Systematics and Biogeography of Burrowing Bryozoans

Current investigations of the three principal families of ectoproctbryozoan burrowers has shown that while two of the families,the Terebriporidae and the Immergentiidae, belong to the minorOrder Ctenostomata, the third family, Penetrantiidae, previouslyconsidered a ctenostome, actually belongs to the major OrderCheilostomata. The implications of this are important; we haveconsidered the burrowing bryozoans to be a small obscure group,specialized for the burrowing mode of existence. We must nowconsider the possibility that there may be many more speciesof burrowing bryozoans as yet undiscovered, that they occurin at least two of the three bryozoan orders, and that burrowingconstitutes an important ecological niche or mode of adaptationfor the bryozoans. While such a change may seem to be merelya taxonomic maneuver, itmay also serve to emphasize the diversityof the ectoproct bryozoan groups which do burrow, and perhapsencourage research on them. At present we are making progressdescribing the living species, their anatomy and histology.We still know almost nothing about how they penetrate the substrate,nothing about possible effects upon the host organism, and nothingabout their means of geographical distribution, although theyseem to occur worldwide, burrowing primarily in molluscan shells.     

Myxomycetes:Biology,Systematics,Biogeography,and Ecology

正黏菌是丰富多彩的生物多样性世界提供给人类的一个独特类群。Myxomycetes:Biology,Systematics,Biogeography,and Ecology是迄今为止全方位、多视角展示黏菌生物学的第一本巨著。由美国阿肯色大学Steven L.Stephenson教授等活跃在当今黏菌各研究领域的,以及来自全球11个国家的29位国际知名黏菌学者共同完成。全书按照领域和专题分为13章,由不同作者分别编写,中国工程院院士、《菌物研究》主编、吉林农业大学李玉教授及其团队成员工琦教授和刘朴教授是"第六章黏菌生理学和生物化学"的作者。     

Systematics and Biogeography of Scaled Woodcreepers (Aves: Dendrocolaptidae)

The geographical variation of three qualitative plumage characters and three body measurements of populations of the Scaled Woodcreeper (Lepidocolaptes squamatus), a species whose range is centered in eastern Brazil, is analyzed. Three distinctive populations are recognized (wagleri, squamatus, and falcinellus). Under the biological species concept (BSC), two species are recognized (L. squamatus, including squamatus and wagleri as subspecies; and L. falcinellus). Under either the phylogenetic species concept (PSC) or under the evolutionary species concept (ESC), the three distinctive populations should be regarded as independent species. Based on plumage similarities, we suggest that squamatus and wagleri form a monophyletic group, with falcinellus as its sister-group. Geological changes (tectonism and formation of river courses) are suggested as causal factors that promoted speciation in Scaled Woodcreepers.     

Phylogenetic Systematics and Biogeography of the Neoephemeridae (Ephemeroptera: Pannota)

A revision of species of the pannote Holarctic and Oriental mayfly family Neoephemeridae is presented. Three genera are recognized in a strictly phylogenetic classification. Potamanthellus [=Neoephemeropsis Ulmer syn. n.] includes P. caenoides (Ulmer) comb. n., P. amabilis (Eaton) [=N. cuaraoensis Dang syn. n.], P. ganges sp. n., P. chinensis (Hsu) [=P. rarus (Tiunova and Levanidova) syn. n.], P. edmundsi sp. n., and the Oligocene fossil Potamanthellus rubiensis Lewis. Neoephemera [=Leucorhoenanthus Lestage syn. n.] includes N. maxima (Joly), N. purpurea (Traver), N. youngi Berner, N. bicolor McDunnough, and N. compressa Berner. Ochernova gen. n., includes O. tshernovae (Kazlauskas) comb. n. Taxa are described, illustrated and keyed. Species cladistics and biogeography are presented.     

Molecular Systematics of Tanagers (Thraupinae): Evolution and Biogeography of a Diverse Radiation of Neotropical Birds

The tanagers (Passeriformes: Emberizidae: Thraupinae) are a diverse group of mostly Neotropical birds with a wide range of feeding morphologies, behaviors, plumage patterns and colors, and habitat preferences. Phylogenetic relationships of genera in this lineage were investigated using cytochromebsequence data. This study indicates that the generaEuphoniaandChlorophonia(traditionally considered part of Thraupinae) do not form a monophyletic group with the other tanagers. Within the rest of Thraupinae, several monophyletic groups are identified that agree with traditional sequential taxonomies. Other monophyletic groups provide novel interpretations of biogeographic patterns and morphological evolution within tanagers. In several lineages, plumage patterns and colors persist despite dramatic changes in bill morphology. Phylogenetic structure and estimated timings of divergence events indicate that tanagers probably originated on Caribbean islands and later diversified throughout Central and South America during the mid-Tertiary.     

Biogeography Revealed by Mariner-Like Transposable Element Sequences via a Bayesian Coalescent Approach

Genetic diversity of natural populations is useful in biogeographical studies. Here, we apply a Bayesian method based on the coalescent model to dating biogeographical events by using published DNA sequences of wild silkworms, Bombyx mandarina, and the domesticated model organisms B. mori, both of which categorized into the order of Lepidoptera, sampled from China, Korea, and Japan. The sequences consist of the BmTNML locus and the flanking intergenic regions. The BmTNML locus is composed of cecropia-type mariner-like element (MLE) with inverted terminal repeats, and three different transposable elements (TE), including L1BM, BMC1 retrotransposons, and BmamaT1, are inserted into the MLE. Based on the genealogy defined by TE insertions/deletions (indels), we estimated times to the most recent common ancestor and these indels events using the flanking, MLE, and indels sequences, respectively. These estimates by using MLE sequences strongly correlated with those by using flanking sequences, implying that cecropia-type MLEs can be used as a molecular clock. MLEs are thought to have transmitted horizontally among different species. By using a pair of published cecropia-type MLE sequences from lepidopteran insect, an emperor moth, and a coral in Ryukyu Islands, we demonstrated dating of horizontal transmission between species which are distantly related but inhabiting geographically close region.     

竹亚科系统学和生物地理学研究进展及存在的问题

对近年来在竹亚科作为一个单系类群的界定、其系统位置的确定、内部系统演化趋势以及地理分布和起源方面研究所取得的进展进行了评述。竹亚科作为一个单系类群仅包括了木本的竹族（Bambuseae)和一个草本的莪利竹族（Olyreae),其中莪利竹族分布在新几内亚的伊里安竹（Buergersiochloa)处于Olyreae最基部。禾本科12个亚科中除了3个亚科为基部类群以外,其余9个亚科分成PACCAD（包括黍亚科,狭义的芦竹亚科,广义的虎尾草亚科,假淡竹叶亚科,三芒草亚科和扁芒草亚科）和BOP单系分支（包括竹亚科,稻亚科和早熟禾亚科）。在BOP支中,竹亚科与早熟禾亚科相近缘,共同组成稻亚科的姐妹群。竹亚科分成草本和木本两个单系类群,木本竹子又分成热带和温带支系,热带支系进一步分成新世界热带和旧世界热带两个单系类群。从现有的化石证据和基部类群的地理分布推断,竹亚科很可能起源于晚白垩纪的冈瓦纳古陆。最后,本文就竹亚科研究尚存在的问题做了初步探讨。     

Ticks, ivermectin, and experimental Chagas disease

Following an infestation of dogticks in kennels housing dogs used for long-term studies of the pathogenesis of Chagas disease, we examined the effect of ivermectin treatment on the dogs, ticks, trypanosome parasites, and also on triatomine vectors of Chagas disease. Ivermectin treatment was highly effective in eliminating the ticks, but showed no apparent effect on the dogs nor on their trypanosome infection. Triatominae fed on the dogs soon after ivermectin treatment showed high mortality, but this effect quickly declined for bugs fed at successive intervals after treatment. In conclusion, although ivermectin treatment may have a transient effect on peridomestic populations of Triatominae, it is not the treatment of choice for this situation. The study also showed that although the dogticks could become infected with Trypanosoma cruzi, this only occurred when feeding on dogs in the acute phase of infection, and there was no evidence of subsequent parasite development in the ticks.     

Systematics,morphology and biological control

Accurate systematics is the foundation on which all meaningful research in biology is based. The importance of sound systematics to practical biological control is illustrated by results from several projects on biological control of coccid pests. Correct identification of the pest species or their natural enemies, and recognition of cryptic species or infraspecific entities, have been of utmost importance to the success of many projects. Accurate morphology is the basis of reliable systematics. Unfortunately, basic morphology of the parasitic Hymenoptera is still imperfectly understood and that which is known often is inadequately used. The scanning electron microscope is a valuable tool for comparative morphological research that will go far toward solving these problems. The taxonomic validity of morphological characters, and the extent of intraspecific variation, should be determined by a detailed biometrical study of large series of cultured specimens whenever possible. This approach is illustrated with results obtained in our recent revision of the species ofAphytis, important parasites of diaspine scale insects. Comparative morphology of developmental stages of parasitic Hymenoptera is recognized as an important approach to the study of cryptic species needing much more emphasis.     

Systematics,conservation and sustainable development

The contribution of systematics to conservation and sustainable use of species is discussed. An adequate inventory of species is required for both areas and recent field work shows that the inventory is far from complete. This supports the first mission of Agenda 2000 which is to discover described and inventory global species diversity. The importance of making these data available in data base format is stressed. Sound systematics is a necessity for conservation legislation where control depends on the ability to identify organisms correctly. The establishment of reserves is also dependent upon data from systematics about centres of diversity and endemism and examples of this are given. Molecular systematics has made new tools available to conservation such as genetic fingerprinting which is useful both to breeding programmes of rare species and for identification for legal proceedings.Systematics is also one of the foundations for programmes of sustainable development especially in the search for new crops, non-timber forest plants from extraction forests and the identification of wild relatives of crop species. Examples of the role of systematics in a fuelwood programme in Zimbabwe, a sustainable development programme in northeast Brazil and in the search for a chemical component with medicinal properties for curing AIDS are given. The more predictive a classification we can develop using modern cladistic and molecular techniques the more useful systematics will be for both conservation and sustainable development. The goal of Agenda 2000 to organize the information derived from the programme in an efficiently retrievable form that best meets the needs of science and society is a laudable target that is crucial for conservation and the sustainable use of the plant resources of the world.     

Systematics and Biogeography of the Red Algal Genus Yonagunia (Halymeniaceae,Rhodophyta) from the Indo-Pacific Including the Description of Two New Species from Taiwan

Carpopeltis maillardii has been regarded as a widely distributed species in the Indo-Pacific region. In this study, we analyzed the genetic diversity of C. maillardii and related species collected from Taiwan and the Indian Ocean based on rbcL sequences, in order to elucidate species boundaries, diversity, and biogeographic patterns. Our analyses show that C. maillardii specimens are only distantly related to the genus Carpopeltis (type: C. phyllophora) but instead form a clade together with species of Yonagunia. We therefore propose the new combination Yonagunia maillardii comb. nov. In addition, two new species (Yonagunia palmata sp. nov. and Yonagunia taiwani-borealis sp. nov.) are described from Taiwan. The close relationship of Yonagunia to Grateloupia is corroborated by detailed observations of the female reproductive structures, which demonstrate that the development of auxiliary cell ampullae before and after diploidization is similar to that of Grateloupia sensu stricto. Namely, the ampullae are composed of only two orders of unbranched filaments in which only a few ampullar cells are incorporated into a basal fusion cell after diploidization of the auxiliary cell and the pericarp consists almost entirely of secondary medullary filaments. Of all Yonagunia species, Y. maillardii has the widest distribution in the Indo-Pacific, and can be identified in the field by its relatively thin, feathery, and highly branched morphology. Most other species, including those that occur in Taiwan, are seemingly more range-restricted. Our phylogenetic analyses resulted in a well-resolved phylogeny of Yonagunia, with an origin estimated in the Eocene–Oligocene, and diversification of species mainly in the Miocene.     

Endemicity,Biogeography, Composition,and Community Structure On a Northeast Pacific Seamount

The deep ocean greater than 1 km covers the majority of the earth''s surface. Interspersed on the abyssal plains and continental slope are an estimated 14000 seamounts, topographic features extending 1000 m off the seafloor. A variety of hypotheses are posited that suggest the ecological, evolutionary, and oceanographic processes on seamounts differ from those governing the surrounding deep sea. The most prominent and oldest of these hypotheses, the seamount endemicity hypothesis (SMEH), states that seamounts possess a set of isolating mechanisms that produce highly endemic faunas. Here, we constructed a faunal inventory for Davidson Seamount, the first bathymetric feature to be characterized as a ‘seamount’, residing 120 km off the central California coast in approximately 3600 m of water (Fig 1). We find little support for the SMEH among megafauna of a Northeast Pacific seamount; instead, finding an assemblage of species that also occurs on adjacent continental margins. A large percentage of these species are also cosmopolitan with ranges extending over much of the Pacific Ocean Basin. Despite the similarity in composition between the seamount and non-seamount communities, we provide preliminary evidence that seamount communities may be structured differently and potentially serve as source of larvae for suboptimal, non-seamount habitats.Open in a separate windowFigure 1Bathymetric map of the Central California Coast with Monterey Canyon and Davidson Seamount.