Karyotypic Study of Some Species of the Family Loricariidae (Pisces)

Abstract

The study of chromosomes has become of interest for classification of species and understanding of evolution. In spite of being used extensively in taxonomic research of invertebrates and even in vertebrates, it is incomplete in most animals because of technical difficulties. Among vertebrates, fishes, form the group for which cytological data are most lacking. There are 25,000 species of teleosts and only about 300 species are known cytologically so far. Fishes of the family Loricariidae occur in Central and South America, and constitute a few less than 300 species gathered in 6 sub-families (Gosline 1947). It is probably the largest and certainly one of the most specialized families of the siluriform fishes. Chromosome study was already effected in two species of this family, Hypostomus plecostomus (2n=54) and Loricaria parva (2n=48) (Hinegardner et al 1972). The main purpose of this paper is to report a chromosome study in some species of this family, contribute to its taxonomy and to oflfer additional data on the karyotypic evolution of fishes. © 1977, Japan Mendel Society, International Society of Cytology. All rights reserved.