Cyprinodontiformes is an order of ray-finned fish, comprising mostly small, freshwater fish. Many popular aquarium fish, such as killifish and live-bearers, are included. They are closely related to the Atheriniformes and are occasionally included with them. A colloquial term for the order as a whole is toothcarps, though they are not actually close relatives of the true carps – the latter belong to the superorder Ostariophysi, while the toothcarps are Acanthopterygii.
Jellyfish, also known as sea jellies, are the medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria.
Paddlefish are a family of ray-finned fish belonging to order Acipenseriformes, and one of two living groups of the order alongside sturgeons (Acipenseridae). They are distinguished from other fish by their elongated rostra, which are thought to enhance electroreception to detect prey. Paddlefish have been referred to as "primitive fish" because the Acipenseriformes are among the earliest diverging lineages of ray-finned fish, having diverged from all other living groups over 300 million years ago. Both living and fossil paddlefish are found almost exclusively in North America and China.
The marbled hatchetfish is a small, 3.5 cm (1.4 in) in length, freshwater ray-finned fish. The small deep-bodied fish, in the genera Carnegiella, is from the family Gasteropelecidae which includes both Gasteropelecus and Thoracocharax. Native to South America, C. strigata can be found in the Caqueta River in Columbia, the lower, middle, and upper Amazon River Basin, south of Amazon, and can be found in rivers and streams.
The white hawk is a bird of prey breeding in the tropical New World of the family Accipitridae. Though it is commonly placed in the subfamily Buteoninae, the validity of this group is doubtful and currently under review.
The smalleye hammerhead, also called the golden hammerhead or curry shark, is a small species of hammerhead shark in the family Sphyrnidae. This species was historically common in the shallow coastal waters of the western Atlantic Ocean, from Venezuela to Uruguay. It favors muddy habitats with poor visibility, reflected by its relatively small eyes. Adult males and juveniles are schooling and generally found apart from the solitary adult females. Typically reaching 1.2–1.3 m (3.9–4.3 ft) in length, this shark has a unique, bright golden color on its head, sides, and fins, which was only scientifically documented in the 1980s. As in all hammerheads, its head is flattened and laterally expanded into a hammer-shaped structure called the cephalofoil, which in this species is wide and long with an arched front margin bearing central and lateral indentations.
Anablepidae is a family of ray-finned fishes which live in brackish and freshwater habitats from southern Mexico to southern South America. There are three genera with sixteen species: the four-eyed fishes, the onesided livebearers and the white-eye, Oxyzygonectes dovii. Fish of this family eat mostly insects and other invertebrates.
The four-eyed fishes are a genus, Anableps, of fishes in the family Anablepidae. They have eyes raised above the top of the head and divided in two different parts, so that they can see below and above the water surface at the same time.
The bigeye thresher is a species of thresher shark, family Alopiidae, found in temperate and tropical oceans worldwide. Like the other thresher sharks, nearly half its total length consists of the elongated upper lobe of the tail fin. Its common name comes from its enormous eyes, which are placed in keyhole-shaped sockets that allow them to be rotated upward. This species can also be distinguished by a pair of deep grooves on the top of its head, from which its scientific name is derived.
The gag grouper, also known as velvet rockfish, the gag, or charcoal belly, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the anthias and sea basses. It comes from warmer parts of the West Atlantic, including the Caribbean and Gulf of Mexico. It is a drab, mottled-gray fish lacking the distinguishing features of most other groupers. Its pattern of markings resemble the box-shaped spots of the black grouper. It lacks the streamer-points on the tail fin that scamp and yellowmouth grouper have and lacks yellow coloration around the mouth.
Jenynsia is a genus of freshwater fishes in the family Anablepidae. Like Anableps species, they are onesided livebearers: some sources indicate that they only mate on one side, right-"handed" males with left-"handed" females and vice versa. However, other sources dispute this. These South American fish are viviparous.
Salmo obtusirostris, commonly known as the softmouth trout, also known as the Adriatic trout, or Adriatic salmon, is a species of salmonid fish endemic to a handful rivers spilling into Adriatic in the Western Balkans, in southeastern Europe, namely in Bosnia and Herzegovina, Croatia and Montenegro. The scientific name has changed several times through history; synonyms include Thymallus microlepis, Salmothymus obtusirostris and Salar obtusirostris.
The daggernose shark is a little-known species of requiem shark, in the family Carcharhinidae, and the only extant member of its genus. It inhabits shallow tropical waters off northeastern South America, from Trinidad to northern Brazil, favoring muddy habitats such as mangroves, estuaries, and river mouths, though it is intolerant of fresh water. A relatively small shark typically reaching 1.5 m (4.9 ft) in length, the daggernose shark is unmistakable for its elongated, flattened, and pointed snout, tiny eyes, and large paddle-shaped pectoral fins.
Citharichthys stigmaeus, the speckled sanddab, is a species of lefteye Blothid flounder in the genus Citharichthys. It is native to the eastern Pacific Ocean, ranging from Alaska in the north to Baja California, Mexico in the south. It is usually found in benthic habitats, in both bays and coastal areas. It varies temporarily both seasonally and annually. It is often found highest in abundance during the spring and summer, but are found in much lower densities in the winter.
Anableps anableps, the largescale four-eyes, is a species of four-eyed fish found in fresh and brackish waters of northern South America and Trinidad. This species grows to a length of 30 centimetres (12 in) total length (TL). This fish can occasionally be found in the aquarium trade. The fish does not actually have four eyes. Instead, each eye is split into two lobes by a horizontal band of tissue, each lobe with its own pupil and separate vision. This allows the fish to see above and below the surface of the water at the same time. This species has been documented to occasionally feed on land. Both sexes exhibit asymmetrical genitalia.
Toxotes blythii, the clouded archerfish or zebra archerfish, is a perciform fish of genus Toxotes. It is found in rivers and estuaries in Myanmar, ranging from the lower Irrawaddy to the Tenasserim Division, including lower Sittaung and Salween. Unlike some other archerfish, it is restricted to fresh water. This species was formerly thought to be identical to T. microlepis. However, differences in structure and colouration caused the splitting of T. blythii into a new species. It is sometimes seen in the aquarium trade, but is generally rare.
The black-necked stilt is a locally abundant shorebird of North and South American wetlands and coastlines. It is found from the coastal areas of California through much of the interior western United States and along the Gulf of Mexico as far east as Florida, then south through Central America and the Caribbean to Brazil, Peru and the Galápagos Islands, with an isolated population, the Hawaiian stilt, in Hawaii. The northernmost populations, particularly those from inland, are migratory, wintering from the extreme south of the United States to southern Mexico, rarely as far south as Costa Rica; on the Baja California peninsula it is only found regularly in winter. Some authorities, including the IUCN, treat it as a synonym of Himantopus himantopus.
The redfin shiner is a freshwater fish in the family Cyprinidae. The redfin shiner is most commonly found in the Ohio and Mississippi River basins, as well as in drainages of the Great Lakes. The diet of the redfin shiner consists mostly of algae and small insects. This species prefers calm water in low-gradient streams over substrates of gravel or sand with some vegetation.
The corsula is a species of ray-finned fish from the mullet family Mugilidae. It is found in the rivers and estuaries of southern Asia, in India, Bangladesh, Nepal and Myanmar. It is presently regarded as the only species in the monospecific genus Rhinomugil.
The Pacific four-eyed fish is a species of four-eyed fish native to the coastal waters on the Pacific side of southern Mexico to Nicaragua. This fish is gregarious and inhabits mangrove swamps, tidal mudflats, and other coastal brackish ecosystems. During low tide, they will crawl onto shore to eat algae and other organic matter. This species has female biased sexual dimorphism, with males growing to 22 cm (8.7 in) TL while females can grow up to 34 cm (13.4 in) TL. The male also has a prominent gonopodium used to impregnate females during mating. As with other members of Anablepinae, this species is livebearing and has left or right leaning genitals to prevent inbreeding.
