Anamorphosis in millipedes (Diplopoda)—the present state of knowledge with some developmental and phylogenetic considerations

A review of the postembryonic development of millipedes (Diplopoda) is given, based mainly on published information. Original observations are, however, also included. Millipedes hatching from the pupoid usually have three pairs of legs; during their postembryonic growth they acquire more segments and more legs. This process is known as anamorphosis. Three types of anamorphosis are recognized. In euanamorphosis, every moult is accompanied by addition of new segments, even after the attainment of sexual maturity. In hemianamorphosis, the addition of new segments goes on until a certain stadium, and further moults take place without addition of segments. In teloanamorphosis, the addition of segments stops at a certain stadium (the adult, and ultimate, stadium) after which no further moults occur. Available information on anamorphosis in each of the millipede orders is reviewed. General patterns are emphasized, but variations are also considered in detail. It is shown that the so-called ‘law of anamorphosis’ is valid only for the ‘ring-forming’ millipedes (Merocheta and Juliformia) in which tergites, pleurites, and sternites of each diplosegment are firmly fused into a complete ‘ring’, and for some other forms (Polyzoniida, Chordeumatida), where there is a constant relationship between rings and legs. The chapter on the order Julida is particularly detailed and includes discussions of patterns in the variation and a section on periodomorphosis. The general chapter on developmental patterns includes inter alia an interpretation of the variations in millipede anamorphosis in terms of the ‘biometabolic modi’ of Remane. The hypothetical ancestral millipede is shown to have developed by hemianamorphosis. Euanamorphosis was acquired by the ancestral species of Helminthomorpha. Within this clade, Chordeumatida and Merocheta have secondarily become teloanamorphic, whereas some Juliformia seem to have returned to hemianamorphosis. The contrasting principles of elongation and contraction, subject of much debate among diplopodologists, are shown both to have played a role in the course of millipede evolution.     

Perspectives from early career researchers on the publication process in ecology – a response to Statzner & Resh (2010)

1. Two senior ecologists summarised their experience of the scientific publication process ( Statzner & Resh, Freshwater Biology, 2010 ; 55 , 2639) to generate discussion, particularly among early career researchers (ECRs). As a group of eight ECRs, we comment on the six trends they described. 2. We generally agree with most of the trends identified by Statzner & Resh (2010) , but also highlight a number of divergent perspectives and provide recommendations for change. Trends of particular concern are the use of inappropriate metrics to evaluate research quality (e.g. impact factor) and the salami slicing of papers to increase paper count. We advocate a transparent and comprehensive system for evaluating the research. 3. We stress the importance of impartiality and independence in the peer review process. We therefore suggest implementation of double‐blind review and quality control measures for reviewers and possibly editors. Besides such structural changes, editors should be confident to overrule biased reviewer recommendations, while reviewers should provide helpful reviews but be explicit if a submission does not meet quality standards. Authors should always conduct a thorough literature search and acknowledge historical scientific ideas and methods. Additionally, authors should report low‐quality copy editing and reviews to the editors. 4. Both early and late career researchers should jointly implement these recommendations to reverse the negative trends identified by Statzner & Resh (2010) . However, more senior scientists will always have to take the lead with respect to structural changes in the publication system given that they occupy the majority of decision‐making positions.     

Pathogenic and Non-pathogenic Entamoeba: Pore Formation and Hemolytic Activity1

Pore-forming activity in planar lipid bilayers and liposomes of extracts from differentially pathogenic Entamoeba and the-capacity of trophozoites and subcellular fractions to lyse human red blood cells (hrbc) were investigated. In all amebas studied, the two activities paralleled each other. They were high in E. histolytica irrespective of the virulence of the particular strain, but low in non-pathogenic E. histolytica-like amebas of human origin as well as in E. invadens, which is pathogenic for reptiles, and in E. moshkovskii isolated from sewage. We conclude that the capacities to insert pores and to lyse are not sufficient for virulence although they may be necessary. The subcellular distribution of the hemolytic activity of E. histolytica and its sensitivity to a variety of inhibitors and activators differ from those of other known amebic cytotoxic activities including pore formation. Therefore, there may be an additional constituent of E. histolytica involved in the cytotoxicity of the parasite.     

Soluble Poison of Pseudokeronopsis rubra Affects Inward Current in Euplotes vannus

ABSTRACT. The marine ciliate Euplotes vannus was used to lest whether keronopsin, the water-soluble component of (he toxic pigment complex from Pseudokeronopsis rubra , narcotizes cells by affecting ion conductance. Keronopsin delays the rate of rise in the regenerative component of action potentials under constant current injection. In depolarizing voltage steps it reduces the rate of rise and the final amplitude of the initial Ca²⁺ inward current. Normal traits are restored after change to keronopsin-free medium. Effects on locomotory behavior, spontaneous membrane depolarization, action potential, and inward current, all provide evidence that keronopsin acts on cells by obstructing Ca²+ influx.     

Historical divergence vs. contemporary gene flow: evolutionary history of the calcicole Ranunculus alpestris group (Ranunculaceae) in the European Alps and the Carpathians

Although many species have similar total distributional ranges, they might be restricted to very different habitats and might have different phylogeographical histories. In the European Alps, our excellent knowledge of the evolutionary history of silicate‐dwelling (silicicole) plants is contrasted by a virtual lack of data from limestone‐dwelling (calcicole) plants. These two categories exhibit fundamentally different distribution patterns within the Alps and are expected to differ strongly with respect to their glacial history. The calcicole Ranunculus alpestris group comprises three diploid species of alpine habitats. Ranunculus alpestris s. str. is distributed over the southern European mountain system, while R. bilobus and R. traunfellneri are southern Alpine narrow endemics. To explore their phylogenetic relationships and phylogeographical history, we investigated the correlation between information given by nuclear and chloroplast DNA data. Analyses of amplified fragment length polymorphism fingerprints and matK sequences gave incongruent results, indicative for reticulate evolution. Our data highlight historical episodes of range fragmentation and expansion, occasional long‐distance dispersal and on‐going gene flow as important processes shaping the genetic structure of the group. Genetic divergence, expressed as a rarity index (‘frequency‐down‐weighted marker values’) seems a better indicator of historical processes than patterns of genetic diversity, which rather mirror contemporary processes as connectivity of populations and population sizes. Three phylogeographical subgroups have been found within the R. alpestris group, neither following taxonomy nor geography. Genetic heterogeneity in the Southern Alps contrasts with Northern Alpine uniformity. The Carpathians have been stepwise‐colonised from the Eastern Alpine lineage, resulting in a marked diversity loss in the Southern Carpathians. The main divergence within the group, separating the ancestor of the two endemic species from R. alpestris s. str., predates the Quaternary. Therefore, range shifts produced by palaeoclimatic oscillations seem to have acted on the genetic structure of R. alpestris group on a more regional level, e.g. triggering an allopatric separation of R. traunfellneri from R. bilobus.