Genetic diversity of Southern hemisphere blue mussels (Bivalvia: Mytilidae) and the identification of non‐indigenous taxa

The taxonomic and evolutionary affinities of Southern hemisphere smooth‐shelled blue mussels are unclear, with studies using different marker types having identified different relationships among various geographic regions. Using an existing and a new molecular assay, the present study builds on previous work to test the distribution of blue mussels native to and introduced to the Southern hemisphere. Populations of Mytilus were sampled from New Zealand, Australia, and Chile. The nuclear‐DNA marker Me 15/16 was used to identify the taxonomic status of 484 individuals. A new restriction fragment length polymorphism (RFLP) assay was used to identify the hemisphere of origin for a subset of Mytilus galloprovincialis. The Me15/16 marker identified 478 pure M. galloprovincialis from Southern hemisphere sites and six Mytilus edulis/M. galloprovincialis hybrids from the Auckland Islands (New Zealand) and Chile. A cytoplasmic RFLP identified Northern hemisphere M. galloprovincialis in almost every Southern hemisphere region. The presence of native M. galloprovincialis at high latitudes (up to 52°S) has implications for our understanding of environmentally induced selective constraints considered to determine species distributions. Widespread occurrence of invasive Northern hemisphere blue mussels in the Southern hemisphere is documented for the first time. Identification of inter‐specific hybrids (M. edulis × M. galloprovincialis) in Chile and in the Auckland Islands (subantarctic New Zealand) illustrates that environments ranging from international ports to remote protected locations are vulnerable to bioinvasion. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 898–909.     

A biogeographical analysis of rotifers of the genus Trichocerca Lamarck, 1801 (Trichocercidae,Monogononta, Rotifera), with notes on taxonomy

An analysis of distribution patterns reveals a unique group of Nearctic endemics in Trichocerca Lamarck, 1801. This group, comprising 13.4% of all taxa analysed in the genus, is of diverse origin. A glacial origin is postulated for one species. The observed biogeographic pattern of eight others, and possibly two New World taxa, suggests a pre-Pleistocene origin followed by differential extinctions during glaciations in the Nearctic and Palaearctic. In general, endemism in Trichocerca is strongly biased towards the Northern hemisphere, with no endemism in tropical regions. This suggests a Laurasian origin of the genus. The analysis further reveals a majority (65.7%) of widely distributed taxa, with strict cosmopolitanism in more than a third of the species analysed. Latitudinal variation is evident in 26.9% of Trichocerca, and a warm-water preference appears to be indicated for a majority of these. Although the results should be interpreted with caution due to confused taxonomy, a Southern hemisphere, warm-water and Northern hemisphere, cold water component appear to be present. Comments on the taxonomy and distribution of several species are provided, along with illustrations of poorly known species. Suggestions include elevating T. maior (Hauer, 1936) to species rank, and several new cases of synonymy.     

A molecular investigation of the genus Ecklonia (Phaeophyceae,Laminariales) with special focus on the Southern Hemisphere

Brown algae of the order Laminariales, commonly referred to as kelps, are the largest and most productive primary producers in the coastal inshore environment. The genus Ecklonia (Lessoniaceae, Phaeophyceae) consists of seven species with four species in the Northern Hemisphere and three in the Southern Hemisphere. It was recently transferred to the family Lessoniaceae based on phylogenetic analyses of nuclear and chloroplastic markers, though the type of the genus was not included and its relationship with allied genera Eckloniopsis and Eisenia remained unresolved. The present study is the first to produce a phylogeny focussed on the genus Ecklonia. It included sequences from nuclear, mitochondrial, and chloroplastic DNA, for most of the distribution range of the three current Southern Hemisphere species (Ecklonia radiata, Ecklonia maxima, and a sample of a putative Ecklonia brevipes specimen), sequences for East Asiatic species (Ecklonia cava, Ecklonia kurome, and Ecklonia stolonifera), as well as the closely related genera Eckloniopsis and Eisenia. Results confirmed E. radiata and E. maxima as two distinct species in South Africa, E. radiata as a single species throughout the Southern Hemisphere (in South Africa, Australia, and New Zealand) and East Asiatic species as a distinct lineage from the Southern Hemisphere clade. Results further pointed out a close sister relationship between Eckloniopsis radicosa and two Eisenia species (including the type species: Eisenia arborea) to the genus Ecklonia suggesting that the genera Eckloniopsis and Eisenia are superfluous.     

中国中生代的马通蕨科植物:化石记录、多样性与时空分布特征*

现生真蕨目马通蕨科(Matoniaceae)植物仅存Matonia和Phanerosorus两属, 集中分布于马来西亚、印度尼西亚等热带地区。马通蕨科植物在中生代时期全球广布, 且主要分布于热带、亚热带地区, 有近9个属, 被作为热带、亚热带气候的标志性植物化石之一。本文梳理总结了中国中生代的马通蕨科化石记录并分析其多样性特征, 共计有2属16种, 包括异脉蕨属(Phlebopteris) 15种和准马通蕨属(Matonidium) 1种。对其化石记录和地质地理分布分析表明, 晚三叠世时期, 异脉蕨属植物广泛分布于热带—亚热带湿热气候区, 包括华南一带的四川、湖北、 云南、西藏、福建等地; 早侏罗世时期, 其分布逐渐向北方扩展, 在南、北方植物区系界线附近均有发现; 中侏罗世局限于湖北、青海等地; 早白垩世时仅在黑龙江和西藏少量发现。准马通蕨属仅在黑龙江地区的早白垩世地层中发现。整体上, 马通蕨科在中国中生代的分布范围变迁与气候带范围变化相吻合。     

Description of six new cyanobacterial species from soil biocrusts on San Nicolas Island,California, in three genera previously restricted to Brazil

As the taxonomic knowledge of cyanobacteria from terrestrial environments increases, it remains important to analyze biodiversity in areas that have been understudied to fully understand global and endemic diversity. This study was completed as part of a larger algal biodiversity study of the soil biocrusts of San Nicholas Island, California, USA. Among the taxa isolated were several new species in three genera (Atlanticothrix, Pycnacronema, and Konicacronema) which were described from, and previously restricted to, Brazil. New taxa are described herein using a polyphasic approach to cyanobacterial taxonomy that considers morphological, molecular, ecological, and biogeographical factors. Morphological data corroborated by molecular analysis including sequencing of the 16S rRNA gene, and the associated 16S–23S ITS rRNA region was used to delineate three new species of Atlanticothrix, two species of Pycnacronema, and one species of Konicacronema. The overlap of genera from San Nicolas Island and Brazil suggests that cyanobacterial genera may be widely distributed across global hemispheres, whereas the presence of distinct lineages may indicate that this is not true at the species level. Our data suggest that based upon global wind patterns, cyanobacteria in both Northern and Southern hemispheres of the Americas may have a more recent common ancestor in Northern Africa, but this common ancestry is distant enough that speciation has occurred since transatlantic dispersal.     

Phylogenetic relationships of mullets (Mugilidae) in China Seas based on partial sequences of two mitochondrial genes

Phylogenetic analyses of Mugilidae species from the China coast were carried out based on 16S and 12S rRNA mitochondrial gene sequences by maximum parsimony, maximum likelihood, Bayesian inference and neighbor joining analysis in the present study. The results suggested that Mugil cephalus is the most genetically divergent species among the Mugilidae. The four Liza species clustered together and formed a monophyletic group. The genera Osteomugil showed closer affiliation with Valamugil than with Ellochelon; these three genera then grouped together to form a monophyletic clade presenting as the sister group to Liza. Analyses of phylogenetic and genetic distance indicated that Southern and Northern lineages of Liza haematocheila may be two different species; likewise, strong genetic divergence existed between Southern and Northern M. cephalus lineages. In addition, our results supported the Southern origin of Chinese Mugilids, which is contrary to the hypothesis based on morphological characters.     

A review of species of the tribe Auletini (Coleoptera,Rhynchitidae) from the Russian fauna: 2. Subtribe pseudomesauletina

The genera Eurostauletes, Aletinus, and Pseudomesauletes from the fauna of Russia are revised. Each genus includes one species in the Russian fauna (Eu. longimanus, A. beckeri, and P. uniformis), their distribution in Russia is clarified. The data on the trophic associations of the species are summarized. The subtribe Pseudomesauletina, the genera Eurostauletes, Aletinus, and Pseudomesauletes, the subgenera Heterauletes and Pseudomesauletes s. str., and the species Eu. longimanus, A. beckeri, and P. uniformis are redescribed. A key to the Palaearctic genera of the subtribe Pseudomesauletina is given.     

A new species of water mite <Emphasis Type="Italic">Atractides</Emphasis> (<Emphasis Type="Italic">Atractides</Emphasis>) <Emphasis Type="Italic">turcicus</Emphasis> sp. n. (Acari: Hydrachnidia: Hygrobatidae) from Turkey

In this study, the structural characteristics, unique features, various organ measurements of males and females of the water mite Atractides (Atractides) turcicus sp. n. from Turkey are described. In addition, the study compares their characteristics with related species.     

大兴安岭南部山地苔藓植物区系多样性研究

于2009～2012年对大兴安岭南部山地6个自然保护区的苔藓植物进行了野外实地调查,对所采集的1 800余号标本进行室内分析鉴定,并计算分析其种类组成、区系地理成分、地区之间相似性系数和相异系数的欧氏距离比较,及其8种生境中苔藓植物多样性指数、丰富度指数、均匀度指数和优势度指数等,为保护区的管理和建设提供基础资料。结果表明:(1)大兴安岭南部山地6个自然保护区共有苔藓植物48科,134属,330种,其中苔类16科,21属,38种,1变种;藓类32科,113属,274种,14变种,2变型,1亚种。(2)首次发现中国新记录4种:长柄紫萼藓(Grimmia longirostris Hook.),毛尖连轴藓[Schistidium lancifolium(Kindb.)Blom.],平叶真藓(Bryumlaevifilum Syed.),凹叶毛灰藓[Homomallium adnatum(Hedw.)Broth.],首次发现本地区新记录12种。(3)以丛藓科为代表的旱生藓类在本区占有优势地位;区系地理成分以温带成分(60.79%)和东亚成分(16.19%)为主。(4)大兴安岭南部山地与兴安北部和燕山北部山地亲缘关系较近;生境条件的变化对苔藓植物多样性产生了一定的影响,湿润土生和石生生境为本区苔藓植物最丰富的生境,水生生境中苔藓植物分布最少。研究发现,大兴安岭南部山地苔藓植物区系是连接华北区、东北区、蒙新区和阴山地区的过渡性地带;与燕山北部和兴安北部相比,大兴安岭南部山地大面积苔藓植物地被层分布较少的主要原因是森林密度和湿度较低。因此,建立保护区对保护大兴安岭南部山地脆弱的森林、草原过渡生态系统,保护中国野生动植物类群及其他珍稀动植物的繁衍均具有十分重要的意义。     

Phylogenetic constraint on male parental care in the dabbling ducks

Phylogenetic constraint and inertia, i.e. limitations on future evolutionary trajectories imposed by previous adaptation, are often invoked to explain behavioural, morphological and physiological traits that defy explanation in an adaptive context. We reconstructed historical changes in male parental care behaviour in the dabbling ducks (family: Anatidae; tribe: Anatini) using a phylogeny based on mitochondrial DNA sequences. Male parental care is observed in many tropical and Southern hemisphere dabbling ducks but is lacking in all Northern hemisphere species. Southern hemisphere species that are very recently derived from Northern hemisphere ancestors, however, are exceptions to this general pattern. Lack of male parental care in these species can be attributed to phylogenetic constraint.     

An RFLP assay to determine if Mytilus galloprovincialis Lmk. (Mytilidae; Bivalvia) is of Northern or Southern hemisphere origin

Mytilus galloprovincialis is one of three smooth shelled blue mussel species belonging to the Mytilus edulis species complex. Naturally occurring and introduced populations of M. galloprovincialis are widely distributed throughout many regions of the globe. Mytilus galloprovincialis includes morphologically indistinguishable Northern and Southern hemisphere mtDNA lineages that have been separated for ～1 my. To distinguish recently introduced Northern M. galloprovincialis from resident Southern M. galloprovincialis in New Zealand, we developed a 16s rRNA RFLP assay. We compared RFLP assignments of 178 mussels with those generated from a 16s rRNA sequence-estimated phylogeny. All mussels were correctly assigned by the RFLP to their sequence-based phylogenetic placement. This assay allows the rapid identification of Northern and Southern hemisphere M. galloprovincialis and will provide an important tool for monitoring human mediated introductions of otherwise cryptic lineages.     

Myrmecochorous dispersal distances: a world survey

Abstract. Myrmecochorous dispersal distances are reviewed; the seed dispersal curve generated by ants shows a characteristic peak at short distances and a long tail, a shape suited to small densities of safe sites. Mean global distance is of 0.96 m (n= 2524) with a range of 0.01–77 m. Data have been broken down by geography (Northern hemisphere v. Southern hemisphere), taxonomy (ant subfamilies) and ecology (vegetation: sclerophyllous v. mesophyllous). Although a statistical difference exists between dispersal curves from the Northern hemisphere and the Southern hemisphere, this may be an artefact of lack of data from mesophyllous myrmecochores from this hemisphere. The four ant subfamilies do show also numerical differences but could not be subjected to statistical analysis. A difference between the shape of dispersal curve for sclerophyllous myrmecochores and mesophyllous myrmecochores has also been detected. We hypothesize that this difference is related to the myrmecological communities from both types of vegetation: dispersing ants from sclerophyllous vegetation would have smaller nest densities and/or bigger foraging areas than dispersing ants from mesic environments.     

The evolution of the protonephridial terminal organ across Rotifera with particular emphasis on Dicranophorus forcipatus,Encentrum mucronatum and Erignatha clastopis (Rotifera: Dicranophoridae)

Riemann, O. and Ahlrichs, W.H. 2009. The evolution of the protonephridial terminal organ across Rotifera with particular emphasis on Dicranophorus forcipatus, Encentrum mucronatum and Erignatha clastopis (Rotifera: Dicranophoridae). —Acta Zoologica (Stockholm) 91 : 199–211 We report on the ultrastructure of the protonephridial terminal organ in three species of dicranophorid rotifers (Dicranophorus forcipatus, Encentrum mucronatum and Erignatha clastopis). Differences between the three species relate to shape and size, the morphology of the filter region and the number of microvilli and cilia inside the terminal organ. A comparison across Rotifera indicates that the terminal organs in D. forcipatus display a number of plesiomorphic characters, but are modified in E. mucronatum and Er. clastopis. This is in accordance with the results of phylogenetic analyses suggesting a basal position of D. forcipatus compared with the more derived species E. mucronatum and Er. clastopis. Moreover, we survey available data on the terminal organ in Rotifera and discuss its evolutionary transformations. The protonephridial terminal organ in the common ancestor of Rotifera consisted of a cytoplasmic cylinder with cilia united into a vibratile flame and a single circle of circumciliary microvilli. Depending on the topology on which characters are optimized, the site of ultrafiltration was formed by longitudinal cytoplasmic columns spanned by a fine filter diaphragm or by pores in the wall of the terminal organ. In several taxa of Rotifera, the terminal organ – probably independently – lost its circumciliary microvilli.     

Bioinvasion threatens the genetic integrity of native diversity and a natural hybrid zone: smooth‐shelled blue mussels (Mytilus spp.) in the Strait of Magellan

Smooth‐shelled blue mussels of the Mytilus edulis species complex are widely distributed bivalve molluscs whose introductions threaten native marine biodiversity (non‐indigenous species – NIS). The aim of the present study was to identify the species and hybrids of Mytilus present in the Magellan Region (southern Chile). Results indicate that three mussel species of the Mytilus edulis complex are found in the region – M. edulis, M. chilensis (or the Southern Hemisphere lineage of Mytilus galloprovincialis), and M. galloprovincialis of Northern Hemisphere origin. For the first time, alleles of the introduced M. trossulus are reported from the Southern Hemisphere. In the Strait of Magellan the native Pacific blue mussel, Mytilus chilensis and the native Atlantic blue mussel, Mytilus edulis, meet and mix at a natural hybrid zone (about 125 km in length). This is the first record of a natural Mytilus hybrid zone in the Southern Hemisphere and is also the first record of the co‐occurrence of genes from all four Mytilus species in any one region. These results contribute to the knowledge of the biodiversity and delimitation of mussel species in southern South America, and highlight how introduced species may threaten the genetic integrity of native species through hybridization and introgression.     

The rust mycobiota of southern Africa: Species richness, composition, and affinities

The rust mycobiota (Uredinales, Basidiomycota) of southern Africa (Botswana, Namibia, and South Africa) is analysed with regard to species richness, generic composition, and similarities to the rust mycobiotas of the remaining African continent and other regions of the world. Southern Africa is home to about 546 rust species: ca 522 species have been reported from South Africa, 73 from Namibia, and less than ten from Botswana. Thirty-two species were considered to be exotics. Two hundred and twenty-five of the species are restricted to southern Africa, suggesting an endemism rate of ca 44 %. At present, the rust fungus:host ratio is 1:38.5, which is much lower than expected from other regions of the world. This low ratio may partly be due to under-exploration of the area, but the results presented here indicate that a natural paucity of rust fungi on certain, especially species-rich plant taxa centred in southern Africa and possibly environmental factors are more important reasons. The predominant genera are Puccinia and Uromyces accounting for ca 59 % of the rust species. The genera Hemileia, Phakopsora and especially Ravenelia, centred in tropical regions, are well represented and sum up to 8 % of the species. Members of Melampsoraceae and Phragmidiaceae, common in temperate regions of the Northern Hemisphere, are scarce. Most of the other 28 recorded teleomorph genera are only represented by three or less species. In an African context, most species are shared with central and east Africa (almost 16 %). Only a few species are disjunct between southern and West Africa or Madagascar. Ca 10 % of the species are shared only with other parts of the paleotropics, especially the Indian subcontinent. Disjunctions of native species with the New World, Australia/New Zealand, or Europe are rare.     

Phylogeny and biogeography of Muusoctopus (Cephalopoda: Enteroctopodidae)

Deep‐sea octopuses of the genus Muusoctopus are thought to have originated in the Pacific Northern Hemisphere and then diversified throughout the Pacific and into the rest of the World Ocean. However, this hypothesis was inferred only from molecular divergence times. Here, the ancestral distribution and dispersal routes are estimated by Bayesian analysis based on a new phylogeny including 38 specimens from the south‐eastern Pacific Ocean. Morphological data and molecular sequences of three mitochondrial genes (16S rRNA, COI and COIII) are presented. The morphological data confirm that specimens newly acquired from off the coast of Chile comprise two species: Muusoctopus longibrachus and the poorly described species, Muusoctopus eicomar. The latter is here redescribed and is clearly distinguished from M. longibrachus and other closely related species in the region. A gene tree was built using Bayesian analysis to infer the phylogenetic position of these species within the species group, revealing that a large genetic distance separates the two sympatric Chilean species. M. longibrachus is confirmed as the sister species of Muusooctopus eureka from the Falkland Islands; while M. eicomar is a sister species of Muusoctopus yaquinae from the North Pacific, most closely related to the amphi‐Atlantic species Muusoctopus januarii. Molecular divergence times and ancestral distribution analyses suggest that genus Muusoctopus may have originated in the North Atlantic: one lineage dispersed directly southward to the Magellan region and another dispersed southward along the Eastern Pacific to the Southern Ocean and Antarctica. The Muusoctopus species in the Southern Hemisphere have different phylogenetic origins and represent independent invasions of this region.     

Rare bryozoans (Stenolaemata) with bilateral colonies from the Jurassic and Cretaceous of the East European Platform

New bryozoans characterized by a bilateral vertical colonies colonies—Cardioecia refuga sp. nov. (Tubuliporida), Elea lyapini sp. nov., E. troshkovensis sp. nov., and E. taylori sp. nov. (Melicerititida) from Middle Jurassic (Middle Callovian) of the Moscow region (Russia), and Biforicula legitima sp. nov. (Melicerititida) from the Upper Cretaceous (Lower Campanian) of the Southern Donets Basin (Ukraine)—are described. All species described in this paper belong to genera that have been recorded for the first time in the East European Platform. Some morphological structures in the colonies of these bryozoans and some distinctive features of the order Melicerititida that emphasize the difference of this order from bryozoans of other orders of the class Stenolaemata are examined.     

Systematic studies of the antarctic species of the phyllophoraceae (Gigartinales,Rhodophyta) based on rbcL sequence analysis

The taxonomic placement of four antarctic species of the marine red algal family Phyllophoraceae (Gigartinales) is assessed within a preliminary molecular phylogeny of the family based on direct sequence analysis of the chloroplast gene rbcL. Parsimony analysis of rbcL sequences indicates that Gymnogongrus antarcticus and Gymnogongrus turquetii cluster in a clade consisting predominantly of southern hemisphere species currently placed in Gymnogongrus and Ahnfeltiopsis, whereas Phyllophora ahnfeltioides and Phyllophora antarctica cluster in a separate clade that is widely divergent from the northern hemisphere Phyllophora clade. Results from molecular and morphological data challenge the current taxonomic concept that type of life history is a phylogenetically valid criterion for recognition of genera in the Phyllophoraceae.