Chromosomal Evolution and Cytotaxonomy in Wrasses (Perciformes; Labridae)

Abstract

The wrasses (family Labridae) represent a suitable model to understand chromosomal evolution and to test the efficacy of cytotaxonomy since they display a remarkable karyotypic variation, rarely reported in marine Perciformes, as well as a high number of species and complex systematics. Therefore, we provided new chromosomal data in 5 labrids from South Atlantic (Doratonotus megalepis, Halichoeres dimidiatus, Halichoeres penrosei, Thalassoma noronhanum, and Xyrichtys novacula) and carried out a detailed comparative analysis of karyotypic data in Labridae using multivariate approaches. Basal diploid values (2n = 48) were observed in most of species studied in the present work but D. megalepis (2n = 46), along with distinct karyotype formulae. Single 18S rDNA sites interspersed with GC-rich heterochromatin were also commonly reported except for both Halichoeres species (2 18S rDNA-bearing pairs), following a species-specific pattern. These data show the high rates of chromosomal evolution in wrasses, ranging from microstructural rearrangements to centric fusions. A revision of chromosomal data in Labridae based on multivariate analysis of 74 taxa allowed inferring karyoevolutionary trends within tribes and genera of wrasses. The dendrogram obtained was in agreement with recent systematic hypotheses. In spite of the independent occurrence of some chromosomal rearrangements, karyoevolutionary trends could be identified within tribes of Labridae. Moreover, the karyotypic features are also suitable as cytotaxonomic markers of wrasses.

Interregional cytogenetic comparisons in Halichoeres and Thalassoma wrasses (Labridae) of coastal and insular regions of the southwestern Atlantic

“…The cytogenetical data extended and consolidated the previous information available for these species (Sena and Molina, 2007;Amorim et al, 2016;Almeida et al, 2017). In fact, the three species present karyotypes with 2n = 48 chromosomes in the marine regions analyzed and a similar chromosomal macrostructure, with only some small differences for T. noronhanum.…”

Genetic Investigation of Some Perciformes Fish Species Using Karyological Analysis

“…Several authors including (Santini et al, 2009;Sato and Nishida, 2010;Kai et al, 2011;Mazzuchelli et al, 2012;Guyomard et al, 2012;Schartl et al, 2013;Eschmeyer and Fong, 2014, Grassi, et al, 2017, Abu Almaaty et al, 2015& 2017aAlmeida, et al, 2017; reported that chromosome numbers confirm a large diversity in species of fishes in Class Actinopterygii which exhibit wide range , ranging from 2n=16 in ( Sphaerichthys osphromenoides ) to 2n=134 (Corydoras aeneus).…”

“…The cytogenetic studies indicated that the diploid chromosome numbers of Actinopterygii ranging from 2n=16 to 2n =134 (Santini et al, 2009;Sato and Nishida, 2010;Kai et al, 2011;Mazzuchelli et al, 2012); Guyomard et al, 2012;Schartl et al, 2013;Eschmeyer and Fong, 2014;Grassi et al, 2017, Abu Almaaty et al, 2015& 2017aAlmeida et al, 2017).…”

Chromosomal Formula of Four Marine Fish Species from The Mediterranean Sea in Egypt

“…Most studies concluded that the diploid chromosome numbers of fishes ranging from 2n=16 to 2n =134. (Grassi et al, 2017, Abu Almaaty et al, 2015, 2017aAlmeida et al, 2017).…”