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Catfish injuries are increasingly common from the recreational activities of hobbyists, fishermen, and "noodling" enthusiasts as well as in the commercial catfish industry, most commonly in Brazil. Injuries can range from mild skin abrasions to life-threatening infections and tissue damage requiring urgent treatment. Most injuries and subsequent morbidity associated with catfish encounters involve the dorsal and pectoral fins. These injuries are most often lacerations involving the upper extremities. Deep, penetrating catfish spine injuries can lead to serious injuries, including arterial and nerve lacerations. Catfish venom is released when a spine is torn. The venom may cause reactions that include erythema, edema, local hemorrhage, tissue necrosis, and muscle contractions. When "finned" by a catfish, the fish's spine may separate from the fish, which can cause a foreign body embedment. Some injuries are not thought to be severe enough at the time of injury to require medical care, although symptoms may arise years later. In this literature review of catfishing injuries, references were obtained through a PubMed search of the following terms: catfish injuries, fishing, envenomation, spine, and aquatic infection. Articles were chosen for citation based on pertinence to the topic of catfishing. [ABSTRACT FROM AUTHOR]

Management of Blue CatfishIctalurus furcatusand Channel CatfishI. punctatusfor trophy production has recently become more common. Typically, trophy management is attempted with length-based regulations that allow for the moderate harvest of small fish but restrict the harvest of larger fish. However, the specific regulations used vary considerably across populations, and no modeling efforts have evaluated their effectiveness. We used simulation modeling to compare total yield, trophy biomass (Btrophy), and sustainability (spawning potential ratio [SPR] > 0.30) of Blue Catfish and Channel Catfish populations under three scenarios: (1) current regulation (typically a length-based trophy regulation), (2) the best-performing minimum length regulation (MLRbest), and (3) the best-performing length-based trophy catfish regulation (LTRbest; “best performing” was defined as the regulation that maximized yield,Btrophy, and sustainability). TheBtrophyproduced did not differ among the three scenarios. For each fishery, the MLRbestand LTRbestproduced greater yield (>22% more) than the current regulation and maintained sustainability at higher finite exploitation rates (>0.30) than the current regulation. The MLRbestand LTRbestproduced similar yields and SPRs for Channel Catfish and similar yields for Blue Catfish; however, the MLRbestfor Blue Catfish produced more resilient fisheries (higher SPR) than the LTRbest. Overall, the variation in yield,Btrophy, and SPR among populations was greater than the variation among regulations applied to any given population, suggesting that population-specific regulations may be preferable to regulations applied to geographic regions. We conclude that LTRs are useful for improving catfish yield and maintaining sustainability without overly restricting harvest but are not effective at increasing theBtrophyof catfish. Received February 1, 2016; accepted June 16, 2016 [ABSTRACT FROM AUTHOR]

Channel catfish, Ictalurus punctatus (Rafinesque), populations in six lakes in northern Idaho, USA, were sampled to describe their population characteristics. During the summers of 2011 and 2012, 4864 channel catfish were sampled. Channel catfish populations had low to moderate catch rates, and length structure was dominated by fish <400 mm. Channel catfish were in good body condition. All populations were maintained by stocking age-1 or age-2 fish. Growth of fish reared in thermally enriched environments prior to stocking was fast compared to other North American channel catfish populations. After stocking, growth of channel catfish declined rapidly. Once stocked, cold water temperatures, prey resources and (or) genetic capabilities limited growth. Total annual mortality of age 2 and older channel catfish was generally <40%. Tag returns indicated that angler exploitation was low, varying from 0 to 43% among lakes. This research provides insight on factors regulating channel catfish population dynamics and highlights important considerations associated with their ecology and management. [ABSTRACT FROM AUTHOR]

This research was undertaken to examine the gender perspective of Catfish farming as a livelihood base and the issue of water quality using a case study of Lagos state, Nigeria. Primary data elicited from a sample size of 70 Catfish farmers (38 male and 32 female Catfish farmers) were employed in the data. Analysis of the data was done using descriptive statistics, gross margin analysis and Z statistic. The result of the data analysis revealed that the profitability of the male Catfish farmers was higher than that of the female Catfish famers and this implies that women with a lower profitability compared to men will tend to have a lower livelihood support from Catfish production in contrast to men who will tend to have a higher livelihood support from Catfish farming as a result of their higher profit margin. All the women catfish farmers attributed poor water quality to be the major constraints militating against their profitability in Catfish farming and invariably their source of livelihood. It is recommended that mainstreaming gender in manpower training, equitable distribution of resources and access to supportive services should be prioritized towards enhancing their Catfish productivity and improving their livelihood support. [ABSTRACT FROM AUTHOR]

Five iso-nitrogenous (39.0% crude protein) and iso-caloric diets (510 kJ gross energy) were prepared with fumaric acid added at varying inclusion levels: 0 (D1), 0.5 (D2), 1.0 (D3), 1.5 (D4) or 2.0 (D5) g kg-1 of diet. Diets were fed to triplicate groups of Clarias gariepinus (mean initial weight 68.14±1.5 g) for 84 days in 50 liters glass tanks. At the end of the experiment, fish fed diet D3 gave significantly higher growth indices closely followed by the control diet (D1). There were significant differences in weight gain, specific growth rate, food conversion ratio and percentage survival in fish fed diet D3 when compared with those fed diet D5. The haematological parameters of experimental fish revealed significant variations among treatments. The highest haemoglobin, packed cell volume (PCV), red blood cell (RBC) and white blood cell (WBC) values were recorded in fish fed diet D2 while the lowest were recorded in those fed diets D3. Challenge test showed that mortality was 100% in the control while it was between 0 and 86.67% in other treatments. Inclusion of 1.0 g kg-1 of fumaric acid in C. gariepinus diets boosted growth. Inclusion of 0.5 g kg-1 of fumaric acid improved fish haematological parameters. In overall, incorporation of fumaric acid in C. gariepinus diets improved fish survival after Aeromonas sobria challenge [ABSTRACT FROM AUTHOR]

Using an original dataset from the Vietnamese catfish sector, we study the impact of vertical coordination options on household welfare and the implications of different stages of vertical coordination for the success of the whole sector. The welfare gain from contract farming and employment on processor-owned estate farms is estimated using a maximum simulated likelihood estimator. Our results show positive welfare effects from participating in contract farming, but not from employment on processor-owned estate farms. The results imply that contract farming presents opportunities for economic growth, but additional effort is required to make the contracts more accessible to smallholders. [ABSTRACT FROM PUBLISHER]

Danube main channel deep pools are in-stream habitats of high ecological relevance. We used dual-frequency identification sonar to investigate seasonal and diel fish abundance in two hydrodynamically different deep pools in the main channel of the Danube River in 2008. In general, fish of different species were present in both deep pools throughout the year, irrespective of water level. High fish abundance was recorded during autumn and winter, low abundance during spring and summer. During low discharge and low temperature and particularly during low flow velocity, low kinetic energy and low shear stress, high fish abundance in densely packed aggregations were observed, a clear indication for the refuge capacity of deep pools. In contrast, during turbulent hydraulic conditions with high flow velocity, high turbulent kinetic energy and high shear stress, low fish abundance occurred, mainly consisting of single fish, small fish shoals and benthic fish specimens. Furthermore, we could reveal that calm as well as turbulent pools fulfil the requirements as refuge and feeding habitat of eurytopic, piscivorous catfish throughout the year. The application of a multiple linear model based on the hydrological parameters discharge and water temperature as well as the hydraulic parameters flow velocity, turbulent kinetic energy and shear stress provided highly significant evidence between the observed and the expected seasonal fish abundance in the deep pools ( R = 0.77, P < 0.001). For the first time these results make clear that the main channel deep pools are important refuge and resource habitats of different species of the Danube fish community. Deep pools are key habitats for the in-stream fish community of the Danube River. [ABSTRACT FROM AUTHOR]

This paper communicates the extension of the distribution range of Batasio merianiensis in Sille River in the upper Brahmaputra drainage, East Siang District, Arunachal Pradesh. Detailed examinations of the specimens revealed existence of few morphological variations against those reported by Heok Hee Ng in 2009 on the following characteristics: by having a longer preanal (70.4-73.4 vs. 66.3-68.2% SL); a longer prepectoral (25.1-29.3 vs. 21.4-25.7% SL); a longer adipose-fin base (22.0-27.6 vs. 16.9-22.2% SL); a shorter post-adipose distance (11.6-13.4 vs.13.4-15.5% SL); a deeper body at anus (depth 18.3-20.8 vs.15.2-18.4% SL) and broader head (width 17.6-20.0 vs.13.5-16.2 % HL). Few additional characters of the fish are included along with brief information on its habitat. The LlPUM, the semi-traditional method of fishing in the river is identified as a major threat to this species. [ABSTRACT FROM AUTHOR]

A simulation was carried out by using a 3D numerical model for estimate the nutrient level discharged from striped catfish, Pangasianodon hypophthalmus intensively farming in the Mekong River, Vietnam. The simulated period was dry season from April 24, 2007, to April 27, 2007. Both dissolved and particulate forms of nutrients were simulated. A real status of water environment and scenario of discharge after applying fishpond effluent for irrigation of rice field were estimated in My Hoa Hung fish farm, An Giang Province. Simulated results were verified by observed data. Our results showed that nutrient levels at farming area in dry season were temporarily high and local. Applying waste water from the fishpond for irrigation of rice field could greatly reduce nutrients level in the fish farming area, the nutrient levels were 77 % for total nitrogen and 73 % for phosphorus. Therefore, recycling nutrient from fishpond effluent for irrigation of rice field illustrated an effective technology for pollution reduction which is a crucial issue to enable sustainable development of intensively farmed striped catfish. [ABSTRACT FROM AUTHOR]

The artificially reared bagrid catfishMystus nemuruswas observed for the histological development of the pineal organ and retina and photoresponse in a test tank at hatching to 14?d after hatching. The pineal organ was functional at hatching, and the lens-like tissue was partly ossified forming a pineal window at 6?d. The retina became morphologically functional when the outer segments of single cones were formed, and the eyes were innervated with the optic tectum at 18?h and rods were formed at 36?h. Long and thin single cones were not observed. The larvae exhibited undirected kinetic movement at hatching to 12?h and directed tactic swimming away from a torch after 18?h in response to a torch light. The photoresponse of the larvae was negative at hatching to 30?h and at 6?d to the end of the observation at 14?d, but neutral during a period at 36?h to 5?d. It was evident that the kinetic movement was mediated by light perception with the pineal organ, which was not capable of detecting directed signal information, and that the larvae were capable of directed tactic movement only when vision was involved. The vigorous negative phototaxis at 6–14?d was attributed to the improvement of photosensitivity of the retina and the pineal organ. [ABSTRACT FROM PUBLISHER]

Abstract: The effects of cyanide, used in illegal fishing, on one of the most economically important Nile fishes, the African catfish (Clarias gariepinus), were studied. Cyanide impacts were evaluated in terms of biochemical, molecular and histopathological characteristics. After exposure to sublethal concentration (0.05mg/l) of potassium cyanide (KCN) for two and four weeks, GOT (glutamate oxaloacetate transaminase) was significantly increased in both male and female, while GPT (glutamate pyruvate transaminase), total plasma protein, phosphoprotein phosphorus (Vgt) in serum, vitellogenin gene expression (Vtg mRNA) and estrogen receptors (ER mRNA) were significantly decreased in female. On the other hand, male C. gariepinus showed a significant increase in Vtg and Vtg mRNA. Liver, testis and ovaries showed distinct histopathological changes. It was concluded that, cyanide caused damaging effects to fish and can cause serious disturbance in the natural reproduction and a drastic decline in fish population. Therefore, it is recommended that, the use of cyanide compounds must be prohibited to conserve the fisheries resources. [Copyright &y& Elsevier]

Commercial catfish farmers are intensifying production by retrofitting ponds with variations of the partitioned aquaculture system. The split-pond system is the most common variation used commercially. The split-pond consists of a small fish-holding basin connected to a waste treatment lagoon by two conduits. Water is circulated between the two basins to remove fish waste and provide oxygenated water to the fish-holding basin. Although much research has been devoted to algal and fish production dynamics in variations of the partitioned aquaculture system, little information is available on basic engineering considerations for devices to circulate water in these systems. This study evaluated performance characteristics for a slow-rotating paddlewheel pump that looked at the relationships among power input, rotational speed (circular tip velocity), water velocity, and water flow rate. Rotational speeds of 1.0, 2.0, 3.0, and 4.0 rpm were evaluated in open channels and in channels with fish barriers. Measured power input was greater than the calculated power input for all four rotational speeds and ranged from 0.11 to 1.80 hp. Water flow rate ranged from 4,548–19,330 gal/min and water discharge per unit power input decreased dramatically as rotational speed increased. Installation of fish barriers decreased channel open area and the resulting frictional losses reduced water flow rates. Results from this study provide initial pump performance data for designing split-pond aquaculture systems. Received September 6, 2012; accepted October 19, 2012 [ABSTRACT FROM AUTHOR]

Abstract: Lipolysaccharide (LPS), a component of outer membrane protein of gram-negative bacteria, reportedly stimulates fish immune system. However, mechanisms driving this immunomodulatory effect are yet unknown. To determine effects of Escherichia coli lipopolysaccharide on regulation of immune response and protein expression of striped catfish (Pangasianodon hypophthalmus), juvenile fish (20–25g) were injected with 3, 15 or 45mg E.coli LPS/kg and challenged with Edwardsiella ictaluri. Plasma cortisol and glucose were rather low and did not differ (p <0.05) among treatments. All LPS treatments differed regarding blood cell count and immune variables such as plasma and spleen lysozyme, complement activity and antibody titer, 3mg LPS/kg yielding best results; red blood cell count was not affected by LPS treatment. Accumulated mortalities after bacterial challenge were 23.4, 32.8, 37.7 and 52.5% for treatment 3, 15, 45mg LPS/kg fish and control respectively. Proteomic analysis of peripheral blood mononuclear cells (PBMC) confirmed that LPS induced differentially over-expressed immune proteins such as complement component C3 and lysozyme C2 precursor. Regulation of other proteins such as Wap65, alpha-2 macroglobulin-3 and transferrin precursor was also demonstrated. Striped catfish injected with E.coli LPS enhanced innate immune responses. [Copyright &y& Elsevier]

This study focused on the development of a protocol for cryopreservation of sperm of the endangered fish species, Pabda CatfishOmpok pabda. The activation of sperm motility was tested at various osmolalities of NaCl. The motility of sperm decreased with the increase of osmolality; it was completely inhibited at 319 mOsmol/kg. Toxicity of cryoprotectants to sperm was evaluated using dimethyl sulfoxide (DMSO), methanol, and ethanol at 5, 10, and 15% concentrations at an incubation time of 0–35 min. Five percent and 10% cryoprotectants produced 45–75% and 40–75% motility for the 5- and 10-min incubation times, respectively. Sperm incubated with 15% cryoprotectant had less motility from the beginning of incubation. The cryoprotectant was toxic to sperm. Three extenders, Alsever's solution, egg-yolk citrate, and urea egg-yolk, as well as three cryoprotectants, DMSO, methanol, and ethanol, were used for the preservation of sperm. Alsever's solution with DMSO showed best performance producing highest equilibration motility (83 ± 3.3%, mean ± SE) and postthaw motility (71 ± 4.4%) followed by levels of 68 ± 1.7% and 51 ± 1.7%, respectively, with Alsever's solution plus methanol. Sperm preserved with Alsever's solution plus DMSO produced 79.33% fertilization and 42.38% hatching while fresh sperm yielded 82% fertilization and 53.49% hatching. No statistical comparisons between cryopreserved and fresh sperm were made as we did not standardize the sperm concentration for fresh and cryopreserved sperm during breeding. Fry produced from both cryopreserved and fresh sperm were reared in aquaria for 6 weeks and no significant differences for length (P= 0.452) and weight (P= 0.431) were observed between the two groups. The protocols developed through this study can be applied for conservation of endangered Pabda Catfish, and the findings of breeding and growth studies suggest it would be useful to disseminate the cryopreservation technology to commercial hatcheries. Received November 20, 2011; accepted September 25, 2012 [ABSTRACT FROM PUBLISHER]

The present study examined the use of hydrolyzed poultry feathers (HPF) as a replacement for soybean meal in diets for pond raised Channel CatfishIctalurus punctatus. Four isonitrogenous (28% crude protein) diets were evaluated that contained 0, 5, 10, or 15% HPF. Fingerling Channel Catfish (mean ± SD initial weight was 47.5 ± 2.2 g) were stocked into twenty 0.04-ha earthen ponds at a rate of 14,830 fish/ha. Fish were fed once daily to apparent satiation for 140 d. No significant differences were observed for weight gain, feed conversion ratio (FCR), and survival among fish fed various levels of HPF. There were also no significant differences in net yield of fish fed diets containing 0, 5, and 10% HPF, but net yield of fish fed a diet containing 15% HPF was significantly lower than that of fish fed the control diet. Fish on diets containing 5% HPF and above were fed significantly less feed than fish fed the control diet. Regression analysis showed that total amount of diet fed, net yield, and weight gain decreased linearly as dietary HPF levels increased. Based on weight gain and net yield data, 5% HPF with supplemental lysine may be used in Channel Catfish diets without marked impact on fish growth performance. However, carcass and fillet yield were significantly reduced in fish fed diets containing 5% HPF and higher. Fillet protein generally decreased and fillet fat increased with increasing dietary HPF levels. Received July 18, 2012; accepted September 12, 2012 [ABSTRACT FROM PUBLISHER]

Effects of high summer temperatures on Channel CatfishIctalurus punctatusare 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 [ABSTRACT FROM PUBLISHER]

Fish culturists strive to efficiently transfer energy from manufactured feed to the fish crop while minimizing adverse impacts on the environment and water quality. In this study, we sought to improve production of age-1 Channel CatfishIctalurus punctatusby testing the effects of full (3% of body weight [BW]/d) and reduced (1% BW/d) feeding rates on fish diets, growth, and survival; lower-trophic-level dynamics; and water quality in earthen ponds. Fish survival was similar between feeding treatments, although length, weight, and yield at harvest were lower for 1% BW/d ponds. Using stable N and C isotopes, we found that the percent contribution of natural prey to Channel Catfish tissue growth was higher for 1% BW/d ponds (median = 74%) than for 3% BW/d ponds (55%). In both feeding treatments, small fish (those with initial BWs < 15 g) had variable diets that included both natural prey and feed, whereas all of the larger fish (>15 g) depended mainly on feed for growth. Reducing the feeding rate decreased neither plankton abundances nor nutrient concentrations in ponds, but it did increase dissolved oxygen levels. We recommend that managers carefully consider the ecological role of feed in ponds and the usage of feed by fish to implement context-dependent sustainable feeding methods. For example, implementing the reduced feeding rate of 1% BW/d may increase the efficiency of producing Channel Catfish at sufficient sizes for stocking into natural waters without reducing survival in the hatchery. Received May 24, 2012; accepted August 27, 2012 [ABSTRACT FROM PUBLISHER]

A 2-year study was conducted to evaluate two phases (phase 2: fingerling to stocker; phase 3: stocker to grow out) of a three-phase modular production system for Channel CatfishIctalurus punctatusin commercial-scale ponds. Fingerlings (mean = 14.3 kg/1,000 fish; 11.9 cm TL) were stocked into each of six 1.62-ha earthen ponds at a density of 123,500 fish/ha and were fed a 35% crude protein floating feed daily to satiation. After 142 d, the mean weight of harvested stockers ranged from 108.9 to 158.8 g and survival ranged from 38.8% to 62.0%. These fish were subsequently stocked (at either 12,350 or 16,055 fish/ha) into 1.62-ha ponds for grow out to food-size fish (≥567.5 kg) and were fed a 35% crude protein floating feed to satiation. A partial (selective) harvest was conducted at 105–130 d poststocking by using an in-pond grader, and a final harvest was conducted at 207–245 d poststocking. Combined production means were 7,124 kg/ha for the 12,350-fish/ha treatment and 7,210 kg/ha for the 16,055-fish/ha treatment. Survival (range = 84.3–105.5%) and feed conversion ratios (range = 2.25–2.65) were not significantly different. Mean weight (659.5 g) and length (41.8 cm) of fish harvested from the 12,350-fish/ha treatment ponds were significantly greater than those of fish harvested from the 16,055-fish/ha treatment (474.8 g; 38.4 cm). Cost of producing a 142-g stocker was $0.409. For the economic analysis, phase-2 production area was based on producing sufficient stockers for all phase-3 ponds within a representative 445-ha operation. Enterprise budgets were developed for the 12,350- and 16,055-fish/ha treatments; the incomes above variable cost were $1,450 and $108 per hectare, respectively, and net returns to land were $399 and −$943 per hectare, respectively. Low survival in phase-2 stocker production reduced the returns. The three-phase modular system should provide additional management benefits that were not valued in this analysis. Received October 13, 2011; accepted August 13, 2012 [ABSTRACT FROM PUBLISHER]

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. [ABSTRACT FROM AUTHOR]

A personal narrative is presented in which the author discusses his experience of catfishing with his family on Pacolet River in South Carolina as a youth and includes a brief overview of the region's and his family's history.

The article focuses on noodling which is also called as handfishing, cooning or hogging in the U.S. It mentions that noodling has no recorded history but only few photos of Native Americans holding up fish. Bradley Beesley, director of Okie Noodling and Okie Noodling 2 fish catching tournament, says that most of the men he has touched are in their forties who are also taught by their fathers who are in their seventies.

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The article determines the successful induction of meiotic gynogenesis in Wels catfish through the heterologous sperm of DNA inactivated-grass carp. The microsatellite DNA analysis confirms the successful induction of meiotic gynogenesis. It shows the maternal inheritance in gynogenetic offspring. It points out that the application of active nucleoli counting analysis verified the gynogenetic offspring ploidy. It discovers that the application of ultraviolet (UV)-irradiation was optimal for the DNA inactivation of the sperm.

Hybrid catfish, Heterobranchus longifilus ♂ x Clarias gariepinus ♀ (mean total length, 29.96±2.23 cm, SD; mean weight, 207.83±12.63g SD) were exposed individually in quadruplicate to 40l of sublethal aqueous extracts of Lepidagathis alopecuroides (0.25, 0.50, 0.75, 1.00, 1.25 and a control, 0.0mg/l) for 21 days in a daily static renewal bioassay. The liver, kidney, gill and muscle tissues where then assayed for enzymes activities. The activities of AST and ALT in the liver were most inhibited at 0.75mg/l, AST activity was inhibited in all the exposure concentrations below the control value, (p<0.05). Generally ALT activity was inhibited. The activities of AST and ALT in the kidney were generally retarded below control values. Activities of AST and ALT declined in gill tissues below the control values. ALP activity was generally enhanced in the liver, kidney and gill of exposed fish. The activities of AST and ALP in the muscle were mostly enhanced at 1.25mg/l, but was ALP inhibition at 0.50 and 0.75mg/l. Although the bio-indicator enzymes could be used for monitoring the toxic effects of the plant in the fish species this will depend on the exposure levels and organs of choice. [ABSTRACT FROM AUTHOR]

This qualitative research, based on interviews and participant observation conducted between 2005 and 2008, examines patterned variations in the masculine identity work of Missouri men noodlers between the ages of 18 and 90. Noodling or hand fishing is a folk tradition that involves submerging in lakes or rivers and feeling under the banks for holes where large catfish are spawning. The fingers are used as a lure to catch the catfish by hand. Noodling is contested terrain in which men with differing age cohort-based identity needs emphasize certain aspects from the tool kit of noodling culture over others. Cohort differences are shaped by structural changes affecting different age cohorts in varied ways. [ABSTRACT FROM AUTHOR]

This study describes hand fishers and their unique method of harvesting catfish. Although the Missouri state legislature outlawed hand fishing in 1919, a segment of anglers still practice this sport. In 2000, some of the participants met with officials from the Missouri Department of Conservation and requested a legalized hand fishing season. Their petition was denied, partly due to the lack of information about this activity. A mail-back questionnaire was administered to hand fishers in Missouri and nearly 56% of them responded to the survey. Results indicated that hand fishers were primarily males who lived in rural areas of the state. Participants went hand fishing about 13 times per year (x = 12.5) and caught approximately 10 catfish annually (x = 10.4). A profile of hand fishers was developed and sent to decision-makers to assist them with policy formation. Since hand fishers reported numerous ways of catching catfish (only 15% used their hands exclusively), a better description of these participants is needed. [ABSTRACT FROM AUTHOR]

Total mercury (Hg) concentrations were determined in fillet tissue of sport fish captured in the Sacramento–San Joaquin River Delta and surrounding tributaries, a region particularly impacted by historic gold and mercury mining activity. In 1999 and 2000, mercury concentrations were measured in 767 samples from ten fish species. Largemouth bass (Micropterus salmoides), the primary target species, exhibited a median Hg concentration of 0.53 μg g−1 (N =406). Only 23 largemouth bass (6%) were below a 0.12 μg g−1 threshold corresponding to a 4 meals per month safe consumption limit. Most of the largemouth bass (222 fish, or 55% of the sample) were above a 0.47 μg g−1 threshold corresponding to a 1 meal per month consumption limit. Striped bass (Morone saxatilis), channel catfish (Ictalurus punctatus), white catfish (Ameirus catus), and Sacramento pikeminnow (Ptychocheilus grandis) also had relatively high concentrations, with 31% or more of samples above 0.47 μg g−1. Concentrations were lowest in redear (Lepomis microlophus) and bluegill (Lepomis macrochirus) sunfish, with most samples below 0.12 μg g−1, suggesting that targeting these species for sport and subsistence fishing may reduce human dietary exposure to Hg in the region. An improved method of analysis of covariance was performed to evaluate spatial variation in Hg in largemouth bass captured in 2000, while accounting for variability in fish length. Using this approach, Hg concentrations were significantly elevated in the Feather River, northern Delta, lower Cosumnes River, and San Joaquin River regions. In spite of elevated Hg concentrations on all of its tributaries, the central Delta had concentrations that were low both in comparison to safe consumption guidelines and to other locations. [Copyright &y& Elsevier]

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 that net returns were sensitive to changes in the key parameters of the model (such as interest rates, feed conversion ratios, survival rates, catfish prices, harvesting costs, and the availability of operating capital), whereas the optimal size of fingerlings to understock was robust to variations in the model's parameters. [ABSTRACT FROM AUTHOR]

The testes of the catfish Conorhynchus conirostris (n=67) from the São Francisco River, Minas Gerais, Brazil were of the fringed type, similar to those of some Pimelodidae. The germ, Sertoli and Leydig cells showed characteristics which are general for all vertebrates although the spermatozoa had a peculiar morphology, with an ovoid head without an acrosome, inverted U-shaped nucleus, a short midpiece and a long tail, typical of teleosts showing external fertilization. The spermatic duct and genital papilla performed a secretory function. [ABSTRACT FROM AUTHOR]

This study analyzed the contribution of the catfish industry to the economy of Chicot County, Arkansas, using an input-output model. The objective was to quantify the economic contribution of the industry in terms of creating new dollars, jobs, and income to the local community. Mail surveys and personal interviews were used to collect data from catfish farmers, processors and other businesses related to the catfish industry. For farmers, the information solicited included production and marketing costs, sales and employment. Out of approximately 85 questionnaires administered to catfish farms, 44 usable questionnaires were obtained for a response rate of 52%. Businesses directly related to the catfish industry provided information on employment and sales and included: processors, seiners and haulers, pond builders, tractor and equipment dealers, and feed bin manufacturers. Other businesses with indirect ties to the catfish industry included: input supply companies, banks, fertilizer and chemical companies, auto shops, electricians, and bookkeeping firms. The survey data were used to modify the IMPLAN database for Chicot County to reflect the 2001 level of catfish production, processing and services available to support the industry. This database was then used to estimate the economic impact of the industry to the county's economy. In 2001, the 85 catfish farmers in the county operated about 7,859 ha (19,500 acres). The farm-gate value of catfish production exceeded $63 million. Employment on catfish farms was approximately 510. In addition, 59 other businesses depended on the catfish industry. Results indicated that total employment created in Chicot County by businesses directly or indirectly involved with the catfish industry was 2,665 jobs. This represented 48% of all employment in Chicot County. Total tax revenue (federal, state, and local taxes) generated from both direct and indirect catfish businesses was $22 million. Combined, the total economic impact of the catfish industry in Chicot County, including direct, indirect and induced effects, was over $384 million. The output multiplier calculated for live catfish production was 6.05. Thus, each $1 of earnings by catfish farms generated $6.05 total economic activity in the Chicot County economy. If current economic difficulties should result in contractions in catfish acreage in Chicot County by 10%, unemployment rates would increase by 2%. This study demonstrates the importance of the catfish industry to the economy of Chicot County. [ABSTRACT FROM PUBLISHER]