Complete mitochondrial genome of a troglobite millipede Antrokoreana gracilipes (Diplopoda, Juliformia, Julida), and juliformian phylogeny

The complete mitochondrial genome of a troglobite millipede Antrokoreana gracilipes (Verhoeff, 1938) (Dipolopoda, Juliformia, Julida) was sequenced and characterized. The genome (14,747 bp) contains 37 genes (2 ribosomal RNA genes, 22 transfer RNA genes and 13 protein-encoding genes) and two large non-coding regions (225 bp and 31 bp), as previously reported for two diplopods, Narceus annularus (order Spirobolida) and Thyropygus sp. (order Spirostreptida). The A + T content of the genome is 62.1% and four tRNAs (tRNA(Ser(AGN)), tRNA(Cys), tRNA(Ile) and tRNA(Met)) have unusual and unstable secondary structures. Whereas Narceus and Thyropygus have identical gene arrangements, the tRNA(Thr) and tRNA(Trp) of Antrokoreana differ from them in their orientations and/or positions. This suggests that the Spirobolida and Spirostreptida are more closely related to each other than to the Dipolopoda. Three scenarios are proposed to account for the unique gene arrangement of Antrokoreana. The data also imply that the Duplication and Nonrandom Loss (DNL) model is applicable to the order Julida. Bayesian inference (BI) and maximum likelihood (ML) analyses using amino acid sequences deduced from the 12 mitochondrial protein-encoding genes (excluding ATP8) support the view that the three juliformian members are monophyletic (BI 100%; ML 100%), that Thyropygus (Spirostreptida) and Narceus (Spirobolida) are clustered together (BI 100%; ML 83%), and that Antrokoreana (Julida) is a sister of the two. However, due to conflict with previous reports using cladistic approaches based on morphological characteristics, further studies are needed to confirm the close relationship between Spirostreptida and Spirobolida.     

Diversity, endemism and species turnover of millipedes within the south-western Australian global biodiversity hotspot

Aim To examine how current and historical environmental gradients affect patterns of millipede (Diplopoda) endemism and species turnover in a global hotspot of floristic diversity, and to identify regions of high endemism and taxonomic distinctness for conservation management. Location South‐western Australia. Methods Museum database records of millipedes (subclasses Pentazonia and Helminthomorpha), supplemented with extensive fieldwork, were used to map species richness, species turnover (β‐diversity), weighted endemism, average taxonomic distinctness and variation in taxonomic distinctness in half‐degree grid squares (c. 2500 km²). Generalized linear models were used to examine relationships between these parameters with rainfall (present day and historical), topography and human disturbance (clearing for agriculture and urbanization). Results Millipede species richness, particularly within the order Spirostreptida, and millipede endemism were positively associated with large within‐cell differences in elevation (mountainous regions). Large variation in taxonomic distinctness (unevenness in the taxonomic tree) in higher‐rainfall areas was mainly due to speciation within the Spirostreptida genus Atelomastix. Hotspots of millipede endemism and taxonomic distinctness were identified within three categories of importance: primary (Stirling Range East, Cape Le Grand, Cape Arid, Walpole, Porongurups), secondary (Mount Manypeaks, Bremer Bay, Stirling Range West, Duke of Orleans Bay, Ravensthorpe, Albany, Busselton) and tertiary (Nornalup). A species turnover boundary was positively associated with rainfall, broadly located in the transition zone of 300–600 mm year^?1. Main conclusions The current lack of knowledge on the endemism of invertebrates hampers their incorporation into conservation planning. With this knowledge we can identify global biodiversity hotspots and, at a smaller scale, significant conservation areas within a region. Here we have shown that weighted endemism and taxonomic distinctness are useful tools in identifying centres of high endemism and speciation for millipedes within the south‐west Australian hotspot. Moreover, it is unlikely that either vertebrates or vascular plants will be useful surrogates for identifying significant areas for invertebrate conservation. While other workers have shown that vascular plants, mammals and frogs have different centres of endemism within south‐west Australia, our results show that centres of endemism for millipedes encompass all of these plus other areas.     

Comparative Anatomy of the Secondary Phloem of the Stem in Cephalotaxus

The family Cephalotaxaceae contains only one genus, Cephalotaxus, with 9 species and some varieties, mostly endemic to China. The present paper deals with the comparative anatomy of secondary phloem of stems in 4 species and I cultivar, of this genus under light microscope and scanning electron microscope. The main results are as follows: (1) The structure of secondary phloem is rather uniform in the various species of this genus. In cross section, sieve cells, phloem parenchyma cells form continuous tangential rows of one cell in width respectively, which occur alternately. Sclerenchyma cells also form continuous tangential rows, each with a radial width of 1-4 cells. The interval between the rows is rather wide. (2) The type of phloem fiber and the quantity of sclereids can be served as the characters for identification of species and the evidence for the separation of two sections of Cephalotaxus, namely: Cephalotaxus and Pectinatae. (3) The secondary phloem of this genus contains more or less crystalliferous parenchyma cells, in the inner tangential walls of which calcium oxalate crystals are embedded. So far this character has not been reported in the other families and the genera of conifers. Our conclusion, therefore, agrees with the opinion that Cephalotaxaceae is a natural taxon and includes only one genus, Cephalotaxus.     

Biodiversity under rocks: the role of microhabitats in structuring invertebrate communities in Brazilian outcrops

There is little knowledge on the factors that can structure communities of tropical arthropods that live under rocks (lapidicolous communities). Using 28 rock shelters in a small granitic outcrop, we examined the relations among area, inclination, organic matter content, substrate moisture and distance from the border of the outcrop and richness and diversity of the communities. In total, we collected 1216 individuals from 106 morphospecies of Araneida, Acarina, Polyxenida, Spirostreptida, Dermaptera, Neuroptera, Orthoptera, Dictyoptera, Psocoptera, Coleoptera, Hymenoptera, Diptera, Embioptera, Homoptera, Isoptera, Heteroptera, Lepidoptera, Collembola, Nematoda and Oligochaeta. The richness and diversity of the lapidicolous communities were significantly correlated with area, inclination and distance from the edge of the outcrop in the dry season. The richness and diversity of lapidicolous communities were significantly correlated with organic matter, substrate moisture and area in the rainy season. Space availability seemed to be an important structuring factor for lapidicolous communities in the present study, the most significant variables (substrate moisture and organic matter) were related to shelter area.     

Assessment of rampant genitalic variation in the spider genus Homalonychus (Araneae, Homalonychidae)

Abstract. Animal genitalia are often complex and thought to vary little within species but differ between closely related species making them useful as primary characters in species diagnosis. Spiders are no exception, with nearly all of the 40,462 (at the time of this writing) described species differentiated by genitalic characteristics. However, in some cases, the genitalia of putative species are not uniform, but rather vary within species. When intraspecific variation overlaps interspecific variation, it can be difficult (if not impossible) to place a name on a specimen. The quantification of shape variation in genitalia has not often been attempted, probably because until recently it was not a methodologically and computationally simple process. In the two currently recognized species of the spider genus Homalonychus , genitalic variation is rampant in both male and female structures, with some parts of the genitalia (e.g., the retrolateral tibial apophysis) differing in each specimen examined. In this study, geometric morphometric analysis employing landmark data is used to quantify both intra- and interspecific variation in this genus. The large amount of variation is condensed into two or three groups depending on the structures examined, and these groups correspond to either the two species or to previously established mitochondrial DNA clades within one of the species. The results also show that analyses of female structures do not separate the groups as readily as the analyses of the male structures. The large amount of variation present in some structures is not correlated with geography or population genetic structure.     

Methane Production and Methanogenic Archaea in the Digestive Tracts of Millipedes (Diplopoda)

Methane production by intestinal methanogenic Archaea and their community structure were compared among phylogenetic lineages of millipedes. Tropical and temperate millipedes of 35 species and 17 families were investigated. Species that emitted methane were mostly in the juliform orders Julida, Spirobolida, and Spirostreptida. The irregular phylogenetic distribution of methane production correlated with the presence of the methanogen-specific mcrA gene. The study brings the first detailed survey of methanogens’ diversity in the digestive tract of millipedes. Sequences related to Methanosarcinales, Methanobacteriales, Methanomicrobiales and some unclassified Archaea were detected using molecular profiling (DGGE). The differences in substrate preferences of the main lineages of methanogenic Archaea found in different millipede orders indicate that the composition of methanogen communities may reflect the differences in available substrates for methanogenesis or the presence of symbiotic protozoa in the digestive tract. We conclude that differences in methane production in the millipede gut reflect differences in the activity and proliferation of intestinal methanogens rather than an absolute inability of some millipede taxa to host methanogens. This inference was supported by the general presence of methanogenic activity in millipede faecal pellets and the presence of the 16S rRNA gene of methanogens in all tested taxa in the two main groups of millipedes, the Helminthophora and the Pentazonia.     

Biological and stratigraphical significance of the Silurian nautiloid Aptychopsis

Turek, Vojtach 1978 04 15: Biological and stratigraphical significance of the Silurian nautiloid
Circular or elliptical structures described as the genus Aptychopsis Barrande 1872 (and mostly referred to the Crustacea) represent the opercula of a specialized group of orthoceratids. Their morphology bears a considerable resemblance to the structure of the lower jaws (aptychi) of some Mesozoic ammonoids, particularly of the genus Physodoceras . Because of its size and structure, however, Aptychopsis cannot have functioned as a jaw apparatus. Observation of an operculumin siru supports this assumption as regards its functional and systematic position. The classification of the genus Aptychopsis as given by Jones and Woodward (1872–1893) is purely typological and hardly applicable in palaeobiology. Continuous gradations exist between the various morphological types. The lack of systematically distinctive features explains the unsuitability of Aptychopsis for biostratigraphical use. Aptychopsids occur in the Silurian of Central Bohemia between the Spirograprus turriculatus Zone and the Neodiversograptus nilssoni Zone, inclusive, with maximum frequency in the uppermost Wenlockian.     

First record of Eretmophyllum (Ginkgoales) with well-preserved cuticle from the Middle Jurassic of the Ordos Basin,Inner Mongolia,China

The genus Eretmophyllum, a characteristic and widespread taxon of the order Ginkgoales, is restricted in the Mesozoic floras of Eurasia. In China, although some specimens were assigned to Eretmophyllum based on gross leaf morphology, none have epidermal structure, which is essential for species delimitation within this genus. In this paper, we describe a new species, Eretmophyllum neimengguensis n. sp., from the Middle Jurassic Yan’an Formation of the Ordos Basin, China. This is the first record of the genus Eretmophyllum (Ginkgoales) from the Ordos Basin as well as from China based upon the gross leaf morphology and the epidermal structure. The new record significantly extends the stratigraphic and geographic distribution of Eretmophyllum in China and Eurasia. It also improves our understanding of its leaf morphology, epidermal structure, and past diversity. The taxonomic position and the stratigraphic and geographical range of the genus Eretmophyllum are discussed. Briefly, leaf morphological and epidermal characters of the new species, associated plant assemblages, and sedimentology indicate that the regional climate of the Ordos Basin was warm and humid with seasonal temperature and precipitation fluctuations in warm-temperate zone during the Middle Jurassic. Furthermore, given the relationship between the distribution/diversity of the genus and the climate, the genus Eretmophyllum may be confined to the warm-temperature climate, is intolerant of heat and frost, and can be considered as an indicator of humid and warm climatic conditions.     

Olifantiella mascarenica gen. & sp. nov., a new genus of pennate diatom from Réunion Island, exhibiting a remarkable internal process

A new diatom genus, Olifantiella gen. nov., has been discovered from the coral reefs of Réunion Island (Western Indian Ocean). This monospecific genus belonging to the Biraphidineae, contains a small, marine taxon, Olifantiella mascarenica sp. nov., which shows close structural similarity with the recently described genus Labellicula Van de Vijver & Lange-Bertalot, but with significant differences: (i) the presence of a remarkable internal tubular process – the buciniportula; (ii) the easily identifiable external funnel-shaped opening of this process; (iii) the design of the external raphe endings; (iv) the general shape of the frustules; and (v) a lateral void and elevated crest. The buciniportula, associated with the other characters, is apparently new, and allows the establishment of a new genus. The morphology of this genus is compared with that of related genera, such as Luticola , Diadesmis , Labellicula, Brachysira , Neidium and Nupela , with some comments on the contribution of scanning electron microscopy towards distinguishing new genera, and the possible superabundance of these new entities, particularly of small diatoms.     

Detailed characterization of the lipid A fraction from the nonpathogen Acinetobacter radioresistens strain S13

The genus Acinetobacter is composed of ubiquitous, generally nonpathogen environmental bacteria. Interest concerning these microorganisms has increased during the last 30 years, because some strains, belonging to the so-called A. baumannii-A. calcoaceticus complex, have been implicated in some severe pathological states in debilitated and hospitalized patients. The involvement of lipopolysaccharides (LPSs) as virulence factors in infections by Acinetobacter has been proven, and ongoing studies are aimed toward the complete serological characterization of the O-polysaccharides from LPSs isolated in clinical samples. Conversely, no characterization of the lipid A fraction from Acinetobacter strains has been performed. Here, the detailed structure of the lipid A fraction from A. radioresistens S13 is reported for the first time. A. radioresistens strains have never been isolated in cases of infectious disease. Nevertheless, it is known that the lipid A structure, with minor variations, is highly conserved across the genus; thus, structural details acquired from studies of this nonpathogen strain represent a useful basis for further studies of pathogen species.     

Phylogeny of the Pluteaceae (Agaricales, Basidiomycota): taxonomy and character evolution

The phylogeny of the genera traditionally classified in the family Pluteaceae (Agaricales, Basidiomycota) was investigated using molecular data from nuclear ribosomal genes (nSSU, ITS, nLSU) and consequences for taxonomy and character evolution were evaluated. The genus Volvariella is polyphyletic, as most of its representatives fall outside the Pluteoid clade and shows affinities to some hygrophoroid genera (Camarophyllus, Cantharocybe). Volvariella gloiocephala and allies are placed in a different clade, which represents the sister group of Pluteus, and a new generic name, Volvopluteus, is proposed to accommodate these taxa. Characters such as basidiospore size and pileipellis structure can be used to separate Pluteus, Volvariella and Volvopluteus. The genus Pluteus is monophyletic and includes species with partial veil traditionally classified in the genus Chamaeota. The evolution of morphological features used in the infrageneric taxonomy of the genus, such as metuloid cystidia and pileipellis structure, was analyzed. Agreement between the molecular phylogeny and morphological subdivision of Pluteus is, generally speaking, good, though some rearrangements are necessary: (i) species with non-metuloid pleurocystidia and pileipellis as a cutis are placed either in sect. Celluloderma, together with the species characterized by a hymenidermal pipeipellis, or in sect. Pluteus, with the metuloid bearing species; (ii) subdivision of sect. Celluloderma according to the presence/absence of cystidioid elements in the pileipellis is not supported by molecular data.     

云南禄丰古猿产地的獾类化石

记述了云南禄丰古猿产地的一些獾类化石,主要据其牙齿和下颌特征订为食肉目、鼬科、獾亚科中一个新的属种——禄丰云南獾(Yunnanotherium lufengense gen.et sp.nov.)。从M1的冠面和牙根的特征看,可把宗冠福1991年提出、1997年所订的Trochotherium yuanmouense 1)的1枚M1(另1枚所谓m2经本文作者鉴定不属于这类动物)以及在元谋雷老发现的1枚M1和1枚m2放入这个属中。另外,产自禄丰古猿产地D剖面6层的1枚单个的m1也可归入这个属中。云南獾与欧洲的Trochotherium在牙齿(主要是M1)方面有某种程度的相像(如冠面较平坦、齿尖较低、齿根多),都是一类主要以软体动物为生的食肉动物,但二者之间在牙齿(特别是M1)的结构和下颌形态方面仍有明显的区别。这可能与二者所生长的时代以及生态环境不同有关。     

Contributions on cardiac physiology in Diplopoda (Myriapoda)

Investigations into cardiac physiology in Myriapoda are rare, but heart beat generation is not considered to be uniform throughout this taxon. Although cardiac automatism in Chilopoda is neurogenic, superimposed onto a myogenic automatism, the present study reveals, on the basis of electrophysiological experiments including electrocardiograms and the first intracellular recordings from dorsal vessel muscle cells of Archispirostreptus gigas Peters, 1855 (Diplopoda: Spirostreptida, Spirostreptidae), that heartbeat generation in Diplopoda is clearly myogenic. Experiments with tetrodotoxin confirm this result, and also show that proctolin, acetylcholine and octopamine have no effect. The results are discussed from the perspective of comparative cardiac physiology in arthropods.     

Chelodesmid studies. XIII. A synopsis of the Brasilian tribe Strongylomorphini

The new diplopod tribe Strongylomorphini (fam. Chelodesmidae) is proposed for the two Brasilian genera Strongylomorpha and Brasilodesmus, characterized by the distal torsion of the solenomerite and form of the apical end of the prefemoral process, of the male gonopod. Strongylomorpha has been of uncertain status since 1897, but study of its type species shows the name to be a senior synonym of Erythrodesmus Silvestri, 1902, Neocamptomorpha Schubart, 1954, and Camptomorphoides Schubart 1962. Drawings of the gonopods are given for several old species, made from Iectotype specimens, and a list of the names considered referable to Strongylomorpha. The new species Brasilodesmus austrocrucis is described from Santa Catarina, Brasil.     

Muscular anatomy of the millipede Phyllogonostreptus nigrolabiatus (Diplopoda: Spirostreptida) and its bearing on the millipede "thorax"

The muscular anatomy of the millipede Phyllogonostreptus nigrolabiatus (Newport, 1844) (Diplopoda; Spirostreptida; Harpagophoridae) is comprehensively surveyed. The musculature of the first three postcollum pleurotergites, the "thorax," and their associated appendages was found to be more complex than that of the postthoracic rings. It is hypothesized that the musculature of the postthoracic segments is derived relative to that of the thoracic segments, which retain primitively free sternites and are not diplosegments. This hypothesis is discussed relative to previous hypotheses positing that the anteriormost three leg-bearing rings in millipedes are diplosegments. The musculature of spirostreptid gonopods is described in detail for the first time. Comparison of the cephalic musculature is made with previously described musculature in Julida showing that, while many aspects of the musculature are conserved, there exist interordinal differences, documenting the potential utility of comparative anatomical studies for resolving millipede phylogeny.     

Fine structure of the midgut epithelium in the millipede <Emphasis Type="Italic">Telodeinopus aoutii</Emphasis> (Myriapoda,Diplopoda) with special emphasis on epithelial regeneration

The midgut of millipedes is composed of a simple epithelium that rests on a basal lamina, which is surrounded by visceral muscles and hepatic cells. As the material for our studies, we chose Telodeinopus aoutii (Demange, 1971) (Kenyan millipede) (Diplopoda, Spirostreptida), which lives in the rain forests of Central Africa. This commonly reared species is easy to obtain from local breeders and easy to culture in the laboratory. During our studies, we used transmission and scanning electron microscopes and light and fluorescent microscopes. The midgut epithelium of the species examined here shares similarities to the structure of the millipedes analyzed to date. The midgut epithelium is composed of three types of cells—digestive, secretory, and regenerative cells. Evidence of three types of secretion have been observed in the midgut epithelium: merocrine, apocrine, and microapocrine secretion. The regenerative cells of the midgut epithelium in millipedes fulfill the role of midgut stem cells because of their main functions: self-renewal (the ability to divide mitotically and to maintain in an undifferentiated state) and potency (ability to differentiate into digestive cells). We also confirmed that spot desmosomes are common intercellular junctions between the regenerative and digestive cells in millipedes.     

Genetic diversity, structure, and patterns of differentiation in the genus Vitis

Vitis (Vitaceae) is a taxonomically complicated genus with ca. 60 taxa divided into two subgenera, Vitis and Muscadinia. We used population genetic approaches to gain insights into the genetic diversity, patterns of evolutionary differentiation and to decipher the taxonomic status of some of the controversial taxa within the genus Vitis. The distance- and model-based analyses were used to examine the phylogenetic structure within the genus Vitis using simple sequence repeat (SSR) and amplified fragment length polymorphism (AFLP) markers. The results closely matched the current classification, but some discrepancies in the identity of taxa at the specific and subspecific levels were still evident. The East Asia and the North American Vitis exhibited strong divergence and each group showed further differentiation into several subgroups with North American subgroups roughly matching the described series. The model based cluster analysis indicated 14 clusters as optimum to explain the genetic structure within the genus Vitis with most clusters containing a moderate frequency of admixed genotypes suggesting interspecific gene flow within the subgenus Vitis. Hierarchical partitioning of molecular variation indicated that a significant amount of the total variation (~74 % and ~69 % for SSRs and AFLPs, respectively) is accounted for by intraspecific variation as compared to the levels due to genetic differentiation among species within series (~17 % and ~20 % for SSRs and AFLPs, respectively) and among series within the genus Vitis (~9 % and ~10 % for SSRs and AFLPs, respectively). Overall, Vitis possesses mild genetic structure characterized by reticulation and incomplete lineage sorting of ancestral polymorphisms.     

A study of the scutellum in eight Chagas disease vector species from genus Triatoma (Hemiptera, Reduviidae) using optical and scanning electron microscopy

The aim of this study was to analyze the external morphology of the scutellum through optical microscopy and scanning electron microscopy (SEM) in male specimens of Triatoma costalimai, T. delpontei, T. eratyrusiformis, T. matogrossensis, T. infestans melanosoma, T. sherlocki, T. tibiamaculata, and T. vandae. A total of 30 photographs of the scutellum were made. Magnification varied from 50X to 750X. Regarding depth and forms of the central depression, the heart-shaped form was predominant, with some exceptions, so that this shape appears to be a common characteristic for species of genus Triatoma Laporte, 1832. In T. eratyrusiformis, a kind of sensillum with important taxonomic value was observed. The different sizes and shapes of the designs found on the posterior process of the scutellum were also of important taxonomic interest. The study of the scutellum based on SEM showed valuable characteristics, allowing the use of this structure to aid the diagnosis of triatomine species. Thus, more specimens in subsequent studies and analyses of morphometric parameters should contribute to agreement on phylogenetic aspects in this genus. A Key to eight species of Triatoma based on male scutellar morphology is presented.