How to Stock a Pond or Lake With Catfish [Species, Prep & Regulations]
Catfish are a prime choice of fish for pond stocking. Members of their own order of ray-finned fish, Siluriformes, they are commercially and biologically important in freshwater systems across the globe. They come in a wide variety of shapes and sizes, with some rivaling the length of sharks and others measuring less than a palm’s breadth at maturity! In between these sizes are a whole host of taxa that can easily be farmed for food or for fun in ponds.
Known for their tasty meat, catfish have been farmed for centuries almost entirely throughout the northern hemisphere and in Africa. Rich in vitamin D, their meat is often considered a delicacy. It can be cooked in all sorts of ways and seasoned with an endless array of flavorful sauces. Many Asian restaurants prefer to prepare the meat while it is freshly harvested for maximum flavor and optimal texture. The live fish must be handled with caution, however, as some species have venomous spines on their fins.
A popular sportfish for anglers, catfish have been introduced into lakes and ponds to meet recreational fishing demands. Also known as mudcats, chuckleheads, or pollywogs, these fish can put up a fantastic fight and are extremely rewarding to catch for beginners and experienced anglers alike.
Nonetheless, introduction into public waterways for the replenishment of fished stock is largely regulated as some species have the tendency to become invasive and compete with native fish for prey. Prior to stocking your pond with catfish, make sure to go over the ideal species for your area, as well as their basic aquaculture requirements for growth and survival.
Popular Types of Catfish for Ponds
1) Channel catfish (Ictalurus punctatus)
Native to the temperate regions of North America, this well-known catfish is the focus of multi-million-dollar food and angling industries. It is one of the most widely grown fish species in the US, where it is reared in both monoculture and polyculture setups. Production of this species was once exclusively controlled by federal agencies to produce fingerlings that could be stocked into reservoirs, streams, ponds, and lakes. Now, commercial farmers intensively culture around 270,000+ tons of this fish a year.
Today, channel catfish are regularly reared in four main types of manmade systems: grow-out ponds, flow-through raceways, tanks, and cages. Intensively stocked ponds, most of which are centered in or around the Mississippi area, produce the majority of the fish that enter the public market. In this region, a combination of flat land, optimal substrate types, and high-quality groundwater supports its continuous culture.
Channel catfish are distinguished by their scaleless, cylindrical bodies and their four pairs of whisker-like barbels. Their keen senses allow them to feed in the benthic zones of murky or darkly stained waters. They typically grow to a maximum size of around 18 – 23 kg (40 – 50 pounds), though a 9-kg (20-pound) specimen would already be considered a spectacular catch. In the wild, this species usually feeds on smaller sunfish, benthic invertebrates, plants, reptiles, and even small birds and mammals.
2) Blue catfish (Ictalurus furcatus)
The blue catfish is widely distributed in freshwater bodies where the channel catfish is frequently found. These two species tend to occupy similar niches, though the former is known for growing larger and being less common. In the US’ aquaculture race to meet the growing demands of catfish, I. furcatus finishes at a close second. It is frequently misidentified as its close cousin due to its similar features. To accurately tell them apart, closely inspect the anal fins. Blue catfish have around 30+ rays, whereas those of a channel catfish number at around 25 – 29.
I. furcatus may become a pest fish due to its tolerance for a wide range of aquatic conditions. It is capable of thriving in brackish waters and on a wide array of prey items. This predatory species can even consume heavy-bodied fish, such as Asian carp. It can become a dominant species wherever it is introduced by altering the food web structure. Moreover, the blue catfish itself has limited predators.
In places where blue catfish are considered a troublesome and non-native species, such as the Chesapeake Bay, local government units strongly encourage anglers to catch them. It turns out that targeting these fish can actually be good for the ecosystem! In an effort to reduce the impact of catfish aquaculture on the environment, robust yet infertile hybrids between blue catfish and channel catfish have been developed. These are increasingly forming a considerable percentage of annually stocked catfish in the US.
3) African sharptooth catfish (Clarias gariepinus)
An airbreathing catfish, C. gariepinus is native to Africa and the Middle East. Due to demand for more farmed, freshwater fish, it has been introduced into other warm countries (e.g. Brazil, India, and Indonesia). Although this catfish favors natural bodies of water, such as lakes, swamps, and rivers, it has been shown to thrive in man-made water bodies too. It can even live in sewage systems due to its tolerance for adverse conditions.
The suitability of the sharptooth catfish for aquaculture production was recognized as early as the 1970s. Its capacity to feed on aquaculture byproducts and convert these into high-protein meat makes it an economically valuable species. It can be grown in intensive densities and in lower-quality aquaculture systems due to its tolerance for poor conditions. It can also reproduce with no trouble in hatcheries. Nonetheless, the use of a hybrid between C. gariepinus and Heterobranchus longifilis (another air-breathing catfish) may be more sustainable due to its preferable white meat and its infertility.
4) Iridescent shark catfish (Pangasianodon hypophthalmus)
Cage cultivation of this popular Asian fish has threatened the commercial value of farmed North American catfish species. Known for being cultivated in rice fields before it was intensively produced, P. hypophthalmus is a migratory species that favors tropical climates. Its white meat is versatile enough to replace more expensive fish fillets in common dishes. Rarely sold as “catfish” in Western regions, its fillets are often labeled as Pangasius, swai, basa, and cream dory.
This catfish is so heavily cultivated in Vietnam that yearly exports from this country alone can reach a value of $1.8 billion! It is usually marketed as a low-cost fish product, as production rates in southeast Asian countries also tend to be much cheaper relative to those of the West. Unfortunately, due to their intensive, widespread, and cheap production, the fillets of this catfish are often branded as low-quality fish meat with a neutral taste. This catfish has thus been nicknamed the ‘swimming chicken’.
Pond Preparation for Catfish
Whether your pond is intended for the growth of commercial species or the recreational cultivation of catfish, it is necessary to test and prepare the substrate and water for ease of fish introduction. Ponds that are to be used for angling or commercial cultivation should be at least a few acres large and at least 6 – 8 feet deep.
As catfish are bottom-feeders, the quality of bottom substrates is crucial. The pond bottom should largely be devoid of mud and aquatic vegetation. In case of heavy rainfall, earthen dikes should be tall enough to withstand a drastic increase in water level.
If you’re working with a fully lined pond, pond preparation would be much easier and would eliminate the need for re-conditioning the substrate. Catfish tend to be reared in earthen ponds that obtain their water from a natural source, so it is necessary to treat these thoroughly before the catfish are stocked. An earthen pond can be treated with lime, chlorine, or a type of fish toxicant to clear the pond several weeks before the stocking date.
Pond Conditioning and Biosecurity
Once the pond has been “disinfected” and any unwanted occupants are removed from the system, you can conduct a heavy water change. Switch out the chemically-treated water with newly filtered fresh water from a clean source. For peace of mind, this step can be performed at least twice. You may opt to “fertilize” the pond water to encourage the growth of beneficial plankton and bacteria. Fertilized ponds are also more likely to sustain a wider diversity and higher concentration of fish species.
Lastly, it may be necessary to screen or net your pond to prevent potential predators from entering the system. This biosecurity measure is optional, but it can significantly reduce the chances of contamination from external sources. Other physical parameters to maintain for successful catfish cultivation would depend on your intentions for rearing them.
If you intend to stock and harvest the pond regularly, it would be best to remove aquatic vegetation and potential sites for catfish spawning. If you intend to stock the pond once and cultivate a self-replenishing system, assuming you would limit harvests to minimal catch rates, you may want to do the reverse (though keep in mind that channel catfish may overpopulate a pond if they are not intermittently harvested). Note that a self-sustaining system would have to be stocked with extensive densities and treated as a natural, polyculture system rather than a heavily farmed pond.
Creating a Stocking Plan
Catfish, as fingerlings or juveniles, should be stocked in spring or whenever temperatures have stabilized at levels above 18˚C (65˚F). Stocking outside of this period may be stressful for the fish due to extreme temperatures. While preparing your pond, consider your capacity to harvest fish, your manpower, and your fishing or harvest demands. Also re-evaluate the carrying capacity of your pond. All of these significantly shape the stocking plan that is ideal for your system.
For extensive, natural ponds that are to be seldom harvested or fished at low capacities, a density of about 100 – 200 catfish fingerlings per acre would suffice. This stocking plan would require the need for stocked prey items while minimizing the demand for fish feeds. Forage fish should be stocked several months prior to introducing catfish. This would allow them to be present in adequate numbers for self-replenishment once catfish, as predators, begin to graze on their populations.
Ideal forage fish include minnows and sunfish. As minnows mature into relatively small adults, they can be stocked at a density of about 1,000 per surface acre. Bluegill, redear sunfish, and threadfin shad can also be added in small numbers as supplementary forage fish if you intend to feed your catfish around 3 – 5 times per week. The provision of fish feeds will allow you to rear more fish in a small area, but note that you will also have to regularly harvest a larger amount.
Determining the Appropriate Catfish Density
In ponds where catfish are fed daily or every other day, fingerlings can be stocked at an initial rate of up to 500 fish per surface area. For intensive monoculture ponds, with consistent aeration, automatic feeding, and regular water changes, this number can go up to 3,500 fingerlings per surface area. Unless you’re commercially rearing catfish, with the intention of marketing evenly-sized catches, it’s fully acceptable to stock your catfish in small increments. High initial densities can result in stunted growth.
If you’re in doubt as to your capacity to control/harvest self-sustaining populations of channel catfish, consider introducing largemouth bass to your pond. These can be added at a density of about 40 – 50 per surface acre. Conversely, if you intend to introduce catfish to ponds or lakes with existing fish populations, limit your stocking rate to just 100 – 200 fish per acre. A heavier catfish stocking plan may adversely affect well-established ecosystems by re-structuring the food chain.
Once you have found a reputable, local producer of catfish fingerlings, it would be best to inquire about the conditions in which their fish are raised and kept. This would help you gauge which measures to take for proper acclimation. Depending on your supplier, you may need to either pick up your catfish fingerlings and juveniles or they may deliver them to your property in aerated bags.
As catfish are quite remarkable at adapting to changes in environmental conditions, they are one of the easiest fish to acclimate and one of the most straightforward to stock and grow. You may simply prepare pails of your pond water, in which the bags of catfish can be left to float, prior to introducing them into the pond. In some cases, the supplier will directly release your purchased catfish into the pails of pond water, skipping the step of bag acclimation.
If the fish are to be transported in pails, you may place a perforated cover on each to minimize spillage. Once they are ready to be released into the pond, simply open the bags or gently lower the pails of fish and allow them to stream out on their own. Do not attempt to pick up or handle them individually as the venomous spines of their fins may cause injury.
Stocking Permits and Considerations
Though the cultivation of catfish rarely calls for special types of permits, make sure to check with your local government units for the necessary requirements. Both monoculture and polyculture ponds that are located inland may require stocking permits and fish transport permits. Also, as some species of catfish are considered invasive (including I. punctatus), there may be strict measures and regulations for stocking them.
As catfish have the tendency to successfully spawn in freshwater bodies with high structural diversity, it may be best to keep a lined or cleared-out pond. Having a large density of catfish may seem tempting and profitable at first, but this would require tight management and multiple harvests. You’ll need to first make arrangements with potential buyers prior to running a pond that encourages spawning. In the event that a pond becomes overcrowded, large harvests will have to be performed to allow the remaining fish to thrive. Apart from the possibility of stunted growth, a high density also increases the chances of infectious disease outbreaks.
If you’re considering regularly restocking catfish fingerlings, it would be best to wait until the initial density has been depleted by about 60%. This way, chances of overcrowding are reduced. This also frees up ample space for the new fingerlings to occupy. Sticking to conservative numbers is best if your manpower is limited to yourself and a few individuals. It also pays off in the long run as the pond system is more likely to remain healthy for much longer.