phd in fisheries in canada

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Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place (a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both in freshwater bodies (about 10% of all catch) and the oceans (about 90%). About 500 million people worldwide are economically dependent on fisheries. 171 million tonnes of fish were produced in 2016, but overfishing is an increasing problem — causing declines in some populations.

Because of their economic and social importance, fisheries are governed by complex fisheries management practices and legal regimes, that vary widely across countries. Historically, fisheries were treated with a “first-come, first-served ” approach; however threats by human overfishing and environmental issues, have required increased regulation of fisheries to prevent conflict and increase profitable economic activity on the fishery. Modern jurisdiction over fisheries is often established by a mix of international treaties and local laws.

Declining fish populations, marine pollutions and destruction of important coastal ecosystems has introduced increasing uncertainty in important fisheries worldwide, threatening economic security and food security in many parts of the world. These challenges are further complicated by the changes in the ocean caused by climate change, which may extend the range of some fisheries while dramatically reducing the sustainability of other fisheries. International attention to these issues has been captured in Sustainable Development Goal 14 “Life Below Water” which sets goals for international policy focused on preserving coastal ecosystems and supporting more sustainable economic practices for coastal communities, including in their fishery and aquaculture practices.

The term fish

  • In biology – the term fish is most strictly used to describe any animal with a backbone that has gills throughout life and has limbs, if any, in the shape of fins. Many types of aquatic animals commonly referred to as fish are not fish in this strict sense; examples include shellfish, cuttlefish, starfish, crayfish and jellyfish. In earlier times, even biologists did not make a distinction—sixteenth century natural historians classified also seals, whales, amphibians, crocodiles, even hippopotamuses, as well as a host of marine invertebrates, as fish.
  • In fisheries – the term fish is used as a collective term, and includes mollusks, crustaceans and any aquatic animal which is harvested.
  • True fish – The strict biological definition of a fish, above, is sometimes called a true fish. True fish are also referred to as finfish or fin fish to distinguish them from other aquatic life harvested in fisheries or aquaculture

Economic importance

Directly or indirectly, the livelihood of over 500 million people in developing countries depends on fisheries and aquaculture. Overfishing, including the taking of fish beyond sustainable levels, is reducing fish stocks and employment in many world regions. It was estimated in 2014 that global fisheries were adding US$270 billion a year to global GDP, but by full implementation of sustainable fishing, that figure could rise by as much as US$50 billion.

In addition to commercial and subsistence fishing, recreational (sport) fishing is popular and economically important in many regions.


Total fish production in 2016 reached an all-time high of 171 million tonnes, of which 88 percent was utilized for direct human consumption, thanks to relatively stable capture fisheries production, reduced wastage and continued aquaculture growth. This production resulted in a record-high per capita consumption of 20.3 kg in 2016. Since 1961 the annual global growth in fish consumption has been twice as high as population growth. While annual growth of aquaculture has declined in recent years, significant double-digit growth is still recorded in some countries, particularly in Africa and Asia.

FAO predicted in 2018 the following major trends for the period up to 2030:

  • World fish production, consumption and trade are expected to increase, but with a growth rate that will slow over time.
  • Despite reduced capture fisheries production in China, world capture fisheries production is projected to increase slightly through increased production in other areas if resources are properly managed. Expanding world aquaculture production, although growing more slowly than in the past, is anticipated to fill the supply–demand gap.
  • Prices will all increase in nominal terms while declining in real terms, although remaining high.
  • Food fish supply will increase in all regions, while per capita fish consumption is expected to decline in Africa, which raises concerns in terms of food security.
  • Trade in fish and fish products is expected to increase more slowly than in the past decade, but the share of fish production that is exported is projected to remain stable.

What is Fisheries

1.The science of producing fish and other aquatic resources for the purpose of providing human food, although other aims are possible (such as sport or recreational fishing), or obtaining ornamental fish or fish products such as fish oil. Learn more in: The CGIAR Virtual Library Bridging the Gap Between Agricultural Research and Worldwide Users2.The activity of catching fish and other living organisms from the wild aiming to be consumed as seafood. Fisheries are harvested for their value either commercial, recreational, or self-consumption

Types of fisheries

Capture fisheries are extremely diversified, comprising a large number of types of fisheries that are categorized by different levels of classification. On a broad level, capture fisheries can be classified as industrial, small-scale/artisanal and recreational. A more specific level includes reference to the fishing area, gear and the main target species, such as the North Sea herring purse seine fishery, Gulf of Mexico shrimp trawl fishery, southern ocean Patagonian toothfish longline fishery. While capture fisheries encompass thousands of fisheries on a global scale, they are often categorized by the capture species, the fishing gear used and the level at which a fishery is managed nationally and/or regionally.

The following brief descriptions provide an overview of capture fishery types.

Industrial fisheries

Capital-intensive fisheries using relatively large vessels with a high degree of mechanization and that normally have advanced fish finding and navigational equipment. Such fisheries have a high production capacity and the catch per unit effort is normally relatively high. In some areas of the world, the term “industrial fisheries” is synonymous with fisheries for species that are used for reduction to fishmeal and fish oil (e.g. the trawl fishery for sandeel in the North Sea or the Peruvian ourse-seine fishery for anchoveta).

Small-scale fisheries

Labour-intensive fisheries using relatively small crafts (if any) and little capital and equipment per person-on-board. Most often family-owned. May be commercial or for subsistence (see below). Usually low fuel consumption. Often equated with artisanal fisheries.

Artisanal fisheries

Typically traditional fisheries involving fishing households (as opposed to commercial companies), using relatively small amount of capital, relatively small fishing vessels, making short fishing trips, close to shore, mainly for local consumption. In practice, definition varies between countries, e.g. from hand-collection on the beach or a one-person canoe in poor developing countries, to more than 20 m. trawlers, seiners, or long-liners over 20m in developed countries. Artisanal fisheries can be subsistence or commercial fisheries, providing for local consumption or export. Sometimes referred to as small-scale fisheries In general, though by no means always, using relatively low level technology. Artisanal and industrial fisheries frequently target the same resources that may give rise to conflict.

Recreational (sport) fisheries

Harvesting fish for personal use, leisure, and challenge (e.g. as opposed to profit or research). Recreational fishing does not include sale, barter or trade of all or part of the catch.

Commercial fisheries

Fisheries undertaken for profit and with the objective to sell the harvest on the market, through auction halls, direct contracts, or other forms of trade.

Subsistence fisheries

A fishery where the fish caught are shared and consumed directly by the families and kin of the fishers rather than being bought by intermediaries and sold at the next larger market. Pure subsistence fisheries are rare as part of the products are often sold or exchanged for other goods or services

Traditional fisheries

Fisheries established long ago, usually by specific communities that have developed customary patterns of rules and operations. Traditional fisheries reflect cultural traits and attitudes and may be strongly influenced by religious practices or social customs. Knowledge is transmitted between generations by word of mouth. They are usually small-scale and/or artisanal.

What’s The Difference Between Fishing and Aquaculture?

Many people do not realize that there is a difference between fishing and aquaculture, so it is important to distinguish between them.

Fishing is the harvesting of already existing populations of fish and other aquatic animals. (Seaweed harvesting is a separate activity.)

Aquaculture is the purposeful cultivation and subsequent harvesting of both freshwater and marine aquatic plants and animals. The cultivation of marine animals is by far the most important sector of aquaculture.

Importance of fisheries for food security across three climate change vulnerable deltas

Deltas are home to a large and growing proportion of the world’s population, often living in conditions of extreme poverty. Deltaic ecosystems are ecologically significant as they support high biodiversity and a variety of fisheries, however these coastal environments are extremely vulnerable to climate change. The Ganges-Brahmaputra-Meghna (Bangladesh/India), the Mahanadi (India), and the Volta (Ghana) are among the most important and populous delta regions in the world and they are all considered at risk of food insecurity and climate change. The fisheries sector is vital for populations that live in the three deltas, as a source of animal protein (in Bangladesh and Ghana around 50–60% of animal protein is supplied by fish while in India this is about 12%) through subsistence fishing, as a source of employment and for the wider economy. The aquaculture sector shows a rapid growth in Bangladesh and India while in Ghana this is just starting to expand. The main exported species differ across countries with Ghana and India dominated by marine fish species, whereas Bangladesh exports shrimps and prawns.

Fisheries play a more important part in the economy of Bangladesh and Ghana than for India, both men and women work in fisheries, with a higher proportion of women in the Volta then in the Asian deltas. Economic and integrated modelling using future scenarios suggest that changes in temperature and primary production could reduce fish productivity and fisheries income especially in the Volta and Bangladesh deltas, however these losses could be mitigated by reducing overfishing and improving management. The analysis provided in this paper highlights the importance of applying plans for fisheries management at regional level. Minimizing the impacts of climate change while increasing marine ecosystems resilience must be a priority for scientists and governments before these have dramatic impacts on millions of people’s lives.

What is a PhD in Aquaculture & Fisheries?

Aquaculture and fisheries refer to breeding and harvesting water plants and animals for commercial purposes. The aquaculture discipline studies biological processes related to fish farming technologies. The field of aquaculture assists in the demand for seafood and also enables existing fisheries remain sustainable and consistent. The aquaculture and fisheries discipline borrows theories from other disciplines like: biology, animal sciences, biodiversity and conservation.

Topics covered by programmes in aquaculture and fisheries include: animal diversity, introductory microbiology, shellfish aquaculture, genetics of fish, politics of the ocean, fish processing, aquaculture systems engineering.

By studying aquaculture and fisheries, future professionals use theories and concepts, develop knowledge of animal breeding, processing and evaluation of their productions. Students will understand and adapt scientific knowledge in aquaculture and natural resource conservation, planning and development. An aquaculture specialist will keep up to date with innovations in the fisheries sector and may take up responsibilities such as protecting resources from overfishing, the dangers of industrial waste and pollution.

Career prospects for graduates cover jobs like: technicians and managers in fish farms, scientific observers, fishing fleet and regional fisheries managers, biologists in organisations such as aqua or fish centres.

PhD Position in Aquaculture Economics

The Norwegian College of Fishery Science (NCFS), UiT The Arctic University of Norway has a PhD position vacant in Aquaculture economics – for applicants who wish to obtain the degree of Philosophiae Doctor (PhD). The position is attached to the research group Marine Resource Economics.

The appointment is for a period of four years. 

The PhD position is for a fixed term, with the objective of completion of research training to the level of a doctoral degree. Admission to a PhD programme is a prerequisite for employment, and the programme period starts on commencement of the position. The PhD Candidate shall participate in the faculty’s organized research training, and the PhD project shall be completed during the period of employment. Information about the application process for admission to the PhD programme and regulations for the degree of Philosophiae Doctor (PhD) are available at the following address Faculty of Biosciences, Fisheries and Economics.

The Norwegian College of Fishery Science (NCFS) is a part of The Faculty of Biosciences, Fisheries and Economics  (BFE) and undertakes research and research-based teaching of high national and international quality in an interdisciplinary environment. Research activity is provisionally organized into the groups of: Living Marine Resources, Sea Food Science, Fish Health, Marine Drug Discovery, Resource Management, Marine Management and Resource Economics.

The purpose of this PhD project is to analyze supply chains and global demand for seafood, with focus on salmon and potentially other seafood that Norway is a major producer of. This requires the use of econometric methods, with focus on price transmission and/or demand analysis in various markets. The results from the analyses will be used to develop an economic model of the market(s) in question with the purpose of determining the effects of historical and future supply and demand shocks. The applicant should be willing to stay abroad for some of the working period to complete PhD courses.

Fisheries Branch

Anadromous Conservation and Management

California is home to several anadromous fish species characterized by spending the majority of their lives in estuarine or marine waters and returning to fresh water to spawn. Native anadromous fishes are widely distributed in California and represented by families of jawless lamprey (Petromyzontidae); cartilaginous, bony-plated sturgeons (Acipenseridae); highly migratory salmon and steelhead trout (Salmonidae); and the small, short-lived smelts (Osmeridae). Because of their dietary, commercial, recreational, tribal, ecologic, and cultural significance, every anadromous species has been the focus of various efforts for conservation, protection, management, and recovery.

The Anadromous Conservation and Management Program is a focus of CDFW efforts and, along with NOAA Fisheries, has been developing a statewide plan to initiate standard monitoring of coastal populations of anadromous fish species from San Diego to Del Norte counties, and expanding into the Central Valley. Scientists work closely with partners and constituents to address applied research necessary to implement sound conservation and population recovery measures.

Inland Fisheries Conservation and Management

Inland Fisheries Conservation and Management consist of multiple programs responsible for conservation, recovery, and management of inland fish species. These programs and associated staff are responsible for fish species conservation including: developing management plans and recommending and conducting management actions; designing, conducting and overseeing resource assessment, monitoring, and research; coordinating habitat enhancement projects; developing angling regulation recommendations, and overseeing angling recognition projects.

Programs and Staff

Fish Production and Aquatic Pathology

CDFW operates 22 cold water fish hatcheries statewide and is one of the largest producers of trout and salmon in North America. The basic objectives of the CDFW trout and salmon hatcheries are conservation, mitigation, and recreation. The CDFW operates 13 trout and inland salmon hatcheries and 9 anadromous salmon and steelhead hatcheries. These facilities operate in the remote redwood forests of the north to the deserts of the south.

Along with supporting conservation efforts and commercial, tribal, and recreational fishing, CDFW fish hatcheries are fun and educational places to visit with many offering great wildlife viewing and picnic areas as well as educational programs for visitors. The CDFW directory of hatcheries describes the individual hatcheries including fish species, locations, driving directions, history of the hatcheries and much, much more!

Programs and Staff

Invasive Species

The Invasive Species Program participates on efforts to prevent the introduction of non-native invasive species in California, detect and respond to introductions when they occur, and prevent the spread of non-native invasive species that have become established.

What are 3 types of fish?

The following classification has been derived primarily from the works of British ichthyologists C. Patterson, R. Miles, P.H. Greenwood, and K.S. Thomson and American ichthyologist D.E. Rosen, with extensive modifications from American ichthyologists G.D. Johnson, W.N. Eschmeyer, M.L.J. Stiassny, L.R. Parenti, S.V. Frank, and W.L. Fink and Canadian ichthyologist J.S. Nelson, among others. Fishes are typically divided into three groups: superclass Agnatha (jawless fishes), class Chondrichthyes (cartilaginous fishes), and superclass Osteichthyes (bony fishes). The latter two groups are included within the infraphylum Gnathostomata, a category containing all jawed vertebrates.

  • SUPERCLASS AGNATHA (jawless fishes)Vertebrates with a suctorial or filter-feeding mouth; no true jaws; 2 (possibly 1 sometimes) semicircular canals; pelvic fins lacking; pectoral finlike structures, when present, lacking fin rays; persistent notochord, without bone or cartilage; bony skeleton, when present, formed in skin; true gill arches absent, gill basket present. Habitat of fossil groups uncertain; earliest probably in fresh water. About 113 living species.
    • Class Myxini
      • Order Myxiniformes(hagfishes)Without dermal ossification of any sort; pectoral appendages absent; eyes poorly developed; 1–16 pairs of external gill openings; tail more or less diphycercal. Primarily bottom-dwelling fishes, but suctorial, rasping and feeding on flesh of dead or dying fishes; horny teeth present. Length about 15–110 cm (roughly 6–43 inches). About 70 species. Marine. Pennsylvanian to present.
    • Class Cephalaspidomorphi (Monorhina)
      • Order Petromyzontiformes(lampreys)Without dermal ossification of any sort; pectoral appendages absent; eyes more or less lateral or dorsal; 7 pairs of external gill openings; tail more or less diphycercal. Primarily bottom-dwelling fishes, but suctorial, feeding on blood and juices of live fishes; horny teeth present. Species are either parasitic or nonparasitic. Length about 15–100 cm (roughly 6–39 inches). About 43 species. Freshwater and marine, breeding in fresh water. Pennsylvanian and present.
  • CLASS CHONDRICHTHYES (OR SELACHII) (cartilaginous fishes)Cartilaginous fishes. Lacks true bone (except in the roots of teeth). Gill clefts: 5–7 in Selachii, 5 gill openings occur on the lower surface of Batoidei, and only 1 in Chimaeriformes. Dorsal fin, fins, and fin spines rigid, not erectile, if present. Approximately 940 species.
    • Subclass ElasmobranchiiChondrichthians with 5–7 pairs of gill clefts not covered by a fold of skin, opening separately to the exterior.
      • Order Selachii (sharks)Elasmobranchs with gill clefts opening at least partly on the side of the body. More than 400 species.
      • Order Batoidei (rays, sawfishes, guitarfishes, skates, and stingrays)5 gill openings, wholly on ventral surface; pectoral fins united with sides of head forward past the gill opening. Differ from all sharks in lacking upper free eyelid. More than 500 species. Jurassic to present.
    • Subclass HolocephaliJaws holostylic (the palatoquadrate) supporting the upper jaw completely fused to cranium; hyoid arch complete, unmodified; branchial arches below cranium; internal skeleton of cartilage, often calcified but never of bone; dermal skeleton of dentine or dentinelike tissue (placoid scales), never with true bone; scales do not continue to grow once fully formed; pelvic and cephalic claspers in males of some groups. About 40 species.
      • Order Chimaeriformes (chimaeras)Teeth in a single series of a few tooth plates along each jaw ramus (half); pectoral with 2, and pelvic fins with 1 basal element; pelvic fin claspers present; dermal armour frequently present on head; primitive forms with placoid scales covering body, lost in certain advanced forms; scales specialized in some; dorsal fin spine present or absent; cephalic clasper present in some. Marine. Late Devonian to present.
    • Class Actinopterygii (ray-finned fishes)Fins supported by rays of dermal bone rather than by cartilage. A group of jawed fishes so diverse that no single definition for them can be derived; better understood by determining the distinctive characters of the primitive members and then tracing their various lines of evolution. Primitive actinopterygians can be separated from the sarcopterygians by the following characteristics: scales ganoid; single dorsal fin; pectoral fins with a series of thin radial bones, rather than basal plates and fleshy lobes; no internal nares. Other important characters: skeleton usually well ossified; scales grow throughout life; swim bladder present (occasionally modified to a lunglike structure). More than 27,000 living species.
      • Subclass ChondrosteiA mixed group that has undergone many evolutionary diversifications. The remaining orders of the Chondrostei are specialized, often for special habitats and ways of life, but many of the groups show trends toward the holostean level of organization, especially in median fin structure and the development of hemiheterocercal tail, in which externally at least the tail appears nearly homocercal. About 40 living species.
        • Order Acipenseriformes (sturgeons and paddlefishes)Almost no internal ossification; scales as large scutes in isolated rows (Acipenseridae); snout enlarged and tactile (Polyodontidae); median fins chondrostean in having more fin rays than basal elements; tail heterocercal. Length (sturgeons) up to 6 metres (roughly 20 feet), weight to 3,200 kg (roughly 7,000 pounds). Marine and freshwater, bottom suctorial feeders (sturgeons, Acipenseridae; Europe, Asia, North America) carnivores and plankton feeders (paddlefishes, Polyodontidae; China and North America). Middle Jurassic to present.
        • Order Polypteriformes (bichirs and reedfish)Relationships controversial, placed in own subclass by some and thought related to crossopterygians by others. Typical chondrostean characters, such as ganoid scales and a paleoniscoid type of preopercle. Fins modified into long continuous dorsal, tail diphycercal. Freshwater, Africa. Late Cretaceous to present.
      • Infraclass HolosteiParaphyletic group. Tail hemiheterocercal; maxillary scale free of preopercle; rays of median fins about equal basal elements in number; spiracle lost; vertebral column tended to increasing ossification; trend toward thinning scales and loss of ganoid layer. Preoperculum intimately bound to and supporting the posterior border of the palate. About 8 species.
        • Order Amiiformes (bowfins and fossil relatives)Relatively conservative holosteans with typical holostean characters as given above; some specialized in body shape (elongate); most typical fusiform holosteans. 1 living member of the family Amiidae, with 1 species, Amia calva (bowfin), of North America. Marine and freshwater, almost worldwide. Middle Jurassic to present.
        • Order Semionotiformes (gar and fossil relatives)3 (2 extinct and 1 living) families of widely divergent fishes; probably independent of the Amiiformes but with typical holostean characters; length to about 3 metres (roughly 10 feet). Late Permian to present.
      • Infraclass Teleostei(advanced bony fishes)Tail homocercal; caudal skeleton with perichordally (around the spinal cord) ossified centra; neural arches modified into elongate uroneurals extending forward onto the preural centra, “stiffening” the joints between the terminal 4 or 5 vertebrae. 2 hypural bones supporting the lower caudal fin lobe. Teleosts never have ganoid scales; typically, their scales when present are thin, overlapping plates of bone that continue to grow throughout life; their lower jaws lack certain bones found in many chondrosteans or at least have some of these bones fused to single elements. 26,840 living species.
        • Superorder Osteoglossomorpha
          • Order Osteoglossiformes(bonytongues, freshwater butterfly fishes, mooneyes, knife fishes, mormyrs)A diverse group of freshwater fishes with a relatively primitive jaw suspension and shoulder girdle. The primary bite of the mouth between parasphenoid and tongue (basihyal and glossohyal); paired rods present, usually bony, at the base of the 2nd gill arch; no bony ethmoid commissure; no leptocephalus larvae. Some with electricity-producing organs; circumorbital bones well-developed or reduced; scales with an irregular reticulated pattern (except Pantodontidae). 6 living families. About 220 species. Freshwater, almost worldwide except extremely cold regions. Middle Cretaceous to present.
        • Superorder ElopomorphaA diverse group including very primitive fishes and specialized fishes such as eels and therefore difficult to define. Some primitive members with a gular plate (absent in eels), ethmoid commissure present in some forms in a dermal rostral bone (absent in many eels); a leptocephalus larva; no bone cells in scales of primitive members; pelvic fins abdominal when present. More than 740 living species.
          • Order Elopiformes (tarpons and ten-pounders)Body fusiform, typical fishlike shape; bone-enclosed ethmoid commissure present; roofed post-temporal fossae; primary bite a tongue-parasphenoid type. 2 families, 2 genera, and 8 species. Marine; worldwide in temperate and tropical zones. Late Jurassic to present.
          • Order Albuliformes (bonefishes, halosaurs, and deep-sea spiny eels)Snout enlarged; mouth small and underslung; crushing teeth on palate; single supramaxillary bone; gular plate small or absent; 6 hypural bones. Length to 70 cm (28 inches), weight to about 6.5 kg (15 pounds). 3 families (Albulidae, Halosauridae, and Notocanthidae), 8 genera, and about 30 species. Middle Cretaceous to present.
          • Order Anguilliformes (eels)Body elongate; fins reduced and gill chamber modified; displaced posterior to much of head; opercular apparatus reduced; pectoral girdle free of skull; caudal and other fins often greatly reduced; bony ethmoid commissure sometimes present. Length about 15–300 cm (roughly 6–120 inches). 15 families, about 141 genera, and more than 790 species. Marine and freshwater, worldwide in temperate and tropical regions. Cretaceous to present.
          • Order Saccopharyngiformes (gulper eels)Jaws and hyomandibular greatly elongate; caudal fin absentor rudimentary; no opercular bones, branchiostegal rays, scales, pelvic fins or ribs. 4 families, 5 genera, and about 28 species. Marine (some bathypelagic), tropical and temperate Atlantic, Indian and Pacific oceans.
        • Superorder ClupeomorphaSpecial type of ear–swim bladder connection present, consisting of a diverticulum of the swim bladder, forming bulla (cavity) within the ear capsule; head lateral line canals on operculum. A diverse group of mostly oceanic, silvery, compressed fishes, many of great commercial importance.
          • Order Clupeiformes (herrings, anchovies, and allies)Characters of the superorder. More than 400 species, worldwide. Marine and freshwater, some anadromous. Early Cretaceous to present.
        • Superorder OstariophysiA group of some 8,000 species, including the majority of known freshwater fishes.
          • Series Anotophysi
            • Order Gonorynchiformes (milkfish, beaked sandfishes, snake mudheads, and relatives)Toothless; with epibranchial organs and a characteristic caudal skeleton. The anterior ribs and vertebrae show affinities with the superorder Ostariophysi, and the group may belong with the ostariophysans rather than with the Protacanthopterygii. Length about 10–150 cm (roughly 4–60 inches). 4 families, about 37 species. Marine of Indo-Pacific and freshwater of Africa. Cretaceous to present.
          • Series OtophysiCharacterized by possession of a complex Weberian apparatus (a swim bladder–internal ear connection with 4 movable bones).
            • Order CharaciformesMouth not protractile; jaws toothed. Characidae most generalized; other families have specialized skeletal structures, jaws, and teeth. North, Central, and South America, and Africa. 18 families with about 270 genera and nearly 1,700 species. Cretaceous (about 112 million years ago) to present.
            • Order Cypriniformes (carps and minnows)Pharyngeal teeth, mouth toothless, protractile. Adipose fin rarely present. About 3,270 species. A few North Asian forms enter the sea. Worldwide in fresh water except South America, Antarctica and Australia. Paleocene to present.
            • Order Siluriformes (catfishes)Parietal, symplectic, suboperculum, and true scales absent; often with dermal plates or little bony spines in the skin. Fusion of the supportive parts of the Weberian apparatus extensive. About 30 families. Distribution of the superorder primarily freshwater but some families marine, with the majority of the 2,867 species in Africa and South America. Paleocene to present.
            • Order Gymnotiformes (knifefishes, gymnotid and electric eels)Body elongated; anal fin very long; electric organs present, some extraordinarily powerful. Size to 2.2 metres (about 7 feet), weight to 22 kg (48 pounds). About 5 families, 30 genera, and about 134 species. Fossils discovered from Upper Miocene.
        • Superorder ProtacanthopterygiiEpicentral cartilages, absence of proximal forking in the intermuscular bones. Vertebrae usually more than 24; adipose fin present in many members; mesocoracoid bone usually present; glossohyal teeth usually prominent (lost in some); upper jaw usually not protrusible; proethmoid and a series of several perichondral ethmoid commissures; 1 supraorbital bone; no gular plate.