The Gobiiformes are an
order
Order, ORDER or Orders may refer to:
* Categorization, the process in which ideas and objects are recognized, differentiated, and understood
* Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...
of fish that includes the
gobies
Gobiidae or gobies is a family of bony fish in the order Gobiiformes, one of the largest fish families comprising more than 2,000 species in more than 200 genera. Most of gobiid fish are relatively small, typically less than in length, and the ...
and their relatives.
The order, which was previously considered a suborder of
Perciformes
Perciformes (), also called the Percomorpha or Acanthopteri, is an order or superorder of ray-finned fish. If considered a single order, they are the most numerous order of vertebrates, containing about 41% of all bony fish. Perciformes means ...
, is made up of about 2,211 species that are divided between seven families. Phylogenetic relationships of the Gobiiformes have been elucidated using molecular data. Gobiiforms are primarily small species 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 gobiiforms 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.
Gobiiformes means "
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 b ...
-like".
Families
The 5th Edition of the ''
Fishes of the World
''Fishes of the World'' by the American ichthyologist Joseph S. Nelson (1937–2011) 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 ...
'' 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
In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...
Amblyopinae
Amblyopinae is a subfamily of elongated mud-dwelling gobies commonly called eel gobies or worm gobies; it has been regarded as a subfamily of the family Gobiidae, while the 5th edition '' Fishes of the World'' classifies it as a subfamily of th ...
,
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 most ...
,
Oxudercinae
Mudskippers are any of the 23 extant species of amphibious fish from the subfamily Oxudercinae of the goby family (biology), family Oxudercidae. They are known for their unusual body shapes, preferences for semiaquatic habitats, limited terrestri ...
and
Sicydiinae
The Sicydiinae are a small subfamily (about 118 species) of freshwater gobies, with only nine genera. They are usually found in fast-moving mountain streams in tropical islands. They are characterized by highly developed rounded suction discs an ...
while merging the families
Kraemeriidae
The sand darters, were formerly considered to be a family the Kraemeriidae, but recent research has placed the nine species formerly classified under the Kraemeriidae as belonging to the family Gobiidae, although the researchers do not define th ...
,
Microdesmidae
The Microdesmidae, the wormfishes and dartfishes, were a family of goby-like fishes in the order Gobiiformes, more recent workers have placed this taxon within the Gobiidae, although the researchers do not define the taxonomic status of this grou ...
,
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 Gob ...
and
Schindleriidae
''Schindleria'' is a genus of marine fish. It was the only genus of family Schindleriidae, among the Gobioidei of order Perciformes but is now classified under the Gobiidae in the Gobiiformes. The type species is ''S. praematura'', Schindler's ...
into the family Gobiidae, though no subfamilies within the Gobiidae were proposed.
Under this classification system the Gobiiformes is divided into the following 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 Gobiiformes.
Odontobutidae
The Odontobutidae, or freshwater sleepers, contains 22 species between 6 genera from eastern Asia. This family is the sister to all the other Gobiiformes in a clade with the Rhyacichthyidae.
Milyeringidae
The Milyeringidae contains two genera of cave fish, one in
Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to th ...
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 Gobiiformes.
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
Stewart Island ( mi, Rakiura, ' glowing skies', officially Stewart Island / Rakiura) is New Zealand's third-largest island, located south of the South Island, across the Foveaux Strait. It is a roughly triangular island with a total land ar ...
, New Zealand, except for the eastern Atlantic. Fossils of Eleotrid gobies are known from the
Late Oligocene
The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage ...
. The families
Milyeringidae
Milyeringidae, the blind cave gobies, is a small family of gobies, in the order Gobiiformes. There are two genera and six species within the family, which is considered to be a subfamily of the Eleotridae by some authorities. Milyeringidae incl ...
and
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 anal ...
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 t ...
to the family
Gobiidae
Gobiidae or gobies is a family of bony fish in the order Gobiiformes, one of the largest fish families comprising more than 2,000 species in more than 200 genera. Most of gobiid fish are relatively small, typically less than in length, and the ...
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
Mudskippers are any of the 23 extant species of amphibious fish from the subfamily Oxudercinae of the goby family Oxudercidae. They are known for their unusual body shapes, preferences for semiaquatic habitats, limited terrestrial locomotion and ...
.
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. Many species have fused pelvic fins that can be used as a suction device; 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
Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousan ...
, not unlike the eels of the family
Anguillidae
The Anguillidae are a family of ray-finned fish that contains the freshwater eels. Eighteen of the 19 extant species and six subspecies in this family are in the genus ''Anguilla''. They are elongated fish with snake-like bodies, their long dorsa ...
. With the
blennies
Blenny (from the Greek and , mucus, slime) is a common name for many types of fish, including several families of percomorph marine, brackish, and some freshwater fish sharing similar morphology and behaviour. Six families are considered "true ...
, the Gobiidae constitute a dominant part of the benthic, small fish fauna in tropical reef habitats. 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 relationships; members of the genera ''
Amblyeleotris
''Amblyeleotris'' is a genus of fish in the family Gobiidae found throughout the Indo-Pacific region. This is the largest genus of the shrimp gobies or prawn gobies, so-called because of their symbiotic relationship with certain alpheid shrimps. ...
'' and ''
Cryptocentrus'', for example, cohabit in burrows with
alpheid shrimps, while other species live as
cleaner fish
Cleaner fish are fish that show a specialist feeding strategy by providing a service to other species, referred to as clients, by removing dead skin, ectoparasites, and infected tissue from the surface or gill chambers. This example of cleaning ...
, e.g ''
Elacatinus
''Elacatinus'' is a genus of small marine gobies, often known collectively as the neon gobies. Although only one species, ''E. oceanops'', is technically the "neon goby," because of their similar appearance, other members of the genus are genera ...
''. They can be
sequential hermaphrodite
Sequential hermaphroditism (called dichogamy in botany) is a type of hermaphroditism that occurs in many fish, gastropods, and plants. Sequential hermaphroditism occurs when the individual changes its sex at some point in its life. In particular, ...
s and numerous species are known to exhibit parental care.
Species status
The
tidewater goby
''Eucyclogobius newberryi'', the Northern tidewater goby, is a species of goby native to lagoons of streams, marshes, and creeks along the coast of California, United States. The Northern tidewater goby is one of six native goby species to Califo ...
(''Eucyclogobius newberryi'') was listed as an endangered species in 1994; it is the only species of goby in the genus ''Eucyclogobius''. ''E. newberryi'' is native to the coastal region of California, in marshes and lagoons with brackish water, predominantly in waters where the salinity is less than 12 parts per thousand (ppt), but has been documented in waters with a salinity of 42 ppt. ''E. newberryi'' prefers water with mild temperatures (8 to 25 °C) and waters with a depth from 25 to 200 cm. These gobies often use thick patches of aquatic vegetation to hide in if threatened or disturbed. The average lifespan of ''E. newberryi'' is only one year. Spawning and reproduction is at its peak during spring and into late summer. However, in the southern region of its range where waters remain at a warmer temperature, ''E. newberryi'' will reproduce year round. The females lay between 300 and 500 eggs into a burrow dug out vertically by the male, which is 10 to 20 cm deep. Spawning locations are usually located out in the open away from any vegetation. The male then guards the eggs until they hatch, which is 9 to 11 days.
Habitat loss and modification are the main threats to ''E. newberryi''. The brackish areas where saltwater and freshwater meet are where they live usually, such as along the coast of California; this area has been altered by development. Barriers such as dikes and levees have been built to protect residents from potential flooding, but the creation of these barriers has reduced habitat for ''E. newberryi''. Other reasons for population declines are attributed to exotic fish and amphibians which have been introduced to the region. Many of these fish prey on ''E. newberryi'', and others outcompete them for food and habitat. The altering of streams flow with diversions has affected the salinity of the water and changed the habitat at creek mouths where ''E. newberryi'' has historically lived. Restoration projects have been started to bring populations back to a more stable number by making more habitat available, as well as providing protective areas. Some levees have been removed and exotic species reduction programs are being initiated.
References
{{Authority control
Percomorpha
Ray-finned fish orders
Taxa named by Albert Günther