The evolutionary history of Mexican ichthyofauna has been strongly linked to natural events, and the impact of pre-Hispanic cultures is little known. The live-bearing fish species Allotoca diazi, Allotoca meeki and Allotoca catarinae occur in areas of biological, cultural and economic importance in central Mexico: Pátzcuaro basin, Zirahuén basin, and the Cupatitzio River, respectively. The species are closely related genetically and morphologically, and hypotheses have attempted to explain their systematics and biogeography. Mitochondrial DNA and microsatellite markers were used to investigate the evolutionary history of the complex. The species complex shows minimal genetic differentiation. The separation of A. diazi and A. meeki was dated to 400–7000 years ago, explained by geological and climate events. A bottleneck and reduction of genetic diversity in Allotoca diazi was detected, attributed to recent climate fluctuations and anthropogenic activity. The isolation of A. catarinae occurred ~1900 years ago. No geological events are documented in the area during this period, but the date is contemporary with P’urhépecha culture settlements. This founder effect represents the first evidence of fish species translocation by a pre-Hispanic culture of Mexico. The response of the complex to climate fluctuation, geological changes and human activity in the past and the future according to the ecological niches predictions indicates areas of vulnerability and important information for conservation. The new genetic information showed that the Allotoca diazi complex consist of two genetic groups with an incomplete lineage sorting pattern: Pátzcuaro and Zirahuén lakes, and an introduced population in the Cupatitzio River.

Taxonomy of the live-bearing fish of the genus Ilyodon Eigenmann, 1907 (Goodeidae), in Mexico, is controversial, with morphology and mitochondrial genetic analyses in disagreement about the number of valid species. The present study accumulated a comprehensive DNA sequences dataset of 98 individuals of all Ilyodon species and mitochondrial and nuclear loci to reconstruct the evolutionary history of the genus. Phylogenetic inference produced five clades, one with two subclades, and one clade including three recognized species. Genetic distances in mitochondrial genes (cytb: 0.5%-2.1%; coxI: 0.5%-1.1% and d-loop: 2.3%-10.2%) were relatively high among main clades, while, as expected, nuclear genes showed low variation (0.0%-0.2%), with geographic concordance and few shared haplotypes among river basins. High genetic structure was observed among clades and within basins. Our genetic analyses, applying the priority principle, suggest the recognition only of Ilyodon whitei and Ilyodon furcidens, with I. cortesae relegated to an invalid species, the populations of which belong to I. whitei.

BackgroundThe Pantosteus plebeius-nebuliferus species-group is a group of freshwater fishes distributed in endo- and exorheic drainage basins in the Mexican Sierra Madre Occidental mountain range system and central North Mexico. The geological history of this region is considered an important factor in explaining the evolutionary history of low vagility animals like freshwaters fishes. The aim of this study was to examine the phylogenetic relationships and describe the evolutionary history of the species-group. We hypothesized that the genetic structure and distribution of the main clades of Pantosteus plebeius-nebuliferus are associated with the geological history of Northern Mexico. To this end, we obtained DNA sequences of mitochondrial and nuclear genes and performed phylogenetic and phylogeographic analyses. Divergence time estimation and ancestral area reconstruction were also carried out to propose a biogeographical hypothesis, and species boundaries within the species-group were also tested.ResultsWe identified four clades within the Pantosteus plebeius-nebuliferus species-group in both markers. Divergence ranged from 5.9% to 9.2% for cytb and 0.1% to 0.9% for GHI. We observed significant genetic structure and no shared haplotypes between clades. We estimated that the clades diverged during the last 5.1 Myr, with a biogeographic scenario suggesting eight vicariant and four dispersal events through the historic range of the species-group. We found that the best species-delimitation model is when four species are assumed, which correspond to the main clades. We identified nine evolutionary significance units (ESUs), pertinent to the conservation of the group, each representing populations present in distinct drainage basins.ConclusionsThe evolutionary history of the Pantosteus plebeius-nebuliferus species-group is characterized by vicariant post-dispersal processes, linked to geological changes in the Sierra Madre Occidental and central Northern Mexico since the Pliocene. This is congruent with biogeographic patterns described for other co-distributed fish species. We propose a new phylogenetic hypothesis for the species-group, clarifying the taxonomy of this evolutionarily complex group. Our results suggest that the species-group consists of at least four clades with independent evolutionary histories, two of which may represent new undescribed species. Our identification of ESUs provides a basis upon which conservation measures can be developed for the species-group.Electronic supplementary materialThe online version of this article (10.1186/s12862-018-1286-y) contains supplementary material, which is available to authorized users.

Following publication of the original article [1], the authors notified us that that one of the authors' names was incorrectly spelled. In this Correction the incorrect and correct author name are shown. The original publication of this article has been corrected.

The Rifian barbel (Luciobarbus rifensis) is a tetraploid cyprinid species from North Africa. The aim of this work is to characterize the mitogenome of Luciobarbus rifensis in order to contribute in the future exploration of regions. The circular mitogenome of the Rifian barbel (16 607bp) consists of 37 genes (13 protein-coding genes, 2 rRNA genes, and 22 tRNA genes). The cyprinid mitogenome is most related to L. rifensis available is L. capito. The species Luciobarbus rifensis Doadrio, Casal-L opez, and Yahyaoui, 2015 is representative of the fish family Cyprinidae and endemic of rivers from the Rif area of Morocco (Casal-L opez et al. 2015). The molecular marker discovered is relevant due the tetraploid condition in Luciobarbus. The aim of this work was to characterize the mitochondrial genome of L. rifensis to contribute to the future exploration of novel regions that will be apply to genetic and evolution studies in this fish group.We used a tissue (caudal fin) of Luciobarbus rifensis collected in the Laou River (Mediterranean slope from Morocco) in Chefchaouen province (35 07 0 08.2"N 5 17 0 20.7"W), stored in the fish collection of the National Museum of Natural Sciences of Madrid, Spain (Voucher specimen: MNCN-235026). Library of genomic-DNA was prepared, tagged and subjected for sequencing in the Illumina MiSeq platform (PE300) in AllGenetics & Biology, SL. Assemblage was performed using SOAPdenovo2 (Luo et al. 2012) and quality evaluation using FastQC (Andrews 2010). Identification of tRNA genes was estimated using tRNAscanSE v1.21 (Schattner et al. 2005). Annotation confirmation was implemented usingMitoAnnotator (Iwasaki et al. 2013). Phylogenetic reconstruction was performed under Neighbour-Joining assumption; including 23 species of the Cyprinidae family available on GenBank. The analysis was conducted with a full alignment built in MAFFT v7.222 (Katoh et al. 2002). The base composition of the circular mitogenome of the Luciobarbus rifensis (GenBank accession: KX348041) was as follows: A ¼ 30.9%, C ¼ 27.9%, G ¼ 16.8%, and T ¼ 24.5% (GC-rich ¼ 44.6%), consisting of 37 genes in 16 607bp (13 protein-coding genes, 2 rRNA genes, and 22 tRNA genes). The size of the tRNA genes in mitogenome is 67-77bp. The phylogenetic relationships for the species (Figure 1) were consistent with those obtained for Cyprinidae (Wang et al. 2012;Wang et al. 2013) differing in some low supported relationship (e.g. for Gymnocypris namensis, Scaphiodonichthys acanthopterus, and Procypris rabaudi). As it has been previously reported (Zardoya & Doadrio 1999;Casal-L opez et al. 2015), of the mitogenomes available, the most related with L. rifensis is L. capito followed by Barbus barbus. our results, the mitogenome of L. rifensis will contribute to when searching new molecular markers for the study of this tetraploid fish group.