''Hyphessobrycon'' is a genus of freshwater fish in the family Characidae. These species are among the fishes known as tetras. The genus is distributed in the Neotropical realm from southern Mexico to Río de la Plata in Argentina. Many of these species are native to South America; about six species are from Central America and a single species, '' H. compressus'' is from southern Mexico. All small fishes, the ''Hyphessobrycon'' tetras reach maximum overall lengths of about . Great anatomical diversity exists in this genus.Lucena, C.A.S.d. (2003)
New characid fish, ''Hyphessobrycon scutulatus'', from the rio Teles Pires drainage, upper rio Tapajós system (Ostariophysi: Characiformes: Characidae).
''Neotropical Ichthyology, 1 (2): 93–96.'' They are generally of typical characin shape, but vary greatly in coloration and body form, many species having distinctive black, red, or yellow markings on their bodies and fins. These species are generally omnivorous, feeding predominantly on small crustaceans, insects,

annelid The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecol ...

worms, and zooplankton. When spawning, they scatter their eggs and guard neither eggs nor young.

Taxonomy

This large genus of characins includes over 150 species. The systematics of ''Hyphessobrycon'' are still largely unresolved.Lima, F.C.T. & Moreira, C.R. (2003)
Three new species of ''Hyphessobrycon'' (Characiformes: Characidae) from the upper rio Araguaia basin in Brazil.
''Neotropical Ichthyology, 1 (1): 21–33.'' Six groups within this genus have been recognized based on color patterns alone.Bertaco, V.A. & Malabarba, L.R. (2005)
A new species of ''Hyphessobrycon'' (Teleostei: Characidae) from the upper Rio Tocantins drainage, with bony hooks on fins.
''Neotropical Ichthyology, 3 (1): 83–88.'' With no phylogenetic analysis of this genus, species are placed into this genus as anatomically defined by

Carl H. Eigenmann Carl Henry Eigenmann (March 9, 1863 – April 24, 1927) was a German-American ichthyologist of the late nineteenth and early twentieth centuries, who, along with his wife Rosa Smith Eigenmann, and his zoology students is credited with identifyin ...

in 1917. By this definition, ''Hyphessobrycon'' is identified by the presence of an adipose fin, incomplete

lateral line The lateral line, also called the lateral line organ (LLO), is a system of sensory organs found in fish, used to detect movement, vibration, and pressure gradients in the surrounding water. The sensory ability is achieved via modified epithelial ...

, two tooth series in the premaxilla, with the teeth of the external series continuous in a single series, teeth not strictly conical, preventral scales arranged in more than one row and lack of scales in the caudal fin. The characteristic of extension of scales onto the caudal fin that differentiates this genus from '' Hemigrammus'' is not satisfactory, as it occurs in intermediate conditions. This genus 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 ...

. A monophyletic group within ''Hyphessobrycon'' has been hypothesized, termed the rosy tetra

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...

; this group is based upon coloration pattern and the shape of dorsal and

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

s of males. Recognition of monophyletic groups among ''Hyphessobrycon'' species is complicated by the difficulty in finding characters useful for hypothesis of relationships among the species. Traditional characters used to identify ''Hyphessobrycon'' are phylogenetically unreliable.

Etymology

The generic name, ''Hyphessobrycon'', is of slightly uncertain origin. The second part derives from the Greek βρύκω (to bite); the first, derives from an ostensible Greek ''hyphesson'', which may be an error for υπελάσσων (slightly smaller).

Relationship to humans

None of the roughly 100 fishes in the genus has been rated by the

IUCN The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

, but many species have small distributions and at least one, '' Hyphessobrycon flammeus'', is believed to be highly threatened. This species only occurs in a few rivers and streams in coastal Rio de Janeiro State and in São Paulo State. Three other species are recognized as threatened in Brazil: ''H. coelestinus'', ''H. duragenys'', and ''H. taurocephalus''. ICMBio (Ministry of the Environment, Brazil)
Portaria MMA nº 445, de 17 de dezembro de 2014
. Lista de Especies Ameaçadas - Saiba Mais. Retrieved 1 December 2018. Many ''Hyphessobrycon'' species are popular

aquarium An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...

fish, and some, including ''H. flammeus'', are bred in large numbers in captivity.''Hyphessobrycon flammeus'' Myers, 1924 Flame Tetra.
Seriously Fish. Retrieved 21 March 2017.Korotev, K. (2017)
Breeding ''Hyphessobrycon flammeus''.
AquaInfo. Retrieved 21 March 2017.

Species

The 156 currently recognized species in this genus are:

References

{{Taxonbar, from=Q132810 Characidae Taxa named by Marion Durbin Ellis Fish of South America Freshwater fish genera Tetras