Molecular genetic divergence of the centric diatom Cyclotella and Discostella (Bacillariophyceae) revealed by nuclear ribosomal DNA comparisons

The centric diatom Cyclotella, including the recently separated Discostella, is commonly present in freshwater and several species are important bio-indicators. Here, we describe molecular characteristics of the nuclear rDNA, spanning 18S to D1/D2 region of the 28S rDNA, of two genera Cyclotella and Discostella, particularly using Korean isolates of C. meneghiniana, Discostella sp. c.f. D. pseudostelligera. Molecular and morphological analyses showed that our isolates had nearly identical genotypes in rDNA and similar morphology as compared to presumably the same species from other geographical areas. Phylogenetic analyses of individual 18S and partial 28S rDNAs of Cyclotella sensu lato showed that all sequences were separated into two clades: one containing Cyclotella, the other Discostella including C. ocellata and C. bodanica. Statistical tests with pairwise genetic distance scores showed that the two genera were significantly different (one-factor ANOVA, p?<?0.01). In addition, divergence in the partial 28S rDNA was significantly high (p?<?0.01) as compared to 18S rDNA. This provides evidence that the two genera, Cyclotella and Discostella, belong to genetically well-separated groups. In addition, 28S rDNAs is a more suitable molecular marker for the discrimination of Cyclotella sensu lato.     

Systematics and evolution of the genus Clathrobaculus Cossmann, 1912 (Gastropoda, Mathildidae)

The morphology and ontogeny of Jurassic gastropods those have been included in the genera Clathrobaculus Cossmann, 1912 and Gordenella Gründel, 1990 are discussed. Based on the ontogenetic research of their shells, several types of ontogeny are established in the species of these genera. The suggestion is made that the genus Gordenella should be considered as a junior synonym of Clathrobaculus within the family Mathildidae. The protoconchs of Clathrobaculus species are studied to reveal their morphological variability and a number of distinguishing characters in which they differ from the protoconchs of other mathildid genera. Four species of Clathrobaculus, of which two are new (C. medidilatatus and C. inconstantiplicatus), are described from the Jurassic deposits of the European part of Russia. The composition of C. fahrenkohli (Rouillier, 1846) and C. krantzi (Rouillier, 1849) is emended, and the protoconchs of these species and of the species C. inconstantiplicatus are described for the first time.     

Chromosome numbers and taxonomic notes for Mexican coreopsis,sections electra and pseudoagarista (compositae: heliantheae)

Notes on morphology and chromosome numbers are given for several species of MexicanCoreopsis, most of which were poorly known prior to recent collections.Coreopsis parvifolia (sectionElectra) is a large, shrubby, octoploid (2n=112) species apparently restricted to a small area in Puebla. It andC. cuneifolia (a diploid with 2n=28) appear to be closely related but differ by a number of morphological features in addition to ploidy level. A first chromosome report forC. pringlei (sectionPseudoagarista) shows this rare species to be diploid (2n=26), a fact which is in agreement with the base number of the section, i.e.,x=13. Additional collections of the very rareC. rudis andC. mcvaughii show them to be similar yet distinct species. Chromosome determinations forC. petrophila from Nayarit and Durango agree with previous counts for Jalisco populations of the species, i.e., 2n=26. Considerable morphological variation exists within this species but no subspecific entities are recognized.     

Chromosome numbers in some North American species of the genus Cirsium. III. Western United States,Mexico, and Guatemala

New data are presented on chromosome numbers for 36 species, two varieties, and two hybrids ofCirsium (Compositae). These include first reports forC. rhothophilum (2n = 34),C. andrewsii (2n = 32),C. crassicaule (2n = 32),C. quercetorum (2n= 32, 112),C. pascuarense (2n= 32),C. douglasii var.canescens (2n = 30, 34),C. hydrophilum (2n = 32),C. neomexicanum (2n = 30),C. cymosum (2n = 30, 34),C. acantholepis (2n= 34),C. radians (2n = 34), C.grahami (2n = 32),C. nigriceps (2n = 36),C. andersonii (2n= 32, 64),C. anartiolepis (2n = 34), andC. subcoriaceum (2n= 34). The published data on chromosome numbers of Eurasian and AmericanCirsium are summarized. In Eurasia, speciation has taken place primarily at the diploid level but is occasionally reinforced by polyploidy. The ancestral base number of 17 has been preserved in almost all species, and there is little evidence that reduction in chromosome number has played a significant role in speciation. In America speciation has proceeded exclusively at the diploid level, but the ancestral genome of 17 chromosomes has been retained in only about half of the species examined. In the remaining species, restructuring of the genome has occurred resulting in a reduction in number from 17 to 9 in extreme cases. Polyploidy, when seen, is of no significance. It is suggested that all species with greatly reduced numbers may represent products of a single reduction series.     

Comparative cytogenetics of eight species of Cycloramphus (Anura, Cycloramphidae)

Several aspects of the biology of Cycloramphus species of the Atlantic Forest are still poorly known, which makes it difficult to understand their historical relationships. Therefore, we were stimulated to promote a comparative cytogenetic analysis of several species of the genus Cycloramphus. The study of Cycloramphus acangatan, C. boraceiensis, C. brasiliensis, C. carvalhoi, C. eleutherodactylus, C. fuliginosus, C. lutzorum, and C. rhyakonastes, revealed that these eight species share a diploid number 2n = 26. Cycloramphus fuliginosus presented the most distinct karyotype, due to the presence of subtelocentric chromosomes in pairs 1 and 4. The main diagnostic feature observed in the other species was the presence of one pair of telocentric chromosomes in C. boraceiensis, C. carvalhoi, and C. eleutherodactylus, while the remaining species presented karyotypes composed exclusively of biarmed chromosomes. Constitutive heterochromatin was predominantly located in pericentromeric regions in all species, although additional C-bands detected on telomeric and/or interstitial regions were partially species-specific. Silver staining revealed Ag-NORs located on the pair 6 in six species, whereas C. acangatan presented it on pair 1 and a multiple pattern was observed in C. fuliginosus with three Ag-NOR bearing chromosomes. Fluorescent in situ hybridization using rDNA probe was performed in specimens of C. eleutherodactylus from Paraná, C. lutzorum, and C. rhyakonastes, which did not reveal inactive NOR. Despite the apparent highly conserved diploid number, data on the karyotype microstructure characterize the cytogenetic profile of the genus and may contribute to clarify the phylogenetic relationships among Cycloramphus, the Cycloramphinae, or even the family Cycloramphidae.     

Calymperes (Musci: Calymperaceae): World ranges,implications for patterns of historical dispersion and speciation,and comments on phylogeny

Refinements in the taxonomy of the genus Calymperes (Musci: Calymperaceae) allow increasingly accurate estimates of the total number of species worldwide and new assessments of world ranges of the species. Instead of the 272 correct names of Calymperes listed in Volume 1 of Index Muscorum, the world total of “good” species now appears to be in the range of 30 to 40, and contrary to the high degree of narrow endemism implied from the compilation of Index Muscorum, many species of Calymperes have broad ranges in the paleo- or neotropics. A few species, including C. afzelii, C. erosum, C. palisotii, C. lonchophyllum, and C. tenerum, are pantropical. World ranges of species of Calymperes are mapped and implications for historical patterns of dispersal and speciation are discussed. Suites of endemic species and species groups in the neotropics differ from those in the paleotropics, demonstrating different ancestries, a long period of geographic separation, and independent evolution in two fundamentally different environments. It is suggested that Calymperes shares close phylogenetic relationship with limbate Syrrhopodon.     

Organic acids,sugars, vitamin C content and some pomological characteristics of eleven hawthorn species (Crataegus spp.) from Turkey

Background

The Hawthorn (Crateagus sp.) mostly occurs around the temperate region of the world with a high number of species, producing a fruit with numerous beneficial effects for human health. The aim of the study was to determine organic acid and sugar contents in the fruit of a number of hawthorn species grown in Erzincan province of Turkey.

Results

Citric acid was the predominant organic acid in all hawthorn species and C. pseudoheterophylla had the highest citric acid content (23.688 g/100 g). There were not statistically significant differences among hawthorn species (except C. atrosanguinea Pojark) in terms of fumaric acid content. C.pontica C.Koch had a higher content of vitamin C (9.418 mg/100 g) compared to other species. Fructose was the predominant sugar component in all species and C. monogyna subsp. monogyna Joiq had the highest fructose content (18.378 g/100 g).

Conclusions

The high fruit quality of the studied species indicates the importance of this fruit in human nutrition as a natural source. The study revealed that there were differences in terms of fruit characteristics among hawthorn species and thus better quality hawthorn genotypes can be selected within the species. Hence, this study is considered to be a valuable reference for forthcoming studies. The high fruit quality of the studied species indicates the importance of this fruit in human nutrition as a natural source.     

Occurrence of ant (hymenoptera, formicidae) and aphid (homoptera, aphidinea) syninclusions in Saxonian and Rovno ambers

Ant species found as syninclusions with aphids in Rovno and Saxonian ambers are listed for the first time. In a collection of 143 pieces of Rovno amber with worker ants, aphids were found in only one syninclusion with Ctenobethylus goepperti (Mayr). In a collection of Saxonian amber, 53 aphids of the genus Germaraphis were found in 152 amber pieces with ant workers; five syninclusions with aphids contained 19 specimens of C. goepperti; two syninclusions contained ten specimens of Lasius schiefferdeckeri Mayr; and three syninclusions contained one specimen each: one Camponotus mengei Mayr, one Anonichomyrma constricta (Mayr), and one Formica flori Mayr. Considering that the Rovno and Saxonian collections are nearly equal in the number of amber pieces, the fundamental difference in the number of syninclusions is striking. The number of C. goepperti in syninclusions is disproportionately high; the proportion of syninclusions with aphids and C. goepperti is 1.6 times that of all inclusions of workers of this species. They are found in 31% of examined inclusions of workers in the collection of the Saxonian amber, but in 50% of syninclusions of the entire collection. This strongly suggests that C. goepperti and Germaraphis formed an association during their lifetime.     

Draconematidae (Nematoda) from cold-water corals in the Porcupine Seabight: The genus Cygnonema Allen & Noffsinger, 1978

Two new and closely related species of the genus Cygnonema Allen & Noffsinger, 1978 are described from a cold-water coral degradation zone in the Porcupine Seabight (NE Atlantic). Both species differ from C. steineri Allen & Noffsinger, 1978 by more pronounced pharyngeal and posterior swellings, a smaller body, a shorter pharynx in relation to body length, a higher number of CAT, and by the absence of a dorsal tooth. Cygnonema verum sp. n. differs from C. belgicae sp. n. by its greater body length, the relatively larger head capsule, a higher number of CAT, a more anteriorly positioned anteriormost laterodorsal CAT, a higher number of PAT, by the external labial sensilla being setiform, a higher number of subcephalic setae, and by a more anterior position of the amphidial fovea on the head capsule. Males of C. verum sp. n. are easily recognised by the presence of two large subventral, precloacal corniform setae. They also differ from males of C. belgicae sp. n. in the smaller amount of cytoplasm in the sperm cells, a knob-like capitulum, and a relatively shorter tail tip. The diagnosis of Cygnonema is emended, a dichotomic identification key to the three species is provided, and their biogeography is discussed.     

New species and records of Charisius Champion from Mexico and Central America (Coleoptera,Tenebrionidae, Alleculinae)

The species of the genus Charisius Champion, from Mexico and Central America are reviewed. The flightless genus Narses Champion, with one included species, N. subalatus Champion, is placed in synonymy with the genus Charisius. Four new species are described and illustrated, C. granulatus and C. punctatus (from Guatemala) and C. apterus and C. howdenorum (from Mexico). Charisius subalatus (Champion) is redescribed and illustrated. The species C. interstitialis Champion is placed in synonymy with C. zunilensis Champion. The genus is redescribed to include the four new species and N. subalatus. New distributional records are presented for all other species of the genus and a revised key is presented for identification of all the species of the genus.     

Analysis of variations of basic morphometric characters in the species of grenadier (Macrouridae, Gadiformes) from the waters of the northern part of the Mid-Atlantic ridge

We investigate variations of the basic morphometric characters (length of head, length of snout, diameter of orbit, interorbital distance, etc.) of ten of the most common species of grenadiers (Macrouridae) in the waters of the northern part of the Mid-Atlantic ridge: Coelorinchus labiatus, Coryphaenoides armatus, C. brevibarbis, C. carapinus, C. guentheri, C. leptolepis, C. mediterraneus, C. rupestris, Macrourus berglax, and Paracetonurus flagellicauda. It is shown that most morphometric characters of the investigated species vary within the wider limits as compared with the published data. The representatives of genera Coelorinchus, Macrourus, and Paracetonurus well differ by a number of characters from the species of genus Coryphaenoides and from each other. In spite of a significant likeness in many characters of the species of genus Coryphaenoides, there are individual characters that differ well from one species to another.     

Two new species of Chrysis Linnaeus (Hymenoptera,Chrysididae) from Iran

The Iranian species in the Chrysis pulchella and C. varidens species groups are investigated. Six species are recognized, two of which are described for the first time: Chrysis gamberoonensis Farhad, Rosa and Talebi sp. nov. and Chrysis brunneamarginata Farhad, Rosa and Talebi sp. nov.. Chrysis gamberoonensis Farhad, Rosa and Talebi sp. nov. belongs to the C. pulchella group and is recognizable within this species group by its unique blue body coloration, scattered mesosoma punctures, polished pit row with elongated pits, and a small median tooth on the lateral edge of metasomal tergum 3. Chrysis brunneamarginata Farhad, Rosa and Talebi sp. nov. belongs to the C. varidens group and is recognizable by the usually colorless apical rim of metasomal tergum 3, and the unique shape of the anterior corners of the scutellum which are enlarged, thickened and directed backward covering the axillary trough. Dichotomous keys and distributional data for Iranian species included in these species groups are provided. Chrysis schwarzi Linsenmaier, 1968 is raised to species rank. The number of Iranian Chrysis species and subspecies is raised to 122.www.zoobank.org/urn:lsid:zoobank.org:pub:F419F860-3B90-4679-9A19-2CF5C255AE6B     

Systematics of Crepidostomum species from the Russian Far East and northern Japan,with description of a new species and validation of the genus Stephanophiala

Current article touched upon the issue of the complicated taxonomic status of some species from the genus Crepidostomum collected from the freshwater fish in the rivers of Primorsky region, Sakhalin, and Hokkaido Islands. Primary morphological analyses showed affiliation of the worms to the species C. farionis (Müller, 1784) Lühe, 1909; C. metoecus Braun, 1900b; C. chaenogobii Yamaguti and Matsumura, 1942; C. nemachilus Krotov, 1959. We described the new species Crepidostomum achmerovi sp. nov. that is a sibling species of C. nemachilus. Molecular-genetic investigation have shown that C. nemachilus and C. achmerovi sp. nov. are closely related to C. metoecus in both 28S rDNA and cox1 mtDNA markers. Crepidostomum nemachilus forms a separate branch within the C. metoecus clade on the 28S BI tree with strong statistical support and separate clade in relation to C. metoecus clade on the cox1 BI tree. Values of p-distances between Crepidostomum species were at intergeneric level. Crepidostomum metoecus species complex including five species (C. metoecus, C. nemachilus, C. oschmarini, C. brinkmanni, and C. achmerovi sp. nov.) was reconsidered as independent genus Crepidostomum sensu stricto. Minimum Spanning Network showed that C. nemachilus, C. metoecus and C. achmerovi sp. nov. were separated by large number of mutational events and represent independent phyletic lines. An amended diagnosis is provided for the subfamily Crepidostomatinae, the genera Crepidostomum s. str. and Stephanophiala Nicoll, 1909, along with keys to species of both genera.     

Effects of Soil Characteristics,Allelopathy and Frugivory on Establishment of the Invasive Plant Carpobrotus edulis and a Co-Occuring Native,Malcolmia littorea

Background

The species Carpobrotus edulis, native to South Africa, is one of the major plant invaders of Mediterranean coastal ecosystems around the world. Invasion by C. edulis exerts a great impact on coastal habitats. The low number of native species in invaded communities points to the possible existence of mechanisms suppressing their germination. In this study we assessed whether soil factors, endozoochory, competition and allelopathic effects of the invader affect its own early establishment and that of the native species Malcolmia littorea. We used laboratory solutions representing different chemical composition and moisture of the soil, herbivore feeding assays to simulate seed scarification and rainwater solutions to account for the effect of differently aged C. edulis litter.

Principal Findings

We show that unlike that of the native species, germination and early growth of C. edulis was not constrained by low moisture. The establishment of C. edulis, in terms of germination and early growth, was increased by scarification of seeds following passage through the European rabbit intestines; the rabbits therefore may have potential implications for plant establishment. There was no competition between C. edulis and M. littorea. The litter of the invasive C. edulis, which remains on the soil surface for several years, releases allelopathic substances that suppress the native plant germination process and early root growth.

Conclusions

The invasive species exhibits features that likely make it a better colonizer of sand dunes than the co-occurring native species. Allelopathic effects, ability to establish in drier microsites and efficient scarification by rabbits are among the mechanisms allowing C. edulis to invade. The results help to explain the failure of removal projects that have been carried out in order to restore dunes invaded by C. edulis, and the long-lasting effects of C. edulis litter need to be taken into account in future restoration projects.     

Cross transferability of SSR markers to endangered Cedrela species that grow in Argentinean subtropical forests,as a valuable tool for population genetic studies

Species of Cedrela with a high economic value from Northwest and Northeastern Argentina are severely exploited. This work evaluates whether 51 nuclear SSRs, developed to study phylogenetically close species in the Meliaceae family (Cedrela odorata, Cedrela fissilis, Swietenia humilis and Swietenia macrophylla), can be used to study C. fissilis, Cedrela balansae, Cedrela saltensis and Cedrela angustifolia. A 62.8% of the total of 194 SSRs/species combinations showed a successful, homologous and cross-species amplification. As expected, a great success in SSRs transferability among Cedrela species was observed. Twenty-one screened SSRs showed a successful amplification pattern in all target species and many of them were polymorphic (9, 13, 13 and 7 SSRs for C. fissilis, C. balansae, C. saltensis and C. angustifolia, respectively). The high number of evaluated SSRs from the Cedrela genus and Meliaceae family, allowed us to obtain a suitable set of validated markers that are highly variable and easily scored, and also identify those which were less sturdy. We were able to retain a useful set of markers for three of the target species, but not for C. angustifolia. This could be due to its greater phylogenetic and morphological distances to the other three species. The lack of SSRs developed for our target species, transforms the transferred SSRs reported here in a valuable tool to monitor the genetic consequences of forest overexploitation on Cedrela species.     

Revision of the Chaetocnema picipes species-group (Coleoptera,Chrysomelidae, Galerucinae,Alticini) in China,with descriptions of three new species

The Chinese Chaetocnema picipes species-group is revised. It contains 5 species including 3 new species: C. cheni sp. n., C. constricta sp. n. and C. kingpinensis sp. n. The lectotype of C. fortecostata is designated. A key to all known species of this group from China and the illustrations of habitus and genitalia are provided. A distribution map of species is given.     

Hidden in the mangrove forest: the cryptic intertidal mite Carinozetes mangrovi sp. nov. (Acari,Oribatida, Selenoribatidae)

The small archipelago of Bermuda is a geologically young landmass in the Western Atlantic Ocean and recently turned out to be inhabited by a number of intertidal oribatid mites. One newly described species, Carinozetes bermudensis, showed an unusual vast range of habitats like sandy beaches, rocky substrate and mangroves. In the present study, 13 Bermudian populations of C. bermudensis were analysed to verify species integrity of specimens from different microhabitats. A morphometric analysis of 17 continuous variables as well as a molecular genetic investigation of the mitochondrial cytochrome oxidase subunit I revealed the existence of a new species Carinozetes mangrovi sp. nov., inhabiting exclusively intertidal algae growing on mangrove roots. Although both species are morphologically nearly identical, the configuration of the genus-specific ventral carinae represents a clear diagnostic character. The high genetic divergence of approximately 12 % of the cytochrome oxidase subunit I gene sequence between C. bermudensis and C. mangrovi sp. nov. suggests that these two species diverged before the emergence of the Bermuda islands. Accordingly, both of them are older than the geologically young archipelago of Bermuda.     

Comparative study of the growth of the two co-occurring introduced green algae Caulerpa taxifolia and Caulerpa racemosa along the Tuscan coast (Italy,western Mediterranean)

Caulerpa taxifolia and C. racemosa are tropical green algae now found in the Mediterranean, where the former was accidentally introduced and the latter presumably also introduced; both species have spread rapidly and invaded a variety of habitats. Since 1996, the two algae have co-inhabited a region along the Tuscan coast near Livorno. The present study has been carried out to evaluate the invasive capacity of the two species. After one year, the increase in surface area was 67.5 % for C. taxifolia and 284.8 % for C. racemosa, while the increase in patch number was 11.4 % and 121.4 % respectively. The stolon growth of the two algae followed a similar trend, as is showing the same temporal variations with the maximum growth rate between August and October. At the end of the study period, the increase in stolon length and number was significantly higher in C. racemosa than in C. taxifolia. The results of the present study show a higher invasive potential in C. racemosa than in C. taxifolia, although further studies are necessary to evaluate the competition between the two algae and the effect of their simultaneous presence on the benthic community.