Pleistocene karyotypic divergence in Hoplias malabaricus (Bloch, 1794) (Teleostei: Erythrinidae) populations in southeastern Brazil

Abstract

The lacustrine system of the middle rio Doce basin is considered a paradigm of Pleistocene geomorphology. In these lakes, two Hoplias malabaricus karyomorphs (2n = 42A and 2n = 42B) live in sintopy in Carioca Lake. Cytogenetic analyses were performed on 65 specimens from 8 lakes (including Carioca Lake) to determine the distribution and relative frequency of these karyomorphs and the degree of cytogenetic divergence caused putatively by recent geographic isolation. All fish were 2n = 42B karyomorphs, except for 1 specimen from the Marola Lake, which was 2n = 42A. Among-population variation was especially high for C-banding patterns. Other characters such as X chromosome size and CMA 3 /DAPI also varied among populations. Our results suggested that the karyotype of H. malabaricus is able to respond rapidly to geographic isolation, and revealed that heterochromatic variation may represent the lowest hierarchical level of chromosomal evolution.O sistema lacustre da bacia do médio rio Doce é considerado um paradigma da geomorfologia do Pleistoceno. Nestes lagos, dois cariomorfos de Hoplias malabaricus (2n = 42A e 2n = 42B) vivem em sintopia na lagoa Carioca. Análises citogenéticas foram realizadas em 65 amostras de 8 lagos (incluindo lagoa Carioca) para determinar a distribuição e frequência relativa destes cariomorfos e o grau de divergência citogenética aparentemente causada pelo isolamento geográfico recente. Todos os peixes apresentaram o cariomorfo 2n = 42B, com exceção de 1 espécime da lagoa Marola, que foi 2n = 42A. Entre as populações, a variação foi especialmente elevada nos padrões de bandamento C. Outros caracteres como o tamanho do cromossomo X e os padrões de CMA 3 /DAPI também variaram entre as populações. Nossos resultados sugerem que o genoma de H. malabaricus é capaz de responder rapidamente ao isolamento geográfico, revelando que a variação de heterocromatina pode representar o nível hierárquico mais baixo de evolução cromossômica.

Cytogenetic and DNA barcoding reveals high divergence within the trahira, Hoplias malabaricus (Characiformes: Erythrinidae) from the lower Amazon River

“…Cytogenetic markers have provided important criteria for the delimitation of H. malabaricus populations and the analysis of the evolutionary pathways of karyotypic diversification in this group (Bertollo et al, 2000;Jacobina et al, 2011;Vitorino et al, 2011). The chromosomal morphology and C-banding patterns of the H. malabaricus specimens analyzed in the present study were consistent with the C karyomorph lineage.…”

Dispersal and vicariance of Hoplias malabaricus (Bloch, 1794) (Teleostei, Erythrinidae) populations of the Brazilian continental margin

“…Although the H. malabaricus populations from the Eastern A and Eastern B haplogroups both have 2 n = 42 chromosomes (Jacobina et al ., ), molecular data indicate no evidence of genetic exchange between the Doce and Paraíba do Sul rivers during glacial periods. Within the Eastern B haplogroup, the two subhaplogroups (Itabapoana/Paraíba do Sul and Macaé/São João/Paraíba do Sul rivers) suggest independent dispersal events between the hydrographical basins to the north and south of the Paraíba do Sul.…”

“…This familial pattern is consistent with at least three demography‐dependent chromosomal speciation models (reviewed in Rieseberg, ). Although the local dynamics of chromosome rearrangement fixation processes may be easily blurred by multiple vicariance and dispersal events in the Neotropical region (Albert & Reis, ), the apparent substitution of karyomorph 42A by its closely related 42B in the Doce River Basin (Santos et al ., ; Jacobina et al ., ) suggests that chromosomal rearrangements may involve selective advantages (Kirkpatrick & Barton, ).…”

Cytogenetic characterization of Hoplias malabaricus (Bloch, 1794) from the Ctalamochita River (Córdoba, Argentina): first evidence for southernmost populations of this species complex and comments on its biogeography

“…Additionally, fluctuations of sea level during glacial-interglacial cycles and temporary connections between adjacent basins would also have had an important role in spreading karyomorph A Hoplias malabaricus populations through coastal regions (Dergam et al 2002, Jacobina et al 2011, Pereira et al 2013). Indeed, the current distribution of several genera of freshwater fishes such as Australoheros , Cnesterodon , Jenynsia and Corydoras in Pampa Plain southernmost areas seems to have been strongly influenced by interconnection of coastal rivers during low sea level periods (Bruno et al 2011, 2016).…”

“…Additionally, combination of cytogenetic and molecular approaches together with geological information (i.e., estimate data of ancient episodes such as stream piracy between rivers, orogenic activity, etc., involved in vicariance events) has been particularly useful in the study of dispersal events and phylogenetic relationships (Dergam et al 1998, 2002, Santos et al 2009, Jacobina et al 2011, Pereira et al 2013). …”