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Asian arowana refers to several varieties of freshwater fish in the genus Scleropages. Native to Southeast Asia, Asian arowanas inhabit blackwater rivers, slow-moving waters flowing through forested swamps and wetlands. Adults feed on other fish, while juveniles feed on insects.

These popular aquarium fish have special cultural significance in areas influenced by Chinese culture. The name dragon fish stems from their resemblance to the Chinese dragon. This popularity has had both positive and negative effects on their status as endangered species.

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Takifugu is a genus of pufferfish, often better known by the Japanese name Fugu (Japanese: 河豚, literally "river pig"). There are 25 species belonging to the genus Takifugu, which can be found worldwide from about 45° latitude north to 45° latitude south, mostly in salt water, but sometimes also in fresh water or brackish water. Their diet consists mostly of algae, mollusks, invertebrates and sometimes crustaceans. The fish defend themselves by inflating their bodies to several times normal size and by poisoning their predators. These defenses allow the fish to actively explore their environment without much fear of being attacked.

The fish is highly toxic, but despite this — or perhaps because of it — it is considered a delicacy in Japan. Every year a number of people die because they underestimate the amount of poison in the consumed fish parts. The fish is featured prominently in Japanese art and culture.

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Paddlefish (family Polyodontidae) are primitive Chondrostian ray-finned fishes. The paddlefish can be distinguished by its large mouth and its elongated snout called a rostrum (bill). These spatula-like snouts comprise half the length of their entire body. There are only two extant species of these fish: the Chinese and the American paddlefish. These fish are not closely related to sharks, but they do have some body parts that resemble those of sharks such as their skeletons, primarily composed of cartilage, and deeply forked heterocercal tail fins. Paddlefish are one of the oldest fish known to man. Fossil records show that they first appeared 300 to 400 million years ago (50 million years before dinosaurs). In some areas, paddlefish are referred to as "Spoonbill", "Spoonies" or "Spoonbill Catfish".

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Salmon is the common name for several species of fish of the family Salmonidae. Several other fish in the family are called trout. Salmon live in both the Atlantic and Pacific Oceans, as well as the Great Lakes and other land locked lakes.

Typically, salmon are anadromous: they are born in fresh water, migrate to the ocean, then return to fresh water to reproduce. Research shows that usually at least 90% of the fish that spawn in a particular stream were born there. The precise method salmon use to navigate has not been entirely established, though their keen sense of smell is certainly involved. In all species of Pacific salmon, the mature individuals die within a few days or weeks of spawning, a trait known as semelparity. Other species average about two or, perhaps, three spawning events per individual.

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A lamprey (sometimes also called lamprey eel) is a jawless fish with a toothed, funnel-like sucking mouth, with which most species bore into the flesh of other fish to suck their blood. In zoology, lampreys are often not considered to be true fish because of their vastly different morphology and physiology.

Lampreys begin life as burrowing freshwater larvae (ammocoetes). At this stage, they are toothless, have rudimentary eyes, and feed on microorganisms. This larval stage can last five to seven years and hence was originally thought to be an independent organism. After these five to seven years, they transform into adults in a metamorphosis which is at least as radical as that seen in amphibians, and which involves a radical rearrangement of internal organs, development of eyes and transformation from a mud-dwelling filter feeder into an efficient swimming predator, which typically moves into the sea to begin a predatory/parasitic life, attaching to a fish by their mouths, secreting an anticoagulant to the host, and feeding on the blood and tissues of the host. In most species this phase lasts about 18 months. Whether lampreys are predators or parasites is a blurred question.

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The pumpkinseed (Lepomis gibbosus) is a freshwater fish of the sunfish family. It is native to northeastern North America but has been introduced elsewhere in North America as well as throughout much of Europe.

These fish reach a maximum overall length of about 40 cm (16 in). The fish present an oval silhouette and are very narrow laterally; it is their body shape, resembling the seed of a pumpkin, which got them their common name. Pumpkinseeds prefer shallow water with some weed cover. They are often found in ponds and small lakes, preferring water temperatures of 4–22 °C (39–72 °F). They are active during the day and rest near the bottoms during the night. These fish reproduce rapidly and are low on the food chain. The pumpkinseed, like other sunfishes, is very popular among anglers, especially the young.

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The coelacanth ('hollow spine' in Greek, coelia (κοιλιά) meaning hollow and acanthos (άκανθος) spine) is the common name for an order of fish that includes the oldest living lineage of jawed fish known to date. The coelacanths, which are closely related to lungfishes, were believed to have been extinct since the end of the Cretaceous period, until a live specimen was found off the east coast of South Africa, off the Chalumna River in 1938. Since then, they have been found in the Comoros, Sulawesi (Indonesia), Kenya, Tanzania, Mozambique, Madagascar, Greater St. Lucia Wetland Park in South Africa.

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The ocean sunfish (Mola mola) is the heaviest bony fish in the world, with an average weight of 1000 kilograms. The species is native to tropical and temperate waters around the globe. It resembles a fish head without a tail, and its main body is flattened laterally. Sunfish can be as tall as they are long, when their dorsal and anal fins are extended.

Sunfish live on a diet that consists mainly of jellyfish. As this diet is nutritionally poor, they consume large amounts in order to develop and maintain their great bulk. Females of the species can produce more eggs than any other known vertebrate. Sunfish fry resemble miniature pufferfish, with large pectoral fins, a tail fin and body spines uncharacteristic of adult sunfish.

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Tiktaalik is a genus of extinct sarcopterygian (lobe-finned) fishes from the late Devonian period, with many features akin to those of tetrapods (four-legged animals). It is an example from several lines of ancient sarcopterygian fish developing adaptations to oxygen-poor shallow-water habitats at that time, which led to the evolution of amphibians. Well preserved fossils were found in 2004 on Ellesmere Island in Nunavut, Canada.

Tiktaalik lived approximately 375 million years ago. Paleontologists suggest that it was an intermediate form between fish such as Panderichthys, which lived about 385 million years ago, and early tetrapods such as Acanthostega and Ichthyostega, which lived about 365 million years ago. Its mixture of fish and tetrapod characteristics led one of its discoverers, Neil Shubin, to characterize Tiktaalik as a "fishapod".

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The weather loaches or weatherfishes of the genus Misgurnus is a genus of loaches in Asia and Europe. They receive their common name from the ability to detect changes in barometric pressure and react with frantic swimming or standing on end. This is because before a storm the barometric pressure changes, and this is known to make these fish more active.

The dojo loach, or Misgurnus anguillicaudatus, an Asian weather loach species, is a common aquarium and food fish. Like many other loaches, they are slender and eel-like. They can vary in color from yellow to olive green, to a common light brown or gray with lighter undersides. The mouth of the loach is surrounded by three sets of barbels. It uses them to sift through silt or pebbles to find food. It also uses them to dig under gravel and sand to conceal itself out of nervousness or defense unlike the other loaches who use the spines beneath the eyes.

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Seahorses are a genus (Hippocampus) of fish belonging to the family Syngnathidae, which also includes pipefish and leafy sea dragons. There are over 32 species of seahorse, mainly found in shallow tropical and temperate waters throughout the world. They prefer to live in sheltered areas such as sea grass beds, coral reefs, or mangroves. Colonies have been found in European waters such as the Thames Estuary. From North America down to South America there are approximately four species, ranging from very small in size (dwarf seahorses are only about an inch long) to those much larger, found off the Pacific Coast of Central America (the foot-long Hippocampus ingens). Hippocampus erectus are larger seahorses found anywhere from Nova Scotia down to around Uruguay. Three different species of seahorse live in the Mediterranean Sea: Hippocampus hippocampus (long snout), Hippocampus brevirostris (short snout) and Hippocampus fuscus (immigrated from the Red Sea). These fish form territories, with males staying in about one square meter of their habitat while females range about one hundred times that area. They bob around in sea grass meadows, mangrove stands, and coral reefs where they are camouflaged by murky brown and grey patterns that blend into the sea grass backgrounds. During social moments or in unusual surroundings, seahorses turn bright colors.

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Tetraodontidae is a family of primarily marine and estuarine fish. The family includes many familiar species which are variously called puffers, balloonfish, blowfish, bubblefish, globefish, swellfish, toadfish, and toadies. They are morphologically similar to the closely related porcupinefish, which have large conspicuous spines (unlike the small, almost sandpaper-like spines of Tetraodontidae). The scientific name, Tetraodontidae, refers to the four large teeth, fused into an upper and lower plate, which are used for crushing the shells of crustaceans and mollusks, and red worms, their natural prey.

Puffer fish are the second most poisonous vertebrate in the world, the first being a Golden Poison Frog. The skin and certain internal organs of many tetraodontidae are highly toxic to humans, but nevertheless the meat of some species is considered a delicacy in both Japan (as fugu) and Korea (as bok). If one is caught while fishing, it is recommended that thick gloves be worn to avoid poisoning and getting bitten when removing the hook.

The tetraodontidae contains at least 121 species of puffers in 19 genera. They are most diverse in the tropics and relatively uncommon in the temperate zone and completely absent from cold waters. They are typically small to medium in size, although a few species can reach lengths of 100 centimetres (39 in).

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