Tags: Atlantic Ocean, Caribbean, Central America, Cero, Commercial fishing, Hawaii, Recreational fishing, Wahoo
Wahoo (Acanthocybium solandri) is a scombrid fish found worldwide in tropical and subtropical seas. It is best known to sports fishermen, as its speed and high-quality flesh make it a prize game fish. In Hawaii, the wahoo is known as ono. Many Hispanic areas of the Caribbean
and Central America refer to this fish as peto.
The body is elongated and covered with small, scarcely visible scales; the back is an iridescent blue, while the sides are silvery, with a pattern of irregular vertical blue bars and have razor sharp teeth. These colors fade rapidly at death. The mouth is large, and both the upper and lower jaws have a somewhat sharper appearance than those of king or Spanish mackerel. Specimens have been recorded at up to 2.5 metres (8 ft 2 in) in length, and weighing up to 83 kilograms (180 lb). Growth can be rapid. One specimen tagged at 5 kilograms (11 lb) grew to 15 kg (33 lb) in one year. Wahoo can swim up to 60 mph (97 km/h). They are some of the fastest fish in the sea.
The wahoo may be distinguished from the related Atlantic king mackerel and from the Indo-Pacific Narrow-barred Spanish mackerel by a fold of skin which covers the mandible when its mouth is closed. In contrast, the mandible of the king mackerel is always visible as is also the case for the smaller Spanish mackerel and Cero mackerel. The teeth of the wahoo are similar to those of king mackerel, but shorter and more closely set together.
The barracuda is sometimes confused with mackerel and wahoo, but is easy to distinguish from the latter two species. Barracuda have prominent scales, larger, dagger-like teeth, and lack the caudal keels and blade-like tail characteristic of the scombrid (mackerel).
Wahoo tend to be solitary or occur in loose-knit groups of two or three fish, but where conditions are suitable can be found in schools as large as 100 or more. Their diet is made up of other fish and squid.
Most wahoo taken have a trematode parasite living in their stomach, the giant stomach worm (Hirudinella ventricosa), which does not appear to harm the fish.
The flesh of the wahoo is white to grey, delicate to dense, and highly regarded by many gourmets. The taste is similar to mackerel, though arguably less pronounced. This has created some demand for the wahoo as a premium priced commercial food fish. In many areas of its range, such as Hawaii, Bermuda and many parts of the Caribbean, local demand for wahoo is met by artisanal commercial fishermen, who take them primarily by trawling, as well as by recreational sports fishermen who sell their catch.
Although local wahoo populations can be affected by heavy commercial and sports fishing pressure, wahoo as a species are less susceptible to industrial commercial fishing than more tightly schooling and abundant species such as tuna. Wahoo are regularly taken as a by-catch in various commercial fisheries, including longline fisheries for tuna, billfish and dolphinfish (a.k.a. mahi-mahi or dorado) and in tuna purse seine fisheries, especially in sets made around floating objects, which act as a focal point for a great deal of other marine life besides tuna. In 2003, the South Atlantic Fishery Management Council issued a Dolphin Wahoo Fishery Management Plan for the Atlantic. However, the species as a whole is not considered overfished. In most parts of its range, the wahoo is a highly prized sport fishing catch. It reaches a good size, is often available not too far from land, and is a very good fighter on light to medium tackle. It is known in sports fishing circles for the speed and strength of its first run. The aggressive habits and razor-sharp teeth of the wahoo can be of considerable annoyance when targeting larger gamefish, however, such as tuna or marlin.
Grilled Marinated Wahoo
1/2 cup Butter, melted (Blue Bonnet Light Stick Butter)
1/2 cup Extra Virgin Olive Oil
6 fresh Garlic Cloves
1/3 cup fresh Cilantro
1 tablespoon Roasted Ground Cumin
2 tablespoons Zatarainn’s Cajun Seafood Seasoning
1 lemon, Juice of
6 Wahoo fillets, about 1/2 inch thick
Lemon wedge (to garnish)
1 – Spray grill with nonstick spray or brush with vegie oil to prevent sticking. Preheat on high for about 10 minutes
2 – Mix first 7 ingredients in a blender. Purée into a smooth sauce.
3 – When ready to cook, brush both sides of fillets with sauce. Place fillets on grill and cook, turning once or twice. Brush more sauce as needed.
4 – Fish is done when it flakes easily (about 5 minutes). Serve with lemon wedges.
Tags: Baltic Sea, Black Sea, cook, France, Norway, Scophthalmidae, Sea salt, Turbot
The turbot (Scophthalmus maximus) is a species of flatfish in the family Scophthalmidae. It is a demersal fish native to marine or brackish waters of the North Atlantic, Baltic Sea and the Mediterranean Sea.
The word comes from the Old French tourbout, which in turn is thought to be a derivative of the Latin turbo (“spinning top”) a possible reference to its shape. Early reference to the Turbot can be found in a satirical poem (The Emperor’s Fish) by Juvenal, a Roman poet of the late 1st and early 2nd centuries A.D., suggesting this fish was a delicacy in the Roman empire.
In the UK, Turbot is pronounced /ˈtɜrbət/ tur-bət. In the US it is pronounced /ˈtɜrboʊ/ tur-boh (the French pronunciation of “turbot” is [tyʁbo]).
In Turkey, where the fish is popular and expensive, it is called “Kalkan” – “shield” – due to the fish’s resemblance to the item. Instead of a smooth skin, Kalkan (Scophthalmus maeoticus), which is from the Black Sea, has small spikes on both sides; it is considered a subspecies of the Mediterranean Turbot (Scophthalmus maximus).
The turbot (Scophthalmus maximus) is a large left-eyed flatfish found primarily close to shore in sandy shallow waters throughout the Mediterranean, the Baltic Sea, the Black Sea and the North Atlantic. The European turbot has an asymmetrical disk-shaped body, and has been known to grow up to 100 cm (39 in) long and 25 kg (55 lb) in weight.
Turbot is highly prized as a food fish for its delicate flavor, and is also known as breet, britt or butt. It is a valuable commercial species, acquired through aquaculture and trawling. Turbot are farmed in France, Spain, Portugal, Romania, Turkey, Chile, Norway, and China. Turbot has a bright white flesh that retains this appearance when cooked. Like all flatfish, turbot yields four fillets with meatier topside portions that may be baked, poached or pan-fried.
4 serving-size portions of Turbot
Juice of 1/2 Lemon
4 pats of Light Butter
Ground White Pepper, to taste
Hungarian Paprika, to taste
Sea Salt, to taste
Preheat the oven to 400 degrees.
Lay the turbot fillets on a baking sheet or baking dish. Drizzle with lemon juice, then sprinkle with white pepper, salt, and paprika. Lay a pat of butter on each portion – you can break the butter in smaller bits if you like.
Bake at 400 degrees until the fish is cooked through – about 20 minutes. Serve hot garnished with a bit of lemon.
Slice the remaining 1/2 lemon into wedges and serve it with the fish.
Tags: Atlantic, Atlantic Ocean, Fish, International Seafood Sustainability Foundation, Japan, Pacific Ocean, Tuna, United States, Yellowfin tuna
A tuna is a saltwater finfish that belongs to the tribe Thunnini, a sub-grouping of the mackerel family (Scombridae) – which together with
the tunas, also includes the bonitos, mackerels, and Spanish mackerels. Thunnini comprises fifteen species across five genera, the sizes of which vary greatly, ranging from the bullet tuna (max. length: 50 cm (1.6 ft), weight: 1.8 kg (4 lb)) up to the Atlantic bluefin tuna (max. length: 4.6 m (15 ft), weight: 684 kg (1,508 lb)). The bluefin averages 2 m (6.6 ft), and is believed to live for up to 50 years.
Their circulatory and respiratory systems are unique among fish, enabling them to maintain a body temperature higher than the surrounding water. An active and agile predator, the tuna has a sleek, streamlined body, and is among the fastest-swimming pelagic fish – the yellowfin tuna, for example, is capable of speeds of up to 75 km/h (47 mph). Found in warm seas, it is extensively fished commercially and is popular as a game fish. As a result of over-fishing, stocks of some tuna species, such as the Southern bluefin tuna, have been reduced dangerously close to the point of extinction.
The tuna is a sleek and streamlined fish, adapted for speed. It has two closely spaced dorsal fins on its back; The first being “depressible” – it can be laid down, flush, in a groove that runs along its back. Seven to 10 yellow finlets run from the dorsal fins to the tail, which is lunate – curved like a crescent moon – and tapered to pointy tips. The caudal peduncle, to which the tail is attached, is quite thin, with three stabilizing horizontal keels on each side. The tuna’s dorsal side is generally a metallic dark blue, while the ventral side, or underside, is silvery or whitish, for camouflage.
Thunnus are widely but sparsely distributed throughout the oceans of the world, generally in tropical and temperate waters between about 45 degrees north and south of the equator. All tunas are able to maintain the temperature of certain parts of their body above the temperature of ambient seawater. For example, bluefin can maintain a core body temperature of 25–33 °C (77–91 °F), in water as cold as 6 °C (43 °F). However, unlike typical endothermic creatures such as mammals and birds, tuna do not maintain temperature within a relatively narrow range.
Tuna achieve endothermy by conserving the heat generated through normal metabolism. The rete mirabile (“wonderful net”), the intertwining of veins and arteries in the body’s periphery, allows much of the heat from venous blood to be “re-claimed” and transferred to the arterial blood via a counter-current exchange system, thus mitigating the effects of surface cooling. This allows the tuna to elevate the temperatures of the highly-aerobic tissues of the skeletal muscles, eyes and brain, which supports faster swimming speeds and reduced energy expenditure, and which enables them to survive in cooler waters over a wider range of ocean environments than those of other fish. In all tunas, however, the heart operates at ambient temperature, as it receives cooled blood, and coronary circulation is directly from the gills.
Also unlike most fish, which have white flesh, the muscle tissue of tuna ranges from pink to dark red. The red myotomal muscles derive their color from myoglobin, an oxygen-binding molecule, which tuna express in quantities far higher than most other fish. The oxygen-rich blood further ables energy delivery to their muscles.
For powerful swimming animals like dolphins and tuna, cavitation may be detrimental, because it limits their maximum swimming speed. Even if they have the power to swim faster, dolphins may have to restrict their speed because collapsing cavitation bubbles on their tail are too painful. Cavitation also slows tuna, but for a different reason. Unlike dolphins, these fish do not feel the bubbles, because they have bony fins without nerve endings. Nevertheless, they cannot swim faster because the cavitation bubbles create a vapor film around their fins that limits their speed. Lesions have been found on tuna that are consistent with cavitation damage.
Tuna is an important commercial fish. The International Seafood Sustainability Foundation (ISSF) compiled a detailed scientific report on the state of global tuna stocks in 2009, which includes regular updates. According to the ISSF, the most important species for commercial and recreational tuna fisheries are yellowfin (Thunnus albacares), bigeye (T. obesus), bluefin (T. thynnus, T. orientalis, and T. macoyii), albacore (T. alalunga), and skipjack (Katsuwonus pelamis).
The report further states:
Between 1940 and the mid-1960s, the annual world catch of the five principal market species of tunas rose from about 300 thousand tons to about 1 million tons, most of it taken by hook and line. With the development of purse-seine nets, now the predominant gear, catches have risen to more than 4 million tons annually during the last few years. Of these catches, about 68 percent are from the Pacific Ocean, 22 percent from the Indian Ocean, and the remaining 10 percent from the Atlantic Ocean and the Mediterranean Sea. Skipjack makes up about 60 percent of the catch, followed by yellowfin (24 percent), bigeye (10 percent), albacore (5 percent), and bluefin the remainder. Purse-seines take about 62 percent of the world production, longline about 14 percent, pole and line about 11 percent, and a variety of other gears the remainder 3.
The Australian government alleged in 2006 that Japan had illegally overfished southern bluefin by taking 12,000 to 20,000 tonnes per year instead of the their agreed 6,000 tonnes; the value of such overfishing would be as much as USD $2 billion. Such overfishing has severely damaged bluefin stocks. According to the WWF, “Japan’s huge appetite for tuna will take the most sought-after stocks to the brink of commercial extinction unless fisheries agree on more rigid quotas”. Japan’s Fisheries Research Agency counters that Australian and New Zealand tuna fishing companies under-report their total catches of southern bluefin tuna and ignore internationally mandated total allowable catch totals.
In recent years, opening day fish auctions at Tokyo’s Tsukiji fish market have seen record-setting prices for bluefin tuna, reflecting market demand. In each of 2010, 2011, 2012 and 2013, new record prices have been set for a single fish – the current record is 155.4 million japanese yen (US $1.76 million) for a 221 kg (490 lb) bluefin, or a unit price of JP¥ 703,167/kg (US$ 3,603/lb). In November 2011, a different record was set when a fisherman in Massachusetts caught an 881-pound tuna. It was captured inadvertently using a dragnet. Due to the laws and restrictions on tuna fishing in the United States, federal authorities impounded the fish because it was not caught with a rod and reel. Because of the tuna’s deteriorated condition as a result of the trawl net, the fish sold for just under $5,000.
Increasing quantities of high-grade tuna are reared in net pens and fed bait fish. In Australia, former fishermen raise southern bluefin tuna,
Thunnus maccoyii, and another bluefin species. Farming its close relative, the Atlantic bluefin tuna, Thunnus thynnus, is beginning in the Mediterranean, North America and Japan. Hawaiʻi approved permits for the first U.S. offshore farming of bigeye tuna in water 1,300 feet (400 m) deep in 2009.
Japan is the biggest tuna consuming nation and is also the leader in tuna farming research. Japan first successfully farm-hatched and raised bluefin tuna in 1979. In 2002, it succeeded in completing the reproduction cycle and in 2007, completed a third generation. The farm breed is known as Kindai tuna. Kindai is the contraction of Kinki University in Japanese (Kinki daigaku). In 2009, Clean Seas, an Australian company which has been receiving assistance from Kinki University managed to breed Southern Bluefin Tuna in captivity and was awarded the second place in World’s Best Invention of 2009 by Time magazine.
Canned tuna was first produced in 1903, quickly becoming popular. Tuna is canned in edible oils, in brine, in water, and in various sauces. In the United States, 52% of canned tuna is used for sandwiches; 22% for salads; and 15% for casseroles and dried, packaged meal mixes.
In the United States, only Albacore can legally be sold in canned form as “white meat tuna”; in other countries, yellowfin is also acceptable. While in the early 1980s canned tuna in Australia was most likely Southern bluefin, as of 2003 it was usually yellowfin, skipjack, or tongol (labelled “northern bluefin”).
As tunas are often caught far from where they are processed, poor interim conservation can lead to spoilage. Tuna is typically gutted by hand, and later pre-cooked for prescribed times of 45 minutes to three hours. The fish are then cleaned and filleted, canned, and sealed, with the dark lateral blood meat often separately canned for pet food. The sealed can itself is then heated under pressure (called retort cooking) for 2 to 4 hours. This process kills any bacteria, but retains the histamine that can produce rancid flavors. The international standard sets the maximum histamine level at 200 milligrams per kilogram. An Australian study of 53 varieties of unflavored canned tuna found none to exceed the safe histamine level, although some had “off” flavors.
Australian standards once required cans of tuna to contain at least 51% tuna, but these regulations were dropped in 2003. The remaining weight is usually oil or water. In the US, the FDA regulates canned tuna.
Tuna can be a good source of omega-3 fatty acids. It can contain 300 milligrams (0.011 oz) per serving. However, the level of omega-3 oils found in canned tuna is highly variable, since some common manufacturing methods destroy much of the omega-3 oils in the fish. Tuna is also a good source of protein.
Mercury content in tuna can vary widely. For instance, testing by Rutgers University reportedly found that a can of StarKist had 10 times more mercury than another can of similarly identified tuna. This has prompted a Rutgers University scientist whose staff conducted the mercury analysis to say, “That’s one of the reasons pregnant women have to be really careful … If you happen to get a couple or three cans in the high range at a critical period when you are pregnant, it would not be good.” Among those calling for improved warnings about mercury in tuna is the American Medical Association, which adopted a policy that physicians should help make their patients more aware of the potential risks.
A study published in 2008 found that mercury distribution in the meat of farmed tuna is inversely related to the lipid content, suggesting that higher lipid concentration within edible tissues of tuna raised in captivity might, other factors remaining equal, have a diluting effect on mercury content. These findings suggest that choosing to consume a type of tuna that has a relatively higher natural fat content might help reduce the amount of mercury intake, compared to consuming tuna with a low fat content.
The industry-sponsored group Center for Consumer Freedom, which does not release the names of its contributors, claims the health risks of methylmercury in tuna might be dampened by the selenium found in tuna, although the mechanism and effect of this is still largely unknown.
Due to their high position in the food chain and the subsequent accumulation of heavy metals from their diet, mercury levels can be high in larger species such as bluefin and albacore.
There are five main tuna fishery management bodies: the Western Central Pacific Ocean Fisheries Commission, the Inter-American Tropical
Tuna Commission, the Indian Ocean Tuna Commission, the International Commission for the Conservation of Atlantic Tunas and the Commission for the Conservation of Southern Bluefin Tuna. The five gathered for the first time in Kobe, Japan in January 2007. Environmental organizations made submissions on risks to fisheries and species. The meeting concluded with an action plan drafted by some 60 countries or areas. Concrete steps include issuing certificates of origin to prevent illegal fishing and greater transparency in the setting of regional fishing quotas. The delegates are scheduled to meet at another joint meeting in January or February 2009 in Europe.
In 2010, Greenpeace International has added the albacore, bigeye tuna, Pacific bluefin tuna, Atlantic bluefin tuna, southern bluefin tuna and the yellowfin tuna to its seafood red list. “The Greenpeace International seafood red list is a list of fish that are commonly sold in supermarkets around the world, and which have a very high risk of being sourced from unsustainable fisheries.”
It is widely accepted that bluefin tuna have been severely overfished, with some stocks at risk of collapse. According to the International Seafood Sustainability Foundation (a global, non-profit partnership between the tuna industry, scientists, and the World Wide Fund for Nature), Indian Ocean yellowfin tuna, Pacific Ocean (eastern & western) bigeye tuna, and North Atlantic albacore tuna are all overfished. In April 2009, no stock of skipjack tuna (which makes up roughly 60 percent of all tuna fished worldwide) was considered to be overfished. However, the BBC documentary, South Pacific, which first aired in May 2009 stated that, should fishing in the Pacific continue at its current rate, populations of all tuna species could collapse within 5 years. It highlighted huge Japanese and European tuna fishing vessels, sent to the South Pacific international waters after overfishing their own fish stocks to the point of collapse.
A 2010 tuna fishery assessment report, released in January 2012 by the Secretariat of the Pacific Community (SPC), supported this finding, recommending that all tuna fishing should be reduced or limited to current levels and that limits on skipjack fishing be considered.
Tuna, light, canned in oil, drained solids
Nutritional value per 100 g (3.5 oz)
Energy 830 kJ (200 kcal)
Carbohydrates 0 g
Fat 8 g
Protein 29 g
Water 60 g
Vitamin A equiv. 23 μg (3%)
Choline 29 mg (6%)
Vitamin D 269 IU (45%)
Calcium 13 mg (1%)
Iron 1.4 mg (11%)
Magnesium 31 mg (9%)
Phosphorus 311 mg (44%)
Potassium 207 mg (4%)
Zinc 0.9 mg (9%)
Percentages are roughly approximated
using US recommendations for adults.
Source: USDA Nutrient Database
Tags: British Nutrition Foundation, Brook trout, Brown trout, Rainbow trout, Salvelinus, Tian Shan, Trout, United States
subfamily Salmoninae of the family Salmonidae. The word trout is also used as part of the name of some non-salmonid fish such as Cynoscion nebulosus, the spotted seatrout or speckled trout.
Trout are closely related to salmon and char (or charr): species termed salmon and char occur in the same genera as do trout (Oncorhynchus – Pacific salmon and trout, Salmo – Atlantic salmon and various trout, Salvelinus – char and trout).
Most trout such as Lake trout live in freshwater lakes and/or rivers exclusively, while there are others such as the Rainbow trout which may either live out their lives in fresh water, or spend two or three years at sea before returning to fresh water to spawn, a habit more typical of salmon. A rainbow trout that spends time in the ocean is called a steelhead.
Trout are an important food source for humans and wildlife including brown bears, birds of prey such as eagles, and other animals. They are classified as oily fish.
Trout that live in different environments can have dramatically different colorations and patterns. Mostly, these colors and patterns form as camouflage, based on the surroundings, and will change as the fish moves to different habitats. Trout in, or newly returned from the sea, can look very silvery, while the same fish living in a small stream or in an alpine lake could have pronounced markings and more vivid coloration; it is also possible that in some species this signifies that they are ready to mate. In general trout that are about to breed have extremely intense coloration. They can look like an entirely different fish outside of spawning season. It is virtually impossible to define a particular color pattern as belonging to a specific breed; however, in general, wild fish are claimed to have more vivid colors and patterns.
Trout have fins entirely without spines, and all of them have a small adipose fin along the back, near the tail. The pelvic fins sit well back on the body, on each side of the anus. The swim bladder is connected to the esophagus, allowing for gulping or rapid expulsion of air, a condition known as physostome. Unlike many other physostome fish, the trout do not use their bladder as an auxiliary device for oxygen uptake, relying solely on their gills.
There are many species, and even more populations that are isolated from each other and morphologically different. However, since many of these distinct populations show no significant genetic differences, what may appear to be a large number of species is considered a much smaller number of distinct species by most ichthyologists. The trout found in the eastern United States are a good example of this. The brook trout, the aurora trout, and the (extinct) silver trout all have physical characteristics and colorations that distinguish them, yet genetic analysis shows that they are one species, Salvelinus fontinalis.
Lake trout (Salvelinus namaycush), like brook trout, belong to the char genus. Lake trout inhabit many of the larger lakes in North America, and live much longer than rainbow trout, which have an average maximum lifespan of 7 years. Lake trout can live many decades, and can grow to more than 30 kilograms (66 lb).
Trout are usually found in cool (50–60 °F or 10–16 °C), clear streams and lakes, although many of the species have anadromous strains as
well. Young trout are referred to as troutlet, troutling or fry. They are distributed naturally throughout North America, northern Asia and Europe. Several species of trout were introduced to Australia and New Zealand by amateur fishing enthusiasts in the 19th century, effectively displacing and endangering several upland native fish species. The introduced species included brown trout from England and rainbow trout from California. The rainbow trout were a steelhead strain, generally accepted as coming from Sonoma Creek. The rainbow trout of New Zealand still show the steelhead tendency to run up rivers in winter to spawn. The closest resemblance of seema trout and other trout family can be found in the Himalayan Region of India, Nepal, Bhutan, Pakistan and in Tian Shan mountains of Kyrgyzstan.
Trout generally feed on other fish, and soft bodied aquatic invertebrates, such as flies, mayflies, caddisflies, stoneflies, mollusks and dragonflies. In lakes, various species of zooplankton often form a large part of the diet. In general, trout longer than about 300 millimetres (12 in) prey almost exclusively on fish, where they are available. Adult trout will devour smaller fish up to 1/3 their length. Trout may feed on shrimp, mealworms, bloodworms, insects, small animal parts, and eel.
1 fillet of trout (79g) contains:
* Calories :117
* Fat (g): 5.22
* Carbohydrates (g): 0
* Fibers (g): 0
* Protein (g): 16.41
* Cholesterol (mg): 46
As a group, trout are somewhat bony, but the flesh is generally considered to be tasty. The flavor of the flesh is heavily influenced by the diet of the fish. For example, trout that have been feeding on crustaceans tend to be more flavorful than those feeding primarily on insect life. Additionally, they provide a good fight when caught with a hook and line, and are sought after recreationally. Because of their popularity, trout are often raised on fish farms and planted into heavily fished waters, in an effort to mask the effects of overfishing. While they can be caught with a normal rod and reel, fly fishing is a distinctive method developed primarily for trout, and now extended to other species. Farmed trout and char are also sold commercially as food fish.
According to the British Nutrition Foundation, trout contain one of the lowest amounts of dioxins (a type of environmental contaminant) of all oily fishes.
Tags: Asia, China, Fish, fish farms, Omega-3 fatty acid, Papua New Guinea, Sarotherodon, Tilapia
Fish of the Week – Tilapia
Tilapia (/tɨˈlɑːpiə/ ti-la-pee-ə) is the common name for nearly a hundred species of cichlid fish from the tilapiine cichlid tribe. Tilapia are mainly freshwater fish, inhabiting shallow streams, ponds, rivers and lakes, and less commonly found living in brackish water. Historically, they have been of major importance in artisan fishing in Africa and the Levant, and are of increasing importance in aquaculture and aquaponics. Tilapia can become problematic invasive species in new warm-water habitats, whether deliberately or accidentally introduced, but generally not in temperate climates due to their inability to survive in cooler waters below about 21 °C (70 °F).
Tilapia were one of the three main types of fish caught in Biblical times from the Sea of Galilee. At that time were called musht, or commonly now even “St. Peter’s fish“. The name “St. Peter’s fish” comes from the story in the Gospel of Matthew about the apostle Peter catching a fish that carried a coin in its mouth, though the passage does not name the fish. While the name also applies to Zeus faber, a marine fish not found in the area, a few tilapia species (Sarotherodon galilaeus galilaeus and others) are found in the Sea of Galilee, where the author of the Gospel of Matthew accounts the event took place. These species have been the target of small-scale artisanal fisheries in the area for thousands of years.
The common name tilapia is based on the name of the cichlid genus Tilapia, which is itself a latinisation of thiape, the Tswana word for “fish”. Scottish zoologist Andrew Smith named the genus in 1840.
Tilapia typically have laterally compressed, deep bodies. Like other cichlids, their lower pharyngeal bones are fused into a single tooth-bearing structure. A complex set of muscles allows the upper and lower pharyngeal bones to be used as a second set of jaws for processing food, allowing a division of labor between the “true jaws” (mandibles) and the “pharyngeal jaws”. This means they are efficient feeders that can capture and process a wide variety of food items. Their mouths are protrusible, usually bordered with wide and often swollen lips. The jaws have conical teeth. Typically tilapia have a long dorsal fin, and a lateral line which often breaks towards the end of the dorsal fin, and starts again two or three rows of scales below.
Tilapia as a common name has been applied to various cichlids from three distinct genera: Oreochromis, Sarotherodon and Tilapia. The members of the other two genera used to belong to the genus Tilapia but have since been split off into their own genera. However, particular species within are still commonly called “tilapia” regardless of the change in their actual taxonomic nomenclature.
The delimitation of these genera among each other and to other tilapiines requires more research; mtDNA sequences are confounded because at least among the species of any one genus, there is frequent hybridization. The species remaining in Tilapia in particular still seem to be a paraphyletic assemblage.
The tilapiines of North Africa are the most important commercial cichlids. Fast-growing, tolerant of stocking density, and adaptable, tilapiine species have been introduced and farmed extensively in many parts of Asia and are increasingly common aquaculture targets elsewhere.
Farmed tilapia production is about 1,500,000 tonnes (1,500,000 long tons; 1,700,000 short tons) annually with an estimated value of US$1.8 billion, about equal to that of salmon and trout.
Unlike carnivorous fish, tilapia can feed on algae or any plant-based food. This reduces the cost of tilapia farming, reduces fishing pressure on prey species, avoids concentrating toxins that accumulate at higher levels of the food chain and makes tilapia the preferred “aquatic chickens” of the trade.
Because of their large size, rapid growth, and palatability, tilapiine cichlids are the focus of major farming efforts, specifically various species of Oreochromis, Sarotherodon, and Tilapia, collectively known colloquially as tilapia. Like other large fish, they are a good source of protein and popular among artisanal and commercial fisheries. Most such fisheries were originally found in Africa, but outdoor fish farms in tropical countries, such as Papua New Guinea, the Philippines, and Indonesia, are underway in freshwater lakes. In temperate zone localities, tilapiine farming operations require energy to warm the water to tropical temperatures. One method uses waste heat from factories and power stations.
China is the largest tilapia producer in the world, followed by Egypt.
In modern aquaculture, wild-type Nile tilapia are not too often seen, as the dark color of their flesh is not much desired by many customers, and because it has a bit of a reputation of being a trash fish associated with poverty. On the other hand, they are fast-growing and give good fillets; leucistic (“Red”) breeds which have lighter meat have been developed and these are very popular.
Hybrid stock is also used in aquaculture; Nile × blue tilapia hybrids are usually rather dark, but a light-colored hybrid breed known as “Rocky Mountain White” tilapia is often grown due to its very light flesh and tolerance of low temperatures.
Commercially grown tilapia are almost exclusively male. Cultivators use hormones, such as testosterone, to reverse the sex of newly spawned females. Because tilapia are prolific breeders, the presence of female tilapia results in rapidly increasing populations of small fish, rather than a stable population of harvest-size animals.
Other methods of tilapia population control are polyculture, with predators farmed alongside tilapia or hybridization with other species.
Whole tilapia fish can be processed into skinless, boneless (Pin-Bone Out, or PBO) fillets: the yield is from 30 percent to 37 percent, depending on fillet size and final trim. The use of tilapia in the commercial food industry has led to the virtual extinction of genetically pure bloodlines. Most wild tilapia today are hybrids of several species.
Tilapia have very low levels of mercury, as they are fast-growing, lean and short-lived, with a primarily vegetarian diet, so do not accumulate mercury found in prey. Feral tilapia, however, may accumulate substantial quantities of mercury. Tilapia are low in saturated fat, calories, carbohydrates and sodium, and are a good protein source. They also contain the micronutrients phosphorus, niacin, selenium, vitamin B12 and potassium.
However, typical farm-raised tilapia (the least expensive and most popular source) have low levels of omega-3 fatty acids (the essential nutrient that is an important reason that dieticians recommend eating fish), and a relatively high proportion of omega-6. “Ratios of long-chain omega-6 to long-chain omega-3, AA to EPA, respectively, in tilapia averaged about 11:1, compared to much less than 1:1 (indicating more EPA than AA) in both salmon and trout,” reported a study published in July 2008. The report suggests the nutritional value of farm-raised tilapia may be compromised by the amount of corn included in the feed. The corn contains short-chain omega-6 fatty acids that contribute to the buildup of these materials in the fish.
The lower amounts of omega-3 and the higher ratios of omega-6 fats in US-farmed tilapia raised questions about the health benefits of consuming farmed tilapia fish. Some media reports even controversially suggested that farm-raised tilapia may be worse for the heart than eating bacon or a hamburger. This prompted the release of an open letter, signed by 16 science and health experts from around the world, that stated that both oily (i.e. high in omega-3 fatty acids) fish and lean fish like tilapia are an important part of the diet and concluded that “replacing tilapia or catfish with ‘bacon, hamburgers or doughnuts’ is absolutely not recommended.”
Multiple studies have evaluated the effects of adding flaxseed derivatives (a vegetable source of omega-3 fatty acids) to the feed of farmed tilapia. These studies have found both the more common omega-3 fatty acid found in the flax, ALA and the two types almost unique to animal sources (DHA and EPA), increased in the fish fed this diet. Guided by these findings, tilapia farming techniques could be adjusted to address the nutritional criticisms directed at the fish while retaining its advantage as an omnivore capable of feeding on economically and environmentally inexpensive vegetable protein. Adequate diets for salmon and other carnivorous fish can alternatively be formulated from protein sources such as soybean, although soy-based diets may also change in the balance between omega-6 and omega-3 fatty acids.
The US produced 1.5 million tons of tilapia in 2005, with 2.5 million projected by 2010.
Tilapia serve as a natural, biological control for most aquatic plant problems. Tilapia consume floating aquatic plants, such as duckweed watermeal (Lemna sp.), most “undesirable” submerged plants, and most forms of algae. In the United States and countries such as Thailand, they are becoming the plant control method of choice, reducing or eliminating the use of toxic chemicals and heavy metal-based algaecides.
Tilapia rarely compete with other “pond” fish for food. Instead, because they consume plants and nutrients unused by other fish species and substantially reduce oxygen-depleting detritus; adding tilapia often increases the population, size and health of other fish.
Arizona stocks tilapia in the canals that serve as the drinking water sources for the cities of Phoenix, Mesa and others. The fish help purify the water by consuming vegetation and detritus, greatly reducing purification costs.
Arkansas stocks many public ponds and lakes to help with vegetation control, favoring tilapia as a robust forage species and for anglers.
In Kenya, tilapia help control mosquitoes which carry malaria parasites. They consume mosquito larvae, which reduces the numbers of adult females, the disease’s vector.
Tilapia also provide an abundant food source for aquatic predators.
Tags: Atlantic, Atlantic Ocean, Fish, Indian Ocean, International Game Fish Association, SeaWeb, Swordfish, United States
Swordfish (Xiphias gladius; from Greek ξίφος: sword, and Latin gladius: sword), also known as broadbill in some countries, are large,
highly migratory, predatory fish characterized by a long, flat bill. They are a popular sport fish of the billfish category, though elusive. Swordfish are elongated, round-bodied, and lose all teeth and scales by adulthood. These fish are found widely in tropical and temperate parts of the Atlantic, Pacific and Indian oceans, and can typically be found from near the surface to a depth of 550 m (1,800 ft). They commonly reach 3 m (9.8 ft) in length, and the maximum reported is 4.55 m (14.9 ft) in length and 650 kg (1,400 lb) in weight.
They are the sole member of their family Xiphiidae.
The swordfish is named after its bill resembling a sword (Latin gladius). This makes it superficially similar to other billfish such as marlin, but upon examination their physiology is quite different and they are members of different families.
They commonly reach 3 m (9.8 ft) in length, and the maximum reported is 4.55 m (14.9 ft) in length and 650 kg (1,400 lb) in weight. The International Game Fish Association‘s all-tackle angling record for a swordfish was a 1,182 lb (536 kg) specimen taken off Chile in 1953. Females are larger than males, and Pacific swordfish reach a greater size than northwest Atlantic and Mediterranean swordfish. They reach maturity at 4–5 years of age and the maximum age is believed to be at least 9 years.
Swordfish are ectothermic animals; however, swordfish, along with some species of shark, have special organs next to their eyes to heat their eyes and brain. Temperatures of 10 to 15 °C above the surrounding water temperature have been measured. The heating of the eyes greatly improves their vision, and consequently improves their ability to catch prey. Out of the 25,000+ fish species, only 22 are known to have a mechanism to conserve heat. These include the swordfish, marlin, tuna and some sharks.
Contrary to popular belief, the “sword” is not used to spear, but instead may be used to slash at its prey in order to injure the prey animal, to make for an easier catch. Mainly the swordfish relies on its great speed and agility in the water to catch its prey. It is undoubtedly among the fastest fish, but the basis for the frequently quoted speed of 60 mph (97 km/h) is unreliable.
Swordfish prefer water temperatures between 18 °C (64 °F) and 22 °C (72 °F), but have the widest tolerance among billfish and can be found from 5 °C (41 °F) to 27 °C (81 °F). This highly migratory species typically moves towards colder regions to feed during the summer. Swordfish feed daily, most often at night when they rise to surface and near-surface waters in search of smaller fish. During the day they commonly occur to depths of 550 m (1,800 ft) and have exceptionally been recorded as deep as 2,878 m (9,442 ft). Adults feed on a wide range of pelagic fish such as mackerel, barracudinas, silver hake, rockfish, herring and lanternfishes, but they also take demersal fish, squid and crustaceans. In the northwestern Atlantic, a survey based on the stomach content of 168 individuals found that 82% had eaten squid and 53% had eaten fish, including gadids, scombrids, butterfish, bluefish and sand lance. Large prey-items are typically slashed with the sword, while small are swallowed whole.
Swordfish are not schooling fish. They swim alone or in very loose aggregations, separated by as much as 10 m (33 ft) from a neighboring swordfish. They are frequently found basking at the surface, airing their first dorsal fin. Boaters report this to be a beautiful sight, as is the powerful jumping for which the species is known. This jumping, also called breaching, is thought by some researchers to be an effort to dislodge pests, such as remora or lampreys. Almost 50 species of parasites have been documented in swordfish. In addition to remoras, lampreys and cookiecutter shark, this includes a wide range of invertebrates such as tapeworms, roundworms and copepods.
Except for humans, fully adult swordfish have few enemies. Among marine mammals, killer whales sometimes prey on adult swordfish. The shortfin mako, an exceptionally fast species of shark, sometimes take on swordfish; dead or dying shortfin makos have been found with broken off swords in their head, revealing the potential danger of this type of prey. Juvenile swordfish are far more vulnerable to predation and are eaten by a wide range of predatory fish.
Swordfish have been fished widely since ancient times, among others in the sea between Sicily and Calabria, such as off the Tyrrhenian coast in the Reggio province. It is a typical dish in the cuisine of this region.
Swordfish were harvested by a variety of methods at small scale (notably harpoon fishing) until the global expansion of long-line fishing.
Swordfish are vigorous, powerful fighters. When hooked or harpooned, they have been known to dive so quickly that they have impaled their swords into the ocean bottom up to their eyes. Although there are no reports of unprovoked attacks on humans, swordfish can be very dangerous when harpooned. They have run their swords through the planking of small boats when hurt.
Recreational fishing has developed a sub-specialty called swordfishing. Because there is a ban on long-lining along many parts of seashore, swordfish populations are showing signs of recovery from the overfishing caused by long-lining along the coast.
There are various ways to fish for swordfish, but the most common method is deep-drop fishing since swordfish spend most daylight hours very deep. The boat is allowed to drift to present a more natural bait. Swordfishing requires strong fishing rods and reels as swordfish can become quite large, and it is not uncommon to use 5 pounds or more of weight to get the baits deep enough during the day, up to 2000 feet is common. Night time fishing baits are usually fished much shallower, often less than 300 feet. Standard baits are whole mackerel, herring, mullet, bonito or squid; one can also use live bait. Imitation squids and other imitation fish lures can also be used, and specialized lures made specifically for sword fishing often have battery powered or glow lights. Even baits are typically presented using glow sticks or specialized deep water proof battery operated lights.
Swordfish are classified as oily fish. Many sources including the United States Food and Drug Administration warn about potential toxicity from high levels of methylmercury in swordfish. The FDA recommends that young children, pregnant women, and women of child-bearing age not eat swordfish.
The flesh of some swordfish can acquire an orange tint, reportedly from their diet of shrimp or other prey. Such fish are sold as “pumpkin swordfish,” and command a premium over their whitish counterparts. (Information from U.S. vendor Whole Foods.)
Swordfish is a particularly popular fish for cooking. Since swordfish are large animals, meat is usually sold as steaks, which are often grilled. Swordfish meat is relatively firm, and can be cooked in ways more fragile types of fish cannot (such as over a grill on skewers). The color of the flesh varies by diet, with fish caught on the east coast of North America often being rosier.
campaign to promote their assertion that the swordfish population was in danger due to its popularity as a restaurant entree.
The resulting “Give Swordfish a Break” promotion was wildly successful, with 750 prominent U.S. chefs agreeing to remove North Atlantic swordfish from their menus, and also persuaded many supermarkets and consumers across the country.
The advertising campaign was repeated by the national media in hundreds of print and broadcast stories, as well as extensive regional coverage. It earned the Silver Anvil award from the Public Relations Society of America as well as Time magazine’s award for the top five environmental stories of 1998.
Subsequently, the US National Marine Fisheries Service proposed a swordfish protection plan that incorporated the campaign’s policy suggestions. Then-US President Bill Clinton called for a ban on the sale and import of swordfish and in a landmark decision by the federal government, 132,670 sq mi (343,600 km2) of the Atlantic ocean were placed off-limits to fishing as recommended by the sponsors.
In the North Atlantic, the swordfish stock is fully rebuilt, with biomass estimates currently 5% above the target level. There are no robust stock assessments for swordfish in the northwestern Pacific or South Atlantic, and there is a paucity of data concerning stock status in these regions. These stocks are considered unknown and a moderate conservation concern. The southwestern Pacific stock is a moderate concern due to model uncertainty, increasing catches, and declining CPUEs (catch per unit effort). Overfishing is likely occurring in the Indian Ocean, and fishing mortality exceeds the maximum recommended level in the Mediterranean, thus these stocks are considered of high conservation concern.
In 2010, Greenpeace International has added the swordfish to its seafood red list. “The Greenpeace International seafood red list is a list of fish that are commonly sold in supermarkets around the world, and which have a very high risk of being sourced from unsustainable fisheries.”
Tags: Black pepper, Common sole, cook, Dover, Home, North Sea, Sole (fish), Soleidae
the name sole is also applied to various other similar flatfish, especially other members of the sole suborder Soleoidei as well as members of the flounder family. In European cookery, there are several species which may be considered true soles, but the common or Dover sole Solea solea, often simply called the sole, is the most esteemed and most widely available.
The word sole in English and French comes from its resemblance to a sandal, Latin solea. In other languages, it is named for the tongue, e.g. German Seezunge, Hungarian nyelvhal, Italian sogliola, Spanish lenguado, Turkish dil.
A complete list can be found using Fishbase’s search function. They include:
* In the sole suborder Soleoidei:
* The true soles, Soleidae, including the common or Dover sole, Solea solea. These are the only fishes called soles in Europe.
* The American soles, Achiridae, sometimes classified among the Soleidae.
* The tonguefishes or tongue soles, Cynoglossidae, whose common names usually include the word ‘tongue’.
* Several species of righteye flounder in the family Pleuronectidae, including the lemon sole, the Pacific Dover sole, and the petrale sole.
The true sole, Solea solea, is sufficiently broadly distributed that it is not considered a threatened species; however, overfishing in Europe has produced severely diminished populations, with declining catches in many regions. For example, the western English Channel and Irish Sea sole fisheries face potential collapse according to data in the UK Biodiversity Action Plan.
Sole, along with the other major bottom-feeding fish in the North Sea such as cod, monkfish, and plaice, is listed by the ICES as “outside safe biological limits.” Moreover, they are growing less quickly now and are rarely older than six years, although they can reach forty. World stocks of large predatory fish and large ground fish such as sole and flounder were estimated in 2003 to be only about 10% of pre-industrial levels. According to the World Wildlife Fund in 2006, “of the nine sole stocks, seven are overfished with the status of the remaining two unknown.”
In 2010, Greenpeace International has added the common sole to its seafood red list. “The Greenpeace International seafood red list is a list of fish that are commonly sold in supermarkets around the world, and which have a very high risk of being sourced from unsustainable fisheries.
Pan Fried Sole Fish With Lemon-Butter Sauce
8 sole fillets
1/2 cup flour
1/2 teaspoon sea salt
1/4 teaspoon black pepper ( or to taste)
7 tablespoons butter
1/4 cup fresh lemon juice
2 tablespoons chopped fresh parsley
* Mix the flour with seasoned salt and pepper in a shallow dish.
* Dredge the fish fillets in the flour mixture.
* Heat a large skillet over high heat.
* Add in about 3 tablespoons butter to the hot skillet.
* Saute the fillets in 2 batches, cooking on each side (on high heat about 2 minutes per side) or until just cooked through; transfer the fish to a plate to keep warm.
*Add in the remaining 4 tablespoons butter and cook until golden in colour; add in lemon juice, bring to a boil and add in the parsley.
* Season the sauce with salt and pepper.
* Pour the warm sauce over the fish.
* Serve immediately
Tags: Alaska, Atlantic, Atlantic Ocean, Atlantic Salmon, Chinook, Pacific, Pacific Ocean, Salmon
Salmon /ˈsæmən/ is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are
called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true. Salmon live along the coasts of both the North Atlantic (the migratory species Salmo salar) and Pacific Oceans (half a dozen species of the genus Oncorhynchus), and have also been introduced into the Great Lakes of North America. Salmon are intensively produced in aquaculture in many parts of the world.
Typically, salmon are anadromous: they are born in fresh water, migrate to the ocean, then return to fresh water to reproduce. However, populations of several species are restricted to fresh water through their lives. Folklore has it that the fish return to the exact spot where they were born to spawn; tracking studies have shown this to be true, and this homing behavior has been shown to depend on olfactory memory.
The term “salmon” derives from the Latin salmo, which in turn may have originated from salire, meaning “to leap”. The nine commercially important species of salmon occur in two genera. The genus Salmo contains the Atlantic salmon, found in the north Atlantic. The genus Oncorhynchus contains eight species which occur naturally only in the north Pacific. Chinook salmon have been introduced in New Zealand. As a group, these are known as Pacific salmon.
* Atlantic salmon (Salmo salar) reproduces in northern rivers on both coasts of the Atlantic Ocean.
* Landlocked salmon (Salmo salar m. sebago) live in a number of lakes in eastern North America and in Northern Europe, for instance in lakes Onega, Ladoga, Saimaa, Vänern and Winnipesaukee. They are not a different species from the Atlantic salmon, but have independently evolved a non-migratory life cycle, which they maintain even when they could access the ocean.
* Masu salmon or cherry salmon (Oncorhynchus masou) is found only in the western Pacific Ocean in Japan, Korea and Russia. A land-locked subspecies known as the Taiwanese salmon or Formosan salmon (Oncorhynchus masou formosanus) is found in central Taiwan’s Chi Chia Wan Stream.
* Chinook salmon (Oncorhynchus tshawytscha) is also known in the US as king salmon or blackmouth salmon, and as spring salmon in British Columbia. Chinook are the largest of all Pacific salmon, frequently exceeding 30 lb (14 kg). The name Tyee is used in British Columbia to refer to Chinook over 30 pounds, and in Columbia River watershed, especially large Chinook were once referred to as June hogs. Chinook salmon are known to range as far north as the Mackenzie River and Kugluktuk in the central Canadian arctic, and as far south as the Central California Coast.
* Chum salmon (Oncorhynchus keta) is known as dog, keta, or calico salmon in some parts of the US. This species has the widest geographic range of the Pacific species: south to the Sacramento River in California in the eastern Pacific and the island of Kyūshū in the Sea of Japan in the western Pacific; north to the Mackenzie River in Canada in the east and to the Lena River in Siberia in the west.
* Coho salmon (Oncorhynchus kisutch) is also known in the US as silver salmon. This species is found throughout the coastal waters of Alaska and British Columbia and as far south as Central California (Monterey Bay). It is also now known to occur, albeit infrequently, in the Mackenzie River.
* Pink salmon (Oncorhynchus gorbuscha), known as humpies in southeast and southwest Alaska, are found from northern California and Korea, throughout the northern Pacific, and from the Mackenzie River in Canada to the Lena River in Siberia, usually in shorter coastal streams. It is the smallest of the Pacific species, with an average weight of 3.5 to 4.0 lb (1.6 to 1.8 kg).
* Sockeye salmon (Oncorhynchus nerka) is also known in the US as red salmon. This lake-rearing species is found south as far as the Klamath River in California in the eastern Pacific and northern Hokkaidō island in Japan in the western Pacific and as far north as Bathurst Inlet in the Canadian Arctic in the east and the Anadyr River in Siberia in the west. Although most adult Pacific salmon feed on small fish, shrimp and squid; sockeye feed on plankton they filter through gill rakers. Kokanee salmon is a land-locked form of sockeye salmon.
* The Danube salmon or huchen (Hucho hucho), is the largest permanent fresh water salmonid species.
Salmon is a popular food. Classified as an oily fish, salmon is considered to be healthful due to the fish’s high protein, high omega-3 fatty acids, and high vitamin D content. Salmon is also a source of cholesterol, with a range of 23–214 mg/100 g depending on the species. According to reports in the journal Science, however, farmed salmon may contain high levels of dioxins. PCB (polychlorinated biphenyl) levels may be up to eight times higher in farmed salmon than in wild salmon, but still well below levels considered dangerous. Nonetheless, according to a 2006 study published in the Journal of the American Medical Association, the benefits of eating even farmed salmon still outweigh any risks imposed by contaminants. The type of omega-3 present may not be a factor for other important health functions.
Salmon flesh is generally orange to red, although white-fleshed wild salmon occurs. The natural colour of salmon results from carotenoid pigments, largely astaxanthin, but also canthaxanthin, in the flesh. Wild salmon get these carotenoids from eating krill and other tiny shellfish.
The vast majority of Atlantic salmon available on the world market are farmed (almost 99%), whereas the majority of Pacific salmon are wild-caught (greater than 80%). Canned salmon in the US is usually wild Pacific catch, though some farmed salmon is available in canned form. Smoked salmon is another popular preparation method, and can either be hot or cold smoked. Lox can refer either to cold-smoked salmon or to salmon cured in a brine solution (also called gravlax). Traditional canned salmon includes some skin (which is harmless) and bone (which adds calcium). Skinless and boneless canned salmon is also available.
Raw salmon flesh may contain Anisakis nematodes, marine parasites that cause anisakiasis. Before the availability of refrigeration, the Japanese did not consume raw salmon. Salmon and salmon roe have only recently come into use in making sashimi (raw fish) and sushi.