agric. Sci., 16: 398-405 The present article surveys the status and the tendencies in the development of the freshwater aquaculture in Bulgaria under the conditions of market economy, and specific attention is paid to the structure and the type compound of the cultivated water organisms, the present state of the production, their actual price for realization, as well as the consumption of fish. Bulgaria possesses a comparatively rich water fund of about 70 000 ha, which accompanied by the climatic conditions in the country creates good conditions for aquaculture development.The main objects for cultivation are the carp (Cyprinus carpio) and the trout (Oncorhynchus mykiss), having in mind that the herbivorous fish species, like silver carp (Hipophthalmichthys molitrix), bighead carp (Aristhichthys nobilis) and grass carp (Ctenopharingodon idella). With good perspectives for increasing the production ca-pacities are the Acipensaridae, the European wels (Silurus glanis) and the channel catfish (Ictalurus punctastus). Fish consumption per capita is 4.6 kg, which ranks Bulgaria among countries with low fish con-sumption.
Invasions by alien species are one of the major threats to the native environment. There are multifold attempts to counter alien species, but limited resources for mitigation or eradication programmes makes prioritisation indispensable. We used the generic impact scoring system to assess the impact of alien fish species in Europe. It prioritises species, but also offers the possibility to compare the impact of alien invasive species between different taxonomic groups. For alien fish in Europe, we compiled a list of 40 established species. By literature research, we assessed the environmental impact (through herbivory, predation, competition, disease transmission, hybridisation and ecosystem alteration) and economic impact (on agriculture, animal production, forestry, human infrastructure, human health and human social life) of each species. The goldfish/gibel complex Carassius auratus/C. gibelio scored the highest impact points, followed by the grass carp Ctenopharyngodon idella and the topmouth gudgeon Pseudorasbora parva. According to our analyses, alien fish species have the strongest impact on the environment through predation, followed by competition with native species. Besides negatively affecting animal production (mainly in aquaculture), alien fish have no pronounced economic impact. At the species level, C. auratus/C. gibelio show similar impact scores to the worst alien mammals in Europe. This study indicates that the generic impact scoring system is useful to investigate the impact of alien fish, also allowing cross-taxa comparisons. Our results are therefore of major relevance for stakeholders and decision-makers involved in management and eradication of alien fish species.
The catfish industry is the largest U.S. aquaculture sector and a major contributor to the rural economies of the Southern states of Alabama, Arkansas, and Mississippi. Economic contributions of this industry to the tristate region were estimated using an input-output modeling approach with the IMPLAN database and software (Impact Analysis for Planning MIG, Inc.). An analysis-by-parts approach was employed as the IMPLAN database does not disaggregate the catfish sector from other livestock industries which have expenditure patterns that differ substantially from those of catfish. All major actors of the catfish industry, i.e. feed mills, hatcheries, foodfish farms, and processing plants, were surveyed to obtain their expenditure patterns and output in terms of sales. Data were obtained from 68 farms (hatcheries and foodfish combined), four feed mills, and eight processing plants in the tristate region. Sales and expenditure values were converted to coefficients employing standard enterprise budgeting techniques and imported to the IMPLAN model for estimating industry contributions during 2019. The direct output from the catfish industry (1.91 billion. The industry directly employed 4,298 people and created an additional 4,868 jobs in the tristate economy for a total employment effect of 9,166 jobs. Catfish industry spending created an indirect economic effect of 254 million. Some of the key sectors influenced by the catfish industry were grain farming, banking and financial institutions, truck transportation services, electricity generation, equipment, and machinery manufacturing. The industry also generated $78 million in local, state, and federal taxes. This study provides critical insights for policymakers and others into the contribution of the U.S. farm-raised catfish industry to local and regional economies as well as its diverse-industry interconnections.
Catfish farming continues to be the largest segment of U.S. aquaculture, and U.S. catfish farmers have demonstrated resilience and resourcefulness in adapting to changing economic conditions. Commercial production began in the 1950s–1960s, with growth leading to processing and marketing challenges in the 1970s. By the early 1980s, the key production, processing, and marketing pieces were in place to transform catfish farming into a major enterprise. Keys included development of efficient aerators, nutritionally complete feeds, multiple-batch production providing year-round supply of fish, processing innovations, and creation of The Catfish Institute (TCI) for marketing and public relations. The successful expansion into nontraditional catfish markets attracted competition of pangasius catfish imported from Vietnam by U.S. seafood importers, free riding on successful marketing programs. The 2003–2013 contraction of the U.S. industry was the combined effect of four external economic shocks; trough of price cycle; 2001 recession; September 11 terrorist attacks; and Vietnamese pangasius imports. Prices fell to historical lows and remained below production cost for 3 years. Adoption of intensive systems (split ponds, intensive aeration) that reduced costs led to steady growth from 2014 to 2019. Lessons for U.S. aquaculture include the importance of fingerling/seed technologies, farmer associations, research, Extension, marketing, and state/federal support.
Given its ubiquity, it is not surprising that agriculture, including finfish aquaculture, contributes to food webs worldwide and is used by numerous wildlife for foraging and meeting other needs. Double-crested Cormorants (Phalacrocorax auritus) impact United States commercial aquaculture and are considered the primary avian predator in catfish (Ictalurus spp.) aquaculture facilities in the Mississippi Delta. Recent changes in aquaculture practices, regulatory policies, and decreased overall hectares in production prompted this study that assessed cormorant consumption of catfish in relation to their night roosts through surveys and diet analysis. Cormorants were collected from night roosts from October through April 2016–2018 (n = 69 collections). On average, catfish constituted 33% of a cormorant's overall diet, which is less than reported in previous studies. There was no statistical difference between consumption of channel (I. punctatus) and hybrid catfish (I. punctatus x I. furcatus) based on biomass estimates, and the greatest consumption of catfish occurred in the months of February and March. The best fit model for predicting catfish consumption was the cubic polynomial function of the area of catfish aquaculture within a 30.6 km forage buffer of a night roost. Our findings will inform wildlife managers about relationships between cormorant night roost locations and consumption of catfish and aid decision making with respect to cormorant management. Despite cormorants having shifted consumption to naturally occurring fish species associated with changes to aquaculture, aquaculture remains an important part of regional food webs.
U.S. catfish producers have been exploring the adoption of alternative-production technologies (intensive-aeration, in-pond raceways, and split-pond systems) in recent years for achieving cost efficiencies. A multi-state (Alabama, Arkansas, and Mississippi) survey was conducted to identify specific reasons influencing the decisions of producers whether or not to adopt these alternative catfish production technologies. High yield and greater control over the production process were the major reasons for the adoption of alternative catfish production technologies. High investment costs and increased risks associated with these technologies were the main reasons for not adopting new technologies. Early adopters had significantly larger farms, greater numbers of ponds, and a significantly greater percentage of use of hybrid catfish. Econometric analysis suggested that characteristics of the technology such as productivity, perceived risk, and adoption costs, influenced early adoption decisions. Institutional factors such as prior involvement in Extension/research programs and farm characteristics of the scale of operation also shaped adoption decisions. Understanding the characteristics (of the technology, farms, and producers) that lead to greater adoption, may provide guidance to increase the rate of successful transfer of new technologies to fish producers.
Seasonal changes in the distribution of the channel catfish, Ictalurus punctatus, in Lake Kasumigaura were examined from December 2003 to December 2004. Nighttime sampling was conducted in three depth zones using bottom gill nets: the shallow (1m depth, 50m offshore), intermediate (4-5m depth, 600m offshore) and deep (7-12m depth, 800m offshore) zones. Fish were caught at depths deeper than 4m from October to March, except in February, when the water temperature in the shallow zone was lower than 10°C. From April to November when the temperature of the shallow water was higher than 10°C, fish were collected from all zones and were abundant in the shallow zone from April to September, when the water temperature was higher than 21°C . Mature fish only occurred in the shallow zone from May to July, during their spawning season. These results indicated that the distribution pattern of channel catfish was related to water temperature, and that the fish aggregated the deep habitat during the cold season, when the water temperature was lower than 10°C, and dispersed to all the habitats in the warm season. Especially, mature fish migrated to the shallow zone to spawn.
Oxygen depletion is a serious problem for the catfish industry, especially as producers attempt to increase their production intensity. Aeration, either emergency or continuous, is the most common method used to address oxygen depletion. A risk?programming model using Target MOTAD methodology was developed to study the aquacultural producer's aeration decision?making process. Effects of stocking rate, aeration yield response and availability of labor, capital and electricity on the selection of aeration strategy were analyzed. Continuous aeration with electric paddlewheels was most often selected as the best aeration strategy. However, as farmers become increasingly concerned with financial risk, they apply continuous aeration with pump sprayers first, then no aeration and lastly emergency aeration with tractor?powered paddlewheels. Emergency aeration was only used when: 1) electricity was not available and the producer desired a highly conservative financial strategy, and 2) the relative efficiency of continuous aeration in the field was dramatically reduced from experimental results.
Off-flavor problems in farm-raised catfish Ictalurus punctatus increase production costs and pose inventory management problems for catfish farmers. Multiperiod mathematical programming techniques were used to test the effect of 16 different off-flavor scenarios on expected net returns above variable cost with and without cash flow restrictions. The patterns of off-flavor incidence had less effect on farm profits than whether or not fish are off-flavor during certain key months of the year. To be feasible, systems designed to purge off-flavor from catfish would need to cost less than 0.06/kg (if cash flow is not a consideration) or 0.25/ke (with cash flow considerations).
Compelled by pending regulatory rule changes, settling basins have been proposed as a treatment alternative for catfish pond effluents, but the associated costs to catfish farmers have not been estimated. Economic engineering techniques were used to design 160 scenarios as a basis for estimating total investment and total annual costs. For static-water, levee-style catfish pond facilities, sizing of settling basins is controlled by factors such as type of effluent to be treated, pond layout, size of the largest foodfish pond, number of drainage directions, scope of regulations governing effluents, and the availability of land. Regulations that require settling basins on catfish farms would increase total investment cost on catfish farms by 19 Á/367 ha (1. More numerous drainage directions on farms resulted in the greatest increase in costs. While both investment and operating costs increased with larger sizes of foodfish ponds, costs per ha were relatively greater on smaller than on larger farms. For farms on which existing fish ponds would have to be converted to settling basins, over half of the cost was due to the production foregone and annual fixed costs of the pond. Requiring catfish farmers to construct settling basins would impose a disproportionately greater financial burden on smaller farms. The magnitude of the increased costs associated with settling basins was too high relative to market prices of catfish for this technology to be economically feasible. #
As part of the San Juan River Basin Recovery Implementation Program (SJRIP), investigations of non-native fishes were conducted during 1991-1997 to characterize interactions with native fishes. The impacts of non-native fish species on natives has often been identified as a key impact, along with habitat alteration, that facilitates loss of native biological diversity. In the San Juan River, the endangered Colorado pikeminnow Ptychocheilus lucius and razorback sucker Xyrauchen texanus, as well as the other members of the native fish community, are the focus of the SJRIP. A major component of native fish recovery efforts in the San Juan River is the mimicry of the natural hydrograph, and SJRIP studies were designed to assess the response of the resident fish community to variable flow conditions affected the releases from upstream Navajo Dam. Section 5.4 of the SJRIP Long Range Plan identified several informational and action needs regarding non-native fish species: 1) characterize distribution and abundance patters of non-native fishes, 2) characterize habitats used by non-native fishes, 3) describe the food habits of non-native fishes, 4) characterize the response of non-native fishes to varying flow regimes, 5) develop a non-native fish stocking policy, 6) develop regulations to restrict bait-fish species harvest, 7) develop regulations to control importation of non-native fishes, and 8) monitor and evaluate non-native fishes control actions implemented as part of the SJRIP. This report presents results of non-native fishes investigations that address items 1-4 and 8 above.
The distribution and abundance patterns of large-bodied non-native fishes were studied to determine responses to varying flow regimes. Sampling was primarily by raft-mounted electrofishing, but also included limited hoop and trammel netting. Main and secondary channel sampling collected 18 species of non-native fish. Channel catfish Ictalurus punctatus and common carp Cyprinus carpio were the most abundant and the most widely distributed species. Seasonal movements of striped bass Morone saxatilis and walleye Stizostedion vitreum out of Lake Powell and upstream into the San Juan River as far as Shiprock, New Mexico were documented. Mark and recapture studies of channel catfish and common carp were used to estimate abundance and to evaluate movement patterns for the entire reach of the San Juan River sampled, Farmington, New Mexico downstream to Clay Hills, Utah. Schnabel population estimates (95% C.I.) for channel catfish ranged from 131,768 (72,143 - 219,393) in 1992 to 274,484 (115,712 - 563,162) in 1995 and for common carp were 26,576 (14,213 - 45,019) in 1992 to 107,268 (61,438 - 172,692) in 1995. The proportional abundance of non-native species sampled during electrofishing surveys in main and secondary channel habitats increased during 1994-1997, after initial declines observed during1991-1994. Implementation of high spring releases from Navajo Dam did not appear to negatively impact non-native species distribution or abundance.
A naturalized population of the channel catfish, Ictalurus punctatus (Rafinesque, 1818) (Siluriformes, Ictaluridae), was reported in the Ombrone River, in the southern part of Tuscany (Central Italy). The investigation, funded by the Amministrazione Provinciale of Grosseto, provided some information on the population dynamics of the species in the Ombrone River. A total of 167 channel catfish specimens, ranging from 5.5 to 33.5 cm of total length (TL), was caught by means of experimental samplings. Females were more abundant than males: the sex ratio was 65%. The analysis of length-frequency distribution outlined the presence of three modal classes, corresponding to age class 0, I, and II, respectively. This observation was confirmed by the age estimation provided by the analysis of the otoliths. The von Bertalanffy growth curve fitted from age-length data was characterized by the following parameters: L∞ = 43.8 cm, k = 0.33, t0 = -0.49 years. A mean size of about 17 cm TL was estimated at age 1 year. The collection of juveniles (≤ 10 cm TL) at the end of September and of adults with spent gonads in July suggested the concentration of the spawning period in late spring. The analysis of stomach contents highlighted that fishes play a dominant role in the diet of the channel catfish. © 2007, Societa Toscana di Scienze Naturali. All rights reserved.
Two thousand fingerlings of channel catfish Ictalurus punctatus were imported from Thailand in a bid to introduce this fish in Pakistan. Five percent mortality occurred during transportation. Experiments were designed to observe catfish acclimatization in tanks or raceways for which five hundred fingerlings (average weight 10.86±1.20g) were placed in five tanks of 2000-liter water capacity and another 500 fingerlings (average weight, 10.56±0.68g) were kept in five raceways of 5000-liter water capacity each. The fish were fed on imported diet for a period of 75 days. Mean weight gain of 27.22±1.75 g and 31.5±1.04 g and surv∼7.5% and 95.9% were recorded in tanks and raceways, respectively. For studying growth of fish two stocking densities (3,000 and 3.500/ha) were maintained in ponds (0.04 ha) from December 2003 - November 2004. The weight gain was significantly higher in low stocking density (1,263.3 ± 60.9 g) compared with high stocking density (1.184.9±57.1 g). Fish production and survival between two stocking densities was not different (P>0.05).
The channel catfish, Ictalurus punctatus, is an invasive alien species introduced from North America. We investigated the present status of the fish in Japan and found that it is widely distributed in the Abukuma, Tone, and Yahagi River systems, as well as in Lake Shimokotori. In 2008 and 2009, several channel catfish were also caught in Lake Hinuma and the Miya and Seta Rivers. We concluded that the distribution of channel catfish has rapidly expanded within natural rivers during the past several years. To avoid severe damage imposed by channel catfish to the river ecosystems and inland fisheries of Japan, risk assessments and examinations of the ecological characteristics and methods of capture of this fish species are urgently required.
Originally, channel catfish broodfish were obtained from the wild and spawned in captivity. Recently, broodfish are rarely taken from the wild because they can carry unwanted diseases, they may be slow growers and generally do not spawn readily in captivity, and are not available in quantities needed to sustain a large aquaculture industry. Wild broodfish captured in spawning condition can be hormonally induced to spawn but are difficult and unreliable spawners the second year. The strains of channel catfish that have undergone several generations of selection are the best choice for broodfish. Performance history such as growth, disease resistance, fecundity, and dress-out weight is lacking for most commercial strains; however, farmers should try to obtain this information for the strain in question. Broodfish management is an important aspect of channel catfish culture because a reliable source of fingerlings is essential to support a large aquaculture industry. Successful management of broodfish includes the genetic principles of selection for the qualities desired by the culturist and processor, and ending with the production of quality fry. This chapter discusses management techniques important to select, maintain, and spawn channel catfish broodfish.
The channel catfish, Ictalurus punctatus, is an important component of the Platte River fishery, representing the most abundant and sought-after sport fish. However, little is known concerning the size structure and growth characteristics of this population. We collected channel catfish from seven sites along the lower Platte River from 1988 to 1991, using a combination of hoop nets, boat electrofishing, and angler tournament harvests. Pectoral spines were removed from a subsample of catfish collected, sectioned, and aged for determination of backcalculated growth. Proportional Stock Density (PSD) calculated from hoop net and electrofishing collections averaged 7.2% and ranged from 4.0 to 10.7%, compared to PSD from angler harvests which averaged 66.6% and ranged from 53.8 to 79.3%. Incremental Relative Stock Density (RSD) analysis showed that anglers were harvesting more fish in the RSD Q-P category, while our sampling indicated that most stock size fish were in the RSD S-Q category. There were no consistent differences in mean monthly and annual K values between sexes of catfish both within or between sampling locations. Backcalculated estimates of the mean total length of age 1 channel catfish averaged 84 mm and ranged from 69 mm in spring 1989 to 101 mm for spring 1991. Mean annual growth increments for the next four years declined steadily from 65 mm between ages 1 and 2 to 54 mm, 50 mm, and 47 mm between ages 2 and 3, 3 and 4 and 4 and 5 respectively. It took four to six years for channel catfish to reach 300 mm in the Platte River. No consistent differences in mean lengths at age between locations were evident. The channel catfish population of the lower Platte River exhibits a longitudinally-uniform pattern of slow growth, with an age structure skewed towards younger age groups.
Channel catfish were widely distributed in 517 km of the mainstream Green and 74 km of the lower Yampa rivers in 1987 and 1988. The fish was most abundant in rocky canyon habitats (average stream gradient >2 m/km), where adult fish comprised 14% of electrofishing and 70% of angling catch. Pectoral spine sections of 364 channel catfish of 27 to 756 mm total length ranged in age from 0 to 22 years respectively, with an average annual growth range of 17 to 53 mm. No difference in growth or condition factor was detected among catfish collected in eight river reaches. Growth of channel catfish in the Green River basin was judged slow in comparison to other areas of the United States and was attributed, in part, to cold water temperatures, short growing seasons, and elevated summer flow conditions. Channel catfish consumed a variety of food items, but piscivory was limited to larger fish (average length 420 mm). Of 575 stomachs with food (76.2%), 31% contained aquatic invertebrates, 28% contained vascular plant material, 22% contained terrestrial insects, 10% contained algae and detritus, and 8.5% contained fish and mice. The abundance, widespread distribution, and omnivorous feeding behavior of this introduced fish may affect populations of rare and endangered fishes in the Green River basin.
Ictalurus lupus is widely distributed and moderately common in headwater and upstream sections of the Rio Grande, Pecos River, Rio San Fernando, Rio Soto la Marina, and the isolated Cuatro Cienegas basin. Museum collections identified as I. lupus from outside this described range are compared with electrophoretically identified specimens using a multivariate statistical analysis. Evidence suggests that I. lupus was at least historically present in the Colorado, Guadalupe, San Antonio, and Nueces rivers of Texas.
A bioenergetics model was constructed and evaluated for estimating Double-crested Cormorant (Phalacrocorax auritus) energy expenditures, food demand and impact on the Channel Catfish (Ictalurus punctatus) industry in the Delta region of Mississippi. Large body mass (mean = 2.27 kg) and higher basal metabolism (115% to 128% of predicted) resulted in an average predicted food demand of 504 g/bird/day (range: 449 to 551) from November to March or 22% of body mass. Factoring in population sizes and proportional intake of catfish, Double-crested Cormorants may have eaten up to 20 million catfish per winter in 1989-90 and 1990-91 or approximately 4% of the estimated standing crop at a replacement cost of ) annually. More than 50% of catfish losses were projected to occur in February and March; negligible losses occurred in November.
Left pectoral spines were collected from 1,478 channel catfish (Ictalurus punctatus) taken in western Lake Erie during 1957, 1958, and 1959. Projected images of thin cross sections of the spines were utilized for age assessment and growth calculations. Spine radius measurements were found to correlate very closely with total lengths (r = 0.996) in a linear relationship. Calculated average total lengths in inches corresponding to each annulus were I--2.5, II--6.5, III--8.9, IV--10.6, V--11.7, VI--13.0, VII--14.3. At least 50 percent of the Lake Erie catfish are mature by the time they reach total lengths ranging from 10 to 12 inches. Data suggest that females mature at a somewhat smaller size than do males. Fifty percent or more of both sexes are mature by the end of their fifth year of life. No difference is evident between the length--weight relationships of the two sexes, nor does there appear to be any significant difference between the rate of length increase in the two sexes until the age of maturity is reached. After the fourth year of life, growth rates seem to decrease, with the male rate declining less than that of the female. Catfish from Lake Erie appear to be heavier per inch of total length than fish from either Oklahoma or the upper Mississippi River, but fish from the latter two areas seem to exhibit a somewhat greater annual weight increment after the second year of growth.
The diet of Double-crested Cormorants (Phalacrocorax auritus) wintering in the Delta region of Mississippi was studied from collections of 202 birds taken at catfish farms during the winters of 1987-88 through 1989-90, and from collections of 461 birds at night roost sites during the winters of 1989-90 and 1990-91. Channel Catfish (Ictalurus punctatus) and Gizzard Shad (Dorosoma cepedianum) were the only two important prey species, comprising >90% of the diet from all samples. However, the proportion of these two prey species in the diet varied dramatically (P<0.05) among months and geographic locations of collections, as well as between sexes of birds collected. Overall, the diet was approximately equal between catfish and shad, but catfish was most often consumed by males during the spring months in the areas of highest catfish concentration. The size range of catfish preyed upon appeared to parallel the size class of fish used for stocking commercial ponds in the spring. Based on these analyses, we recommend strategies for reducing cormorant predation on commercial catfish.
Juvenile razorback sucker (Xyrauchen texanus), 45 to 168 mm standard length, reintroduced within their native range into the Gila River, Arizona, suffered intensive predation by two, non-native ictalurids, channel catfish (Ictalurus punctatus) and flathead catfish (Pylodictis olivaris). Estimated losses in the 2.5-km study reach over a 2-day post-stocking period were up to 900 individuals/km in autumn. If typical, predation may be high enough to preclude local re-establishment of the species by juvenile stockings at that time of year. Predation in autumn was lower when average size of stocked fish was increased from 68 to 113 mm standard length. Extrapolated total loss to predation in winter, when channel catfish did not feed actively, was about one-sixth that in autumn. Cold-weather planting of larger razorback suckers, in the range of 300 mm long, may be one way to enhance post-stocking survival.