Divergence between karyotypical pattern and speciation events in Serranidae fish (Perciformes)

• Published in: Caryologia Vol. 55; no. 4; pp. 299 - 305
• Main Authors: Molina, W.F., Maia-Lima, F.A., Affonso, P.R.A.M.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 01-01-2002
• Subjects: Alphestes; Epinephelus; fish cytogenetics; reefs; Serranidae; Serranus
• ISSN: 0008-7114; 2165-5391
• DOI: 10.1080/00087114.2002.10797880

The family Serranidae (Perciformes) represents a group of species widely distributed in tropical and subtropical waters, most of them presenting economical value. Some species are associated to coral reefs and lack genetic information. Cytogenetical analyses were carried out on three Serranidae species from Northeastern Brazilian coast, Epinephelus adscencionis, Alphestes afer and Servatius flaviventris. All of them presented a karyotype typical of Perciformes, composed by 48 acrocentric chromosomes (2n=48, FN=48). Active NORs were located at interstitial position on 24
th
pair in E. adscencionis and A. afer and on 16
th
pair in S. flaviventris. Besides the major NOR-bearing pair, extra ribosomal sites were also detected at telomeric position on long arms of the 2
nd
chromosomal pair of E. adscencionis. Heterochromatic blocks were restricted to centromeric or pericentromeric regions in all chromosomes, without any differences among the three species. The cytogenetical evidences support the monophyletism proposed for the subfamily Epinephilinae. It is possible that the karyotype structure associated to peculiar behavioral and biological features could be restraining chromosomal changes. These factors, not acting over the morphological diversification, would contribute for the observed asynchrony between karyotype (endophenotype) and morphology (exophenotype) of Serranidae species.