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Freshwater Fish

Freshwater Fish Primary-Freshwater-Fish
Review of: Freshwater Fish
Article by:
Charles Scribner's Sons

Reviewed by:
On July 10, 2017
Last modified:July 10, 2017


Why are fish a major source of food?

Primary Freshwater Fish

Fish are a primary source of human food and oil, fertiliser, and feed for domestic animals since the dawn of history. Efforts to disperse fish as a source of high protein for human consumption are more recent but still date to ancient China and the Roman Empire.

In the twenty-first century, Fish supply about 25 percent of the animal protein consumed by people in developing countries and up to 75 percent in countries like Bangladesh and the Philippines.

One reason for the long-standing Prevalence of fish as food is absolute numbers. More than 70 percent of the planet’s surface is covered with water, and well over twenty thousand unique species of fish live in marine, fresh, and brackish waters, making them the most varied of all of the animals.

Fish can live at temperatures ranging from below freezing in Antarctic waters to over 100oF (40oC) in hot springs. They vary in size in the .5-inch (1.3-centimeter) dwarf goby of the Philippine Islands to the 45-foot (14-meter), 25-ton whale shark of the tropical waters. The nutrient profile of fish is also outstanding. Rich in the essential omega-3 polyunsaturated fatty acids so lacking in other foods, fish can also be high in protein low in calories, sodium, sugars, saturated fats, and cholesterol.

Biology-Aquatic Vertebrates

Scientifically speaking, Fish are aquatic vertebrates with gills instead of lungs and fins rather than outside limbs. Compared to the higher animals, fish can also be cold-blooded, that is, their body temperatures remain just like that of the water. A few species, such as carrot, have the ability to keep their body temperatures a degree or two higher than the water.

The chain of life resulting in Fish production starts with the microscopic diatoms and algae in lakes, rivers, and the sea. These aquatic plant collectively termed phytoplankton, utilise the energy in sunlight to convert carbon dioxide dissolved in the water to the organic matter that finally becomes food for fish.

Freshwater Fish humminbird-fishfinder1-300x82
Freshwater Fish

Fish were the earliest creatures With backbones to appear in the fossil record, evolving from more primitive forms over 500 million years back. Subsequently, the terrestrial animals evolved from the fishes.

Biologists course the more than twenty thousand known species of fish into three principal groups. The Agnatha (primitive jawless fishes, like the blood-sucking lamprey), the Chondrichthyes (sharks, skates, and rays that have skeletons of cartilage rather than bone), and the Osteichthyes (fishes with a bony skeleton, such as salmon and trout). All the fish significant as meals are members of the latter group.

A typical bony fish is Torpedo-shaped with a head containing a mind and eyes, a back with a muscular wall, and a post-anal tail. Fish propel themselves through the water by undulating motions of the muscular trunk, using their fins to control management.

All have skins covered with a Layer of mucus that reduces friction with the water, and almost all are coated with an outside layer of scales (catfish are one exception). Fishes also have a method of sensory organs along their sides, called the lateral line, that can detect pressure changes in the water brought on by sounds.

Fish obtain oxygen and remove carbon dioxide (breath) by sucking water into the mouth and pumping it out over the gills. Oxygen dissolved in the water thus diffuses into the blood, and carbon dioxide diffuses out. A few species (like the African lungfish) have air-breathing lungs as another way of respiration.

Most fish live in Saltwater or freshwater, but some important food fish are physiologically capable of migrating from one to another. As an instance, Pacific and Atlantic salmon are hatched and reared in freshwater but then migrate to the sea to grow and mature, returning to their natal streams and lakes to spawn. The eel has the contrary life history pattern. Therefore, eel and salmon might be thought of as either freshwater or saltwater fishes based on season and age.

Over the years, some Other aquatic animals are given common names that include the term “fish,” such as shellfish, but these don’t resemble and aren’t associated with actual fish. Furthermore, some animals that have adopted an aquatic lifestyle, like whales, seals, and sea snakes, superficially resemble fish and might even be called fish. But they are air breathers, and their anatomical structure is that of land animals.

Preparation Fish and Food Safety

Fish are an Extremely perishable food item, and historically They had to be promoted live or preserved (treated) by smoking, salting, pickling, or a combination of these approaches. Fish to be cured by any method are cleaned, scaled, and eviscerated.

They’re salted by packaging them between layers of salt or by immersion in brine. Smoking keeps fish both by permeation of smoke ingredients and by partial drying because of heat penetration. Fish may also be dried per se by carefully controlling temperature, humidity, and air speed.

Freshwater fishing is idealised in this nineteenth-century engraving of a brook trout fisherman by James Merritt Ives

But, dried fish are relatively unappetizing, and rehydration is slow. Except for smoked fish, the ready availability of ice and contemporary freezing and canning facilities has largely supplanted curing for a technique of fish preservation. Fish are routinely shipped around the world either fresh or frozen.

Fresh fish are sent on ice And have an acceptable shelf life of approximately ten days. Frozen fish packed in an oxygen-impermeable plastic wrap, for example, Saran, may be stored frozen in 20oF (29oC) for up to six months without a substantial loss in quality.

Fresh fish are nearly always Marketed as whole fish on ice (viscera removed), dressed fish (head, fins, and viscera removed), fillets (sides cut lengthwise away from the backbone), or steaks (cut longitudinally into segments). Due to customer demand, boneless cuts are increasingly available in the USA and Europe.

Fish is a naturally tender Protein meals, free of tough fibres that will need to be softened by cooking. Therefore, fish products are cooked using high-temperature, short time techniques. They might be deep-fat fried (325-350oF; 163-177oC), pan fried (sautéed) in a small quantity of butter, broiled, poached (simmered, never boiled), or baked (400-450oF; 204-232oC).

Pan frying or sautéing is one of The most frequently used methods of cooking thin fillets. Microwaving is especially ideal for the High-temperature, short-time process of cooking fish. The arrival of independently quick-frozen fish fillets has empowered time-saving cooking methods, such as brushing marinades directly on the frozen goods and grilling or oven roasting without the requirement of defrosting.

Fish is prepared to consume when cooked to a temperature of 140oF (60oC), and the flesh has turned opaque and flakes easily. Fish is consumed raw by some cultural groups (such as Asians). Other cultural speciality preparations, such as Blackened Fish (Cajun) or gefilte fish (Yiddish), are also standard.

To guarantee food security, fresh fish ought to be clean smelling, and the flesh should be firm and resilient when pressed. Fish should be kept wrapped and covered at 40oF (4oC) or less and eaten within two days. Frozen fish should be rock hard, free of ice crystals, and don’t have any white spots, visible drying, or browning around the edges. In the house, fish should be stored frozen at 0oF (18oC) or under and for no longer than three months. It needs to be thawed in a refrigerator, never at room temperature.

Freshwater Fish Commonly Used as Food

Historically, the human race has used thousands of different species of fish in its ongoing search for sustainable sources of food. From the nineteenth century, the most popular in North America and Europe include carp, catfish, crappie, eel, lake herring, mullet, muskellunge, yellow perch, yellow pike, pickerel, salmon, suckers, sunfish, tilapia, trout, lake trout, and whitefish. In Indonesia, the Philippines, and Taiwan, milkfish have been used for food for centuries. In Asia, carp, ayu, and eel are important freshwater food fish. Some of the most exciting of the freshwater fish are discussed in more detail below.


The ayu (Plecoglossus altivelis), also called delicious fish in Japan and odour fish in China is a common and economically significant freshwater food fish in several Asian nations. Historically, it was captured by Japanese fishermen utilising trained cormorants with rings around their necks to keep them from swallowing.

In the nineteenth century, it’s wild-caught in rivers by commercial and sports anglers or raised commercially for both restaurant ingestion and house use. Ayu is usually marketed live, on ice in the ground, or suspended. The food quality of wild-caught ayu is particularly desirable, characterised by a sweet, delicate flavour and an odour reminiscent of cucumber or watermelon.

Freshwater Fish humminbird-fishfinder1-300x82
Freshwater Fish


Carp (Cyprinus carpio) are the largest members of the minnow family and can quickly reach a weight of ten kilogrammes or more. Although significantly underutilised in North America, the common carp has always been a favourite freshwater food fish in the rest of the world.

History documents that carp were grown in ponds for food in ancient China in the fifth century B.C.E. In Europe, carp were cultured in monastery ponds as early as the sixth century C.E. so the monks could have something to eat through the many meatless fasting times prescribed by the church.

From the late Middle Ages, carp had turned into a well-established food item to the general people. In the nineteenth century, carp are wild-caught or developed for food in Russia, Ukraine, Hungary, Poland, India, China, Japan, Latin America, Egypt, Iran, Indonesia, and Israel, to name only the significant consumer nations. The world’s top manufacturer in China, where carp are often grown in rice paddies in spinning or even concurrently.

The most frequent market forms of carp are fresh whole fish, dressed fish, or fillets. Gefilte fish, fish balls mixed with egg and matzo meal and simmered in a vegetable broth, is an ethnic speciality item (Yiddish) traditionally made of carp.


The channel catfish (Ictalurus punctatus), native to warm water lakes and rivers in North America, is a popular food fish in the southern United States. Consumer demand has moved from regional to national and even global. In America, the per capita consumption of catfish is exceeded only by that of fish, poultry, Pollack, and salmon. To satisfy American customer demand, several hundred million metric tons of channel catfish are produced by aquaculture every year in the southern United States.

Imported catfish from Vietnam has been promoted aggressively by restaurant chains and food service companies with considerable success. Advertised as delta-raised catfish, it’s, in fact, a catfish relative increased in the delta of the Mekong River. Another catfish species, the walking catfish, is a popular food fish in tropical areas and even in some European countries, notably the Netherlands.

Catfish is firm textured and has a mild, slightly nutty taste that matches an assortment of flavours. It’s a lean fish, and modern processing techniques have removed bones. That, together with its lack of a fishy odour, gives it broad consumer appeal. Catfish were traditionally wild-caught and promoted as iced whole dressed fish.

Modern farm-raised catfish are processed within minutes and sent either on ice or as separately quick-frozen fillets, which makes it one of the freshest fish available. Along with fresh or frozen fillets, steaks and nuggets (bits) breaded or marinated with spices and flavours, such as Cajun spices or mesquite, are also common in fish restaurants and markets and have been introduced to school lunch programs. As Mark Twain once said, “The Catfish is a plenty good enough fish for anyone.”


Although appreciated before the Civil War in North America, freshwater eels (mostly Anguilla and A. japonica) are a favourite food item in Asian countries, especially Japan, Korea, China, and Taiwan. Eels are also an essential delicacy in Europe, especially Italy, where they have to be produced commercially from aquaculture to fulfil consumer demand.

Overall, however, China produces more than 70 percent of the eels sold in the world, and several rice paddies are converted to eel production. Japan is the world’s biggest eel consumer, where kabayaki, eel fillets grilled with a sweet basting sauce, is almost a national dish.

As previously mentioned, eel consumption in North America is minor. But, freshwater eel Unagi is common in Japanese restaurants in America, where it might be served grilled with teriyaki sauce or used in sushi or unadon (eel over rice). Additionally, each year many heaps of market-sized eels are wild-caught by U.S. fishermen and exported to Europe, where it’s eaten roasted or even jellied and baked into pies.

Eels have an interesting life history because they live in freshwater lakes and ponds, where they grow to adult size, they then migrate to the sea, where they float long distances into the Sargasso Sea to spawn and die. The newly hatched young eels can then ride the ocean currents for many years until they hit coastal waters and swim back into freshwater rivers. There they grow to adult size and may be harvested for food.

Eels under a kilogramme in size are the most tender. The creamy, sweet, firm flesh of eel has to be refrigerated and eaten immediately, so the best restaurants maintain live eels in aquarium tanks. The chef removes the epidermis and outer layer of fat, and the fillets are either roasted or grilled. Eel is also available frozen, smoked, or jellied in cans.

Asian folklore holds that eel consumption confers strength and energy, especially in hot summer weather. Eels are amazingly full of vitamin E and at the omega-3 fatty acids (DHA) which are crucial to brain functions involving disposition.


Milkfish (Chanos chanos) is an important food fish for people in Southeast

Traditional fish cage made from split bamboo and reeds (China, twentieth century). Fish is placed in the cage, which was then submerged in water to keep them living for the market.

centuries. Although they’re a marine fish, milkfish spawn in shallow coastal regions, where fry and fingerlings are collected in nets and transported to freshwater or brackish water ponds for rearing to market size. Milkfish have been increased in this fashion for at least seven hundred years in the Philippines and Indonesia.

Taiwan is also a significant producer. Milkfish (bangus) is sold in Asian markets and restaurants fresh, smoked, marinated, like fish balls, as fish sausages, or as fish nuggets. It’s also exported suspended to North America, where sinigang na bangus (milkfish in sour broth) is a popular dish among ethnic Indonesians and Filipinos.


Although relatively new to North American fish markets, tilapia is truly a set of fish (cichlid) which traces its roots to North Africa and the Middle East. These mild, white, sweetly flavoured fish are wild-caught or pond-raised across the world for centuries. Called St. Peter’s fish in many areas of the world, legend has it that the fish Jesus multiplied to feed the multitudes from the narrative of the seven loaves and fishes was tilapia.

Due to their versatility, tilapia has been nicknamed “the aquatic chicken” and can be baked, broiled, fried, blackened, broiled, poached, or sautéed. Sautéing is among the most traditional procedures of preparing thin fillets generally, and in most recipes, tilapia can easily substitute for catfish or even sole and flounder.

Tilapia are grown in floating cages, ponds, or rice areas in tropical and temperate areas around the world. Just Chinese carp and salmon or trout exceed tilapia in total worldwide fish production.

Though they are not as prevalent in America, tilapia consumption has grown to equal trout one of the commercially raised fish species. Since U.S. aquaculture creates relatively modest quantities of tilapia, significant amounts of frozen fillets are imported from Indonesia, Taiwan, and Mexico to fulfil consumer demand. Many big U.S. cities report that a substantial requirement for live tilapia delivered to Asian cultural markets.


Many trout species have been utilised for food, but rainbow trout (Oncorhynchus mykiss) have been by far the most popular. Originally native to cold water environments in the north temperate zone, this prized food fish was transplanted across the world and is well established in North and South America, Japan, China, Europe, Australia, New Zealand, and parts of Africa. Leading trout-producing countries include Chile, Denmark, France, Italy, and the USA.

Most rainbow trout are marketed as head-on dressed fish, like fresh or frozen boneless fillets, or as smoked fish. Farmed trout are usually abundant in the omega-3 fatty acids so crucial for healthy eye and brain function, while they are less costly than most other fish products.

Walleye Pike

Walleye (Stizostedion vitreum), a part of the perch family with a superb reputation for its food quality, is a widely sought cool-water fish mainly captured by anglers for home use but also available in fish markets and restaurants in much of the northern United States and Canada. In the USA, a limited commercial harvest comes in the Great Lakes.

Freshwater Fish humminbird-fishfinder1-300x82
Freshwater Fish

However, most of the commercial harvest is from Canadian fishing on Lake Erie and the inland waters of Ontario and Saskatchewan. The walleye is Canada’s most economically valuable freshwater fish. Only a few commercial growers create food-size walleye, but due to its reputation for exceptional food quality (aroma, flavour, and texture), its name recognition, and its high retail price, walleye have considerable aquaculture potential. Traditionally, walleye is marketed as scaled, skin-on fillets. A two-pound fish yields about two eight-ounce dinner-size fillets.


Lake whitefish (Coregonus clupeaformis) native into the deep cold lakes of North America is popular food fish in the USA and Canada. They are frequently sold in restaurants, and some think their flaky, non-oily white meat is the best tasting of all of the freshwater fish. Early settlers claimed they could eat the only whitefish for days at a time and never tire of it.

A significant commercial fishery for whitefish is present in Lake Superior and the other Great Lakes of the midwestern United States. In Canada, close to 600,000 kilogrammes of whitefish annually is captured and marketed by tribal fishermen of the Great Slave Lake alone. Many whitefish are marketed frozen and sold in supermarkets or restaurants, but limited amounts are also available fresh or smoked. Whitefish eggs, termed freshwater or golden caviar, are sometimes marketed as a less-expensive substitute for sturgeon caviar.

Why are fish a major source of food?