''Fluviphylax'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of tiny

cyprinodontiform Cyprinodontiformes is an order of ray-finned fish, comprising mostly small, freshwater fish. Many popular aquarium fish, such as killifish and live-bearers, are included. They are closely related to the Atheriniformes and are occasionally inc ...

fish native to the

Amazon Basin The Amazon basin is the part of South America drained by the Amazon River and its tributary, tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries ...

, Orinoco Basin, and

Oyapock The Oyapock or Oiapoque ( ; ; ) is a long river in South America that forms most of the border between the French overseas department of French Guiana and the Brazilian state of Amapá. Course The Oyapock runs through the Guianan moist for ...

Basin in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

. It is the only member of the family Fluviphylacidae. Members of this genus are known as American lampeyes. Until recently, it was placed within the

Poecilidae Poeciliidae are a family of freshwater ray-finned fishes of the order Cyprinodontiformes, the tooth-carps, and include well-known live-bearing aquarium fish, such as the guppy, molly, platy, and swordtail. The original distribution of the fami ...

(namely within the otherwise-African clade

Procatopodinae Procatopodidae, the African lampeyes, is a family of ray-finned fish in the order Cyprinodontiformes. It was formerly treated as a subfamily (Procatopodinae) of the Poecilidae. Despite containing mostly African genera (including ''Pantanodon'') ...

, which is now also treated as its own family), but more recent studies have found it to be the

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 ...

to the clade consisting of Poecilidae and

Anablepidae Anablepidae is a family of ray-finned fishes which live in brackish and freshwater habitats from southern Mexico to southern South America. There are three genera with sixteen species: the four-eyed fishes (genus '' Anableps''), the onesided li ...

Species

Five recognized species are placed in this genus: * '' Fluviphylax obscurus'' W. J. E. M. Costa, 1996 * '' Fluviphylax palikur'' W. J. E. M. Costa & Le Bail, 1999 * '' Fluviphylax pygmaeus'' ( G. S. Myers & J. de P. Carvalho, 1955) * '' Fluviphylax simplex'' W. J. E. M. Costa, 1996 * '' Fluviphylax zonatus'' W. J. E. M. Costa, 1996

References

Cyprinodontiformes Freshwater fish genera Fish of the Amazon basin Ray-finned fish genera Taxa named by Gilbert Percy Whitley {{Poeciliidae-stub