Species of Catfish

Most catfish inhabit shallow running water — either inland or in coastal waters of every continent except Antarctica. The majority of catfish species live in the Americas. There are more than 2,000 species of catfish worldwide. The most commonly raised and consumed species in the United States are the Channel catfish and Blue catfish. The following are species most often sold in the United States.

Channel catfish (Ictalurus punctatus) — make up 90% of U.S. farm-raised catfish. They are the most important species of aquatic animal commercially cultured in the United States.

Blue catfish (Ictalurus furcatus) — are larger than Channel catfish, have smaller heads and have a higher percentage of edible meat. However, they take a longer time to spawn and reach maturity.

Basa (Pangasius bocourti) — a Siluriformes fish species primarily from Vietnam. It cannot be labeled “catfish” in the U.S.; it is typically sold as “basa.”

Swai (Pangasius hypothalamus) — a Vietnamese import; the frozen fillets may be labeled as “striped pangasius”, “tra” or “sutchi.” It cannot be labeled “catfish” in the U.S

Hybrid catfish (not pictured) — a cross between the Channel and Blue catfish.

What do Catfish Look Like?

Catfish are usually slender with a flattened underside and do not have scales. Catfish are white-to-silvery on the undersides, shading to grayish-blue or olive-green to nearly black at the top of the back. Albino Channel catfish are a peach color. Up to eight barbels (whisker-like appendages) are located on the chin or sides of the mouth. The barbels’ function is to detect food. Channel catfish are also distinguished by their deeply forked tail. Catfish have no incisors (cutting teeth); they generally feed through suction or gulping rather than biting and cutting.

How Large are Catfish?

Catfish are the largest freshwater fish, but range greatly in size. A giant Basa catfish caught in Thailand’s Mekong River in 2005 reportedly weighed 650 pounds. Many specimens on record measure more than eight feet long and exceed 220 pounds. Farmed catfish are generally smaller in size. The ideal weight for U.S. farm-raised catfish is 1.7 pounds; it yields two (four to six -ounce) fillets.

What is Aquaculture?

Aquaculture refers to the breeding, rearing and harvesting of plants and animals in all types of water environments, including ponds, rivers, lakes and oceans. Seafood produced by aquaculture are generally referred to as farm-raised seafood. According to the U.S. Department of Commerce’s National Oceanic and Atmospheric Administration (NOAA), “Aquaculture is the fastest growing form of food production in the world. Globally, nearly half the fish consumed by humans is produced by fish farms.”

Where are U.S. Catfish Farm-Raised?

U.S. production of catfish by aquaculture is concentrated in southeastern states, with Mississippi producing over 50% of U.S. catfish. Alabama, Arkansas, Louisiana and Mississippi together produce 94% of all U.S. farm-raised catfish. Although the U.S. domestic fish-growing process primarily utilizes fish-raising ponds, FSIS recognizes that wild-caught fish are commercially processed.

How are U.S. Catfish Farm-Raised?

U.S. farm-raised catfish are grown in environmentally controlled, clay-based ponds filled with fresh water pumped from underground wells. The average pond, constructed by building above-ground levees to serve as natural barriers, is 10 to 20 land-acres in area and four to six feet deep. Mature breeding catfish remain in production an average of four to six years and lay 3,000 to 4,000 eggs annually per pound of body weight. The fertilized eggs are taken to special hatcheries where they hatch after seven days. Soon, the tiny, swimming catfish are moved to special ponds where they grow into “fingerlings” (the size of an index finger). When the fingerlings are about four to six inches long, they are placed in artificially made ponds. After about two years or when they reach approximately 1.7 pounds each, the catfish are harvested with seines (large, weighted nets), transferred to aerated tank trucks and taken to processing plants.

What do Catfish Eat?

The largest ingredient in high-protein catfish feed is soybean meal with some corn, rice and fish meal ingredients. The feed is made into pellets that float on the surface of the pond. For young fish (fingerlings), the pellets are crushed into meal. The feed is routinely analyzed for moisture, protein, fat, fiber and micronutrients to ensure nutritional value.

How Are Catfish Processed?

Catfish are cleaned, processed and placed on ice or frozen to a temperature of 40 degrees F below zero using an individually quick-frozen method that preserves the taste and quality of the fish. The catfish is then sold as whole fish, steaks, fillets, strips and nuggets as well as marinated and breaded or precooked in frozen dinners.

How is Catfish Inspected?

Catfish is under mandatory Federal inspection performed by FSIS under the Federal Meat Inspection Act. The FSIS inspector verifies the establishment’s sanitation, food safety procedures and labeling for the catfish products.

All containers of meat, poultry and egg products that are required to be inspected must be labeled with a USDA mark of inspection and establishment (EST number), which is assigned to the plant where the product was produced. The “Inspected and Passed by USDA” seal ensures the catfish has been produced under FSIS inspection and regulatory requirements. The establishment number may appear on the package within the USDA mark of inspection such as pictured on this page. It may also appear elsewhere on the exterior of the package container or package labeling (for example, on the lid of a can) if shown in a prominent and legible manner and in a size sufficient to insure easy visibility and recognition.

Is Catfish Graded?

Inspection is mandatory but grading is voluntary. NOAA established U.S. Grades A, B and C for fresh or frozen catfish. Grade A catfish will possess good flavor and odor and be within the limits specified for defects in the grade determination. Grades B and C will possess reasonably good flavor and odor and be within the limits specified for defects in the grade determination.

Can Hormones and Antibiotics be Used in U.S. Catfish Raising?

U.S. farm-raised catfish are not given hormones. These fish are also not routinely raised with antibiotics. U.S. farm-raised catfish may be treated with a prescribed dose of antibiotics only when medication is required to treat an illness. Catfish must be off the antibiotic treatment for a specified “withdrawal” period before the fish can be harvested. This ensures that no residues are present in the fish’s system. Catfish are randomly tested for drug residues as part of FSIS’ inspection activities.

What Color is Catfish Meat?

The color of raw catfish varies from ivory to pale grey or yellow.

Dating of Catfish Product

Product dating is not required by Federal regulations, but many stores and processors voluntarily date packages of catfish and catfish products. If a calendar date is placed on the package, here must be an explanation of its meaning such as “sell by” or “use before” immediately adjacent.

The “use before” date is for quality assurance; after the date, peak quality begins to lessen but the product may still be used. It’s always best to buy a product before the date expires. If a “use-by” date expires while the catfish is frozen, the food can still be used. Raw fish should be kept in the refrigerator (40 degrees F/4.4 degrees C or less) only one or two days before cooking or freezing. After cooking, store seafood in the refrigerator three to four days. Any frozen fish will be safe indefinitely; however, the flavor and texture will lessen after lengthy storage.

Foodborne Organisms Associated with Catfish

As on any perishable meat, fish or poultry, bacteria can be found on raw or undercooked catfish. They multiply rapidly in the “Danger Zone” at temperatures between 40 degrees F and 140 degrees F (out of refrigeration and before thorough cooking occurs). Freezing doesn’t kill bacteria, but they are destroyed by thorough cooking.

The following are two types of bacteria commonly associated with catfish:

• Listeria monocytogenes bacteria are common in the intestines of humans and animals and in milk, soil, leafy vegetables and food environments. It grows slowly at refrigerator temperatures. It is destroyed by cooking, but a cooked product can be contaminated by poor handling and cross-contamination.

• Salmonella may be found in the intestinal tracts of humans, livestock, poultry, dogs, cats and other warm-blooded animals. There are about 2,000 kinds of Salmonella bacteria. It is destroyed by cooking products to a minimum safe internal temperature as measured by a food thermometer, but cooked product can be contaminated by poor handling and cross-contamination.

Rinsing or Washing Catfish

Washing or rinsing fish before cooking is not recommended. During washing, bacteria can be easily splashed onto surfaces of your kitchen, possibly spreading bacteria to other foods, utensils and surfaces. We call this cross-contamination.

How to Handle Catfish Safely

• Fresh catfish: Catfish is kept cold during distribution to retail stores to prevent the growth of bacteria and to increase its shelf life. Catfish should feel cold to the touch when purchased. Select fresh catfish just before checking out at the register. Put packages of catfish in disposable plastic bags (if available) to contain any leakage that could cross-contaminate cooked foods or produce. Make the grocery store your last stop before going home.
  • At home, immediately place catfish in a refrigerator that maintains 40 degrees F and cook or freeze it within one or two days or freeze at zero degrees F. If kept frozen continuously, it will be safe indefinitely.
  • Catfish may be frozen in its original packaging or repackaged. If freezing longer than two months, overwrap the porous store packages with airtight heavy-duty foil, plastic wrap or freezer paper, or place the package inside a freezer bag. Use these materials or airtight freezer containers to repackage family packs into smaller amounts or freeze the catfish from opened packages.
  • Proper wrapping prevents “freezer burn,” which appears as leathery spots and is caused by air reaching the surface of food. Cut freezer-burned portions away either before or after cooking the catfish. Heavily freezer-burned products may have to be discarded because they might be too dry or tasteless.
• Ready-to-eat catfish: When purchasing cooked catfish, be sure it is hot at the time of purchase. Use it within two hours or refrigerate in shallow, covered containers. Eat within three to four days, either cold or reheated to 165 degrees F as measured with a food thermometer before removing the food from the heat source. It is safe to freeze ready-to-eat catfish.

Safe Thawing

FSIS recommends three ways to thaw catfish: in the refrigerator, in cold water and in the microwave. Never defrost catfish on the counter or in other locations. It’s best to plan ahead for slow, safe thawing in the refrigerator. Catfish fillets will usually thaw overnight. Whole catfish may take one to two days to thaw. Once the raw catfish thaws, it can be kept in the refrigerator an additional day or two before cooking. During this time, if catfish thawed in the refrigerator is not used, it can safely be refrozen without cooking first but the quality may be affected.

Catfish may be thawed in cold water in airtight packaging or in a leak proof bag. Submerge the package in cold water, changing the water every 30 minutes to be sure it stays cold. Fillets should thaw in about an hour. Whole catfish should defrost in two to three hours and should be cooked immediately after thawing.

Catfish defrosted in the microwave should be cooked immediately after thawing because some areas of the fish may become warm and begin to cook during microwaving.

Holding partially cooked food is not recommended because any bacteria present may not have been destroyed and can multiply at holding temperatures. Foods defrosted in the microwave or by the cold-water method should be cooked fully before refrigerating or refreezing.

Catfish can be cooked from the frozen state in the oven or on the stove. The cooking time may be about 50% longer than for fresh or thawed catfish.

How Long Should You Marinate Catfish?

Catfish absorbs marinades rapidly. Marinate the fish only two to four hours in the refrigerator. It’s safe to store purchased vacuum-packaged marinated catfish for one to two days before cooking. Boil used marinade before brushing on cooked catfish and discard any uncooked leftover marinade.

Safe Cooking

All catfish should reach a safe minimum internal temperature of 145 degrees F as measured with a food thermometer before removing the meat from the heat source.

Approximate Catfish Cooking Times

For approximate cooking times to use in meal planning, see the following chart compiled from various resources.

Storage Times

Since product dates aren’t a guide for safe use of a product, how long can the consumer store the food and still use it at top quality? Follow these tips:

• Purchase the product before the date expires.

• Follow handling recommendations on product.

• Keep catfish in its package until using.

• Freeze catfish in its original packaging, overwrap or re-wrap.