New Spirorbidae (Polychaeta: Sedentaria) from the East Pacific, Adantic, Indian and Southern Oceans

Spirorbis bifurcatus, Spirorbis rothlisbergi, Spirorbis spatulatus, Pileolaria lateralis, Pileolaria marginals, Pileolaria spinifer, Pileolaria tiarata and Pileolaria potswaldi are described from California, Spirorbis strigatus from Madeira, Pileolaria dakarensis from W. Africa, Pileolaria (Duplicaria) zibrowii from Madagascar, Pileolaria alata and Pileolaria (Nidularia) nidica from Curacao, Pileolaria (Nidularia) palliata from S. Africa, Pileolaria (Jugaria) atlantica from north of the Azores, Romanchella bicava from Amsterdam Island, Romanchella pustulata from Chile and Helicosiphon platyspira from Marion Island. Of the new subgenera, Jugaria is proposed for forms having compound opercula (as in Pileolaria granulata L. and most Sinistrella species) and Nidularia for those with opercula that do not completely protect the embryos.
Some of the Californian forms have probably resulted from sympatric speciation in both the genera concerned. The morphology and zoogeography of spirorbids suggest division into the subfamilies Spirorbinae, Circeinae, Pileolariinae, Januinae, Romanchellinae and Paralaeospirinae.     

Vertebrate hosts of Ixodes pacificus (Acari: Ixodidae) in California.

The western black-legged tick, Ixodes pacificus Cooley & Kohls, is an important parasite and vector of disease agents that affect human and animal health in the western United States. This paper presents a review of all published California host records for I. pacificus. Unpublished data from public health, academic, and vector control agencies and researchers were reviewed as well. Host species were identified for each active life stage (larvae, nymph and adult). A total of 108 vertebrate species in three classes (Mammalia, Aves, and Reptilia) were identified as hosts for at least one life stage of I. pacificus. Adult I. pacificus were recorded from 29 species of mammals, 2 species of birds, and 1 reptile species. Nymphal I. pacificus were recorded from 30 species of mammals, 38 species of birds, and 8 reptile species. Larval I. pacificus were recorded from 29 species of mammals, 43 species of birds, and 8 species of reptiles. A table depicting the taxonomic classification of host species is provided. This review adds eight new host records to the California list of recognized vertebrate host species for I. pacificus.     

中国等高熊虫属二新种和一新纪录种(缓步动物门,高生熊虫科)

报道了中国缓步动物门2新种和1新纪录种(真缓步纲,高生熊虫科):李氏等高熊虫Isohypsibius liae sp.nov.,拉氏等高熊虫Isohypsibius rahmi sp.nov.和Isohypsibius borkini Tumanov.Isohypsibius liae sp.nov.背部有12列横向排列的隆起,宽窄不等,整个身体表面布满网状饰纹;吸咽球有3个近似粒状的大板,无小板;前3对肢上的内侧爪靠内侧近基部处有角质条,爪主枝上附棘存在.Ⅰ.liae sp.nov.以其背部横向隆起、饰纹或缺少半月板区别于所有已知的Isohypsibius属的种类.Isohypsibius rahmi sp.nov.背部有10排大的突起:按身体前端到后端的顺序,第1～5排、第7排以及第8排每排有4个突起,第6排和第9排每排有2个突起,第10排有1个突起;身体背面、侧面和四肢上密布半球形小颗粒;吸咽球有3个近似粒状的大板,第1大板和第2大板几乎相接;前3对肢的内侧爪内侧近基部有角质条,爪主枝上不见附棘.J.rahmi sp.noV.以其大的突起排列方式和数目或前3对肢的内侧爪内侧近基部有角质条区别于Isohypsibius属的所有已知种类.     

中国水韭属植物的染色体数目及其分类学意义

利用细胞学方法观察统计了中国4种水韭属Isoestes植物的染色体数目。结果发现4个种的染色体基数均为x=11,其中高寒水韭I．hypsophila Hand.-Mazz．为2n=22,为首次报道;台湾水韭 I．taiwanensis DeVol为2n=22;中华水韭I．sinensis Palmer 2n=44为四倍体;而产于云南贵州一带并一直被当作是宽叶水韭I．japonica A．Br．的水韭属植物2n=22,与文献报道的宽叶水韭(2n=66,67,77,87,88,89)完全不同,应重新予以认识和评价。依据本文和其他相关的研究结果,对东亚水韭属植物进行了分类处理。     

Revealing unknown or extinct lineages within Isoetes (Isoetaceae) using DNA sequencesfrom hybrids

Iso?tes, a heterosporous lycopod with a fossil record dating back to the Paleozoic, has numerous putative allopolyploids (resulting from hybridization events coupled with doubling of chromosome number). By using the highly variable nucleotide sequences from the second intron of a LFY homologue in Iso?tes, species could be delimited and hybrid origins determined. The data suggest that reticulate evolution is both common and complex within a more derived species complex of Iso?tes. Sequences of identifiable parentage and sequences that are unlike any diploid species known were recovered, leading to the conclusion that one or both of the putative parents have not yet been discovered or are extinct. A range of observations concerning allopolyploid speciation were categorized as follows: (1) verification of previous hypotheses regarding parentage (e.g., I. riparia, I. appalachiana), (2) determination that two morphologically distinct allotetraploid species can share the same parentage (I. azorica and I. acadiensis), (3) recognition of a cryptic allotetraploid species, indicated by the presence of different parental genomes (I. "appalachiana" from Florida), and (4) identification of allotetraploid species with one or two unknown parents (e.g., I. tuckermanii, I. acadiensis, I. azorica, and I. hyemalis). Some sequences from diploid species are remarkably uniform among populations (e.g., I. echinospora from various locations in North America, Iceland, and Wales), while others are variable at the subspecies level (e.g., northern and southern populations within I. engelmannii).     

Two new species ofIsoetes (Isoetaceae) from Jeju Island, South Korea

We name and describe two new species,Isoetes jejuensis and I.hallasanensis, from Jeju Island, South Korea. These taxa are compared with related species in East Asia, including I.coreana andI. sinensis. The rugulate megaspore ornamentation ofI. jejuensis differs from those otherIsoetes species. Furthermore,I. hallasanensis varies fromI. asiatica in its microspore ornamentation and chromosome number, although both species have an echinate megaspore ornamentation. These new species are tetraploid (2n = 44), whereasI. coreana is hexaploid (2n = 66).     

A stochastic dispersal-limited trait-based model of community dynamics

I present a model of stochastic community dynamics in which death occurs randomly in the community, propagules disperse randomly from a regional pool, and recruitment of new individuals of a species is proportional to the species local abundance multiplied by its local competitive ability. The competitive ability of a species is assumed to be determined by a function of one trait of the species, and I call this function the environmental filtering function. I show that information on local species abundances in a network of plots, together with trait data for each species, enables the inference of both the immigration rate and the environmental filtering function in each plot. I further study how the diversity patterns produced by this model deviate from the neutral predictions, and how this deviation depends on the characteristics of the environmental filtering function. I show that this inference framework is more powerful at detecting trait-based environmental filtering than existing statistical approaches based on trait distributions, and discuss how the predictions of this model could be used to assess environmental heterogeneity in a plot, to detect functionally meaningful trade-offs among species traits, and to test the assumption that there exists a simple relationship between species traits and local competitive ability.     

进口美国松木中截获齿小蠹的鉴定(鞘翅目:小蠹科)

本文对2010—2015年全国口岸从美国进境松木中截获的齿小蠹进行了分析,分别对美云杉齿小蠹Ips borealis、美雕齿小蠹I.calligraphus、混点齿小蠹I.confusus、重齿小蠹I.duplicatus、南部松齿小蠹I.grandicollis、蒙大拿齿小蠹I.montanus、似混齿小蠹I.paraconfusus、白云杉齿小蠹I.perturbatus、美松齿小蠹I.pini、平额重齿小蠹I.plastographus、十二齿小蠹I.sexdentatus、云杉八齿小蠹I.typographus 12种昆虫的进境寄主进行统计,对截获频次进行分析对其成虫的主要形态特征进行了描述,编制了分种检索表,对检疫鉴定工作具有指导意义。     

Serological reactions of Fraction I proteins from interspecific hybrids in the genusNicotiana

The serological reactions of Fraction I proteins from interspecific hybrids in the genusNicotiana have been examined by immunodiffusion in agar gels using antisera to crystalline Fraction I proteins fromN. glutinosa, N. gossei, andN. tabacum. The serological reactions of the proteins from the hybrids resembled the reactions of the proteins from the maternal parent species but not from the paternal species. Changes in ploidy level did not affect the serological reactions of Fraction I proteins from hybrids. It is suggested that serological examination of Fraction I proteins from polyploid species and their known progenitors can indicate the direction of the cross giving rise to the polyploid species.     

Tests of pre- and postpollination barriers to hybridization between sympatric species of Ipomopsis (Polemoniaceae)

The Ipomopsis aggregata species complex (Polemoniaceae) includes species pairs that hybridize readily in nature as well as pairs that meet along contact zones with no apparent hybridization. Artificial hybrids can be made between I. aggregata and I. arizonica, yet morphological intermediates between these two species have not been observed in natural populations. This apparent lack of hybridization is perplexing given that plants of the two species often grow within a few metres of each other and both species have red flowers visited by the same species of hummingbirds. We used trained hummingbirds to examine pollen transfer within and between species. We also hand-pollinated flowers to examine paternal success of heterospecific and conspecific pollen, testing paternity with electrophoretic examination of seeds. Hummingbirds were not simply better at transferring pollen within than between species. Instead, I. arizonica was a better pollen donor so that considerable pollen transfer was observed from I. arizonica to I. aggregata, but very little in the opposite direction. Conversely, once pollen arrived at stigmas, I. arizonica pollen performed very poorly on I. aggregata pistils. However, pollen from I. aggregata could, in some cases, sire seeds on I. arizonica. We hypothesize that hybrids are scarce in nature, in part, because of asymmetric barriers to reproduction: little pollen transfer in one direction and poor pollen performance in the other.     

Speciation pathway of Isoetes (Isoetaceae) in East Asia inferred from molecular phylogenetic relationships

Polyploidy plays an important role in the speciation of Iso?tes. Increasing our knowledge about the specific origin of each polyploid or phylogenetic relationship among species has been hampered because of conserved morphological variation and scarce habitats. We present several hypotheses concerning the speciation pathways of Iso?tes species distributed in East Asia. Our hypotheses are inferred from phylogenetic relationships that were elucidated using sequences of the internal transcribed spacer regions of nuclear ribosomal DNA, a second intron of LEAFY, and chloroplast DNA trnS-psbC spacer regions. These inferred phylogenetic relationships indicated that (1) the Chinese tetraploid, I. sinensis, is closely related to I. yunguiensis; (2) the Korean endemic species, I. hallasanensis, is an autotetraploid derived from I. taiwanensis or closely related taxa; (3) the hexaploid I. coreana forms a clade and has its closest evolutionary relationships with I. taiwanensis or I. hallasanensis; and (4) the Japanese hexaploid I. japonica is closely related to I. taiwanensis-I. coreana and I. sinensis-I. yunguiensis. These results suggest that interspecific hybridization and polyploidization have played central roles in speciation of East Asian Iso?tes. Furthermore, I. taiwanensis, an endemic species in Taiwan, has been involved in at least three cases of autopolyploid or allopolyploid speciation in East Asia.     

Systematics and evolution of Iolania (Hemiptera: Fulgoromorpha: Cixiidae) from Hawai'i

Abstract.  Within the planthopper taxon Cixiidae, which is distributed worldwide, only two lineages have colonized the Hawaiian Islands: Iolania Kirkaldy, 1902, and Oliarus Stål, 1862 , and subsequently given rise to endemic species. Neither radiation has been studied in depth hitherto. Here the degree of speciation within Iolania is assessed and a taxonomic revision including a key to the species based on the male genitalic characters is provided. Six endemic species are recognized: I. perkinsi Kirkaldy, I. koolauensis Giffard, I. oahuensis Giffard, I. lanaiensis Giffard, I. mauiensis Giffard and I. kraussohana sp.n. A lectotype is designated for the type-species I. perkinsi Kirkaldy, and I. perkinsi notata Kirkaldy is interpreted as an invalid name. Morphological arguments for the monophyly of Iolania and phylogenetic relationships among the species are discussed. A plausible scenario for the sequence of speciation events and history of colonization within the Hawaiian Islands is attempted. Combined information from taxon- and area-cladograms suggests progressive inter-island dispersal from older to younger islands in the Hawaiian chain as the major pattern of colonization and speciation.     

Assessing species boundaries and evolutionary relationships in a group of south-western European species of Isotomurus (Collembola, Isotomidae) using allozyme data

In this study allozyme data were used to examine evolutionary relationships in the cosmopolitan collembolan genus Isotomurus . Fifty-six south-western European populations from 13 species were compared, with the aim of delimiting species boundaries and testing the robustness of the most frequently used morphological characters for species identification. Observed allozyme variability suggests that genetic differentiation is more pronounced than the amount of morphological variability among and within species. Convergence in models of pigmentation pattern may lead to erroneous taxonomic identification when this is the only feature used for species diagnosis. In this respect, this study confirms that diagnosis is greatly improved when assisted by biochemical or molecular analyses. Allozyme data have also been used to reconstruct evolutionary hypotheses for relationships at the species and population level. The monophyly of Isotomurus maculatus , I. unifasciatus , I. fucicolus , I. nebulosus and I. pseudopalustris was confirmed on molecular grounds. Conversely, the monophyly of I. ghibellinus and I. palustris was rejected, suggesting the presence of cryptic species.     

复齿叶蜂属分类研究(膜翅目,蕨叶蜂科)

记述了中国新纪录属复齿叶蜂属2种,包括1新种黑股复齿叶蜂Iconia nigrofemoratga sp.nov.和中国1新纪录种白股复齿叶蜂I.versicolor Malaise 1944.该属仅分布于亚洲东南部,已知仅模式种1种.新种与模式种的主要区别是后足基节和股节黑色,触角基部3节和腹部第3、第6～7背板黑色无白斑,中胸前侧片刻点间具粗糙刻纹.编制了分种检索表,绘制了形态特征图.新种模式标本分别保存于中南林学院昆虫标本室和中国科学院上海昆虫研究所.     

Are species lists derived from modeled species range maps appropriate for macroecological studies? A case study on data from BIEN

Because survey-based species lists for fine-scale areas are generally lacking, ecologists have been using species lists derived from modeled range maps in macroecological studies. Here I evaluate whether it is appropriate to use species lists derived from modeled range maps in macroecological studies. I compared species lists derived from about 90,000 range maps in the Botanical Information and Ecology Network (BIEN) for over 180 geographic regions (12 broad regions covering the whole of the New World; 172 smaller regions, i.e. Taxonomic Databases Working Group units) with those representing complete or nearly complete species lists obtained from the literature for the regions. I determined the completeness of native species composition and proportion of false presences and exotic (non-native) species in species lists derived from range maps in BIEN. I determined whether errors in species lists derived from modeled range maps affect macroecological inferences by comparing the relationships of α- and β-diversity with geographic and climatic variables between different datasets (i.e. species lists derived from range maps versus complete or nearly complete species lists derived from the literature). The completeness for native species lists derived from range maps was 60–74%, depending on spatial scale. On average, 65% of the species in a species list derived from BIEN for a geographic area are false presences or non-native species to the area. The relationships of α- and β-diversity derived from the BIEN dataset with geographic and climatic variables differ significantly from those derived from complete species lists. This study shows that the results of a macroecological study based on species lists derived from modeled range maps may be substantially incorrect due to high percentages of missing native species, and high numbers of non-native species and false presences. Thus, it may not be appropriate to use species lists derived from modeled range maps in the macroecological studies that require complete or nearly complete species lists.     

Host usage and seasonal activity patterns of Ixodes kingi and I. sculptus (Acari: Ixodidae) nymphs in a Colorado prairie landscape, with a summary of published North American host records for all life stages.

We examined host usage and seasonal activity patterns of the nymphal stage of the ticks Ixodes kingi and I. sculptus within a prairie rodent community in north-central Colorado. Ixodes kingi was commonly encountered on both northern grasshopper mice (Onychomys leucogaster) and thirteen-lined ground squirrels (Spermophilus tridecemlineatus), whereas I. sculptus frequently infested S. tridecemlineatus but was absent from O. leucogaster. Low numbers of ticks of both species were collected from deer mice (Peromyscus maniculatus) and Ord's kangaroo rats (Dipodomys ordii). Nymphal loads of I. kingi and I. sculptus increased dramatically on commonly infested rodent species from spring (May-June) to summer (July-August). Further, rodents trapped on prairie-dog towns tended to experience increased nymphal loads of I. kingi (O. leucogaster, S. tridecemlineatus) but decreased loads of I. sculptus (S. tridecemlineatus) following plague epizootics among prairie dog populations. A summary of published North American host records revealed that I. kingi has been recorded from humans, domestic animals (cat, dog), 17 species of carnivores, 40 species of rodents, and four species of lagomorphs, and that I. sculptus has been recorded from humans, domestic animals (cat, dog, goat), 13 species of carnivores, 34 species of rodents, and three species of lagomorphs. In accordance with our observations from Colorado, I. kingi commonly has been found to infest heteromyid and murid rodents (such as grasshopper mice), whereas I. sculptus most frequently has been collected from ground-dwelling sciurid rodents, especially Spermophilus ground squirrels. The potential roles of I. kingi and I. sculptus as enzootic vectors of human pathogens, particularly the agents of tularemia (Francisella tularensis), Q fever (Coxiella burnetii), and Colorado tick fever (CTF virus), are discussed.     

Morphological and molecular species delimitation within the Holarctic Ilybius angustior complex with a focus on Beringia (Coleoptera: Dytiscidae)

A fourth species of the Holarctic Ilybius angustior complex, Ilybius minakawai n. sp., is described from the Island of Sakhalin in the Russian far east. Male genitalia are diagnostic within this species complex, although from body size and shape the new species cannot be separated from I. churchillensis Wallis from north Alaska and the Canadian low arctic. The small and narrow body characteristic of these two species represents an extreme of the cold climate form of the widespread I. angustior (Gyllenhal). Low variation within the studied large ribosomal and cytochrome c oxidase subunit I mitochondrial genes suggest that speciation events within the I. angustior-complex are fairly recent. In combination with known geographical ranges, the low genetic variation within this species complex suggest speciation within Pleistocene refugia including Beringia.     

Probing structural changes in the α and β domains of copper- and silver-substituted metallothionein by emission spectroscopy and electrospray ionization mass spectrometry

Steady-state emission spectra, excited-state lifetimes, kinetic data, and mass spectroscopic properties are reported for Ag(I)- and mixed Ag(I)/Cu(I)-substituted α and β domains of recombinant human metallothionein (MT1a). Kinetic analysis of the changes in the Cu(I) emission spectra during the stepwise displacement of Cu(I) ions by Ag(I) at room temperature shows that the rate of displacement of Cu(I) is unexpectedly slow. Although the first Ag(I) added results in major changes in the Cu(I)-MT binding site, Cu(I) displacement by Ag(I) does not take place until the addition of the third Ag(I), and is completed by the addition of the seventh Ag(I). The emission from Ag(I) and mixed Cu(I)/Ag(I)-MT species at 77 K shows that the band maxima shift as a function of Ag(I) loading, which can be correlated with shifts in coordination geometry from trigonal to digonal. Two phosphorescence lifetimes were detected for the Ag(I)-substituted α and β domains of MT, which are attributed to the presence of Ag(I) ions in two different environments. The lifetime of Ag(I)-substituted MT was found to be shorter when the Ag(I)-MT species were formed by Ag(I) additions to the Cu(I)-substituted α and β fragments than when the Ag(I)-MT species were formed from the apo-α and apo-β fragments, suggesting the formation of structurally different Ag(I)-MT clusters. Electrospray ionization mass spectrometric studies suggest the metallation reactions of Ag(I) with MT take place in a series of steps to form a series of Ag(I)-substituted MT species. Ag(I)-substituted MT species are not detected until past the addition of 3 mol equiv of Ag(I), suggesting that cluster formation begins only at this point, stabilizing the metallated species sufficiently to survive ionization.     

Nuclei purified from cauliflower mosaic virus-infected turnip leaves contain subgenomic, covalently closed circular cauliflower mosaic virus DNAs

Nuclei isolated from cauliflower mosaic virus (CaMV) infected turnip leaves contain subgenomic CaMV DNA species in addition to the genome length CaMV DNA. These subgenomic CaMV DNA species are present as covalently closed circles (form I), relaxed circles (form II) and linear (form III) molecules. The subgenomic form I DNA species range in size from about 10% of genome length to nearly genome length. These subgenomic DNA species appear in tissue infected with cloned CaMV DNA, indicating that they arise rapidly and have not accumulated in the virus population from serial propagation of CaMV. No specific region of the CaMV genome appears to be preferentially deleted to form the subgenomic CaMV DNA species. At least three distinct subgenomic species appear to accumulate preferentially in nuclei isolated from infected tissue. Two of these abundant subgenomic CaMV DNA species are form I and the other one is form III. Some of the subgenomic CaMV DNA species appear to be minichromosomes.