Fishes of the World by Joseph S. Nelson is a standard reference for fish systematics. Now in its fifth edition (2016), the work is a comprehensive overview of the diversity and classification of the 30,000-plus fish species known to science.
The book begins with a general overview of ichthyology, although it is not self-contained. After a short section on Chordata and non-fish taxa, the work lists all known fish families in a systematic fashion. Each family gets at least one paragraph, and usually a body outline drawing; large families have subfamilies and tribes described as well. Notable genera and species are mentioned, while the book generally does not deal with the species-level diversity. The complexities of the higher taxa are described succinctly, with many references for difficult points. The book does not involve color illustrations.
The fourth edition was the first to incorporate the wide use of DNA analysis, revising many earlier classifications.
The first edition appeared in 1976, the second in 1984, the third in 1994 (John Wiley & Sons, ISBN 0-471-54713-1), the fourth in March 2006 (ISBN 0-471-25031-7), and the fifth in April 2016 (ISBN 9781118342336).
Amblyopinae is a subfamily of elongated mud-dwelling gobies commonly called eel gobies or worm gobies, they have been regarded as a subfamily of the family Gobiidae, while the 5th edition Fishes of the World classifies it as a subfamily of the family Oxudercidae. Their two dorsal fins are connected by a membranous structure and their eyes are highly reduced. They are usually pink, red, or purple in coloration.Apogonidae
Cardinalfishes are a family, Apogonidae, of ray-finned fishes found in the Atlantic, Indian, and Pacific Oceans; they are chiefly marine, but some species are found in brackish water and a few (notably Glossamia) are found in fresh water. A handful of species are kept in the aquarium and are popular as small, peaceful, and colourful fish. The family includes about 370 species.
They are generally small fish, with most species being less than 10 cm (3.9 in), and are often brightly coloured. They are distinguished by their large mouths, and the division of the dorsal fin into two separate fins. Most species live in tropical or subtropical waters, where they inhabit coral reefs and lagoons.They are nocturnal, spending the day in dark crevices within the reef. At least some species brood their eggs inside the mouths of the males.Butidae
Butidae is a family of sleeper gobies in the order Gobiiformes. The family was formerly classified as a subfamily of the Eleotridae but the 5th Edition of Fishes of the World classifies it as a family in its own right. Molecular phylogenetic analyses have demonstrated that the Butidae are a sister clade to the clade containing the families Gobiidae and Gobionellidae and that the Eleotridae is a sister to both of these clades. This means that the Eloetridae as formerly classified was paraphyletic and that its subfamilies should be raised to the status of families.The species in the Butidae are largely restricted to tropical and sub-tropical waters of Africa, Asia, Australia, and Oceania. They are especially diverse in New Guinea, Australia and New Zealand where they can be important components of brackish and freshwater ecosystems. They are mostly quite small species but the marbled goby (Oxyeleotris marmorata) is a freshwater species of Buitdae from Southeast Asia that can grow to 65 cm (25.6 in) long and is an important food fish.Caprodon
Caprodon is a small genus of fish belonging to the subfamily Anthiadinae. It contains three species.Characiformes
Characiformes is an order of ray-finned fish, comprising the characins and their allies. Grouped in 18 recognized families, there are more than two thousand different species, including the well-known piranha and tetras.Cichliformes
Cichliformes is an order of fishes, previously classifies under the order Perciformes but now many authorities consider it to be an order within the subseries Ovalentaria.Eleotridae
Eleotridae is a family of fish commonly known as sleeper gobies, with about 34 genera and 180 species. Most species are found in the tropical Indo-Pacific region, but there are also species in subtropical and temperate regions, warmer parts of the Americas and near the Atlantic coast in Africa. While many eleotrids pass through a planktonic stage in the sea and some spend their entire lives in the sea; as adults, the majority live in freshwater streams and brackish water. One of its genera, Caecieleotris, is troglobitic. They are especially important as predators in the freshwater stream ecosystems on oceanic islands such as New Zealand and Hawaii that otherwise lack the predatory fish families typical of nearby continents, such as catfish. Anatomically, they are similar to the gobies (Gobiidae), though unlike the majority of gobies, they do not have a pelvic sucker.Like the true gobies, they are generally small fish that live on the substrate, often amongst vegetation, in burrows, or in crevices within rocks and coral reefs. Although goby-like in many ways, sleeper gobies lack the pelvic fin sucker and that, together with other morphological differences, is used to distinguish the two families. The Gobiidae and Eleotridae likely share a common ancestor and they are both placed in the order Gobiiformes, along with a few other small families containing goby-like fishes.Dormitator and Eleotris, two of the most widespread and typical genera, include a variety of species that inhabit marine, estuarine and freshwater habitats. Among the largest members of the family are predatory species such as the bigmouth sleeper (Gobiomorus dormitor) at up to 90 cm (3.0 ft) from freshwater near the West Atlantic region and the fat sleeper (Dormitator maculatus), which grows to 70 cm (2.3 ft) and is widely found in fresh to brackish and shallow marine waters of the southeastern United States and Mexico, However, most are much smaller, such as the fresh- and brackish-water species from Australia and New Guinea, including Hypseleotris, known locally as gudgeons (not to be confused with the Eurasian freshwater cyprinid Gobio gobio, also known as the gudgeon and after which the Australian sleeper gobies were likely named). A few of these, such as the empire gudgeon (H. compressa) and peacock gudgeon (Tateurndina ocellicauda), are sometimes kept in aquariums. The smallest in the family are the Amazonian Leptophilypnion with a standard length of less than 1 cm (0.4 in).Gobiinae
True gobies were a subfamily, the Gobiinae, of the goby family Gobiidae, although the 5th edition of the Fishes of the World does not subdivide the Gobiidae into subfamilies. They are found in all oceans and a few rivers and lakes, but most live in warm waters. Altogether, the Gobiinae unite about 1149 described species in 160 genera, and new ones are still being discovered in numbers.Gobionellinae
The Gobionellinae are a subfamily of fish which was formerly classified in the family Gobiidae, the gobies, but the 5th Edition of Fishes of the World classifies the subfamily as part of the family Oxudercidae. Members of Gobionellinae mostly inhabit estuarine and freshwater habitats; the main exception is the genus Gnatholepis, which live with corals in marine environments. The subfamily is distributed in tropical and temperate regions around the world with the exception of the northeastern Atlantic Ocean, the Mediterranean Sea, and the Ponto-Caspian region. It includes around 370 species and 55 genera: Wikipedia articles about genera list about 389 species.Goby
Goby is a common name for many species of small to medium sized ray-finned fish, normally with large heads and tapered bodies, which are found in marine, brackish and freshwater environments. Traditionally most of the species called gobies have been classified in the order Perciformes as the suborder Gobioidei but in the 5th Edition of Fishes of the World this suborder is elevated to an order Gobiiformes within the clade Percomorpha. Not all the species in the Gobiiformes are referred to as gobies and the "true gobies" are placed in the family Gobiidae, while other species referred to as gobies have been placed in the Oxudercidae.. Goby is also used to describe some species which are not classified within the order Gobiiformes, such as the engineer goby or convict blenny Pholidichthys leucotaenia. The word goby derives from the Latin gobius meaning "gudgeon", and some species of goby, especially the sleeper gobies in the family Eleotridae and some of the dartfishes are called "gudgeons", especially in Australia.Mullet (fish)
The mullets or grey mullets are a family (Mugilidae) of ray-finned fish found worldwide in coastal temperate and tropical waters, and some species in fresh water. Mullets have served as an important source of food in Mediterranean Europe since Roman times. The family includes about 78 species in 20 genera.Mullets are distinguished by the presence of two separate dorsal fins, small triangular mouths, and the absence of a lateral line organ. They feed on detritus, and most species have unusually muscular stomachs and a complex pharynx to help in digestion.Myliobatiformes
Myliobatiformes is one of the four orders of batoids, cartilaginous fishes related to sharks. They were formerly included in the order Rajiformes, but more recent phylogenetic studies have shown the myliobatiforms to be a monophyletic group, and its more derived members evolved their highly flattened shapes independently of the skates.Notacanthiformes
The Notacanthiformes are an order of deep-sea ray-finned fishes, consisting of the families Halosauridae and Notacanthidae (spiny eels).The order is of relatively recent vintage; Fishes of the World (2006) lists it as the suborder Notacanthoidei of Albuliformes. The notacanthiforms are much more eel-like than the albuliforms; for instance, the caudal fin has disappeared.
Fish of the order are found in oceans worldwide, at depths from 120 to 4,900 metres (390 to 16,080 ft). They are elongated fish, although not as much so as the true eels. They typically feed on slow-moving or sessile animals, such as molluscs, echinoderms, and sea anemones. Like the true eels, they have a leptocephalus larva that floats in the surface waters before transforming into an adult. Unusually, the larva can often be larger than the adult.Ophidiiformes
Ophidiiformes is an order of ray-finned fish that includes the cusk-eels (family Ophidiidae), pearlfishes (family Carapidae), viviparous brotulas (family Bythitidae), and others. Members of this order have small heads and long slender bodies. They have either smooth scales or no scales, a long dorsal fin and an anal fin that typically runs into the caudal fin. They mostly come from the tropics and subtropics, and live in both freshwater and marine habitats, including abyssal depths. They have adopted a range of feeding methods and lifestyles, including parasitism. The majority are egg-laying, but some are viviparous.Ovalentaria
Ovalentaria is a clade of ray-finned fishes within the Percomorpha, referred to as a subseries. It is made up of a group of fish families which are referred to in Fishes of the World's fifth edition as incertae sedis as well as the orders Mugiliformes, Cichliformes and Blenniiformes. It was named by W. L. Smith and T. J. Near in Wainwright et al. (2012) using molecular characteristics rather than morphology. Some authors have used the ordinal name Stiassnyiformes for a clade including Mugiloidei, Plesiopidae, Blenniiformes, Atherinomorpha, and Cichlidae, and this grouping does appear to be monophyletic.Percomorpha
The Percomorpha is a large clade of bony fish that includes the tuna, seahorses, gobies, cichlids, flatfish, wrasse, perches, anglerfish, and pufferfish.Synbranchiformes
Synbranchiformes, often called swamp eels, is an order of ray-finned fishes that are eel-like but have spiny rays, indicating that they belong to the superorder Acanthopterygii.Syngnathiformes
The Syngnathiformes are an order of ray-finned fishes that includes the pipefishes and seahorses.These fishes have elongated, narrow, bodies surrounded by a series of bony rings, and small, tubular mouths. The shape of their mouth—in at least syngnathids—allows for the ingestion of prey at close range via suction. Several groups of Syngnathiformes live among seaweed and swim with their bodies aligned vertically, to blend in with the stems.
The most defining characteristic of this order is their reserve sexual system. In this order, males conduct in specialized brooding and rearing of the embryos. The males house eggs in an osmoregulated pouch or adhere eggs to their tail until the eggs reach maturity.
The name Syngnathiformes means "conjoined-jaws". It is derived from Ancient Greek syn (συν, "together") + gnathos (γνάθος, "jaw"). The ending for fish orders "-formes" is derived from Latin and indicates "of similar form".