The gobies form the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Gobiidae, which is one of the largest families of fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

, with more than 2,000 species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 in more than 200 genera
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

. Most are relatively small, typically less than 10 cm (4 in) in length. Gobies include some of the smallest vertebrates in the world, like species of the genera Trimmatom nanus
Trimmatom nanus
Trimmatom nanus is a species of marine fish in family Gobiidae of Perciformes. It is the type species of its genus. One of the fishes called dwarf gobies, it is native to the Chagos Archipelago and the Maldives in the western Indian Ocean....

and Pandaka pygmaea
Pandaka pygmaea
The dwarf pygmy goby is a tropical freshwater fish of the family Gobiidae. It is one of the smallest fish in the world by mass, and is also one of the shortest freshwater fish. Mature males can reach up to 1.1 cm, while the females can grow up to 1.5 cm. Average weight is from 4 to 5 mg...

, which are under 1 cm (3/8 in) long when fully grown. There are some large gobies, such as some species of the genera Gobioides or Periophthalmodon, that can reach over 30 cm (1 ft) in length, but that is exceptional.
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