中国北鳅谱系地理学分析

北鳅(Lefua costata)为冷水性鱼类,分布于淮河以北,分析遗传结构能够反映其适应环境变迁的响应.基于线粒体D-loop区211条序列分析了我国北鳅的谱系地理学和遗传多样性,样本采自9条水系共18个样点.单倍型分析显示共计55个单倍型,呈高单倍型多样性(h=0.9304)和高核苷酸多样性(π=0.0087).单...     

Collapse of a new living species of giant clam in the Red Sea

Giant clams are among the most spectacular but also the most endangered marine invertebrates. Their large size and easy accessibility has caused overfishing and collapse of the natural stocks in many places and local extinction in some of the species [1, 2]. The diversity of giant clams is extremely low because of reliction in this Tethyan group [3, 4]. The latest additions of living species date back almost two decades [5-7], fixing the number of extant Tridacna at seven species [3]. Here, we report the discovery of a new species of giant clam: Tridacna costata sp. nov. features characteristic shells with pronounced vertical folds, is genetically distinct, and shows an earlier and abbreviated reproduction than its Red Sea congeners. This species represents less than 1% of the present stocks but up to >80% of the fossil shells. The decline in proportion and shell size (20x) indicates overharvesting [8] dating back to the early human occupation of the Red Sea >125,000 years ago [9]. This earliest depletion reported so far of a shallow-water megafaunal invertebrate has important ramifications for human dispersal out of Africa [10]. Its oversight in one of the best-investigated reef provinces [11-13] illustrates the dearth of knowledge on marine biodiversity.     

Phylogenetic study of Baylisascaris schroederi isolated from Qinling subspecies of giant panda in China based on combined nuclear 5.8S and the second internal transcribed spacer (ITS-2) ribosomal DNA sequences

The nuclear ribosomal DNA (rDNA) region spanning 5.8S rDNA and the second internal transcribed spacer (ITS-2) of Baylisascaris schroederi isolated from the Qinling subspecies of giant panda in Shaanxi Province, China were amplified and sequenced. Sequence variations in the two rDNA regions within B. schroederi and among species in the family Ascarididae were examined. The lengths of B. schroederi 5.8S and ITS-2 rDNA sequences were 156 bp and 327 bp, respectively, and no nucleotide variation was found in these two rDNA regions among the 20 B. schroederi samples examined, and these ITS-2 sequences were identical to that of B. schroederi isolated from giant panda in Sichuan province, China. The inter-species differences in 5.8S and ITS-2 rDNA sequences among members of the family Ascarididae were 0-1.3% and 0-17.7%, respectively. Phylogenetic relationships among species in the Ascarididae were re-constructed by Bayesian inference (Bayes), maximum parsimony (MP), and maximum likelihood (ML) analyses, based on combined sequences of 5.8S and ITS-2 rDNA. All B. schroederi samples clustered together and sistered to B. transfuga with high posterior probabilities/bootstrap values, which further confirmed that nematodes isolated from the Qinling subspecies of giant panda in Shaanxi Province, China represent B. schroederi. Because of the large number of ambiguously aligned sequence positions (difficulty of inferring homology by positions), ITS-2 sequence alone is likely unsuitable for phylogenetic analyses at the family level, but the combined 5.8S and ITS-2 rDNA sequences provide alternative genetic markers for the identification of B. schroederi and for phylogenetic analysis of parasites in the family Ascarididae.     

Ribosomal DNA and ITS-2 sequence comparisons as a tool for predicting genetic relatedness

The determination of the secondary structure of the internal transcribed spacer (ITS) regions separating nuclear ribosomal RNA genes of Chlorophytes has improved the fidelity of alignment of nuclear ribosomal ITS sequences from related organisms. Application of this information to sequences from green algae and plants suggested that a subset of the ITS-2 positions is relatively conserved. Organisms that can mate are identical at all of these 116 positions, or differ by at most, one nucleotide change. Here we sequenced and compared the ITS-1 and ITS-2 of 40 green flagellates in search of the nearest relative to Chlamydomonas reinhardtii. The analysis clearly revealed one unique candidate, C. incerta. Several ancillary benefits of the analysis included the identification of mislabelled cultures, the resolution of confusion concerning C. smithii, the discovery of misidentified sequences in GenBank derived from a green algal contaminant, and an overview of evolutionary relationships among the Volvocales, which is congruent with that derived from rDNA gene sequence comparisons but improves upon its resolution. The study further delineates the taxonomic level at which ITS sequences, in comparison to ribosomal gene sequences, are most useful in systematic and other studies. Received: 14 February 1997 / Accepted: 28 March 1997     

Molecular and morphometric evidence for separate species of Uncinaria (Nematoda: Ancylostomatidae) in California sea lions and northern fur seals: hypothesis testing supplants verification

California sea lions (Zalophus californianus) and northern fur seals (Callorhinus ursinus) are each believed to host distinct hookworm species (Uncinaria spp.). However, a recent morphometric analysis suggested that a single species parasitizes multiple pinniped hosts, and that the observed differences are host-induced. To explore the systematics of these hookworms and test these competing hypotheses, we obtained nucleotide sequences of nuclear ribosomal DNA (D2/D3 28S, D18/D19 28S, and internal transcribed spacer [ITS] regions) from 20 individual hookworms parasitizing California sea lion and northern fur seal pups where their breeding grounds are sympatric. Five individuals from an allopatric population of California sea lions were also sampled for ITS-1 and D18/D19 28S sequences. The 28S D2/D3 sequences showed no diagnostic differences among hookworms sampled from individual sea lions and fur seals, whereas the 28S D18/D19 sequences had one derived (apomorphic) character demarcating hookworms from northern fur seals. ITS sequences were variable for 7 characters, with 4 derived (apomorphic) states in ITS-1 demarcating hookworms from California sea lions. Multivariate analysis of morphometric data also revealed significant differences between nematodes representing these 2 host-associated lineages. These results indicate that these hookworms represent 2 species that are not distributed indiscriminately between these host species, but instead exhibit host fidelity, evolving independently with each respective host species. This evolutionary approach to analyzing sequence data for species delimitation is contrasted with similarity-based methods that have been applied to numerous diagnostic studies of nematode parasites.     

Seasonal changes in the dorsal coloration in the lizard Aspidoscelis costata costata (Squamata: Teiidae)

Color and color patterns in animals are important characteristics that bring protection, by dampening the ability of predators that depend on their sight to detect their preys. In lizards, the dorsal coloration plays a key role in communication of intraspecific signals such as social cues. In this study, we evaluated the seasonal changes in the dorsal coloration of the wide foraging lizard A. costata costata, in Tonatico, State of Mexico, Mexico. The seasonal evaluation included: the rainy season from mid June to mid September (can also include the end of May to early October); and the dry season for the rest of the year. The dorsal coloration of A. costata costata and their microhabitats were evaluated by contrasting the color pattern with an identification guide and the control colors of Pantone, during 11 samplings carried out from February-October 2007. Individual lizard analysis recorded snout-vent length, sex and stage (juveniles and adults). Besides, all animals were marked by toe-clipping, allowing to distinguish dorsal coloration between seasons, sex and stage. A total of 95 lizards were analyzed (53 and 42 for the dry and rainy seasons respectively). We found that the dorsal coloration in A. costata costata varies seasonally and with microhabitats: during the dry season individuals show a brown coloration whereas during the rainy season becomes greener, as the background dominant vegetation color. The results of the present study suggest that: 1) the variation in dorsal coloration in A. costata costata plays an important role in the survival (by cryptic camouflage) of this widely foraging species; 2) the changes in the dorsal coloration of A. costata costata are individually expressed traits, since the coloration of the same lizard is either brown or green depending on the season; and 3) the cryptic functions of the dorsal coloration in widely foraging species have been largely underestimated. We discuss the possible influence of the changes in coloration in an habitat that changes drastically between both dry and rainy seasons.     

Differential precocious sexual development of Proctoeces lintoni (Digenea: Fellodistomidae) in three sympatric species of keyhole limpets Fissurella spp. may affect transmission to the final host.

The prevalence, abundance, and developmental status of the digenetic trematode Proctoeces lintoni Siddiqui et Cable 1960 were compared in 3 species of keyhole limpets Fissurella. A total of 197 limpets was collected at Caleta Chome, south-central Chile. Fissurella picta and F. costata had the highest prevalence of infection, whereas F. picta showed the greatest abundance of parasites, which increased with host shell length. However, the frequency of P. lintoni specimens with eggs in the uterus was greatest in F. costata. These results suggest that an increased rate of development of a parasite in the intermediate host may shorten the residence time necessary for maturation in the final host. Thus, faster development of the parasite in F. costata suggests the possibility that the parasites transmitted through this host species have shorter maturation times in clingfishes than individuals transmitted via other limpet species.     

Molecular characterization of Fasciola spp. from the endemic area of northern Iran based on nuclear ribosomal DNA sequences

Fasciolosis caused by Fasciola spp. (Platyhelminthes: Trematoda: Digenea) is considered as the most important helminth infection of ruminants in tropical countries, causing considerable socioeconomic problems. In the endemic regions of the North of Iran, Fasciola hepatica and Fasciola gigantica have been previously characterized on the basis of morphometric differences, but the use of molecular markers is necessary to distinguish exactly between species and intermediate forms. Samples from buffaloes and goats from different localities of northern Iran were identified morphologically and then genetically characterized by sequences of the first (ITS-1) and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA). Comparison of the ITS of the northern Iranian samples with sequences of Fasciola spp. from GenBank showed that the examined specimens had sequences identical to those of the most frequent haplotypes of F. hepatica (n = 25, 48.1%) and F. gigantica (n = 20, 38.45%), which differed from each other in different variable nucleotide positions of ITS region sequences, and their intermediate forms (n = 7, 13.45%), which had nucleotides overlapped between the two Fasciola species in all the positions. The ITS sequences from populations of Fasciola isolates in buffaloes and goats had experienced introgression/hybridization as previously reported in isolates from other ruminants and humans. Based on ITS-1 and ITS-2 sequences, flukes are scattered in pure F. hepatica, F. gigantica and intermediate Fasciola clades, revealing that multiple genotypes of Fasciola are able to infect goats and buffaloes in North of Iran. Furthermore, the phylogenetic trees based upon the ITS-1 and ITS-2 sequences showed a close relationship of the Iranian samples with isolates of F. hepatica and F. gigantica from different localities of Africa and Asia. In the present study, the intergenic transcribed spacers ITS-1 and ITS-2 showed to be reliable approaches for the genetic differentiation of Fasciola spp., providing bases for further studies on F. hepatica, F. gigantica and their intermediate forms in the endemic areas in Asia.     

Sequence variation in ITS spacers and 5.8S rDNA and relationship of E, St, P, Ns, Xm, and H genomes in the genera of Agropyron, Elytrigia, Leymus, Pascopyrum, Psathyrostachys, and Hordeum

Understanding species evolution and improvement requires information of their genome origin and differentiation. Among the species in the family Gramineae, genome identities of Agropyron-Elytrigia-Leymus group are still ambiguous. In order to delineate the genome relationship, nucleotide sequence analysis in the rDNA ITS regions was carried out among the species in the genera Elytrigia, Agropyron, Psathyrostachys, Leymus, and Psacopyrum containing E, St, P, Ns, and Xm genomes. The ITS-1 and ITS-2 showed a narrow range of variation in length except for the presence of a pentanucleotide, TGGGG, in/del in some haplotypes, whereas higher numbers of nucleotide substitutions were observed in most genera. There were 187 variable sites in the ITS-1, 5.8S, and ITS-2 regions, in which a few genome specific mutations were observed. While the level of variation was similar between ITS-1 and ITS-2, the rate of transition mutation versus transversion mutations was different among the ITS-1, 5.8S, and ITS-2 segments. GC contents of the ITS regions ranged between 55–65% between genomes and the haplotypes of P and H genomes were slightly higher than others. In phylogenetic analysis, the ITS haplotypes were classified into two groups; one containing H, Ns, NsXm genomes, and another containing P, St, and E genomes, which are congruous to the genome affinities from other studies. Among the four genomes in Pascopyrum smithii (2n=8x=56, StStNsNsHHXmXm), the haplotypes of H and St genomes were identified with the reference diploid species, but the haplotypes having Ns and Xm genomes were not found in the present analysis.     

Phylogenetic analysis of nuclear and mitochondrial DNA reveals a complex of cryptic species in Crassicutis cichlasomae (Digenea: Apocreadiidae), a parasite of Middle-American cichlids

We obtained nuclear ITS-1 and mitochondrial cox1 sequences from 225 Crassicutis cichlasomae adults collected in 12 species of cichlids from 32 localities to prospect for the presence of cryptic species. This trematode is commonly found in species of cichlids over a wide geographic range in Middle-America. Population-level phylogenetic analyses of ITS-1 and cox1, assessments of genetic and haplotype diversity, and morphological observations revealed that C. cichlasomae represents a complex of seven cryptic species for which no morphological diagnostic characters have been discovered thus far. Bayesian and Maximum Likelihood analyses of concatenated datasets (906 bp) recovered eight lineages of C. cichlasomae, all with high posterior probabilities and bootstrap branch support. Values of genetic divergence between clades ranged from 1.0% to 5.2% for ITS-1, and from 7.2% to 30.0% for cox1. Morphological study of more than 300 individuals did not reveal structural diagnostic traits for the species defined using molecular evidence. These observations indicate that some traditional morphological characters (e.g., testes position) have substantial intra-specific variation, and should be used with caution when classifying C. cichlasomae and their sister taxa. Additionally, phylogenetic analyses did not reveal a strict correlation between these cryptic species and their host species or geographic distribution, however it appears that genetic distinctiveness of these cryptic species was influenced by the diversification and biogeographical history of Middle-American cichlids.     

A molecular perspective on the phylogeny of the Hyla pulchella species group (Anura, Hylidae)

A molecular phylogenetic analysis of the Hyla pulchella species group was performed to test its monophyly, explore the interrelationships of its species, and evaluate the validity of the taxa that were considered subspecies of H. pulchella. Approximately 2.8 kb from the mitochondrial genes 12s, tRNA valine, 16s, and Cytochrome b were sequenced. The analysis included 50 terminals representing 10 of the 14-15 species currently recognized in the H. pulchella group, including samples from several localities for some taxa, several outgroups, as well as two species previously suspected to be related with the group (Hyla guentheri and Hyla bischoffi). The results show that the H. pulchella and Hyla circumdata groups are distantly related, and, therefore, should be recognized as separate groups. As currently defined, the H. pulchella group is paraphyletic with respect to the Hyla polytaenia group; therefore, we recognize the Hyla polytaenia clade in the H. pulchella group. Two subspecies of H. pulchella recognized by some authors are considered full species including Hyla pulchella riojana because it is only distantly related to H. pulchella, and Hyla pulchella cordobae because molecular and non-molecular evidence suggests that it is specifically distinct. With the inclusion of the H. polytaenia clade, H. guentheri, and H. bischoffi, and the recognition of the two former subspecies of H. pulchella as distinct species, the H. pulchella group now comprises 25 described species. All representatives of the H. pulchella group with an Andean distribution are monophyletic and nested within a clade from the Atlantic forest from south-southeastern Brazil/northeastern Argentina, and Cerrado gallery forest from central Brazil.     

The evolution of extreme shell shape variation in the land snail Ainohelix editha: a phylogeny and hybrid zone analysis

Ainohelix editha from Hokkaido, Japan, exhibit great geographical variation in their shell morphology. In particular, A. editha in two quite separate locations, Shimamaki and Samani, are striking because they are extremely flat and have a sharp keel, whereas at adjacent sites the shells are globular or depressed-globular. We used mitochondrial 16S rRNA and nuclear ITS-2 sequences to infer a phylogeny among 47 snails from 29 locations. Snails from the two keeled-flat populations clustered separately in the phylogeny, suggesting that this unusual shell form could have evolved independently. A morphological analysis of shells collected along a transect between keeled-flat and globular snail sites showed a cline for shell shape and the angle of the keel. Two different mtDNA lineages were found across the transect, with a cline for an ITS-2 single nucleotide polymorphism. Together, the results may suggest a lack of reproductive isolation between keeled-flat and globular snails, with possible introgression by hybridization.     

On the systematics and phylogeography of eight-barbel loaches the genus Lefua (Cobitoidea: Nemacheilidae): mtDNA typing of L. pleskei

Comparative analysis of personal sequence data for the mtDNA control region (926 to 928 bp) from eight-barbel loaches inhabiting eight localities in the Amur River basin (4) and the Sea of Japan (4) and the GeneBank/NCBI data for the Lefua individuals from the other regions of the world showed that eight-barbel loaches from Primorskii krai water basins were marked by a specific group of mtDNA haplotypes. This finding is considered as supporting the species status of L. pleskei. Genetic distances within L. pleskei are small (on average 0.355) and close to those within L. nikkonis (on average 0.48%). The distances between this species pair are the least (on average 2.15%) among all other pairs compared. In MP, ML, and Bayesian trees, L. pleskei and L. nikkonis haplotypes formed a common clade with high statistically significant support. In all tree variants, L. costata mtDNA haplotypes were located out of the group of interest. A clade consisting of highly diverged lineages of Lefua sp. and L. echigonia haplotypes occupied even more independent position. The mtDNA haplotypes of L. pleskei and L. costata from the Amur River basin were evolutionary young and derived from the haplotypes found in these species from the Sea of Japan (L. pleskei) or the Yellow Sea (L. costata) basins. It is thereby suggested that both species rather recently migrated into the Amur River system. According to the molecular clock data, basal diversification of the eight-barbel loach lineages took place at the end of middle Miocene (about 11 to 12 Myr ago), while divergence of L. pleskei and L. costata ancestral forms probably occurred approximately, 5 Myr ago. Since all main lineages of eight-barbel loaches were found in the Sea of Japan basin (continental coastline and the islands), the divergence order and dispersal patterns of the Lafua species might have been largely determined by the geological development pattern of this water body and the adjacent territories.     

Combining DNA sequences and morphology in systematics: testing the validity of the dragonfly species Cordulegaster bilineata

Morphological and molecular techniques are rarely combined when answering questions of taxonomic validity. In this study, we combine morphological techniques with DNA sequences to determine the validity of the dragonfly species Cordulegaster bilineata. The two dragonfly species C. bilineata and C. diastatops are very similar in size, body color, and morphological characters, and due to these similarities, the status of C. bilineata as a valid species is in question. In this study we compare morphological measurements of males and internal transcribed spacer 1 (ITS-1) sequences of rDNA between the two taxa. The hamule measurements (where copulation occurs) of males show little difference between the taxa in question, but the anal appendage measurements (where the male first contacts the female) show marked divergence between the two taxa. Cluster analysis with these anal appendage measurements correctly assigns almost all individuals measured into their respective taxon. PCR amplification products of ITS-1 display a approximately 50 bp size difference between C. bilineata (n = 4) and C. diastatops (n = 5) regardless of collection site. Sequence data for these amplifications show 51 bp missing in one locus in the ITS-1 of C. bilineatarelative to C. diastatops. A lone population of C. diastatops from Wisconsin has three individuals with ITS-1 products that match the size of both C. bilineata and C. diastatops. One individual from this population appears to yield two ITS-1 amplification products that match both C. bilineata and C. diastatops. Although this population may be evidence for hybridization between the two taxa, such hybridization is not necessarily sufficient to disqualify the validity of a separate species designation for C. bilineata. Morphology and ITS-1 sequences depict a high degree of divergence that is consistent with species-level differences.     

Fossil calibration of molecular clocks and the divergence times of geminate species pairs separated by the isthmus of panama

Calibration of nucleotide sequence divergence rates provides an important method by which to test many hypotheses of evolution. In the absence of an adequate fossil record, geological events, rather than the first appearances of sister taxa in the geological record, are often used to calibrate molecular clocks. The formation of the Isthmus of Panama, which isolated the tropical western Atlantic and eastern Pacific oceans, is one such event that is frequently used to infer rates of nucleotide sequence divergence. Isthmian calibrations assume that morphologically similar "geminate" species living now on either side of the isthmus were isolated geographically by the latest stages of seaway closure 3.1-3.5 MYA. Here, I have applied calibration dates from the fossil record to cytochrome c oxidase-1 (CO1) and nuclear histone-3 (H3) divergences among six pairs of geminates in the Arcidae to test this hypothesis. Analysis of CO1 first and third positions yield geminate divergences that predate final seaway closure, and on the basis of CO1 first positions, times for all six geminates are significantly greater than 3.5 Myr. H3 sequences produce much more recent geminate divergences, some that are younger than 3.1 Myr. But H3-derived estimates for all arcid geminates are not significantly different from both 0 and 15 Myr. According to CO1, one of the two most divergent pairs, Arca mutabilis and A. imbricata, split more than 30 MYA. This date is compatible with the fossil record, which indicates that these species were morphologically distinct at least 16-21 MYA. Across all CO1 nucleotide sites, divergence rates for arcids are slower than the rates reported for other taxa on the basis of isthmian calibrations, with the exception of rates determined from the least divergent species pair in larger surveys of multiple transisthmian pairs. Rate differences between arcids and some taxa may be real, but these data suggest that divergence rates can be greatly overestimated when dates corresponding to final closure of the Central American Seaway are used to calibrate the molecular clocks of marine organisms.     

New record for Galba neotropica (d'Orbigny, 1835) in Argentina,with a detailed analysis of its morphology and molecular characteristics

We report for the first time the presence of Galba neotropica in Santa Fe province, Pampean Argentina. Until the present work, the identity of the intermediate host of Fasciola hepatica in this region, the most important livestock production area of Argentina, was unknown. This report extends the geographic distribution of G. neotropica and is the first to provide molecular and morphological information on this species in Argentina. During summer 2013, snails were collected on private livestock farms with high prevalence of fasciolosis in cattle. Specimens were identified by using the nuclear sequences of the internal transcribed spacers ITS-1 and ITS-2, the shell and the shape and size of the male reproductive organs. Molecularly, ITS-1 and ITS-2 nuclear sequences exhibit 100% nucleotide identity with G. neotropica from Lima, Peru. Morphologically, G. neotropica from Santa Fe province was indistinguishable from Galba viatrix and Galba cubensis, the other two cryptic species within this South American group of lymnaeids. The combination of molecular and morphological analyses is strongly recommended to identify lymnaeids at species level. The identity of the intermediate host and the subsequent knowledge of its susceptibility, behaviour, distribution, ecology and biology are important components in developing effective measures to control fasciolosis.     

Nuclear rDNA-based molecular clock of the evolution of triatominae (Hemiptera: reduviidae), vectors of Chagas disease

The evolutionary history and times of divergence of triatomine bug lineages are estimated from molecular clocks inferred from nucleotide sequences of the small subunit SSU (18S) and the second internal transcribed spacer (ITS-2) of the nuclear ribosomal DNA of these reduviids. The 18S rDNA molecular clock rate in Triatominae, and Prosorrhynchan Hemiptera in general, appears to be of 1.8% per 100 million years (my). The ITS-2 molecular clock rate in Triatominae is estimated to be around 0.4-1% per 1 my, indicating that ITS-2 evolves 23-55 times faster than 18S rDNA. Inferred chronological data about the evolution of Triatominae fit well with current hypotheses on their evolutionary histories, but suggest reconsideration of the current taxonomy of North American species complexes.     

The First Internal Transcribed Spacer (ITS-1) of Ribosomal DNA as a Molecular Marker for Phylogenetic and Population Analyses in Crustacea

The objective of the present study is to explore the feasibility of using the first internal transcribed spacer (ITS-1) of ribosomal DNA as a molecular marker for studying the interspecific and intraspecific genetic variations among crustaceans. We designed primers that could amplify ITS-1 from a majority of taxonomic groups of crustaceans. The gene was found to exhibit a high degree of length polymorphism among different groups, ranging from 182 bp in the barnacle Balanus amphitrite to approximately 820 bp in the spiny lobster Panulirus japonicus. With respect to differences between congeneric species, it was found that the ITS-1 sequences of 3 mitten crabs, Eriocheir sinensis, Eriocheir leptognathus, and Eriocheir formosa, exhibit 5.4% to 16.3% nucleotide divergence, suggesting that ITS-1 is informative for phylogenetic analysis at the species level. Yet there are extensive (0.9%–2.3%) variations within individual E. formosa, so that phylogenetic analyses could be obscured. ITS-1 was found to vary between 2 geographical populations of the shrimp Penaeus japonicus. The variations involved substitutions as well as insertions/deletions between shrimp from Australia and South China Sea. These results show that ITS-1 is highly divergent among different crustaceans and could be an appropriate marker for molecular systematic studies at the species and population levels, although the presence of intragenomic variation needs to be taken into consideration. Received August 15, 2000; accepted February 9, 2001     

Phylogeography of loaches of the genus lefua (balitoridae, cypriniformes) inferred from mitochondrial DNA sequences

In order to elucidate phylogenetic relationships and intraspecific variations and to infer the evolutionary process of loaches of the genus Lefua, we analyzed nucleotide sequences of the mitochondrial D-loop region of 100 specimens obtained from 97 localities in Japan and Korea. The genus Lefua includes three described species, L. nikkonis, L. echigonia, and L. costata and an undescribed species, Lefua sp. Our results showed that each species of Lefua formed a monophyletic group, indicating clearly that Lefua species can be genetically distinguished from one another. Lefua nikkonis was the most closely related to L. costata, while L. sp. was the most closely related to L. echigonia. Specimens of L. sp. were grouped into two intraspecific populations and specimens of L. echigonia were grouped into six populations. These populations were well separated geographically from one another by mountain ranges and highlands. We estimated the evolutionary time for splitting of the species and intraspecific populations, and speculated on the evolutionary process of the genus Lefua. Species of Lefua are severely threatened. Fundamental genetic information is indispensable for conservation. We presented genetic background in order to protect these threatened loaches.     

Comment on Altaba (2015): a case of species misidentification?

Previously in this journal, Altaba (2015) presented an original hypothesis on the dispersal of small wetland snails in Central Europe after the Last Glacial Maximum, based on the discovery of rare species of the genus Vallonia at the foot of the Devín Hill (Slovakia). On the basis of the evidence available to us, it is our opinion that the existence of Vallonia declivis, Vallonia suevica, Vallonia enniensis, and Vallonia tenuilabris at Devín Gate has not been established, and that the hypothesis advanced in Altaba (2015) is therefore unsubstantiated by hard evidence.