The Mediterranean freshwater fish fauna has evolved under constraints imposed by the seasonal weather/hydrological patterns that define the Mediterranean climate. These conditions have influenced the genetic and demographic structure of aquatic communities since their origins in the Mid‐Pliocene. Freshwater species in Mediterranean‐type climates will likely constitute genetically well‐differentiated populations, to varying ext...

In this study, genetic variation was assessed in Aphanius fasciatus and Aphanius iberus characterized by similar ecological traits but with very different distribution ranges in the Mediterranean area. Five populations of A. iberus and five of A. fasciatus were analysed using five polymorphic microsatellite loci and partial mitochondrial control region (D‐loop) sequences. Congruent results were found with both nuclear and mito...

Biogeographic patterns of the three main Nearctic groups of continental fishes inhabiting river drainages in central Mexico (livebearing goodeids, southern Mexican notropins and species of Algansea , the last two representing independent lineages of cyprinids) were obtained and compared by following two approaches: an estimate of divergence times and using a well‐defined biogeographic method. Three concordant biogeographic eve...

Using the mitochondrial non‐coding region I, it was shown that the two Spanish Lampetra planeri populations (Cares–Deva and Olabidea–Ugarana) correspond to different genetic units. The Cares–Deva population is probably a recent offshoot of Lampetra fluviatilis , being the Olabidea–Ugarana population less diverse and of older origin.

The endangered twoline skiffia Neotoca bilineata , a viviparous fish of the subfamily Goodeinae, endemic to central Mexico (inhabiting two basins, Cuitzeo and Lerma‐Santiago) was evaluated using genetic and habitat information. The genetic variation of all remaining populations of the species was analysed using both mitochondrial and microsatellite markers and their habitat conditions were assessed using a water quality index...

This study explores the effects of microsatellite size homoplasies on the reconstruction of phylogenetic relationships and estimates of population parameters as the fixation index ( F ST ) using as a case study a truncated microsatellite from the picote splitfin Zoogoneticus quitzeoensis . The results suggest that the use of imperfect microsatellites may have only a minor effect in phylogenetic and population studies.

The jarabugo Anaecypris hispanica , considered endemic to the Guadiana River basin, has been found in the Guadalquivir River. First genetic data showed a high degree of similarity to those of the Guadiana River populations. The genetic study recovered five different groups of haplotypes, the Guadalquivir River specimens belong to the largest and most widely extended group.

Several phylogeographic studies using mtDNA sequence data have revealed an expressed geographic structure in nearly every European freshwater fish species studied. The authors present a phylogeographic study of Misgurnus fossilis on the base of 43 specimens from 17 localities across a major part of the known distribution area of M. fossilis . Despite the large geographic distance between the sampling points and their origin fr...

The origin, the phylogeographical structure and divergence times of hybridrogenetic Squalius alburnoides complex were analysed based on the complete mitochondrial cytochrome b gene (1140 pb). The molecular phylogenetic analyses suggest that the S. alburnoides complex has at least five asexual lineages of independent origin. The events that produced this ancestral hybridization took place over a long period of time. There have...

Twelve polymorphic allozyme loci were employed to assess the genetic change in a captive breeding population of the endangered killifish Aphanius baeticus in the Doñana National Park, south‐western Spain. The initial founder event did not significantly reduce the allelic richness or the expected heterozygosity. No genetic bottleneck signature was detected by tests for deviation from mutation‐drift equilibrium. The F ST between...

The current taxonomy within the subgenus Profundulus was reviewed and at least five different species were recognized on the basis of unique genetic characters. Two of them are considered to be new species not yet described: one is known only from a single spring in the Tehuantepec basin (Mexico); the second extends mainly through springs in the Mixteca region of Mexico. The maximum Nei distances were found between P. oaxacae...

In 23 populations of Greek Leuciscus ( Squalius ), the percentage of polymorphic allozyme loci ranged between 0·034 and 0·379 (P=0·19) and expected heterozygosity was 0·011–0·166 (H e =0·067). Current taxonomy is confusing and does not correspond to genetic data that support the presence in Greece of at least seven different species: L. cephalus , L. peloponnensis , L. prespensis , L. moreoticus , L. borysthenicus , L. keadicu...