Cytogenetic characterization of Crenicichla (Pisces, Perciformes, Cichlidae) of the Iguaçu River.
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.
Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Maringá, PR, Brasil.
S M H K
SM
Mizoguchi
A L B
AL
Portela-Castro
I C
IC
Martins-Santos
D000818:Animals; D002875:Chromosomes / Q000378:metabolism; D023681:Cichlids / Q000235:genetics*; D020732:Cytogenetic Analysis; D007621:Karyotyping; D008677:Metaphase; D009697:Nucleolus Organizer Region / Q000378:metabolism; D045483:Rivers