Butidae

For other gobies with this family's common name, see sleeper goby (disambiguation).

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.^[2] 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.^[3]

Butidae Temporal range: Early Eocene to present PreꞒ Ꞓ O S D C P T J K Pg N
Butis butis
Ophiocara porocephala
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Gobiiformes
Suborder:	Gobioidei
Family:	Butidae Bleeker, 1874[1]

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.^[3] 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.^[4][5]

The earliest known member of the Butidae is the stem group-butid †Carlomonnius Bannikov & Carnevale, 2016 from the Early Eocene-aged Monte Bolca site of Italy. This genus is also the earliest gobioid known from skeletal remains. It was previously considered a gobioid of uncertain affinities^[6], but a 2025 study analyzing more specimens found strong evidence for it being closely related to the Butidae. Carlomonnius had a lifestyle unlike any extant butids, being a very small marine genus that inhabited reef environments, suggesting a similar lifestyle to coral gobies of the Gobiidae. This is unlike extant butids, which primarily inhabit freshwater and brackish habitats, with none inhabiting reef ecosystems.^[7]

Genera

The following genera are classified within the family Butidae:^[8]

• Bostrychus Lacépède, 1801
• Butis Bleeker, 1856
• Incara Visweswara Rao, 1971
• Kribia Herre, 1946
• Odonteleotris Gill, 1863
• Ophiocara Gill, 1863
• Oxyeleotris Bleeker, 1874
• Parviparma Herre, 1927
• Pogoneleotris Bleeker, 1875
• Prionobutis Bleeker, 1874

The following fossil genera are also known:

• †Carlomonnius Bannikov & Carnevale, 2016 (Early Eocene of Italy)^[7]
• †Lepidocottus Sauvage, 1875 (Early Oligocene to Early Miocene of Italy, France, Germany, and central Europe)^[9][7]