Moenkhausia Oligolepis

Moenkhausia Oligolepis

Tetra is the common name for various small, often colorful, tropical, freshwater fish within the two characiform (order Characiformes) families Characidae—and in particularly its subfamilyTetragonopterinae, the "South American tetras"—and Alestiidae, the "African tetras." The African tetras formerly were classified in Alestiinae as a subfamily of Characidae, and remain within Characidae in some classifications.

The term tetra is not a formal taxonomic rank, but rather is the common name used for numerous small fish scattered over numerous genera and different families and subfamilies. Because of the popularity of tetras in the fish-keeping hobby, many unrelated fish are commonly known as tetras. Even fish that are vastly different may be called tetras, such as Hydrolycus scomberoides, occasionally known as the sabretooth tetra or vampire tetra, which is placed in the Characinae subfamily within Characidae.

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

 A general analysis showed a mean value of 2.9 pg of DNA per diploid nucleus. Very similar DNA content values were observed in the species of the family Cynodontidae which showed a variation of 3% between the two genera studied. Small variations were observed between populations of Gymnocorymbus ternetzi, Astyanax fasciatus and Moenkhausia sanctaefilomenae (Characidae, Tetragonopterinae). The subfamilies Tetragonopterinae and Acestrorhynchinae (Characidae) presented the widest range, about 96%. Even in those families in which diploid number and karyotypic formulae were conserved such as the families Anostomidae, Curimatidae, and Prochilodontidae, episodes leading to losses or gains of genetic material became fixed in their evolutionary history.

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis

Moenkhausia Oligolepis