Macaronesian islands as promoters of diversification in amphipods: The remarkable case of the family Hyalidae (Crustacea,Amphipoda)

The north‐east Atlantic (NEA) is an important and complex biogeographic region with a very rich marine fauna. However, little is known about the role of the Macaronesian islands in the evolutionary history and diversification of marine invertebrates in the NEA. Among the amphipods, the members of the family Hyalidae are particularly common and abundant in intertidal rocky shores of NEA. In this study, we aimed to investigate the genetic structure and diversity of seven hyalid species inhabiting the Macaronesian, European and Moroccan Atlantic coasts, with a focus on the genetic differentiation between island and Continental populations. Analysis of mitochondrial DNA sequences of the cytochrome oxidase I gene, unravelled a very high level of hidden diversity, consisting of 26–32 molecular operational taxonomic units (MOTUs), the majority of them recorded in Macaronesian populations. Except for Apohyale stebbingi, all remaining MOTUs were in general allopatrically distributed, with a trend for segregation between islands and Continental populations on one side, but also for the occurrence of private MOTUs among islands. Results indicate distinct evolutionary and diversification patterns among Hyalidae species, but a strong separation between Continental and islands’ lineages appears to be a common feature to all of them. Apparently, the complex geomorphological history of the Macaronesian archipelagos served as an important promoter of extensive diversification of marine invertebrates in NEA, a phenomenon which only now starts to be fully appreciated through the use of molecular data.     

Evolutionary systematics of the Australian Eocyzicus fauna (Crustacea: Branchiopoda: Spinicaudata) reveals hidden diversity and phylogeographic structure

Although ‘large branchiopods’ are an important faunal element of the temporary water bodies in Australia's vast (semi)arid regions, knowledge of their diversity, distribution and ecology is still poor. Here, on the basis of one mitochondrial [cytochrome oxidase subunit I (COI)] and three nuclear (EF1α, ITS2 and 28S) markers, we present new data relating to the diversity and phylogeography of eastern and central Australian Eocyzicus (Spinicaudata) fauna. Using a combination of phylogenetic, haplotype network and DNA barcoding analyses of COI, 312 individuals were grouped into eleven main lineages. To infer whether these lineages are reproductively isolated from each other (the prerequisite for species delineation according to the Biological or Hennigian Species Concepts), separate analyses of each nuclear marker were performed on a subset of specimens. Although some lineages are non‐monophyletic in the analysis of one nuclear marker, this is mostly attributed to processes such as incomplete lineage sorting rather than ongoing reproduction. The eleven lineages translate into at least seven species whose reproductive isolation is additionally indicated by sympatry, including both Australian Eocyzicus species previously described. Another three lineages may constitute further species, but their clear allopatric distribution rendered the test for reproductive isolation inapplicable. One lineage appears not to be reproductively isolated and is therefore considered a genetically distinct lineage within one of the other species, and one divergent lineage within E. argillaquus may constitute an additional species. Although sympatry is very common – six species occur in the central Paroo River catchment in eastern Australia, for instance – syntopic occurrence is rare. It is possible that a combination of differing habitat preferences and priority effects inhibits the presence of more than one Eocyzicus species per water body. There is little to no genetic differentiation between certain populations of the species found in eastern and central Australia (e.g. the Murray–Darling Basin, the Bulloo River catchment and the eastern and northern Lake Eyre Basin; LEB), suggesting high dispersal rates within this large area. Between the central Australian populations themselves, however (e.g. those inhabiting the central and western LEB), genetic differentiation is pronounced, probably as a result of the lack of abundance of important dispersal vectors (aquatic birds) and the lower diversity and density of suitable habitats in the area. The most prominent biogeographical break exists towards north‐eastern Australia (north‐east LEB), which does not share species with any other region studied.     

Description and post-glacial demography of Gammarus jazdzewskii sp. nov. (Crustacea: Amphipoda) from Central Europe

The fresh waters of the Baltic German and Polish lowlands are inhabited by several Gammarus species. One of them, Gammarus fossarum, a common inhabitant of lowland and submontane waters in western and central Europe, is known to show different morphotypes of unclear taxonomic status. Recent molecular studies showed that Gammarus fossarum is a complex of numerous highly divergent lineages. We characterized one of these lineages genetically and morphologically, described it as a species new to science and named it in honour of Krzysztof Ja?d?ewski as Gammarus jazdzewskii. The newly described species is widely distributed in Central Europe, from the Western Carpathians to the Baltic Lowlands. Its ancestral lineage appeared in the Miocene and diversified largely throughout the Pleistocene, presumably in the Western Carpathians. Its current distribution is predominantly a result of postglacial expansion from local refugia located in the Western Carpathians.     

Morphological and molecular differentiation of invasive freshwater species of the genus Corbicula (Bivalvia, corbiculidea) suggest the presence of three taxa in French rivers

Asiatic Clams are common in brackish and fresh water in Asia, and they were introduced into North America in 1924 and have now spread throughout the continent. During the last two decades they have been reported in Europe, but the number of species here is uncertain. Populations of Corbicula from France and the Netherlands were analysed morphologically and genetically to quantify the degree of species and/or population differentiation. The morphological and genetic data, based on allozymes and mitochondrial sequences, were in full agreement. They indicate that there are two distinct species, identified as C. fluminalis and C. fluminea, in the two countries. Analyses of the mitochondrial COI gene revealed an unexpected divergent population of Corbicula in the Rhône. All these individuals were morphologically identified as C. fluminea, but had a COI sequence different from the two previous species. This population may, therefore, be a more ancient population, or a distinct species introduced via a different colonization route.     

Description of a new cryptic,shallow‐water tonguefish (Pleuronectiformes: Cynoglossidae: Symphurus) from the western North Pacific Ocean

Combined results based on morphological characters and analyses of partial sequences of the 16s rRNA and coI genes confirm the validity of a new, cryptic, symphurine tonguefish from the western North Pacific Ocean. Symphurus leucochilus n. sp., a diminutive species reaching sizes to c. 67 mm standard length, is described from nine specimens that were collected from fish‐landing ports and from trawls made at c. 150 m off Taiwan and Japan. Symphurus leucochilus shares many similar features with those of Symphurus microrhynchus and that of several undescribed species that are morphologically similar to S. microrhynchus. Symphurus leucochilus has also been misidentified as Symphurus orientalis in fish collections because of shared similarities in some aspects of their morphology. The new species differs from all congeners by the following combination of meristic, morphological and pigmentation features: a predominant 1–2–2–2–2 pattern of interdigitation of proximal dorsal‐fin pterygiophores and neural spines; 12 caudal‐fin rays; 89–92 dorsal‐fin rays; 76–80 anal‐fin rays; 49–51 total vertebrae; four hypurals; 75–83 longitudinal scale rows; 32–35 transverse scales; 15–17 scale rows on the head posterior to the lower orbit; absence of a fleshy ridge on the ocular‐side lower jaw and a membranous connection between the anterior nostril and lower part of the eye; a narrow interorbital space and dorsal‐fin origin anterior to the vertical through the anterior margin of the upper eye; absence of both dermal spots at bases of anterior dorsal‐fin rays and melanophores on the isthmus; uniformly yellow to light‐brown ocular‐side colouration without bands; dorsal and anal fins with alternating series of dark rectangular blotches and unpigmented areas; a uniform white blind side and a bluish‐black peritoneum. Despite overall similarities in morphology between S. leucochilus and S. orientalis, as well as between two of the nominal species morphologically similar to S. microrhynchus, analyses of partial 16s rRNA and coI gene sequences show that S. leucochilus, S. orientalis and the two other nominal species represent three distinct lineages within the genus Symphurus.     

Cryptic diversity in flathead fishes (Scorpaeniformes: Platycephalidae) across the Indo‐West Pacific uncovered by DNA barcoding

Identification of taxonomical units underpins most biological endeavours ranging from accurate biodiversity estimates to the effective management of sustainably harvested, protected or endangered species. Successful species identification is now frequently based on a combination of approaches including morphometrics and DNA markers. Sequencing of the mitochondrial COI gene is an established methodology with an international campaign directed at barcoding all fishes. We employed COI sequencing alongside traditional taxonomic identification methods and uncovered instances of deep intraspecific genetic divergences among flathead species. Sixty‐five operational taxonomic units (OTUs) were observed across the Indo‐West Pacific from just 48 currently recognized species. The most comprehensively sampled taxon, Platycephalus indicus, exhibited the highest levels of genetic diversity with eight lineages separated by up to 16.37% genetic distance. Our results clearly indicate a thorough reappraisal of the current taxonomy of P. indicus (and its three junior synonyms) is warranted in conjunction with detailed taxonomic work on the other additional Platycephalidae OTUs detected by DNA barcoding.     

基于COI基因5′端与3′端序列田间常见粉虱的分子鉴定

【目的】粉虱种类繁多,个体微小,其种类识别与鉴定常需借助分子生物学技术。本研究旨在明确线粒体COI基因(mitochondrial cytochrome c oxidase subunit I gene) 5′端和3′端序列对常见种类粉虱识别鉴定的可行性。【方法】以我国田间常见的16种粉虱为对象,以COI基因5′端(641 bp)和3′端(738 bp)序列为靶标进行比对分析,以MEGA 5.10软件的K2-P模型计算种内与种间遗传距离,以邻接法(NJ法)构建进化树并进行系统发育分析。【结果】当以5′端为靶标时,16种粉虱的种内平均遗传距离为0.0015,种间平均遗传距离为0.2897,种间遗传距离为种内遗传距离的193.1倍;而且种内、种间遗传距离没有重叠区域。当以3′端为靶标时种内平均遗传距离为0.0007,种间平均遗传距离为0.2817,种间遗传距离为种内遗传距离的402.4倍;但桑粉虱Pealius mori与烟粉虱Bemisia tabaci Asia II 1的种内和种间遗传距离重叠。系统发育分析结果显示,以5′端为靶标时,16种粉虱可以形成独立的进化分支;以3′端为靶标时,除桑粉虱与传统分类学不一致外,其余种类均可形成独立的分支。【结论】结果表明,5′端序列更适用于基于DNA条形码技术的物种识别鉴定研究。     

Phylogeography of silver‐studded blue,Plebejus subsolanus (Lepidoptera: Lycaenidae), in the central mountainous regions of Japan

The silver‐studded blue, Plebejus subsolanus, is widely distributed in the Russian Altai mountains, northeastern China, the Korean Peninsula, and the Japanese archipelago. In Japan, the species is distributed across wide elevation ranges from the lowlands of Hokkaido to the subalpine zone of Honshu. Current subspecies classification in Japan is as follows: ssp. iburiensis, occurring in lowland grasslands in Hokkaido; ssp. yaginus in lower mountain grasslands in Honshu; and ssp. yarigadakeanus in higher mountain grasslands in Honshu. The habitat of this species has been markedly reduced due to recent habitat destruction and land‐use changes. Here, we undertook phylogeographic analyses of two subspecies, ssp. yaginus and yarigadakeanus in the central mountainous regions of Japan, based on two mitochondrial gene sequences, in order to collect information for establishing effective conservation strategies. From 57 samples from the four mountain ranges, we obtained a haplotype network comprised of 12 haplotypes. Because of the haplotype network topology, the geographic distribution of haplotypes and the correspondence of haplotype divergence to subspecies taxonomy, we provisionally divided the haplotypes into three haplogroups: YR1 and YR2, which comprised ssp. yarigadakeanus, and YG, which comprised ssp. yaginus. Mitochondrial DNA genetic differentiation generally agreed with morphological subspecies classification. The haplotype network suggested that ssp. yarigadakeanus populations had multiple origins, and the subspecies character of “bright blue of the male's wings” was assumed to have evolved independently in each subalpine meadow. We found that P. subsolanus was genetically differentiated depending upon the elevation at each mountain region, suggesting that each haplogroup should be a conservation unit.     

Interpretation of mitochondrial diversity in terms of taxonomy: a case study of Hyponephele lycaon species complex in Israel (Lepidoptera,Nymphalidae, Satyrinae)

It is difficult to interpret mitochondrial diversity in terms of taxonomy even in cases in which a concordance exists between mitochondrial, ecological and morphological markers. Here we demonstrate this difficulty through a study of Israeli Hyponephele butterflies. We show that samples commonly identified as Hyponephele lycaon are represented on Mount Hermon in Israel by two sympatric groups of individuals distinct both in mitochondrial DNA-barcodes (uncorrected p-distance = 3.5%) and hindwing underside pattern. These two groups were collected in different biotopes. They also tended to be different in length of brachia in male genitalia, although the latter character is variable. We reject the hypothesis that the discovered COI haplogroups are selectively neutral intraspecific characters. We hypothesize that they represent: either (1) two different biological species, or (2) a consequence of a strong positive selection acting at intraspecific level and resulting in two intraspecific clusters adapted to low and to high elevations. If we accept the first hypothesis, then provisionally these two haplogroups can be attributed to transpalearctic Hyponephele lycaon sensu stricto and to Hyponephele lycaonoides, previously known from Iran and East Turkey.     

DNA barcoding in closely related species: A case study of Primula L. sect. Proliferae Pax (Primulaceae) in China

DNA barcoding is a method of identifying species by analyzing one or a few short standardized DNA sequences. There are particular challenges in barcoding plants, especially for distinguishing closely related species. Hence, there is an urgent need to evaluate the performance of candidate loci for distinguishing between species, especially closely related species, to complement the rbcL + matK combination suggested as the core barcode for land plants. We sampled 48 individuals representing 12 species in Primula sect. Proliferae Pax in China to evaluate the performance of eight leading candidate barcode loci (matK, rbcL, rpoB, rpoC1, trnH-psbA, psbK-psbI, atpF-atpH, and internal transcribed spacer (ITS)). The core combination rbcL+matK gave only 50% species resolution in sect. Proliferae. In terms of intraspecies and interspecies divergence, degree of monophyly, and sequence similarity, ITS, trnH-psbA, and psbK-psbI showed good performance as single-locus barcodes. Internal transcribed spacer displayed the highest genetic divergence and best discriminatory power, both alone and in combination with rbcL+matK (83.3% species resolution). We recommend evaluating the use of ITS for barcoding in other species. Low or single copy nuclear regions would provide more sophisticated barcoding tools in the long term, even though further research is required to find suitable loci.     

Cryptic species in the Pyropia yezoensis complex (Bangiales,Rhodophyta): Sympatric occurrence of two cryptic species even on same rocks

In a previous study on wild populations of Pyropia, the occurrence of two possible new species (Pyropia sp. 2 and Pyropia sp. 3) which are closely related to the two commercially important Pyropia species, P. yezoensis and P. tenera, was confirmed as the result of molecular phylogenetic analyses. To characterize the morphological features of the two wild Pyropia species, we collected Pyropia blades in a natural population in which Pyropia sp. 3 was known to occur, and carried out molecular identification before detailed morphological observations. Through the molecular identification we found, unexpectedly, that Pyropia sp. 2 blades grew sympatrically in the same site. Therefore, after molecular identification, we examined in detail the external morphology and anatomy of the two wild Pyropia species using more than 10 blades each. As a result, it is concluded that all of the blades of the two species are morphologically identical to P. yezoensis, but distinct from P. tenera. It is therefore considered that both of the two wild Pyropia species are cryptic species within the P. yezoensis complex. Furthermore, this study revealed that the two cryptic species grew sympatrically, even on the same rocks within the natural habitat.     

Contracting montane cloud forests: a case study of the Andean alder (Alnus acuminata) and associated fungi in the Yungas

Alnus acuminata is a keystone tree species in the Yungas forests and host to a wide range of fungal symbionts. While species distribution models (SDMs) are routinely used for plants and animals to study the effects of climate change on montane forest communities, employing SDMs in fungi has been hindered by the lack of data on their geographic distribution. The well‐known host specificity and common biogeographic history of A. acuminata and associated ectomycorrhizal (ECM) fungi provide an exceptional opportunity to model the potential habitat for this symbiotic assemblage and to predict possible climate‐driven changes in the future. We (1) modeled the present and future distributions of suitable habitats for A. acuminata; (2) characterized fungal communities in different altitudinal zones of the Yungas using DNA metabarcoding of soil and root samples; and (3) selected fungi that were significant indicators of Alnus. Fungal communities were strongly structured according to altitudinal forest types and the presence of Alnus. Fungal indicators of Alnus, particularly ECM and root endophytic fungi, were also detected in Alnus roots. Current and future (year 2050) habitat models developed for A. acuminata predict a 25–50 percent decrease in suitable area and an upslope shift of the suitable habitat by ca. 184–380 m, depending on the climate change scenario. Although A. acuminata is considered to be an effective disperser, recent studies suggest that Andean grasslands are remarkably resistant to forest invasion, and future range contraction for A. acuminata may be even more pronounced than predicted by our models.     

Crossing the uncrossable: novel trans‐valley biogeographic patterns revealed in the genetic history of low‐dispersal mygalomorph spiders (Antrodiaetidae,Antrodiaetus) from California

Antrodiaetus riversi is a dispersal‐limited, habitat‐specialized mygalomorph spider species endemic to mesic woodlands of northern and central California. Here, we build upon prior phylogeographic research using a much larger geographic sample and include additional nuclear genes, providing more detailed biogeographic insights throughout the range of this complex. Of particular interest is the uncovering of unexpected and replicated trans‐valley biogeographic patterns, where in two separate genetic clades western haplotypes in the California south Coast Ranges are phylogenetically closely related to eastern haplotypes from central and northern Sierran foothills. In both instances, these trans‐valley phylogenetic patterns are strongly supported by multiple genes. These western and eastern populations are currently separated by the Central Valley, a well‐recognized modern‐day and historical biogeographic barrier in California. For one clade, the directionality is clearly northeast to southwest, and all available evidence is consistent with a jump dispersal event estimated at 1.2–1.3 Ma. During this time period, paleogeographic data indicate that northern Sierran rivers emptied to the ocean in the south Coast Ranges, rather than at the San Francisco Bay. For the other trans‐valley clade genetic evidence is less conclusive regarding the mechanism and directionality of biogeographic exchange, although the estimated timeframe is similar (approximately 1.8 Ma). Despite the large number of biogeographic studies previously conducted in central California, to the best of our knowledge no prior studies have discussed or revealed a northern Sierran to south Coast Range biogeographic connection. This uniqueness may reflect the low‐dispersal biology of mygalomorph spiders, where ‘post‐event’ gene exchange rarely erases historical biogeographic signal.     

Biodiversity and Molecular Phylogeny of Australian Clevelandella Species (Class Armophorea,Order Clevelandellida,Family Clevelandellidae), Intestinal Endosymbiotic Ciliates in the Wood‐Feeding Roach Panesthia cribrata Saussure, 1864

There are over 100 species in the Order Clevelandellida distributed in many hosts. The majority is assigned to one of the five families, the Nyctotheridae. Our knowledge of clevelandellid genetic diversity is limited to species of Nyctotherus and Nyctotheroides. To increase our understanding of clevelandellid genetic diversity, species were isolated from intestines of the Australian wood‐feeding roach Panesthia cribrata Saussure, 1864 from August to October, 2008. Four morphospecies, similar to those reported in Java and Japan by Kidder [Parasitologica, 29 :163–205], were identified: Clevelandella constricta, Clevelandella nipponensis, Clevelandella parapanesthiae, and Clevelandella panesthiae. Small subunit rRNA gene sequences assigned all species to a “family” clade that was sister to the clade of species assigned to the Family Nyctotheridae in the Order Clevelandellida. Genetics and morphology were consistent for the first three Clevelandella species, but isolates assigned to C. panesthiae were assignable to three different genotypes, suggesting that this may be a cryptic species complex.     

Speciation history of three closely related oak gall wasps,Andricus mukaigawae,A. kashiwaphilus,and A. pseudoflos (Hymenoptera: Cynipidae) inferred from nuclear and mitochondrial DNA sequences

The Andricus mukaigawae complex of oak gall wasps is composed of cyclically parthenogenetic species: A. mukaigawae and Andricus kashiwaphilus, and a parthenogenetic species, Andricus pseudoflos. The component species differ in life history, host plant, karyotype, and asexual gall shape, although little difference is found in the external morphology of asexual adults. To understand the speciation history of this species complex, DNA sequences of one mitochondrial region and nine nuclear gene regions were investigated. The genetic relationship among the species suggested that a loss of sex occurred after host shift. Unexpectedly, two or three distinct groups in the parthenogenetic species, A. pseudoflos, were revealed by both mitochondrial and nuclear DNA data. Gene flow in nuclear genes from the species not infected by Wolbachia (A. kashiwaphilus) to the species infected by it (A. mukaigawae) was suggested by a method based on coalescent simulations. On the other hand, gene flow in mitochondrial genes was suggested to be in the opposite direction. These findings indicate possible involvement of Wolbachia infection in the speciation process of the A. mukaigawae complex.     

Description of a new species of the genus Resseliella (Diptera: Cecidomyiidae), a pollinator of Kadsura longipedunculata (Schisandraceae) in China,with comments on its flower‐visiting habit

A gall midge pollinating flowers of Kadsura longipedunculata is described as Resseliella kadsurae sp. nov. based on adult specimens collected in 2006 from Langshan, Xinning County, Hunan Province, China. The new species is distinguishable from other known congeners in the combination of the following characteristics: gynecoid male flagellomeres, mottled wings, simple claws on all legs; male hypoproct with a transverse bridge‐like structure ventrally connecting both sides of hypoproct. In particular, the gynecoid male flagellomeres and transverse bridge‐like structure are unique to the new species. Partial sequencing of the cytochrome oxidase subunit I mitochondrial gene indicates that R. kadsurae is grouped with the R. theobardi + R. yagoi clade, but this clade and the monophyly of the genus Resseliella are not statistically supported. The new species is nocturnal, and mating occurs at dusk. At the time of mating, males and females hang on opposite sides of non‐sticky old spider webs in a venter‐to‐venter position. Immature stages and the life history of R. kadsurae are unknown. The flower‐visiting habit of R. kadsurae is contrasted with that of other flower‐visiting gall midges and the probability that this behavior exists in other congeners is discussed.     

Molecular,quantitative and abiotic variables for the delineation of evolutionary significant units: case of sandalwood (<Emphasis Type="Italic">Santalum austrocaledonicum</Emphasis> Vieillard) in New Caledonia

Various approaches have been developed to define conservation units for plant and animal species. In this study we combined nuclear microsatellites (from a previous published study) and chloroplast microsatellites (assessed in the present study), leaf and seed morphology traits and abiotic variables (climate and soil) to define evolutionary significant units (ESU) of Santalum austrocaledonicum, a tree species growing in New Caledonia. Results for chloroplast microsatellites showed that the total population heterozygosity was␣high, (H _cp = 0.84) but varied between islands. Differentiation was strong in the total population (F _stcp = 0.66) but also within the main island Grande Terre (F _stcp = 0.73) and within Iles Loyauté (F _stcp = 0.52), highlighting a limited gene flow between populations. These results confirmed those obtained with nuclear microsatellites. The cluster analysis on molecular markers discriminated two main groups constituted by the populations of Grande Terre and the populations of Iles Loyauté. A principal component analysis of leaf and seed morphology traits singled out the populations of Iles Loyauté and the western populations of Grande Terre. Quantitative genetic analyses showed that the variation between populations was under genetic control (broad sense heritability close to 80%). A high correlation between rainfall and morphological traits suggested an impact of climate on this variation. The integration of these results allows to define two ESUs, one corresponding to Grande Terre and Ile des Pins and the other the Iles Loyauté archipelago. This study stresses the need to restore some populations of Grande Terre that are currently threatened by their small size.