Resumo

NIRCHIO, Mauro; GRANADO, Alberto; RON, Ernesto  e  PEREZ, Julio E.. Karyotype and nucleolar organizer regions in serrasalmus rhombeus (serrasalminae) from caicaradel orinoco,venezuela. INCI [online]. 2002, vol.27, n.12, pp.676-678. ISSN 0378-1844.

Summary Cytogenetic studies were conducted on Serrasalmus rhombeus from Caicara del Orinoco, Venezuela. The diploid chromosome number 2n=60 was composed of 30 metacentric, 16 submetacentric, 4 subtelocentric and 10 acrocentric chromosomes (NF= 110). Four pairs of NOR-bearing chromosomes were detected. NOR are located terminally on the short arms of one pair of medium sized subtelocentric chromosomes, and on three small sized acrocentric chromosome pairs. The karyotype diversity in this species suggests that karyotype formulae and NOR number could be useful for characterization of intraspecific stocks or populations.

Palavras-chave : Karyotype ; NOR ; Serrasalmus rhombeus .