''Xenisthmus chi'' (Japan wriggler, chi xenisthmid) is a species of fish in the wriggler

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Xenisthmidae Collared wrigglers are perciform fishes in the family Xenisthmidae. They are native to the Indian and Pacific Oceans, where they are mostly reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath ...

, which is regarded as a

synonymous A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

with the

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 th ...

,. Japan wrigglers are tiny and clear. Before ''

Paedocypris progenetica ''Paedocypris progenetica'' is a species of tiny cyprinid fish endemic to the Indonesian islands of Sumatra and Bintan where it is found in peat swamps and blackwater streams. It was discovered by Singaporean ichthyologist Heok Hui Tan. He has ...

'' and the dwarf goby (''

Pandaka pygmaea The dwarf pygmy goby or Philippine goby (''Pandaka pygmaea'') is a tropical species of fish in the subfamily Gobionellinae from brackish water and mangrove areas in Southeast Asia. It is one of the smallest fish species in the world. Males reach ...

'') were discovered, the Japan wriggler was the smallest known fish.

Distribution

Southwest

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

References

chi Chi or CHI may refer to: Greek *Chi (letter), the Greek letter (uppercase Χ, lowercase χ); Chinese *Chi (length), ''Chi'' (length) (尺), a traditional unit of length, about ⅓ meter *Chi (mythology) (螭), a dragon *Chi (surname) (池, pin ...

Fish described in 2004 {{Gobiiformes-stub