Allopatric divergence in Astyanax aff. fasciatus Cuvier, 1819 (Characidae, Incertae sedis) inferred from DNA mapping and chromosomes

Medrado, Aline S.; Affonso, Paulo Roberto Antunes de Mello; Carneiro, Paulo Luız Souza; Vicari, Marcelo Ricardo; Artoni, Roberto Ferreira; Costa, Marco A. Dalla

doi:10.1016/j.jcz.2015.05.005

Cited by 11 publications

(3 citation statements)

References 52 publications

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“…From a conservation viewpoint, this result implies that the specimens from Cachoeira River should be managed as a unique and endangered stock, particularly because of the intensified deforestation of marginal areas and pollution of this basin [ 39 ]. From a biogeographic perspective, this result contradicts the putative similarity between Almada and Cachoeira River basins based on fauna composition, geographic distance, and chromosomal data [ 40 , 41 ]. Otherwise, the evolution of coastal hydrographic basins in Bahia seems to be more complex, probably alternating periods of connectivity and isolation such as headwater capture, as demonstrated in other reports [ 41 , 42 ].…”

Section: Resultsmentioning

confidence: 78%

Molecular Identification and Traceability of Illegal Trading inLignobrycon myersi(Teleostei: Characiformes), a Threatened Brazilian Fish Species, Using DNA Barcode

Rodrigues

Brandão

Bitencourt

et al. 2016

The Scientific World Journal

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Lignobrycon myersi is a threatened freshwater fish species and endemic of a few coastal rivers in northeastern Brazil. Even though the Brazilian laws prohibit the fisheries of threatened species, L. myersi is occasionally found in street markets, being highly appreciated by local population. In order to provide a reliable DNA barcode dataset for L. myersi, we compared mitochondrial sequences of cytochrome c oxidase subunit I (COI) from fresh, frozen, and salt-preserved specimens. Phylogenetically related species (Triportheus spp.) and other fish species (Astyanax fasciatus) commonly mixed with L. myersi in street markets were also included to test the efficiency of molecular identification. In spite of the differences in conservation processes and advanced deterioration of some commercial samples, high-quality COI sequences were obtained and effective in discriminating L. myersi specimens. In addition, while populations from Contas and Almada River basins seem to comprise a single evolutionary lineage, the specimens from Cachoeira River were genetically differentiated, indicating population structuring. Therefore, DNA barcoding has proved to be useful to trace the illegal trading of L. myersi and to manage threatened populations, which should focus on conservation of distinct genetic stocks and mitigation on human impacts along their range.

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Section: Resultsmentioning

confidence: 78%

Molecular Identification and Traceability of Illegal Trading inLignobrycon myersi(Teleostei: Characiformes), a Threatened Brazilian Fish Species, Using DNA Barcode

Rodrigues

Brandão

Bitencourt

et al. 2016

The Scientific World Journal

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“…For instance, this pattern has been reported in Astyanax scabripinnis (Jenyns, 1842) (Moreira Filho & Bertollo, 1991), Hasemania nana (Lütken, 1875) (Moreira et al, 2007), Hyphessobrycon anisitsi (Eigenmann, 1907) (Mendes et al, 2011), Hollandichthys multifasciatus (Eigenmann & Norris, 1900) (Balen et al, 2013) and Rhoadsia altipinna Fowler, 1911 (Romero et al, 2015), being considered a plesiomorphic condition of characins (Scheel, 1973;Morelli et al, 1983). The presence of distinct types of chromosomes (m, sm, st, and a) without variation in diploid number suggests the occurrence of pericentric inversions, another common rearrangement in characins (Medrado et al, 2015).…”

Section: Discussionmentioning

confidence: 99%

Allopatric chromosomal variation in Nematocharax venustus Weitzman, Menezes & Britski, 1986 (Actinopterygii: Characiformes) based on mapping of repetitive sequences

et al. 2016

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Characiformes is the most cytogenetically studied group of freshwater Actinopterygii, but karyotypical data of several taxa remain unknown. This is the case of Nematocharax, regarded as a monotypic genus and characterized by marked sexual dimorphism. Therefore, we provide the first cytogenetic report of allopatric populations of Nematocharax venustus based on distinct methods of chromosomal banding and fluorescence in situ hybridization (FISH) with repetitive DNA probes (18S and 5S rDNA). The karyotype macrostructure was conserved in all specimens and populations, independently on sex, since they shared a diploid number (2n) of 50 chromosomes divided into 8m+26sm+14st+2a. The heterochromatin was mainly distributed at pericentromeric regions and base-specific fluorochrome staining revealed a single pair bearing GC-rich sites, coincident with nucleolar organizer regions (NORs). On the other hand, interpopulation variation in both number and position of repetitive sequences was observed, particularly in relation to 5S rDNA. Apparently, the short life cycles and restricted dispersal of small characins, such as N. venustus, might have favored the divergence of repetitive DNA among populations, indicating that this species might encompass populations with distinct evolutionary histories, which has important implications for conservation measures.Characiformes é o grupo de Actinopterygii de água doce mais estudado citogeneticamente, porém dados cariotípicos de vários taxa permanecem desconhecidos. Este é o caso de Nematocharax, considerado um gênero monotípico e caracterizado pelo acentuado dimorfismo sexual. Em vista disso, nós fornecemos a primeira descrição citogenética de populações alopátricas de Nematocharax venustus, baseada em métodos distintos de bandamento cromossômico e hibridação fluorescente in situ (FISH) com sondas de DNA repetitivo (DNAr 18S e 5S). A macroestrutura cariotípica mostrou-se conservada em todos os espécimes e populações, independentemente do sexo, uma vez que compartilharam um número diploide (2n) de 50 cromossomos dividido em 8m+26sm+14st+2a. A heterocromatina distribuiu-se principalmente nas regiões pericentroméricas e a coloração com fluorocromos base-específicos revelou um único par portador de sítios GC-ricos, coincidentes com as regiões organizadoras de nucléolo (RONs). Por outro lado, foi observada uma variação interpopulacional no número e na posição das sequências repetitivas, especialmente em relação ao DNAr 5S. Aparentemente, ciclos de vida curtos e dispersão restrita dos pequenos caracídeos, tal como N. venustus, podem ter favorecido a divergência do DNA repetitivo entre as populações, indicando que essa espécie pode englobar populações com distintas histórias evolutivas, o que tem implicações importantes para medidas de conservação.

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“…Some of these studies represent the few citations regarding species of Astyanax to the rio de Contas basin, usually solely as syntopic fauna to their new species. Other relevant studies including species of Astyanax from the rio de Contas have citogenetic or molecular approaches (e.g., Affonso et al, 2007;Medrado et al, 2008Medrado et al, , 2015Pamponet et al, 2008), or are represented by not published thesis (e.g., Silva, 2015). Recent ichthyological surveys in the rio de Contas basin yielded a new species of Astyanax apparently endemic to this basin that is described herein.…”

Section: Introductionmentioning

confidence: 99%

A new species of Astyanax (Characiformes: Characidae) from the rio de Contas basin, Bahia, Brazil

et al. 2019

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A new species of Astyanax from tributaries of the rio de Contas, Bahia, Brazil, is described. The new species differs from congeners by having three horizontal series of scales from lateral line to pelvic-fin origin and the distal margin of third infraorbital distinctly separated from vertical and horizontal limbs of preopercle, leaving a broad area not covered by superficial bones. The new species further differs from most congeners by the presence of bony hooks on all fins of mature males. Particularly from congeners occurring in rivers of the Northeastern Mata Atlântica freshwater ecoregion, it further differs by having the highest body depth just anterior to the dorsal-fin origin, 34-37 pored lateral line scales, a vertically elongated conspicuous dark humeral blotch reaching below the lateral line and a conspicuous dark wide midlateral stripe extending from the clear area on the rear of the humeral blotch to the end of middle caudal-fin rays and forming an inconspicuous blotch on caudal peduncle.

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Allopatric divergence in Astyanax aff. fasciatus Cuvier, 1819 (Characidae, Incertae sedis) inferred from DNA mapping and chromosomes

Cited by 11 publications

References 52 publications

Molecular Identification and Traceability of Illegal Trading inLignobrycon myersi(Teleostei: Characiformes), a Threatened Brazilian Fish Species, Using DNA Barcode

Molecular Identification and Traceability of Illegal Trading inLignobrycon myersi(Teleostei: Characiformes), a Threatened Brazilian Fish Species, Using DNA Barcode

Allopatric chromosomal variation in Nematocharax venustus Weitzman, Menezes & Britski, 1986 (Actinopterygii: Characiformes) based on mapping of repetitive sequences

A new species of Astyanax (Characiformes: Characidae) from the rio de Contas basin, Bahia, Brazil

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