A redescription ofDiaphanosoma modigliani Richard, 1894 (Crustacea : Daphniiformes : Sididae)and an evaluation of its occurence outside Lake Toba (Sumatra)

A pelagic species of Diaphanosoma, D. modigliani is redescribed on material from the type locality (Lake Toba, Sumatra, Indonesia). Other records of this species in tropical Asia (India, Philippine Islands, Malaysia, Sri Lanka, Thailand) are either unsubstantiated or erroneous.     

New species in the rheophilous genus Nicsmirnovius Chiambeng & Dumont, 1999 (Branchiopoda: Anomopoda: Chydoridae) and reassignment of Alona eximia Kiser, 1948 and Alonella fitzpatricki Chien, 1970

A morphological comparison of specimens previously assigned to Alona eximia Kiser, 1948 from tropical Africa, Eastern Asia and the Americas shows that this species-group shares a number of morphological characters on the postabdomen, head pores, first antenna and second and fourth limb that separate them from Alona Baird, 1843 but unite them with Nicsmirnovius Chiambeng & Dumont, 1999. Alonella fitzpatricki Chien, 1970, formerly believed to be a junior synonym of A. eximia, is separated from the latter and assigned to the genus Nicsmirnovius. Two new taxa, from Africa and the Island of Socotra (Yemen) are added to the genus. The relationship between the specialised habitat of these chydorids and their morphology is discussed. The geographic range of all known populations is figured and a key to species is presented.     

A comparison of populations from the Daphnia similis group (Cladocera: Daphniidae)

European populations of Daphnia similis Claus have been compared with populations from tropical Asia. Daphnia similoides n. sp. from tropical Asia was described as the sibling species of D. similis. The female has characteristic neonate, postabdomen, head, and ephippium. The male has characteristic rostrum, antennules, and the distalmost part of the postabdomen. The D. similis group was compared with D. carinata s. str. Australian populations.     

Antibiotic Susceptibility as a Taxonomic Characteristic of Proteobacteria of the Genera Alteromonas, Pseudoalteromonas, Marinomonas, and Marinobacter

Type strains of bacteria of the genera Alteromonas, Pseudoalteromonas, Marinomonas, and Marinobacterand symbiotrophic bacteria isolated from the Far Eastern bivalve mollusks Crenomytilus grayanusand Mizuhopecten yessoensisand identified as Pseudoalteromonas nigrifaciensand P. citreawere tested for susceptibility to antibiotics. Of the ten antibiotics used in this study, benzylpenicillin, polymyxin, lincomycin, and oleandomycin were valuable for the polyphasic taxonomy of marine aerobic proteobacteria. Marine bacteria of the genera studied exhibited characteristic antibiotic susceptibility profiles, which were useful for the differentiation of the genera.     

Development of microsatellite markers for Diaphanosoma dubium (Crustacea,Cladocera) and application to seasonal population dynamics

Diaphanosoma, the “tropical Daphnia”, is common and ubiquitous in South China. Like other ctenopods, Diaphanosoma has a reproductive mode similar to Daphnia’s, but its resting eggs are rarely observed and lack an ephippium. With limited dispersal and reduced buffer effect from resting egg banks, Diaphanosoma is expected to have a population genetic structure different from that of temperate Daphnia. To facilitate genetic comparison, we developed microsatellite markers using next-generation sequencing for the most common species in tropical and subtropical East Asia, Diaphanosoma dubium. Thirty-one polymorphic microsatellite markers were obtained, and 29 of them were efficient for the congeneric species D. excisum, D. orghidani, D. mongolianum and D. chankensis. The markers allowed intra- and interspecific genetic analysis, including population structure, hybridization and introgression. We used 11 selected microsatellite markers to analyze spatial and temporal heterogeneity of genetic diversity in four (sub)tropical D. dubium populations from two large reservoirs and two temporary ponds. In contrast to temperate Cladocera, higher genetic diversity in summer rather than in spring suggested weak contribution from resting eggs in spring. Clustering of DAPC and STRUCTURE analyses indicated a clear-cut genetic structure in the four populations. Variation partitioning revealed that water storage and depth were key factors in genetic differentiation. Within large reservoirs, we detected backward (reversing time) gene flow from resting egg banks. We conclude that resting eggs have an effective contribution to the genetic diversity in large water bodies during growing seasons and that large water bodies can host higher genetic diversity in summer due to environmental heterogeneity and high carrying capacity. Spatial and temporal heterogeneity of genetic diversity detected by our microsatellite markers showed the newly developed markers can be applied for further study of populations of D. dubium and other species of Diaphanosoma at a contemporary scale.

     

The Finding of the Yeast Species Saccharomyces bayanusin Far East Asia

The genetic analyses of nine Far East Asian Saccharomyces isolates allowed us to identify three species (S. cerevisiae, S. paradoxus, and S. bayanus). The occurrence of the last species in Far East Asia was shown for the first time. A new methodology for the molecular genetic differentiation of Saccharomyces sensu stricto species is described. The ecogeographical distribution of Saccharomyces yeasts is discussed.     

Formation of morphological defences in response to YOY perch and invertebrate predation in two <Emphasis Type="Italic">Daphnia</Emphasis> species coexisting in a mesotrophic lake

This study examined the formation of morphological defences by two coexisting Daphnia species, the large-sized D. pulicaria (2 mm) and the small-sized D. mendotae (1.4 mm), in response to the presence of young-of-the-year (YOY) yellow perch (Perca flavescens) and invertebrate predators (Chaoborus, Leptodora) during summer in a mesotrophic lake. We hypothesized that due to differential size-selective predation risk by YOY fish and invertebrates, the large-sized and the small-sized Daphnia species would show different morphological responses to predation threats. We followed changes in two morphological traits (relative length of the tail spine in D. pulicaria and of the helmet in D. mendotae) among different periods during summer according to YOY fish and invertebrate predation. We defined four YOY fish predation periods based on the presence of YOY perch in the pelagic zone of the lake and the relative abundance of Daphnia preys in their gut contents, and two invertebrate predation periods based on exclusive or mutual occurrence of the invertebrate predators. The large-sized (D. pulicaria) and the small-sized (D. mendotae) species showed different morphological responses to YOY fish and invertebrate predators, respectively. The tail spine ratio of the juveniles and adults of D. pulicaria did not change in response to YOY fish predation or to invertebrate predation. A gradual increase in the helmet ratio was observed in the small-sized D. mendotae over the summer period. This change was related to the co-occurrence of the invertebrate predators (Chaoborus and Leptodora) and to YOY fish predation. The warmer temperature cannot be accounted for helmet elongation since it was constant across depths, and not related with the co-occurrence of D. mendotae and YOY perch. Guest editor: Piet Spaak Cladocera: Proceedings of the 7th International Symposium on Cladocera     

Impact of fish predation on coexisting Daphnia taxa: a partial test of the temporal hybrid superiority hypothesis

Fish predation was tested as a factor mediating the coexistence of Daphnia taxa in the shallow, hypertrophic Lake Blankaart. Naturally co-occurring populations of D. galeata and the hybrid D. galeata x cucullata were subjected to different levels of fish predation in in situ enclosures. In control enclosures without fish, the largest taxon D. galeata rapidly became dominant over the intermediate sized D. galeata x cucullata, mainly as a result of higher birth rates. In enclosures with fish, population densities of D. galeata dropped relative to D. galeata x cucullata, due to higher mortality rates. These results are in concordance with the `temporal hybrid superiority hypothesis', and can be explained by a higher vulnerability of the large and more conspicuous D. galeata to the size selective predation exerted by visually hunting planktivorous fishes. After approximately one month, however, population growth rates of D. galeata and D. galeata x cucullata in the enclosures with fish converged, due to a relative reduction in the mortality rate of D. galeata. This suggests that, in the presence of fish, D. galeata may co-exist with hybrids due to a decrease in its relative vulnerability to visual predation with time. Indeed, both D. galeata and the hybrid showed strong reductions in adult body size in the enclosures with fish, but this size reduction tended to be stronger in D. galeata than in D. galeata x cucullata. In addition, turbidity increased in the enclosures with fish and may additionally have reduced the relative advantage of D. galeata x cucullata with regard to mortality caused by visual predation.     

Direct and indirect impacts of predation by fish on the zooplankton community: an experimental analysis using tanks

The impact of Pseudorasbora parva, a common zooplanktivorous fish species in Japan, on a zooplankton community was analyzed in experimental tanks, half of which were stocked with the fish. Different zooplankton species showed different responses to the introduction of the fish. In the presence of the fish, the populations of the large cladoceran Ceriodaphnia and the predatory copepod Mesocyclops were reduced, but the population of the herbivorous copepod Eodiaptomus and the small cladocerans Bosmina fatalis and Bosminopsis deitersi increased relative to the controls. The increase of Mesocyclops seen in the control tanks might have suppressed the populations of the small cladocerans, which are vulnerable to invertebrate predation. The results suggest that the population densities of the large prey items preferred by the fish, Ceriodaphnia and Mesocyclops, were controlled directly by fish predation, but the population densities of the smaller and less preferred zooplankton were controlled indirectly through the food-web cascade.     

A new species of Clausia (Copepoda, Poecilostomatoida, Clausiidae) associated with the polychaete Arenicola brasilliensis Nonata in Korea

A new species of the genus Clausia associated with the polychaete Arenicola brasilliensis Nonata is described from intertidal sands in Korea. The new species, as a primitive member of the genus, has a large, non-transformed body and fully segmented rami on legs 1–4. This is the second record of Clausiidae in the Far Eastern seas. The genus Doviella Rocha, originally placed in the Clausidiidae, is synonymized with the genus Clausia in the Clausiidae.     

Genetic identification of units for conservation in tomato frogs, genus Dyscophus

Dyscophus antongilii and D. guineti are two morphologically very similar microhylid frogs from Madagascar of uncertain taxonomy. D. antongilii is currently included in Appendix I of the Convention on the International Trade in Endangered Species (CITES) and its exportation is banned completely. In contrast, D. guineti does not receive any legal protection and it is regularly exported. Field data on ecology and behaviour are to a large extent lacking. Here we report on a genetic survey of D. antongilii and D. guineti using nuclear and mitochondrial DNA markers. Sequences of a fragment of 501 bp of the mitochondrial cytochrome b gene from one population of D. antongilii and two populations of D. guineti resulted in a single haplotype network, without haplotype sharing among the populations. However, haplotypes of D.␣guineti were only 1–4 mutational steps from those of D. antongilii, and did not form a clade. The analysis of eight microsatellites newly developed and standardized for D. antongilii revealed an excess of homozygotes and the absence of Hardy–Weinberg equilibrium. The microsatellite data clearly distinguished between D. antongilii and D. guineti, and fixed differences were observed at one locus. Although confirmation of the status of Dyscophus antongilii and D. guineti as separate species requires further data, our study supports the definition of these two taxa as different evolutionary significant units under the adaptive evolutionary conservation concept.     

Geographic differentiation in wing shape inDrosophila melanogaster

Genetic variation of a suite of 12 morphometric wing characters was examined in 16 natural populations ofDrosophila melanogaster from Eastern Europe and Central Asia using principal component analysis. The posterior wing compartment was found to differ in shape between the Eastern European and Central Asian populations. This result is in agreement with data on wing shape variation from exposure to high and low temperatures under laboratory conditions.     

The effect of earthworms and snails in a simple plant community

Snails and earthworms affected the dynamics of a simple, three-species plant community, in the Ecotron controlled environment facility. Earthworms enhanced the establishment, growth and cover of the legume Trifolium dubium, both via the soil and interactions with other plant species. Worms increased soil phosphates, increased root nodulation in T. dubium, and enabled T. dubium seedlings to establish in the presence of grass (Poa annua) litter, by increasing soil heterogeneity. Worms also buried the seeds of Poa annua and Senecio vulgaris, reducing the germination of new seedlings. Snails reduced nitrogen-fixing Trifolium dubium and increased cover of plant litter, thereby reducing ammonia-nitrogen concentrations in the soil. These effects and their interactions demonstrate that the detritivore food chain, and earthworms in particular, cannot be ignored if we are to understand the spatial and temporal dynamics of plant communities.     

The genus Valdivianemertes Stiasny-Wijnhoff 1923 (Nemertea,Enopla, Hoplonemertea): nomenclatural status and proper systematic position

The genus Akrostomum was erected by Grube in 1840 for a single species A. stannii which remained a nomen dubium until redescribed by Bürger in 1895 as Amphiporus stanniusi. Bürger (1909) described Drepanophorus valdiviae which shared many characters with A. stannii. Stiasny-Wijnhoff (1923) noted that these two forms belonged neither to Amphiporus nor Drepanophorus and united them in a new genus Valdivianemertes but did not mention the earlier name Akrostomum nor a family affiliation. Several major characters are examined. The nomenclatural status is analyzed, with retention of the junior synonym Valdivianemertes, and the type species is fixed as V. stannii by subsequent designation. Family affiliation is discussed, and the genus is transferred to the Cratenemertidae.     

Host Suitability of Four Cereal Stem Borers (Lepidoptera: Crambidae, Noctuidae) for Different Geographic Populations of Cotesia sesamiae (Cameron) (Hymenoptera: Braconidae) in Kenya

This study focused on the suitability of four species of cereal stem borers for the development of five geographic populations of Cotesia sesamiae (Cameron). C. sesamiae, an indigenous larval parasitoid of gramineous stem borers, is widespread in Africa. Four stem borers, Chilo partellus (Swinhoe), Chilo orichalcociliellus Strand (Lepidoptera: Crambidae), Busseola fusca Fuller, and Sesamia calamistis Hampson (Lepidoptera: Noctuidae), were offered to C. sesamiae for oviposition. Parasitoid individuals originated from five locations in Kenya. Biological parameters such as developmental time, percentage parasitism, progeny production, mortality of immature parasitoids, and proportion of female progeny were compared across host species. The two populations from western Kenya developed well on B. fusca. However, populations from the coast and the Eastern Province could not successfully parasitize B. fusca. With the exception of B. fusca, the percentage of hosts successfully parasitized by the different C. sesamiae populations was not different. The size of the host appeared to be an important factor influencing the development and reproductive potential of the parasitoid. We conclude that the different parasitoid populations were adapted to location-specific characteristics. Parasitoid–host compatibility must be evaluated before release for better establishment and colonization.     

Chloroplast DNA phylogeography of <Emphasis Type="Italic">Pedicularis</Emphasis> ser. <Emphasis Type="Italic">Gloriosae</Emphasis> (Orobanchaceae) in Japan

Phylogeographic analyses using chloroplast DNA (cpDNA) variation were performed for Pedicularis ser. Gloriosae (Orobanchaceae). Eighty-one plants of 18 populations of 6 species (P. gloriosa, P. iwatensis, P. nipponica, P. ochiaiana, P. sceptrum-carolinum and P. grandiflora) were analyzed. Fifteen distinct haplotypes were identified based on six cpDNA regions: the intergenic spacer between the trnT and trnL 3′exon, trnL 3′exon-trnF, atpB-rbcL, accD–psaI, the rpl16 intron and the trnK region (including the matK gene). Via phylogenetic analyses of the haplotypes, two continental species, P. sceptrum-carolinum and P. grandiflora, were placed at the most ancestral position in the trees. The former species is widely distributed in the Eurasian continent, and the latter is distributed in Far East Asia. Two robust major cpDNA clades (clades I and II) were revealed in the Japanese archipelago, although the statistical values of monophyly of these clades were weak. Clade I included the haplotypes (A-1, A-2, B-1, B-2 and J) of three species (P. gloriosa, P. iwatensis and P. ochiaiana), and Clade II included seven haplotypes (C-D, E-1, E-2 and F-H) of P. nipponica. These results suggest that this series originated on the Eurasian continent and that subsequently populations at the eastern edge of the continent differentiated into the two Japanese lineages. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Phylogeny, biogeography, and species boundaries within the Alexandrium minutum group

The geographic range and bloom frequency of the toxic dinoflagellate Alexandrium minutum and other members of the A. minutum group have been increasing over the past few decades. Some of these species are responsible for paralytic shellfish poisoning (PSP) outbreaks throughout the world. The origins of new toxic populations found in previously unaffected areas are typically not known due to a lack of reliable plankton records with sound species identifications and to the lack of a global genetic database. This paper provides the first comprehensive study of minutum-group morphology and phylogeny on a global scale, including 45 isolates from northern Europe, the Mediterranean, Asia, Australia and New Zealand.Neither the morphospecies Alexandrium lusitanicum nor A. angustitabulatum was recoverable morphologically, due to large variation within and among all minutum-group clonal strains in characters previously used to distinguish these species: the length:width of the anterior sulcal plate, shape of the 1′ plate, connection between the 1′ plate and the apical pore complex, and the presence of a ventral pore. DNA sequence data from the D1 to D2 region of the LSU rDNA also fail to recognize these species. Therefore, we recommend that all isolates previously designated as A. lusitanicum or A. angustitabulatum be redesignated as A. minutum. A. tamutum, A. insuetum, and A. andersonii are clearly different from A. minutum on the basis of both genetic and morphological data.A. minutum strains from Europe and Australia are closely related to one another, which may indicate an introduction from Europe to Australia given the long history of PSP in Europe and its recent occurrence in Australia. A minutum from New Zealand and Taiwan form a separate phylogenetic group. Most strains of A. minutum fit into one of these two groups, although there are a few outlying strains that merit further study and may represent new species. The results of this paper have greatly improved our ability to track the spread of A. minutum species and to understand the evolutionary relationships within the A. minutum group by correcting inaccurate taxonomy and providing a global genetic database.     

The first study on the bacterial flora of the european spruce bark beetle, Dendroctonus micans (Coleoptera: Scolytidae)

The European spruce bark beetle, Dendroctonus micans Kugelann (Coleoptera, Scolytidae), is one of the most serious pests of oriental spruce (Picea orientalis L.) in Turkey. In this study, we investigated bacterial flora of D. micans collected from different populations of the forests of Eastern Black Sea Region of Turkey from 2002 to 2004. Seven different bacteria were isolated from healthy, diseased and dead specimens based on the color of colony and morphology. According to morphological, physiological and biochemical properties, metobolic enyzme profile by BIOLOG microtiter plate system, and total cellular fatty acid profile by Microbial Identification System (MIS), isolates were identified as Micrococcus luteus, Bacillus thuringiensis subsp. morrisoni, Serratia grimesii, Enterobacter cloaceae, Enterobacter intermedius, Streptococcus sp. and Pseudomonas putida. This is the first study on the bacterial flora of D. micans.     

Species of Pleuroxus (Anomopoda,Chydoridae) from the subantarctic islands and southernmost South America: a partial unravelling of the Pleuroxus aduncus problem

Whereas previously all populations of Pleuroxus (now P.) known from the subantarctic islands and southernmost South America were considered to belong to a subspecies of P. aduncus (described from France), now there are five distinct species, only one of which resembles P. aduncus to any significant extent, but even it is a good species. Thus, the taxa are all distinctly different, and none of them could possibly be considered an infraspecies of P. aduncus sens. str. P. macquariensis from Macquarie Island and P. paroplesius and P. varidentatus from South America are new. Of the five species, P. varidentatus resembles P. aduncus most closely, but is separated from it by a number of significant characters. P. wittsteini is presently known from five islands in the south Indian Ocean, but there is considerable uncertainty as to whether all these populations really are the same taxon, because they differ somewhat in the shape of the labrum and in the intensity of sculpturing of the carapace and head. P. scopuliferus from South America is the most distinctive species of the group, having 9 gnathobasic filter setae on trunklimb III instead of the usual 8, a weak ridge on the shell, and a recurved rostrum extending beyond the tip of the labrum. No species of Pleuroxus (or of P., another subgenus of animals formerly assigned simply to Pleuroxus are known from the islands in the Scotia Arc between South America and Antarctica. The patterns of distribution cannot be explained by an on-going passive dispersal of resting eggs. No populations of species on the subantarctic islands are known from any of the southern land masses. Conditions on these islands intuitively must have been more severe during the glacial ages than during the present interglacial, suggesting that any anomopods present were eliminated during the severe glacial periods. Yet, the presence of isolated populations of endemic species on some islands and the complete lack of Pleuroxus on others (e.g. those in the Scotia Arc) argues that conditions, although more severe, still provided opportunities for the maintenance of active populations. Moreover, the morphological differences between populations of P. wittsteini on islands from a few hundred to several thousand kilometers apart likewise argue for genetic isolation over a very long period of time. Deceased