''Theraps'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

cichlid Cichlids are fish from the family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, the Labroidei, along with the wrasses ( Labridae), in the order Perciformes, but molecular studies have contradicted this ...

fish found in moderately to fast-flowing rivers and streams on the Atlantic slope of southern

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

and northern

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. ...

. They are medium-sized cichlids.

Species and taxonomy

Historically, ''Theraps'' was included in ''

Cichlasoma ''Cichlasoma'' is a genus of freshwater fish in the cichlid family. The genus was previously very large (a wastebasket taxon), including cichlids from North America, including Central America, and South America. Reclassification and subsequent s ...

''. Once recognized as its own genus, it sometimes included a wide range of species now known to belong in other genera, including '' Cincelichthys'', '' Chortiheros'', ''

Chuco ''Atole'' (, from Nahuatl '' ātōlli'' ), also known as ''atolli'' and ''atol de elote'', is a traditional hot corn- and masa-based beverage of Mexican origin. Chocolate ''atole'' is known as ''champurrado'' or ''atole''. It typically accompa ...

'', ''

Cryptoheros ''Cryptoheros'' is a genus of small cichlid fishes from Central America and southeast Mexico. They reach up to in length. Taxonomy and species The genus formerly contained nine species that had been included within the genus '' Archocentrus''. ...

'', ''

Kihnichthys ''Kihnichthys ufermanni'', the Usumacinta cichlid, is a species of cichlid found in a few rivers in the Usumacinta River basin in Guatemala and southern Mexico. It typically occurs in rivers that are about wide, fairly deep, have few or no aq ...

'', '' Oscura'', ''

Paraneetroplus ''Paraneetroplus'' is a genus of cichlid fish native to moderately to fast-flowing waters in the Coatzacoalcos, Grijalva and Papaloapan river basins in southern Mexico. They reach up to in length. Taxonomy and species Historically, ''Paraneet ...

'', ''

Rheoheros ''Rheoheros'' is a genus of cichlids. These freshwater fish are found in the Atlantic slope of Mexico and Guatemala in moderately to fast-flowing waters of the Grijalva- Usumacinta River system. Depending on species, they reach up to in length. ...

'', '' Talamancaheros'', ''

Tomocichla ''Tomocichla'' is a genus of cichlid fish native to moderately and fast-flowing rivers along the Atlantic slope of Central America, ranging from the Escondido drainage in Nicaragua to Bocas del Toro in Panama. ''Tomocichla'' was formerly includ ...

'' and '' Wajpamheros''. In a major review of 2015, only five species remained in this genus, but in 2016 it was shown that four of these were not close relatives of the ''Theraps''

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

, ''T. irregularis'', resulting in them being moved to ''Chuco'' and ''Wajpamheros''. As a consequence, Catalog of Fishes now recognizes ''Theraps'' as only including the type species ''T. irregularis'', but

FishBase FishBase is a global species database of fish species (specifically finfish). It is the largest and most extensively accessed online database on adult finfish on the web.

include both it and the three ''Chuco'' species in ''Theraps'', resulting in a genus that is not

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

. The four species placed in this genus by FishBase are: * '' Theraps godmanni'' ( Günther, 1862) (Southern checkmark cichlid) * '' Theraps intermedius'' ( Günther, 1862) (Northern checkmark cichlid) * '' Theraps irregularis'' Günther, 1862 (Arroyo cichlid) * ''

Theraps microphthalmus ''Theraps'' is a genus of cichlid fish found in moderately to fast-flowing rivers and streams on the Atlantic slope of southern Mexico and northern Central America. They are medium-sized cichlids. Species and taxonomy Historically, ''Theraps'' w ...

'' ( Günther, 1862)

References

Heroini Cichlid genera Taxa named by Albert Günther {{Cichlidae-stub