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Cytogenetics analysis and heterochromatin distribution in ZZ/ZW sex chromosomes of th mailed catfish Loricariichthys platymeton (Loricariidae: Siluriformes)

Márcia Denise P. Scavone; Horácio Ferreira Julio Jr.

Departamento de Biologia Celular e Genética, Universidade Estadual de Maringá, Av. Colombo 3690, 87020-900 Maringá, PR, Brasil. Send correspondence to H.F.J.Jr.

ABSTRACT

A cytogenetic study was conducted on 26 Loricariichthys platymetopon specimens from the region of Porto Rico, State of Paraná, Brazil. Both males and females had a diploid number equal to 54, with a probable sex mechanism of the ZZ/ZW type. Constitutive heterochromatin was located in the centromeric region of all chromosomes in the karyotype and coincided with the nucleolus organizer region.

Keywords: Cytogenetics analysis; heterochromatin; sex chromosomes; catfish; Loricariichthys platymeton.

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