Karyotype analysis in South Atlantic perciforms Micropogonias furnieri and Abudefduf saxatilis.

Accession number;02A0714923
Title;Karyotype analysis in South Atlantic perciforms Micropogonias furnieri and Abudefduf saxatilis.
Author; BRUM M J I (Univ. Federal Do Rio De Janeiro, Rj, Bra) DE OLIVEIRA CORREA M M (Univ. Federal Do Rio De Janeiro, Rj, Bra) DE AGUILAR C T (Univ. Federal Do Rio De Janeiro, Rj, Bra)
Journal Title;Chromosome Sci
Journal Code:S0638B
ISSN:1344-1051
VOL.5;NO.2;PAGE.83-89(2001)
Figure&Table&Reference;FIG.2, REF.24
Pub. Country;Japan
Language;English
Abstract;Chromosome studies were carried out on two species of the order Perciformes, Micropogonias furnieri and Abudefduf saxatilis, collected in the coast of Guanabara Bay, Rio de Janeiro, Brazil. M. furnieri presented 48 chromosomes, most being acrocentrics and few subtelocentrics(FN=48) and A. saxatilis also showed 48 chromosomes but with the karyotype consisting of two metacentrics, two submetacentrics and 44 acrocentrics(FN=52). Two NOR-bearing chromosomes were evidenced by silver nitrate staining in both species. In M. furnieri the Ag-NORs were located on the telomeric region of the short arms of the third acrocentric chromosome pair. The Ag-NORs in A. saxatilis were located on the telomeric region of the short arms of the first chromosome pair of the complement(a submetacentric one). In the later species the Ag-NORs were located in the secondary constrictions. A size heteromorphism of the Ag-NORs was also detected in the two species studied. C-banding analysis revealed pericentromeric blocks of constitutive heterochromatin in all chromosomes, as well as some telomeric ones in both species. In M. furnieri a conspicuous heterochromatic block was also observed in one of the largest pair, apparently coincident with the NORs. Considering a karyotype of 48 acrocentrics as synapomorphic to the Clupeomorpha and Euteleostei, we may, therefore, inter that the M. furnieri karyotype, with 2n=48, FN=48, represents a typical primitive characteristic of Percoidei, while the karyotype presented by Abudefduf saxatilis, with 2n=48 and FN=52, seems to be a more derived one, typical of Labroidei. (author abst.)