Mackerel is a common name applied to a number of different species of pelagic fish, mostly from the family Scombridae. They are found in both temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment.
Herring are forage fish, mostly belonging to the family of Clupeidae.
Sardine and pilchard are common names for various species of small, oily forage fish in the herring family Clupeidae. The term 'sardine' was first used in English during the early 15th century; a somewhat dubious etymology says it comes from the Italian island of Sardinia, around which sardines were once supposedly abundant.
Poecilia is a genus of fishes in the family Poeciliidae of the order Cyprinodontiformes. These livebearers are native to fresh, brackish and salt water in the Americas, and some species in the genus are euryhaline. A few have adapted to living in waters that contain high levels of toxic hydrogen sulfide and a population of P. mexicana lives in caves.
The sailfin molly is a livebearer fish typically found in both freshwater and brackish waterways along the East Coast of the United States, from North Carolina south to Florida, and around the Gulf of Mexico to Texas, and south to the Yucatán Peninsula of México. Given their preference for more brackish water conditions, mollies are often found within just a few yards or miles of the ocean, inhabiting coastal estuaries, lagoons, river deltas and swamps, as well as tidal areas with a regular inflow of oceanic minerals and nutrients mixing with inland freshwater sources.
The widemouth gambusia is a species of fish in the family Poeciliidae of the order Cyprinodontiformes. It is endemic to Mexico, specifically to the Baños del Azufre near Teapa, Tabasco. The Baños del Azufre are sulfidic springs that contain high concentrations of toxic hydrogen sulfide. This prevents most animals from living in them; the only other fish found in the toxic sections of Baños del Azufre is the sulphur molly.
The Ash Meadows killifish is a species of killifish from the subfamily Empetrichthyinae, part of the family Goodeidae, which was first documented by C. H. Gilbert in 1893 and historically occupied numerous springs near Ash Meadows, Nye County, Nevada, United States. This species was last seen in 1948 and is believed to have gone extinct in the early 1950s, likely as a result of habitat alteration and competition with and predation by introduced crayfish Procambarus clarkii, mosquitofish, black mollies, and bullfrogs.
The Arctic cisco, also known as omul, is an anadromous species of freshwater whitefish that inhabits the Arctic parts of Siberia, Alaska and Canada. It has a close freshwater relative in several lakes of Ireland, known as the pollan, alternatively regarded as conspecific with it, or as a distinct species.
The Amazon molly is a freshwater fish native to warm, fresh waters between Tuxpan River in northeastern Mexico and the Rio Grande and the Nueces River in the southern parts of the U.S. state of Texas. It reproduces through gynogenesis, and essentially all individuals are females. The common name of "Amazon molly," acknowledges this trait as a reference to the Amazon warriors, a female-run society in Greek mythology.
The Cauca molly is a freshwater fish in the family Poeciliidae. This fish is found in Panama, Venezuela, and Colombia, where it lives in shallow waters in the basins of the Lebrija, Magdalena, Cauca and other rivers. P. caucana eats mosquito larvae and algae.
Poecilia velifera, known as the Yucatan molly and also as the giant sailfin molly amongst aquarists, is a large livebearer that lives in coastal waters of the Yucatan peninsula. These live-bearer (Poeciliidae) fish are particularly well known for both the extreme size variation among males, and the sexual dimorphism between males and females in both body shape and behavior.
Neolamprologus multifasciatus is one of the small shell-dwelling cichlids endemic to Lake Tanganyika. The male reaches 5 cm (2 in) in length, and the female only 2.5 cm (1 in) in the aquarium. In the wild, they reach only 3 centimetres (1.2 in) in standard length of male and female reaches less than 2.2 centimetres (0.87 in) in standard length. This makes them one of the smallest cichlid species in the world. Its natural habitat is the Neothauma shell beds of Lake Tanganyika, where it forms huge colonies with thousands of individuals. Their unique behavior is associated with their affinity to shells. They burrow sand to move shells, take refuge in shells and also breed in them. They have pale white coloring with black vertical bars running the length of their bodies. The species is sexually monomorphic, meaning sexing individuals is extremely hard or impossible based on external appearance alone.
Thunnus is a genus of ocean-dwelling, ray-finned bony fish from the mackerel family, Scombridae. More specifically, Thunnus is one of five genera which make up the tribe Thunnini – a tribe that is collectively known as the tunas. Also called the true tunas or real tunas, Thunnus consists of eight species of tuna, divided into two subgenera.
The greater pipefish is a pipefish of the family Syngnathidae. It is a seawater fish and the type species of the genus Syngnathus.
The broadspotted molly, locally known as molly del Tamesi, is a critically endangered species of fish in the family Poeciliidae, endemic to a small part of the Tamesí River system in Mexico.
The sulphur molly, locally known as molly del Teapa, is an endangered species of fish in the family Poeciliidae. It is endemic to Mexico, specifically to the Baños del Azufre near Teapa, Tabasco. The Baños del Azufre are sulfidic springs that contain high concentrations of toxic hydrogen sulfide. Poecilia sulphuraria has apparently evolved the ability to tolerate the toxic conditions. A few other Poecilia species are known from similar habitats in Mexico.
The liberty molly is a fish species from El Salvador. It is one of the short fin molly species in the Poecilia sphenops complex, and had been often regarded as synonymous with P. sphenops until recently.
Poecilia mexicana, commonly known as the shortfin molly or Atlantic molly, is a species of poeciliid fish native to fresh and brackish water in Mexico and Guatemala. One population is found in caves and known as the cave molly.
Poecilia parae, also known as the melanzona guppy, is a species of fish from the family Poeciliidae which is found in northern South America from Guyana to the mouth of the Amazon River.
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 TL while females can grow up to 34 cm 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.
