The Mugil curema species complex (Pisces, Mugilidae): a new karyotype for the Pacific white mullet mitochondrial lineage

Abstract

Recent molecular phylogenetic analyses have shown that the Mugil curema Valenciennes, 1836 species complex includes M. incilis Hancock, 1830, M. thoburni (Jordan & Starks, 1896) and at least four “M. curema” mitochondrial lineages, considered as cryptic species. The cytogenetic data on some representatives of the species complex have shown a high cytogenetic diversity. This research reports the results of cytogenetic and molecular analyses of white mullet collected in Ecuador. The analyzed specimens were molecularly assigned to the Mugil sp. O, the putative cryptic species present in the Pacific Ocean and showed a 2n = 46 karyotype, which is composed of 2 metacentric and 44 subtelocentric/acrocentric chromosomes. This karyotype is different from the one described for M. incilis (2n = 48) and from those of the two western Atlantic lineages Mugil curema (2n = 28), and Mugil margaritae (2n = 24). Data suggest the need for a morphological analysis to assign a species name to this Pacific lineage.

Identification of a New Mullet Species Complex Based on an Integrative Molecular and Cytogenetic Investigation of Mugil hospes (Mugilidae: Mugiliformes)

“…Cytogenetic analysis shows that the 48 acrocentric chromosome karyotype detected in M. hospes is consistent with the generally available data on diploid chromosome number and karyotype structure in Mugilidae ( Sola et al, 2007 ; Rossi et al, 2016 ). This confirms that the only exception is represented by the mullets belonging to the Mugil curema species complex ( Nirchio et al, 2017 ).…”

“…DNA samples were obtained for eight specimens (one male, two female, five immature), according to procedures described by Aljanabi and Martínez (1997) . A 655 bp fragment of the mitochondrial COI was amplified by PCR and sequenced using primers and protocols reported by Nirchio et al (2017) . DNA sequences were aligned using the software Clustal X ( Thompson et al, 1997 ) and deposited in GenBank (Accession numbers: KY964500 - KY964504 ).…”

“…These studies have also shown that it is necessary to use integrative approaches to study mugilids. Indeed, the use of repetitive sequences such as ribosomal genes (18S rDNA and 5S rDNA) as probes in FISH mapping has been shown to be a very informative cytotaxonomic tool in revealing different lineages/species within Mugilidae ( Nirchio et al, 2007 , 2017 ; Sola et al, 2007 ). On the other hand, the utility of molecular markers in this family to identify the species, better define the genera, and reconstruct their phylogenetic relationships, is well-represented by the huge amount of literature on this topic published in the last 15 years (see Rossi et al, 2016 for a review and Durand et al, 2017 ).…”

Do the Fish Scales Shape of Mugil curema Reflect the Genetic Structure Using Microsatellites Markers and the Mexican Marine Ecoregions Classification?

“…There is currently a taxonomic problem still under discussion: if M. curema in the Pacific is the same species as that in the Atlantic. According to Durand et al (2012), Durand and Borsa (2015), and Nirchio et al (2017), the genetic distance between both coasts is from 3.2% to 5.4%, enough to be considered as cryptic species. 15.4 1.9 1.9 1.9 7.7 9.6 1.9 100.0 The locations BA and CU from the Pacific (with exception of HU to be discussed later) showed more integrity within them in the canonical discrimination analysis ( Table 3).…”

Molecular Analysis and Chromosome Mapping of Repetitive DNAs in the Green TerrorAndinoacara rivulatus(Cichlidae: Cichlasomatini)

“…15 Fish cytogenetics is a very active research area that provides information for taxonomy and for the understanding of the phylogenetic relationships among taxa. [16][17][18][19][20][21][22][23] The most recent checklist of cytogenetically analyzed fish species reveals that only *8% of cichlid fishes are included. 24 The diploid number in the group ranges from 2n = 32 to 2n = 60, but in neotropical cichlids, the modal diploid number is 2n = 48.…”