The Gobioidei are a

suborder Order () is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized ...

of percomorph fish. Many of these fishes are called gobies. It is by far the largest and most diverse order within the order Gobiiformes, and one of the most diverse groups of

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

in general. The suborder, which was previously considered a suborder of

Perciformes Perciformes (), also called the Acanthopteri, is an order or superorder of ray-finned fish in the clade Percomorpha. ''Perciformes'' means " perch-like". Among the well-known members of this group are perches and darters ( Percidae), and als ...

, is made up of about 2,211 species that are divided between seven families. Phylogenetic relationships of the Gobioidei have been elucidated using molecular data. Gobies are primarily small species, often with large heads and tapered bodies, that live in marine water, but roughly 10% of these species inhabit fresh water. This order is composed chiefly of benthic or burrowing species; like many other benthic fishes, most gobioids do not have a gas bladder or any other means of controlling their buoyancy in water, so they must spend most of their time on or near the bottom. Traditionally most of the species called gobies have been classified in the order

as the

Gobioidei but in the 5th Edition of ''

Fishes of the World ''Fishes of the World'' is a standard reference for the systematics of fishes. It was first written in 1976 by the American ichthyologist Joseph S. Nelson (1937–2011). Now in its fifth edition (2016), the work is a comprehensive overview of t ...

'' this suborder is elevated to an order Gobiiformes within the

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

Percomorpha. In the most recent taxonomic treatment, they are again placed as the suborder Gobioidei within an expanded Gobiiformes.

Nomenclature

Not all the species in the Gobiiformes are referred to as gobies; "true gobies" are placed in the family

Gobiidae Gobiidae or gobies is a family (biology), family of bony fish in the order (biology), order Gobiiformes, one of the largest fish families comprising over 2,000 species in more than 200 genus, genera. Most of gobiid fish are relatively small, typ ...

, 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 Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''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.

Evolution

The earliest known

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

member of the group is '' Carlomonnius'' Bannikov & Carnevale, 2016, an indeterminate gobioid from the

Early Eocene In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...

of Italy. Phylogenetic evidence suggests that two of the most diverse families within the group,

and Oxudercidae, are relatively young compared to many other fish families, diverging during the

Late Eocene The Priabonian is, in the International Commission on Stratigraphy, ICS's geologic timescale, the latest age (geology), age or the upper stage (stratigraphy), stage of the Eocene epoch (geology), Epoch or series (stratigraphy), Series. It spans ...

or middle

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

. Uniquely, they appear to have diversified during the midst of the Eocene-Oligocene extinction event.

Taxonomy

Until the early 21st century, the gobies were placed within the

as the suborder Gobioidei. However, phylogenetic studies identified them as being a particularly basal percomorph group related to the cardinalfish and nurseryfish. For this reason, the 5th Edition of the ''

'' reclassified the former superfamily Goboidei as the order Gobiiformes and also rearranged the families within the order compared to the previous edition. The largest change is that the Oxudercidae and the Gobiidae are split into two families, with the Oxudercidae containing the species formerly classified as the Gobiidae subfamilies Amblyopinae,

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 mostl ...

, Oxudercinae and Sicydiinae while merging the families Kraemeriidae, Microdesmidae,

Ptereleotridae Dartfishes are a group of fish, formerly considered to be a subfamily, Ptereleotrinae, of goby-like fishes in the family Microdesmidae of the order Gobiiformes, Authorities now consider the species in the family Microdesmidae are within the Gobi ...

and Schindleriidae into the family Gobiidae, though no subfamilies within the Gobiidae were proposed. More recently, ''

Eschmeyer's Catalog of Fishes Catalog of Fishes is a comprehensive on-line database and reference work on the scientific names of fish species and genera. It is global in its scope and is hosted by the California Academy of Sciences. It has been compiled and is continuously up ...

'' has retained aspects of this classification, but returned the Gobioidei to being a suborder, now within an expanded Gobiiformes that also includes the Apogonoidei and the Trichonotoidei. In addition, Xenisthmidae is now recognized as its own family, while Butidae and Milyeringidae have returned to being treated as subfamilies of Eleotridae. The following classification is based on ''

'', with

taxa also added: * Suborder Gobioidei ** Genus †'' Carlomonnius'' Bannikov & Carnevale, 2016 (fossil;

of Italy) ** Genus †'' Laubeichthys'' Reichenbacher & Přikryl, 2024 (fossil;

Early Oligocene The Rupelian is, in the geologic timescale, the older of two age (geology), ages or the lower of two stage (stratigraphy), stages of the Oligocene epoch (geology), Epoch/series (stratigraphy), Series. It spans the time between . It is preceded b ...

of the Czech Republic) ** Genus †'' Paralates'' Sauvage, 1883 (fossil;

of England & Early Oligocene of France) ** Genus †'' Simpsonigobius'' Dirnberger, Bauer & Reichenbacher, 2024 (fossil;

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to ...

of Turkey) ** Family Rhyacichthyidae

Jordan Jordan, officially the Hashemite Kingdom of Jordan, is a country in the Southern Levant region of West Asia. Jordan is bordered by Syria to the north, Iraq to the east, Saudi Arabia to the south, and Israel and the occupied Palestinian ter ...

, 1905 (loach gobies) ** Family Odontobutidae Hoese & Gill, 1993 (Asian freshwater sleepers) ** Family Milyeringidae Whitley, 1945 (cave gudgeons) ** Family Eleotridae Bonaparte, 1835 (sleepers or bullies) ** Family Xenisthmidae Miller, 1973 (collared wrigglers) ** Family Butidae Bleeker, 1874 (gudgeons) ** Family Thalasseleotrididae Gill & Mooi, 2012 (ocean sleepers) ** Family † Pirskeniidae Obrhelová, 1961 (fossil; Early Oligocene of the Czech Republic) ** Family Oxudercidae Günther, 1861 (mudskippers and allies) *** Subfamily Oxudercinae Günther, 1861 (mudskippers) *** Subfamily Amblyopinae Günther, 1861 (mudburrowing gobies) *** Subfamily

Bleeker, 1874 (estuarine gobies) *** Subfamily Sicydiinae

Gill A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow r ...

, 1860 (rock-climbing gobies) ** Family

Cuvier, 1816 (gobies) *** Subfamily Kraemeriinae Whitley, 1935 (1911) (sand darts) *** Subfamily Ptereleotrinae Bleeker, 1875 (dart-gobies) *** Subfamily Gobiinae Cuvier, 1816 (sea gobies) *** Subfamily Microdesminae Regan, 1912 (wormfishes)

Families

Rhyacichthyidae

The loach-gobies are a small family, with only three species split between two genera, which inhabits marine and fresh water in Oceania and the western Pacific. These are thought to be among the more primitive species of the Gobioidei.

Odontobutidae

The Odontobutidae, or freshwater sleepers, contains 22 species between 6 genera from eastern Asia. This family is the sister to all the other Gobioidei in a clade with the Rhyacichthyidae.

Milyeringidae

The Milyeringidae contains two genera of cave fish, one in

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

and one at the other side of the Indian Ocean in Madagascar; both genera contain three recognized species. This family forms a second clade of the Gobioidei.

Eleotridae

The sleeper gobies are a family of twenty six genera and 126 species found in freshwater and mangrove habitats throughout the tropical and temperate parts of the world as far north as the eastern United States and as far south as Stewart Island, New Zealand, except for the eastern Atlantic. Fossils of Eleotrid gobies are known from the Late Oligocene. The families Milyeringidae and Butidae were formerly classified as subfamilies of the Eleotridae but are not found to be close to the Eleotridae ''senus stricto'' in this system.

Butidae

The Butidae are one of the two families which are given the common name "sleeper gobies", and indeed were formerly classified as subfamily of the traditional sleeper goby family Eleotridae, although some phylogenies have placed them closer to the Oxucerdidae and the Gobiidae than to the Eleotridae. They are found in the

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

and in West Africa, and contains 10 genera with 46 species split between them.

Thalasseleotrididae

The family Thalasseleotrididae is considered to be a

sister group In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

to the family

and is separated as a family by the authors of this classification based on recent molecular studies. It comprises two genera of marine gobies from the temperate waters of Australia and New Zealand, with a total of three species between them.

Oxudercidae

Oxudercidae is a family of gobies comprising species previously split between four subfamilies of the family Gobiidae. The family is sometimes referred to as the Gobionellidae, but Oxucerdidae has priority. The species in this family have a cosmopolitan distribution in temperate and tropical areas and are found in marine and freshwater environments, typically in inshore, euryhaline areas with silt and sand substrates. The family contains 86 genera and about 600 species. Many species in this family can be found in fresh water and a number of species are found on wet beaches; some are able to survive for extended periods out of water, most famously the mudskippers.

Gobiidae

The Gobiidae as recognized in this classification now includes the former members of several families which other classifications have regarded as valid families. As classified in this work the family remains one of the most speciose families of marine fish, as well as being one of the most numerous groups of fishes in freshwater habitats on oceanic islands. They are most diverse in the tropical Indo-West Pacific but the family is well represented in temperate waters in both the northern and southern hemispheres. They are mostly free living fishes found alone or in small schools, but some form associations with invertebrates, especially in coral reefs. About 120 species are known to form such

symbiotic relationship Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biolo ...

s; members of the genera '' Amblyeleotris'' and '' Cryptocentrus'', for example, cohabit in burrows with alpheid shrimps, while other species live as cleaner fish, e.g '' Elacatinus''. They can be sequential hermaphrodites and numerous species are known to exhibit

parental care Parental care is a behavioural and evolutionary strategy adopted by some animals, involving a parental investment being made to the evolutionary fitness of offspring. Patterns of parental care are widespread and highly diverse across the animal k ...

. Many species have fused pelvic fins that can be used as a suction device#In fish; some island species, such as the red-tailed stream goby ('' Lentipes concolor''), are able to use these pelvic fins to ascend rock faces alongside waterfalls, allowing them to inhabit waters far from the ocean. Some of the species that are found in fresh water as adults spawn in the ocean and are catadromous, not unlike the eels of the family Anguillidae. Along with the blennies, the Gobiidae constitute a dominant part of the benthic, small fish fauna in tropical reef habitats. File:Rhyacichthys aspro 43696913 (cropped).jpg, '' Rhyacichthys aspro''; Rhyacichthyidae File:Odontobutis obscura1.jpg, '' Odontobutis obscura''; Odontobutidae File:Typhleotris madgascarensis.jpg, '' Typhleotris madagascariensis''; Milyeringidae File:Eleotrinae oxycephala(Yaizu,Shizuoka,Japan,2007).jpg, '' Eleotris oxycephala''; Eleotridae File:Butis koilomatodon (Bleeker, 1849).jpg, '' Butis koilomatodon''; Butidae File:ThalasseleotAdelaHolotype.jpg, '' Thalasseleotris adela''; Thalasseleotrididae File:Clariger taiwanensis paratype - ZooKeys-199-013-g002-a.jpeg, '' Clariger taiwanensis''; Oxudercidae File:Nemateleotris magnifica 1.jpg, '' Nemateleotris magnifica'';

References

* * Milius, Susan. "Goby Fish React To Corals' Cue By Helping Keep Algae At Bay." ''Science News'' 182 no. 11 (2012): 7–8. * Olivotto, Ike, Alessio Zenobi, Arianna Rollo, Beatrice Migliarini, Matteo Avella, and Oliana Carnevali. "Breeding, Rearing And Feeding Studies In the Cleaner Goby Gobiosoma evelynae." ''Aquaculture'' 250 no. 1-2 (2005): 175–182. * Quintao, Thais L., Ryan Andrades, Raphael M. Macieira, Ana Carolina Loss, and Jean-Christophe Joyeux. "The Evolutionary History Of Priolepis (Gobiidae) In The Atlantic Ocean." ''Marine Biology'' 169 no. 7 (2022): 1–17. {{Authority control Percomorpha Ray-finned fish orders Taxa named by Albert Günther