Cytogenetic characterization of Crenicichla (Pisces, Perciformes, Cichlidae) of the Iguaçu River

S.M.H.K. Mizoguchi, A.L.B. Portela-Castro and I.C. Martins-Santos
Departamento de Biologia Celular e Genética,
Universidade Estadual de Maringá, Maringá, PR, Brasil
Corresponding author: I.C. Martins-Santos
E-mail: icmdsantos@uem.br

Genet. Mol. Res. 6 (3): 650-656 (2007)
Received July 3, 2007
Accepted August 8, 2007
Published September 30, 2007

ABSTRACT. Three populations of the genus Crenicichla, namely Crenicichla iguassuensis, Crenicichla sp 1 and Crenicichla sp 2, from the Iguaçu River, were analyzed cytogenetically, and their nucleolus organizer regions, constitutive heterochromatin distribution and chromomycin A₃ markings were studied. Karyotype analyses showed a diploid number of 48 chromosomes, made up of 2 metacentric pairs, 2 submetacentric pairs, 7 subtelocentric pairs, and 13 acrocentric pairs for the three Crenicichla species and no sexual chromosome differentiation. Nucleolus organizer regions showed strong interstitial marking on the first chromosome pair, coincident with a constriction presented by Giemsa and positive marking by chromomycin. Although constitutive heterochromatin patterns were also similar, with pericentromeric markings, small differences in the three species could be observed. Crenicichla sp 2 presented some chromosomes with bitelomeric markings absent in Crenicichla iguassuensis and Crenicichla sp 1.

Key words: Karyotype, Nucleolus organizer region banding, C banding, Cichlidae, Crenicichla iguassuensis, Perciformes