Harvest Of Catfish Research Articles

PILAT (FRESHWATER CATFISH FARMING) IN AN EFFORT TO OPTIMIZE FACILITIES AND IMPROVE THE ECONOMY AT NURUL AMANAH BOARDING SCHOOL

Background: Nurul Amanah Islamic boarding school has adequate catfish production facilities, including 12 biofloc catfish ponds, plenty of water, seed and feed wholesalers near the pesantren, and fish collectors ready to sell the catfish harvest. The facilities are still not being used properly. Objective: To establish the economic potential of catfish culture, as well as how to manage and spawn catfish in order to carry out catfish cultivation sustainably. Method: Education is provided by presenting maintenance procedures, feed management that uses maggots as feed support, and proper spawning techniques that identify catfish gonads based on maturity level. The practice of catfish cultivation is carried out by forming the organizational structure of the catfish cultivation board, as well as a rotating picket schedule, the practice of spawning mature catfish by separating them in a concrete pool and giving fibers as a place for catfish to lay eggs later, and after laying eggs within 24 hours, the fibers are taken and separated from the mother to avoid the mother eating eggs. The next practice is to feed catfish on a regular basis in the morning and evening, using maggot as a mixture. Results: The training of freshwater catfish cultivation, it can re-optimize the function of the facilities that are already available. Conclusion: The initiative has been effectively implemented at Pondok Pesantren Nurul Amanah.

Bussiness Management System Of Catfish Cultivation Using Fuzzy Inference System Tsukamoto Methods

Catfish is a type of freshwater fish that is in great demand among people because it has high nutritional value. The high demand for catfish on the market is a promising business opportunity. The relatively fast maintenance period makes this cultivation much in demand. Management of a catfish farming business requires good strategy and planning so that the business process can provide optimal profits. Appropriate management practices, good planning can predict crop yields with minimal error rates. Based on past data from catfish farming businesses, catfish pond production results are influenced by several factors including pond area, number of seeds, and amount of feed. The catfish cultivation management system produces predictions of catfish harvest but ignores weather conditions, natural disasters and infectious diseases. The method used in crop yield prediction management is the Tsukamoto Fuzzy inference system. The Tsukamoto method applies monotonous reasoning and rules are built using expert knowledge, enabling the system to be able to conclude and manage predictions of catfish harvest based on data regarding pond size, number of seeds and amount of feed. System testing using 10 data shows prediction results obtained through manual calculations and system calculations, resulting in identical results. Further testing uses the white box method to ensure that the data implemented in the Tsukamoto fuzzy management system accurately produces logical decisions. Hence, it can be concluded that the management system using the Tsukamoto method is able to show effective performance in predicting harvest results based on data on pond area, number of seeds and amount of feed consumption. This management system is expected to be able to provide recommendations for catfish cultivation business planning for the community.

Implementation Internet of Things for Feeding Catfish Water Quality Analysis Using Linear Regression and K-Nearest Neighbor

Cultivation of catfish (Clarias Gariepinus) is a promising business field and also a very productive activity because public interest in catfish is high. This factor is observed by market demand for catfish which is increasing from year to year. In catfish farming, you must pay attention to the acidity of the water (pH), temperature, and oxygen levels, which can change if too much feed is given. This can cause catfish seedlings to die and affect the catfish harvest. Catfish farmers often provide excessive food which causes many catfish seeds to die. This research will conduct a study on an Internet Of Things technology that can be used to monitor the acidity level in water pH, temperature, and oxygen levels as well as feed fish. The Internet of Things is very influential for monitoring the quality of catfish ponds by distributing information data resulting from sensor monitoring. The data obtained will be predicted for water quality in the pond by implementing a Linear Regression method. Furthermore, the acquisition of data from the predictions that have been carried out will be processed again to go to the next phase, namely classifying with the K-Nearest Neighbor algorithm method to carry out the identification phase of water types based on the nearest neighbors. This prediction is used to anticipate and notify catfish farmers through applications if there is a water acidity level (pH), temperature, and oxygen and feed levels that have run out

Ekonomi Kreatif Dengan Program Warung Keluarga Melalui Budidaya Ikan Dalam Ember

Budikdamber or known as Fish Cultivation in a Bucket is a form of creative economy business that can be done in a family in order to fulfill some basic needs. This research is a Research and Development, which is to continue and modify various findings and problems in the implementation of Warung Keluarga through Budikdamber. The discussion and report models use a qualitative approach. This research was conducted in several places in Boyolali in 2020, 2021, and early 2022. The results show that the Warung Keluarga program through Budikdamber can be done easily, does not require a large space, large capital, and is side-by-side. However, it will result in a significant economic increase in meeting the basic needs of the family, and can be used as a business opportunity if taken seriously. The Budikdamber program can be developed through the media of drums, Pengaron, Plastic Sheeting, and Permanent Pools. Catfish harvest success rate 75% - 95%. The success for the types of catfish and gourami can reach 90% - 98%.

Penerapan Teknologi Pembuatan Pakan Ikan Berbahan Baku Ampas Tahu untuk Peningkatan Kualitas Ikan Lele dan Ekonomi Usaha Ikan Lele Rumahan di Kelurahan Asam Kumbang

The purpose of this research is to apply the technology of making fish from tofu dregs to improve the quality of catfish and the economy of home-based catfish business in Asam Village. The tofu dregs used were obtained from the tofu and tempeh Home Industry in the Asam Kumbang Village area. The composition of the raw material for making catfish feed used is 80% tofu dregs + 20% shrimp head. The catfish feed that has been made is then tested for characteristics, namely protein 43.87%, fat 25.04%, carbohydrates 68, 73%. Observations were made for 42 days on catfish that were given fish feed from tofu dregs or those that were not given. The results obtained during 42 days of feeding fish from tofu waste with observations made on days 7, 14, 21, 28, 35 and 42 with the average weight (weight) of each fish (grams): 21, 58 , 92, 147, 193 and 240. Catfish that are ready to harvest have 5-6 tails per kg with the physical characteristics of large/fat fish. The cost of purchasing catfish seeds is Rp. 25 and the cost of making fish feed from tofu dregs for availability for 42 days (harvest mass) is Rp. 12,250. The catfish harvest period per kg is 5 fish and the selling price to the catfish seller is IDR 20,000 / kg. The catfish harvest for 42 days was 5 kg with a total selling price of Rp. 100.00. So the profit obtained from the sale of 4 kg of catfish is Rp. 87,750 or Rp. 3,500/head.Â

Growth performance and economic analysis of hybrid Catfish (Channel Catfish Ictalurus punctatus ♀ × Blue Catfish, I. furcatus ♂) and Channel Catfish (I. punctatus) produced in floating In-Pond Raceway System

The In-Pond Raceway System (IPRS) is a promising technology that addresses issues that have troubled the U.S. catfish industry for decades. This case study evaluated hybrid and Channel Catfish growth performance and economic efficiency in two sizes of floating IPRS units using two stocking density approaches. Each IPRS unit was placed into a 0.4 ha pond. In year 1, hybrids were raised in the IPRS and net yields ranged from 12,848 kg/ha to 15,330 kg/ha, with survival from 75%–97%. Individual hybrid Catfish harvest weights ranged from 671 to 825 g (268 days of production) with 90–97% of the fish in the premium size class (0.454–1.82 kg) and had a feed conversion ratio (FCR) of 1.50–1.64. In year 2, Channel Catfish were raised in the IPRS, with net yields from 7,416 to 9,819 kg/ha, and survival from 67% to 94%. The average Channel Catfish weight at harvest ranged from 525 to 861 g (217 days of production) with 79–94% in the premium size class and a FCR range from 1.78 to 2.40. Total investment for each 63 m3 raceway was US$34,570 in year 1, plus an additional US$2,280 for year 2. Total investment for each 45 m3 raceway was US$14,949 in year 1, plus an additional US$2,280 for year 2. Income above variable cost was positive for all four raceways in year 1, though negative for large raceways when fixed costs were included. In year 2, all four raceways had negative incomes above variable costs and net returns. This IPRS study showed better performance and economic results for hybrid over Channel Catfish and further research is needed to assess more efficient management strategies for Channel Catfish and, also, to lower initial investment and production costs.

Using Creel Data to Evaluate Blue and Channel Catfish Aggregate Harvest Regulations for Texas Reservoirs

AbstractThe Texas Parks and Wildlife Department’s strategic management plan for catfishes (Ictaluridae) called for the development of alternative harvest regulations for Blue Catfish Ictalurus furcatus and Channel Catfish I. punctatus. Angler harvest of these species in most Texas reservoirs has been regulated using a 305‐mm minimum length limit (MLL) and a 25‐fish aggregate daily bag limit (DBL) since 1995. Using existing creel data collected in 2003–2018 at 86 Texas reservoirs managed under this statewide harvest regulation, we examined Blue and Channel Catfish harvest size structure and composition, percent release of legally harvestable‐size fish, and harvest density (number and biomass). Additionally, for reservoirs having long‐term creel data, we evaluated temporal change in percent release of legally harvestable‐size fish and harvest size structure, and we estimated the impact of alternative harvest regulations by using a theoretical harvest reduction (THR) model. Channel Catfish were the predominant species harvested (>75% of harvest) in 63% of the reservoirs. Harvest size structures of Blue and Channel catfish differed, but the difference in percent harvest of fish smaller than 406 mm was negligible (52% and 48%, respectively). Percent release of legally harvestable‐size fish (≥305 mm) was low at most reservoirs (median = 13%). Total number of catfish harvested per hectare per quarter (HHQ) ranged widely (0.0–11.3) but was less than 1.0 at 58% of reservoirs. Harvest size structure was truncated over time coincident with a high harvest level (HHQ > 3.0) at two of four reservoirs with long‐term data, suggesting growth overfishing. The THR model revealed that increases in MLL resulted in variable harvest reductions among reservoirs and that removal of the 305‐mm MLL could increase harvest by 6–39%. Additionally, we found that length‐graduated DBLs would have a negligible impact on reducing the harvest of larger fish. We suggest that MLLs are not necessary for most Texas catfish fisheries and that a 356‐mm MLL may be appropriate for high‐harvest fisheries.

Ergothioneine accumulated in the catfish muscle by supplementation of Flammulina velutipes extract prevents lipid oxidation, improves color stability, and limits soft structure of the fillet during frozen storage

This study aimed to evaluate whether ergothioneine (ESH) accumulated in catfish muscle affected to fillet quality during frozen storage. The fish after fed by feed supplemented 0 to 15% concentrated extract (CE) from Flammulina velutipes for 30 days were filleted and stored at −18 ± 0.2°C for 90 days. The results show that with 10% CE, the highest accumulation of ESH in fish muscle was 21.02 mg/Kg. During preservation, ESH decreased gradually with DPPH. Peroxide and FFA were the lowest value at 1.09 meq/Kg and 0.35% on day 90, respectively. L* achieved lower while a* and b* values were quite stable during the first 60 days. The a* dropped slightly, but the b* and ∆E increased slowest from days 60 to 90. The muscle hardness was more stable during storage. Therefore, high accumulation of ESH in catfish muscle could prevent lipid oxidation, improving color stability, and limit soft structure during frozen storage. Novelty impact statement The Pangasius processing industry in the Mekong Delta depends on the catfish harvest time point and export demand, so it usually needs 1 to 3 months preservation in the freezer in which the quality of the fillet may be changed. The results from this study indicated that the highest ESH accumulation corresponding to 10% CE of F. velutipes supplemented with feed for 30 days feeding showed the most effectiveness during 90 days preservation in terms of limiting lipid oxidation, preventing discoloration, and making the fish structure less soft after thawing from frozen storage. Therefore, the supplementation of F. velutipes during feeding shows a great solution for improving catfish fillet quality during frozen storage.

STRATEGI MARKETING 4.0 PADA PASCA PANEN IKAN LELE DI DESA CURUG KECAMATAN GUNUNG SINDUR KABUPATEN BOGOR

Community Service Program, especially the Appropriate Technology Application Program (PPTTG) in the village of Curug, Gunung Sindur District, Bogor Regency, which involves the community, especially catfish farmers, in an effort to increase community economic empowerment and marketing of catfish farming crops. Since the occurrence of Covid-19 has become a problem and has had an impact on the business activities of catfish farmers in marketing the catfish harvest because the amount of catfish consumption needs has decreased due to the decreasing purchasing power of the people around the village of Curug, the price of catfish feed has tended to rise so this condition has add to the burden of new problems for the community. PPTTG program help catfish farmers in village Curug as partners to be able to market their catfish harvest through direct sales and digital (online) marketing so that economic income increases and is able to buy catfish feed at a reasonable price, provide training and business assistance. catfish. The solutions offered in dealing with partner problems in developing catfish marketing through websites and internet marketing 4.0, making dumplings from catfish, help establish a special cooperative for catfish farmers so that catfish farmers have a formal organization that can assist in capitalizing catfish farmer members, providing tools for catfish production. The results of the PPTTG are the establishment of cooperatives for catfish farmers, diversifying catfish products such as dumplings, online marketing of catfish (marketing strategy 4.0), and owning the copyright and production brand rights so that catfish farmers can run catfish farming more increased. As for the sustainability of this program, it is hoped that catfish farmers in the village of Curug can continue to maintain the potential of catfish business and increase economic income

Changes in recreational catfish Silurus glanis harvest rates between years 1986–2017 in Central Europe

The European catfish Silurus glanis is an important fish species in both commercial and recreational fisheries. Catfish is a spreading species that was reported to potentially benefit from increasing temperatures. The goal of this study was to estimate long-term changes in harvest rates of catfish in Central Europe. This study used individual mandatory angling logbooks collected by the Czech Fishing Union in the Czech Republic (Central Europe) over the course of years 1986–2017 (32 years) to assess harvest rates of catfish. This study discovered that harvest of catfish has been increasing over time. Moreover, rivers that previously showed zero harvested catfish are beginning to display higher harvest rates of catfish. Increasing average air temperature and angling effort in the study area have positively affected harvest rates of catfish. The increased harvest of catfish could not be reliably explained by intensive fish stocking. In conclusion, while other studies show that many fish species are negatively affected by human activities and therefore show decreased harvest rates, catfish angling seems to benefit from anthropogenic changes.

Angler Misidentification of Catfishes at Wilson Reservoir, Kansas

Catfish are an important part of the fishing experience for Kansas anglers. Channel and Flathead catfish have been commonly angled in Kansas waters throughout recorded history, but the statewide popularity of Blue Catfish has been a recent development. These three catfishes now share a much larger distribution than they did 20 years ago. Furthermore, the Blue Catfish is stocked for its trophy potential and, as such, is regulated more conservatively. These regulations vary from minimum-length limits to protected slot lengths and lower creel limits. Channel and Flathead catfish are regulated more liberally in Kansas. The recent Blue Catfish range expansion and varying harvest regulations among catfish species have increased concerns of fisheries managers regarding the ability of anglers to distinguish among the species. We presented anglers at Wilson Reservoir with live Blue and Channel catfish and quantified misidentification rates. We compared misidentification rates from participants with varying angling experience and catch-related attitudes. Anglers misidentified catfish 27.4% of the time despite their mean angling experience of 26.7 years, and rates of misidentification varied based on catch-related attitudes. Although not always intentional, there is significant potential for illegal harvest of catfish at Wilson Reservoir and, likely, statewide.

Impact of Integrated Farming of Water Chestnut and Cat Fish on Livelihood of Farmers in Seasonal Waterlogged Areas of Odisha

The paper has assessed the impact of integration of water chestnut cultivation with cat fish culture on livelihood of farmers in the seasonal waterlogged areas of Balasore district in Odisha. It has revealed an increase in production of water chestnut by 1.99 t/ha with an additional harvest of catfish to the extent of 0.78 tonnes, resulting in more than 50 per cent increase in the income of farmers. The study has observed that before adoption of technology, four out of five types of assets measuring the changes in livelihood of farm families were below the average level (barring social assets), which increased considerably after adoption of technology with highest gain in financial assets (41%), followed by physical assets (35%), social assets (31%) and human assets (29%). About 86 per cent farmers could be brought to above average level of living with the change in farming situation on adoption of water chestnut cultivation integrated with cat fish farming in Odisha. The developed package of practices for integrated farming of water chestnut and catfish has been adopted by the “CARE India” under their dissemination programme in tribal districts of Odisha.

Organic Carbon and Dissolved Oxygen Budgets for a Commercial‐Size, In‐pond Raceway System

AbstractIntensive production of ictalurid catfish in the USA has increased over the past several years, and a better understanding of the amount of organic carbon (OC) and dissolved oxygen (DO) in these culture environments is needed. Budgets for OC and DO were estimated over a production season (March to November) for an in‐pond raceway system for channel catfish, Ictalurus punctatus, and hybrid catfish (channel catfish × blue catfish, Ictalurus furcatus), with co‐culture of paddlefish, Polyodon spathula, and Nile tilapia, Oreochromis niloticus. Feed input ranged from 45 to 263 kg/ha/d with an overall average of 80 kg/ha/d. Production of each kilogram of live catfish required 1.5 kg of feed and released into the water 0.70 kg of OC, and led to the synthesis of an additional 3.36 kg of OC by photosynthesis. Consequently, production of 1 kg of live catfish resulted in 4.06 kg OC, and harvest of catfish accounted for only 29.5% of OC applied from the feed. Removal of OC increased to 34.3% with the additional harvest of paddlefish and tilapia. OC was consumed in respiration, and some OC accumulated in sediment. Total respiration within the system exceeded the DO produced by photosynthesis, while diffusion and mechanical aeration aided in maintaining suitable DO levels for fish production.

Approximate Water and Chemical Budgets for an Experimental, In‐pond Raceway System

There is increasing interest in intensive production of Ictalurid catfish in the United States and a better understanding of water quality dynamics in intensive culture is needed. Budgets for water, nitrogen, and phosphorus were estimated over a production season (March–November) for an In‐pond Raceway System for channel catfish, Ictalurus punctatus, and hybrid catfish, I. punctatus×I. furcatus, with co‐culture of paddlefish, Polyodon spathula, and Nile tilapia, Oreochromis niloticus. In addition to the rainfall and runoff, 70 cm of water was applied from a well to offset evaporation and seepage. Production of each kilogram of live catfish required 1.50 kg of feed and released 51.7 g nitrogen and 9.7 g phosphorus. Harvest of catfish accounted for 34.0% of nitrogen and 37.1% of phosphorus applied in feed. Seepage and overflow removed only small portions of nitrogen and phosphorus, while denitrification and ammonia volatilization removed large amounts of nitrogen. Some nitrogen accumulated in sediment. Phosphorus was harvested in fish and absorbed by pond sediment. Mechanical aeration aided in maintaining appropriate dissolved oxygen levels for fish production.

Fishery and Population Characteristics of Blue Catfish and Channel Catfish and Potential Impacts of Minimum Length Limits on the Fishery in Lake Wilson, Alabama

AbstractA popular recreational and commercial fishery for blue catfish Ictalurus furcatus and channel catfish I. punctatus exists at Lake Wilson, Alabama (Tennessee River). We examined the fishery, exploitation, angler size selectivity, and population demographics of these two species at Lake Wilson. In addition, we explored management strategies to enhance the fishery of trophy blue catfish. Currently, Alabama has no bag or minimum‐length‐limit regulations for catfish, except for the harvest of fish over 864 mm total length (TL). From April to October 2006, catfish harvest was high (8 kg/ha), and angler catch and harvest rates averaged 1.5 and 1.2 fish/h, respectively. The majority of fish harvested were between 300 and 600 mm TL, and anglers harvested larger fish in proportion to the sample population. Catfish were collected by low‐frequency (15‐MHz) DC electrofishing; they were aged with otoliths from 180 and 122 blue catfish and channel catfish, respectively, subsamples of 2,905 blue catfish and 699 channel catfish. Fish over 300 mm TL were tagged with Carlin dangler tags to estimate exploitation. Accounting for tag loss and variations in angler nonreporting rates (20–70%), we estimated that annual exploitation ranged from 8% to 22% for blue catfish and from 4% to 11% for channel catfish. Of the tagged fish harvested, 33% came from seven commercial fishers. Blue catfish and channel catfish displayed different life histories, which pointed to contrasting management strategies for increasing yield. Blue catfish were longer‐lived (maximum age = 25 years), expressed slower growth (von Bertalanffy K = 0.081), and had lower natural mortality (M = 0.16) than channel catfish (maximum age = 12 years; von Bertalanffy K = 0.148; M = 0.29). Increasing minimum length limits from 300 to 660 mm for blue catfish would increase yield up to 50%, prevent growth overfishing, and increase the abundance of memorable‐length (890‐mm) blue catfish over our range of estimated exploitation. However, for channel catfish, minimum length limits greater than 300 mm would result in a lower yield. High length limits could drastically reduce the angler harvest of catfish but increase the abundance of memorable‐length and larger blue catfish. Even so, the anglers surveyed preferred to harvest smaller fish. Fishing mortality was probably equal to natural mortality for blue catfish, but for channel catfish fishing mortality was less than natural mortality. On the basis of these observations, angler catches, the lack of angler species recognition, and the abundance of small catfish, we currently do not recommend bag or minimum length limits for this fishery.

Utility of Tournament Data for Assessing Effects of Eliminating Commercial Catfish Harvest in the Missouri River

Abstract We examined tournament records for 1989 through 1998 from the 4F Flathead Club in St. Joseph, Missouri, to determine whether tournament data from catfish (i.e., channel catfish Ictalurus punctatus, blue catfish I. furcatus, and flathead catfish Pylodictis olivaris) anglers could be used to detect changes in adult catfish populations (primarily flathead catfish) after commercial harvest of catfish from the Missouri River was prohibited in July 1992. Data from 1989 through 1992 were considered preregulation, and 1993–1998 data were considered postregulation. We found that the fish weight needed to place first, second, or third in a tournament increased significantly (P < 0.01) after the regulation. The mean weight of the big fish for each tournament increased after the commercial ban, and the total weight of fish for each two-person team was 3 lb greater after the regulation. These changes coincided with findings of angler surveys on the Missouri River near St. Joseph, which had indicated that catc...

Recreational catfish harvest in reservoirs in the USA

The recreational catfish harvest was classified in 349 reservoirs larger than 200 ha distributed over 40 states of the contiguous USA. Harvesting occurred in 282 reservoirs, averaged 2.8 kg ha−1 year−1 and represented 15.6% of the total fish yield. The genus Ictalurus contributed most to catfish fisheries (mean = 2.0 kg ha−1), followed by Ameiurus (1.1 kg ha−1) and Pylodictis (0.4 kg ha−1). Five distinct clusters of reservoirs were identified, differing relative to geographical distribution, catfish harvests, angler favouritism towards catfish and physicochemical characteristics. Reservoir clusters across the northern USA had low harvests and essentially featured reservoirs in the upper periphery of the native range of catfish. Harvesting in reservoirs in the south‐west of the country, where catfish have been introduced, was higher than in the north, yet yield remained low. Within their native range, three overlapping clusters included one with medium and another with high harvests, both types dominated by Ictalurus, and a cluster with very high harvest dominated by Ameiurus. Variability in harvests was attributed to zoogeography, reservoir physicochemical characteristics and fishing effort. Management of catfish fisheries of the three less‐productive clusters may focus on enhancement through habitat manipulation and stocking; the two more productive clusters offer the greatest flexibility for management through regulation of harvest.

Assessment of Catfish Stocking in Public Fishing Lakes in Alabama

Abstract From 1974 to 1993, nearly 2 million catfish Ictalurus spp. (primarily channel catfish I. punctatus), weighing about 500,000 lb, were stocked into 18 public fishing lakes throughout Alabama where natural recruitment to the fishery was nil. Using stocking and angler catch and effort records for these lakes, we examined factors related to catfish harvest, identified the most and least successful catfish fisheries, and attempted to determine optimal stocking size and cost-benefit ratio. About 1 million catfish, weighing 1.5 million pounds, were harvested; this conferred a minimum exploitation rate of 52% and a net return of 300% by weight. Harvest rates were highly variable and ranged from 0.4 to 311 fish/acre and from 1 to 320 lb/acre. In multiple regressions for all lakes and years pooled, biomass and number of catfish stocked and angler effort explained the most variation in catfish harvest rates. These models explained 68% of the variation in number of catfish harvested and 56%o of the weight har...

Maximizing First‐Year Growth of Mixed‐Sex Blue Tilapia Oreochromis aureus in Polyculture with Catfish Ictalurus spp.

AbstractMixed‐sex blue tilapia Oreochromis aureus fry were produced from indoor spawns in March and April. Fry were stocked in May at an average weight of 0.5 g at 0, 250, 750, or 2,500/ha into ponds which had been stocked previously with three catfish strains at a combined density of 10,000 fingerlings/ha. After a 167‐d culture period, from 15 May until 4 November, tilapia stocked at 250 or 750/ha grew to average harvest size approaching 0.45 kg. No significant difference in average size was observed between males and females except at the 2,500 tilapia/ha stocking density. Sixty percent of the tilapia polyculture ponds yielded no reproduction at harvest and maximum reproduction observed was 13.5 kg/ha. Lack of reproduction and the undeveloped state of sampled female ovaries indicated that most females had yet to attain sexual maturity. Catfish production and catfish feed conversion was not significantly different between tilapia polyculture and catfish monoculture ponds (P &gt; 0.05). First seine hauls yielded over 88% of the total catfish harvest, but only an average of 3.9% of the marketable tilapia. Tilapia had no measurable impact on the incidence of catfish off‐flavor at any of three sample intervals. Overall average levels of TAN and nitrites did not differ significantly between treatments; however, mean chlorophyll a concentration was significantly higher (P &gt; 0.05) in the 2,500 tilapia/ha treatment than at lower tilapia densities.

Comparison of Slat Traps, Wire Cages, and Various Baits for Commercial Harvest of Catfish

Abstract Slat traps and wire cages fished for 2,414 trap-days in southwest Louisiana between February 8, 1984, and March 11, 1985, yielded 3,218 lb of catfish. Wire cages were most effective, catching 71% of the total. Only 24% of the channel catfish Ictalurus punctatus taken in wire cages were greater than the legal size restriction of 11.0 in total length. By comparison, 55% of the catfish caught in the slat traps were legal size. Cages caught an average of 2.0 lb of catfish per trap-day; slat traps caught 0.7 lb/trap-day. Both gears were highly selective for channel catfish, even though blue catfish Ictalurus furcatus was the dominant catfish species present in those waters. Cheese bait accounted for 46% of the channel catfish harvested in wire traps and 60% of the fish caught in slat traps. Soybean chips used as bait in wire cages and slat traps yielded 28 and 33% of the total catch, respectively. Game fish catches in cages were minimal.