Chromosome evolution in the erythrinid fish, Erythrinus erythrinus (Teleostei: Characiformes)

Abstract

The genus Erythrinus belongs to the family Erythrinidae, a neotropical fish group. This genus contains only two described species, Erythrinus erythrinus being the most widely distributed in South America. Six samples of this species from five distinct Brazilian localities and one from Argentina were studied cytogenetically. Four groups were identified on the basis of their chromosomal features. Group A comprises three samples, all with 2n ¼ 54 chromosomes, a very similar karyotypic structure, and the absence of chromosome differentiation between males and females. One sample bears up to four supernumerary microchromosomes, which look like 'double minute chromosomes' in appearance. Groups B-D comprise the three remaining samples, all sharing an X 1 X 1 X 2 X 2 /X 1 X 2 Y sex chromosome system. Group B shows 2n ¼ 54/53 chromosomes in females and males, respectively, and also shows up to three supernumerary microchromosomes. Groups C and D show 2n ¼ 52/51 chromosomes in females and males, respectively, but differ in the number of metacentric, subtelocentric, and acrocentric chromosomes. In these three groups (B-D), the Y is a metacentric chromosome clearly identified as the largest in the complement. The present results offer clear evidence that local samples of E. erythrinus retain exclusive and fixed chromosomal features, indicating that this species may represent a species complex.

Comparative chromosome mapping of 5S rDNA and 5S<i>Hin</i>dIII repetitive sequences in Erythrinidae fishes (Characiformes) with emphasis on the <i>Hoplias malabaricus</i> ‘species complex’

“…The karyotype analyses of the Erythrinidae species agreed with previous karyotype descriptions of the representatives of the family (Bertollo et al, , 2004Diniz and Bertollo, 2003). In H. malabaricus, the 5S rDNA was clustered interstitially in a large submetacentric chromosome pair (pair No.…”

Karyological and molecular diversity in three freshwater species of the genusChanna(Teleostei, Perciformes) from India

“…A similar reduction in chromosome number has also been reported in Erythrinus spp. (Bertollo et al 2004). A decrease in 2n and FN in C. striata compared to C. gachua may be attributed to Robertsonian arrangements and pericentric inversion, as also opined by Choudhury et al (1982).…”

Karyotypic diversity and chromosome evolution in the armored catfishes Callichthyinae (Siluriformes, Callichthyidae)

“…Although the chromosome variation that leads to a variation in diploid number within each genus is an independent event, the same types of rearrangements suggested above occur in different genera of Callichthyinae and are recurrent (homoplasic) events. This situation has been observed in the origin of multiple sex chromosome systems in different genera of Erythrinidae [Hoplias malabaricus (Bloch 1794), Bertollo et al 1997; Erythrinus erythrinus (Bloch and Schneider 1801), Bertollo et al 2004] and different families of Gymnotiformes [Eigenmannia virescens (Valenciennes 1836), Almeida-Toledo, Foresti, et al 2000; Brachyhypopomus pinicaudatus (Hopkins 1991), ; Gymnotus pantanal (Fernandes et al 2005), Silva et al 2011b].…”