Large Channel Catfish Research Articles

Evaluation of Recently Implemented Harvest Regulations in a Data‐Limited Catfish Fishery with Bayesian Estimation

AbstractIn 2015, the Illinois Department of Natural Resources changed size and harvest limits for catfishes (Blue Catfish Ictalurus furcatus, Flathead Catfish Pylodictis olivaris, and Channel Catfish I. punctatus) in the lower Ohio River to match those of neighboring states. The new regulations imposed a daily limit of one 88.9‐cm (35‐in) or larger Blue or Flathead Catfish per fisher, one 71.1‐cm (28‐in) or larger Channel Catfish per fisher, and a 33.0‐cm (13‐in) minimum length limit for all species, with no harvest restrictions between these limit lengths (permissive slot). When these management regulations were implemented, potential efficacy was unknown. The goal of this study was to evaluate the potential effects of these regulations using the limited data for baseline demographic parameters. Bayesian modeling was used to estimate growth and mortality because of the ability to estimate derived functions of parameters and associated uncertainty (as credible intervals). Yield‐per‐recruit (YPR) modeling was used to estimate and evaluate the fishing mortality rates (F) that would induce growth overfishing (FMAX) and the yield at FMAX (YPRMAX) for three management scenarios: no harvest restrictions (former regulation), a 33.0‐cm minimum length limit, and the enacted permissive slot limits. Model results suggested that catfish stocks are unlikely to benefit from current regulations given the near‐complete overlap of YPRMAX credible intervals for all estimable scenarios and the small significant differences (1–3%) based on FMAX between the most permissive and most restrictive scenarios. Despite the existence of significant differences in FMAX, they are likely biologically irrelevant based on the life histories of these species. Although modeling results suggested that the implemented harvest regulations will not likely affect catfish population demographics or fishery yield in the lower Ohio River, a post hoc evaluation examining the accuracy of these predictions is needed and would improve the accuracy and precision of parameter estimates.

Genetic Evidence of Isolation by Distance and Impact of Impoundments on Genetic Diversity of Riverine Channel Catfish

AbstractThis study used microsatellite loci to provide evidence of isolation by distance and an effect of artificial impoundments on the genetic diversity of Channel Catfish Ictalurus punctatus from the Wabash and Ohio rivers. The Wabash River is the longest free‐flowing river east of the Mississippi River in the USA, and the Ohio River is highly impounded, yet both rivers support large Channel Catfish fisheries. There was a significant positive relationship between genetic differentiation and geographic distance indicating isolation by distance. Clustering with the programs, STRUCTURE and GENELAND, and principal component analysis revealed multiple genetic clusters, and several sites had results consistent with adults existing as mixtures of genetic groups. These results suggest that the rate of straying among reproductive sites or dispersal is dependent on geographic distance. Channel Catfish from the unimpounded Wabash River had higher genetic diversity (Ho and He) than that from the impounded Ohio River. The impoundments had discordant effects on genetic structure; two site comparisons across a dam were differentiated more strongly than would be expected by geographic distance, whereas genetic differentiation was not detected in another comparison across a dam. Thus, the effect of artificial impoundments on Channel Catfish biology may be affected by river or site‐specific characteristics, and the presence of genetic differentiation may be minimized by large population sizes.

Contact Selectivity for Four Fish Species Sampled with North American Standard Gill Nets

AbstractThe American Fisheries Society (AFS) has recommended standard gears and methods for collecting North American freshwater fish data, but selectivity of these gears, including gill nets, is poorly described for most species. We calculated contact selectivity for species commonly collected with AFS standard gill nets in lakes and reservoirs of North America, including Black Bullhead Ameiurus melas, Channel Catfish Ictalurus punctatus, Walleye Sander vitreus, and Yellow Perch Perca flavescens. The normal selectivity curve provided the best fit to empirical catch data for all species. Inclusion of a tangle factor improved model fit for Black Bullhead, Channel Catfish, and Walleye, indicating that tangling is an important means of capture for these species. Channel Catfish were more susceptible to tangling than the closely related Black Bullhead, likely because larger Channel Catfish are more vulnerable to tangling by spines in the smallest meshes, whereas Black Bullhead in the same meshes were wedged. Failure to include a tangle factor for Channel Catfish and Walleye would have underestimated peak length of captured fish by 80 and 40 mm, respectively. Tangling was not an important factor in Yellow Perch capture. Total selectivity curves for each species captured with the AFS standard gill net were calculated, and relative selectivity values are provided as correction factors for size‐selectivity bias. Our correction factors and modeled selectivity curves for Channel Catfish, Walleye, and Yellow Perch corroborate previous studies that modeled selectivity of the AFS standard gill net for Channel Catfish, Walleye, and Yellow Perch, but our study provided novel information on Black Bullhead. Improved selectivity information for the AFS standard gill net may help to promote further voluntary adoption of AFS standard gears and methods.Received July 15, 2016; accepted October 24, 2016 Published online January 3, 2017

Effect of Stocking Large Channel Catfish in a Biofloc Technology Production System on Production and Incidence of Common Microbial Off-Flavor Compounds

Density-dependent production and incidence of common microbial off-flavors caused by geosmin and 2-methylisoborneol were investigated in an outdoor biofloc technology production system stocked with stockersize (217 g/fish) channel catfish at 1.4, 2.1, or 2.8 kg/m3. Individual weight at harvest ranged from 658-829 g/fish and was inversely related to stocking density. Net fish yield ranged from 3.8-5.4 kg/m3, and increased linearly as stocking density increased. The percentage of sub-marketable fish (<0.57 kg/fish) increased linearly with increasing stocking rate. Mean total feed consumption increased linearly with stocking density, but feed consumed per fish was inversely related to stocking density. Feed conversion ratio did not differ significantly among treatments. Concentrations of geosmin and 2-methylisoborneol in biofloc water were low throughout the study. All sampled fillets contained low concentrations of geosmin and 2-methylisobornel, but these fillets likely would not be deemed as having objectionable “earthy” or “musty” off-flavors when evaluated by trained processing plant flavor testers because of the low concentrations present. Data from this study combined with data from our two previous studies provide strong evidence that the incidence of geosmin- and 2-methylisoborneol-related off-flavor episodes is low in the BFT production system.

Biological Feasibility and Costs of Production of Large Channel Catfish, Ictalurus punctatus, for a Specialty Product Market

Restaurant patrons, particularly in upscale locations, increasingly prefer entrées developed from portions cut from fillets larger than those currently sold by the US catfish, Ictalurus punctatus, industry. A production study evaluated the feasibility of producing the necessary size (1.6 kg) of catfish. Twelve 0.1‐ha earthen ponds were stocked with 0.363‐kg channel catfish at 2500 (low); 5000 (medium); or 7500 (high) fish/ha, with four replicates. Mean individual weight at harvest exceeded the mean target weight (1.6 kg) at the two lower densities, and the minimum target weight (1.36 kg) at the highest density. Percentages of fish (by weight) that did not meet the minimum weight required were: 1, 5, and 18%, in the low, medium, and high density treatments, respectively. Yields were significantly greater at higher densities (P &lt; 0.05). Costs of production at the two higher densities were 4 to 7% higher than in the traditional multiple‐batch system, but increased to 51% at the lowest density. Results demonstrated the biological feasibility of producing channel catfish of a mean weight of 1.6 kg. Economic feasibility depends on (1) the price premium paid and (2) development of a market for fish sizes between current acceptable maximum sizes accepted and 1.36 kg.

Competitive Feeding Interactions between Small and Large Channel Catfish Cultured in Mixed-Size Populations

Abstract Production of channel catfish Ictalurus punctatus in ponds may be affected by competitive feeding interactions between large fish that remain after incomplete harvest and small fish that are stocked following harvest. To study the effect of channel catfish size on competition for feed, we examined consumption by feeding colored feeds sequentially to fish held either in raceways or ponds. Colored feeds were created by adding pigments to a floating catfish feed (35% crude protein). A preliminary study showed no significant differences in consumption of the colored feeds, suggesting no selection for color. Following a 2-week conditioning period in the raceway or pond, mixed-size fish populations were fed a red and green feed sequentially at 1% body weight for each. Fish were subsequently sacrificed and red and green colored feeds were separated from the stomach contents. In the raceway, small fish consumed a significantly higher mean percentage of red feed (59.3%) than large fish (50.4%). In an unre...

The Influence of Feeding Time and Frequency on the Growth, Survival, Feed Conversion, and Body Composition of Channel Catfish, Ictalurus punctatus, Cultured in a Three-Tier, Closed, Recirculating Raceway System

ABSTRACT Studies were conducted over two years to establish a feeding strategy which would optimize growth, feed conversion, and survival of channel catfish, Ictalurus punctatus, in three-tier, closed, recirculating raceway systems. Small and large fingerling channel catfish (mean weights of 26 g/fish and 219 g/fish, respectively) were stocked into culture systems and maintained for 70 and 120 days, respectively. Three feeding treatments were examined in this study. The treatments were: channel catfish fed 3% of body weight once daily at 0800; channel catfish fed 3% of body weight once daily at 1700; and channel catfish fed 1.5% of body weight twice daily at 0800 and 1700. Raceway effluent total ammonia nitrogen (TAN) levels 6.5 hours post-feeding for small and large channel catfish in the single feeding treatments were twice (P<0.05) those of channel catfish receiving the daily ration over two feedings. The feeding treatments examined were found not to significantly influence the response variables of the smaller channel catfish (P >0.05). Mean weight gain of the larger channel catfish in the treatment receiving two daily feedings was 10 to 15% greater than channel catfish fed once daily (P< 0.05). Additionally, increased feeding frequency significantly improved specific growth rate and feed conversion rate of channel catfish in the multipass systems (P< 0.05). Body composition was unaltered by feeding regimens (P >0.05). The results of the current study indicate that feeding small fingerling channel catfish (26 g) a total ration once daily, and larger grow-out channel catfish (200 g) twice daily, would be a useful culture strategy in a multipass, closed, recirculating raceway system.

The Influence of Water Velocity on the Growth, Survival, Feed Conversion, and Condition Factor of Fingerling Channel Catfish

Two experiments (105 days each) were conducted to examine the influence of water velocity on the growth, survival, feed conversion, and condition factor of fingerling channel catfish, Ictalurus punctatus. In the first experiment, no significant digerences (P > 0.05) were found for channel catfish (3.1 g initial mean weight) raised in tanks with water velocities of 0, 2, and 6 cm/second. Weight gain averaged 23.6 g/fish; specific growth ranged from 2.10 to 2.20%/day; survival averaged over 98%; feed conversion ranged from 1.02 to 1.06; and mean condition factor was 0.0082. In the second experiment, no significant differences were found for larger channel catfish (73.2 g initial mean weight) raised in tanks with water velocities of 0, 2, and 6 cm/second. Weight gain averaged 132.6 g/fish; specific growth ranged from 0.95 to 1.00%/day, mean survival was 97%; feed conversion averaged from 1.84 to 1.98; and mean condition factor was 0.0095. These results indicate that channel catfish can be raised in tanks whe...

Survival of Paddlefish Fingerlings Stocked with Large Channel Catfish

Abstract Fingerling paddlefish (Polyodon spathula; 9–15 cm total length, TL) were stocked with two densities of large channel catfish (Ictalurus punctatus; >38 cm TL). No paddlefish were recovered from any of the six ponds at harvest, probably due to predation by the large channel catfish. Advanced paddlefish fingerlings (25–30 cm TL) may be required for polyculture in ponds that contain large channel catfish.

Apparent Inability of Channel Catfish to Utilize Dietary Mono- and Disaccharides as Energy Sources

Purified diets containing equivalent amounts of glucose, maltose, fructose, sucrose, corn starch and dextrin were fed to fingerling channel catfish (Icatalurus punctatus) to compare the growth responses to these various carbohydrates. The best growth response was achieved with dextrin and the next best with corn starch. Fish grew at the same rate when glucose, maltose or sucrose was the only dietary carbohydrate source. Dietary fructose resulted in the lowest growth rate. Feed efficiency and percent retained energy values followed the same pattern as growth rates. These data suggest that the catfish is apparently unable to utilize dietary mono- and disaccharides as energy sources. Oral carbohydrate tolerance tests using glucose, maltose, fructose, sucrose and dextrin were conducted with larger channel catfish. Oral glucose and maltose resulted in a, persistent hyperglycemia indicative of a diabetic-like status. Fructose appeared to be poorly absorbed from the intestinal tract and did not appear to be converted to glucose. Oral administration of sucrose was followed by a gradual increase in plasma glucose, with no detectable fructose being absorbed until the 6-h period. Oral dextrin resulted in less than a twofold increase in plasma glucose, which remained constant from 2 to 4 h after administration and then declined. These observations are consistent with the hypothesis that certain fishes, including the channel catfish, resemble diabetic animals by having insufficient insulin for maximum carbohydrate utilization.

Increasing Size of Fingerling Channel Catfish by Supplemental Feeding

Many state conservation departments have been stocking fingerling channel catfish, Ictalurus punctatus (Rafinesque), in farm ponds and lakes. As a result, this species has become a favorite sport fish in many waters of central and southern United States. Swingle (1958) indicated the feasibility of growing fingerling channel catfish to marketable size in fertilized and unfertilized ponds by supplemental feeding of dry pelleted feeds. Prather (1959) stocked a 12.4-acre lake with fingerling channel catfish at 2,000 per acre and fed pelleted feed. Fishermen harvested 1,295.5 pounds of fish per acre or 62 percent of the total production. An additional 391.2 pounds per acre was obtained when the lake was drained. Tiemeier and Elder (1960) reported on the recovery of stunted channel catfish with a supplemental feeding program and Tiemeier (1962 in press) discussed results of preliminary feeding experiments on fingerling channel catfish. The present paper compares results in 1960 and 1961 of feeding experiments. It has not been definitely established why some clear lakes in Kansas have not produced enough channel catfish by natural spawning to provide continued good fishing. Presumably few small fish escape their predators. Stocking fingerling channel catfish in clear lakes that contain some large channel catfish and populations of other fishes has not improved the channel catfish harvest because the fingerling fish did not survive.