Genome reduction in novel, obligately methyl-reducing Methanosarcinales isolated from arthropod guts (Methanolapillus gen. nov. and Methanimicrococcus).

Recent metagenomic studies have identified numerous lineages of hydrogen-dependent, obligately methyl-reducing methanogens. Yet, only a few representatives have been isolated in pure culture. Here, we describe six new species with this capability in the family Methanosarcinaceae (order Methanosarcinales), which makes up a substantial fraction of the methanogenic community in arthropod guts. Phylogenomic analysis placed the isolates from cockroach hindguts into the genus Methanimicrococcus (M. hacksteinii, M. hongohii, and M. stummii) and the isolates from millipede hindguts into a new genus, Methanolapillus (M. africanus, M. millepedarum, and M. ohkumae). Members of this intestinal clade, which includes also uncultured representatives from termites and vertebrates, have substantially smaller genomes (1.6-2.2 Mbp) than other Methanosarcinales. Genome reduction was accompanied by the loss of the upper part of the Wood-Ljungdahl pathway, several energy-converting membrane complexes (Fpo, Ech, and Rnf), and various biosynthetic pathways. However, genes involved in the protection against reactive oxygen species (catalase and superoxide reductase) were conserved in all genomes, including cytochrome bd (CydAB), a high-affinity terminal oxidase that may confer the capacity for microaerobic respiration. Since host-associated Methanosarcinales are nested within omnivorous lineages, we conclude that the specialization on methyl groups is an adaptation to the intestinal environment.

The Chemistry of the Defensive Secretions of Three Species of Millipedes in the Genus Brachycybe.

Millipedes have long been known to produce a diverse array of chemical defense agents that deter predation. These compounds, or their precursors, are stored in high concentration within glands (ozadenes) and are released upon disturbance. The subterclass Colobognatha contains four orders of millipedes, all of which are known to produce terpenoid alkaloids-spare the Siphonophorida that produce terpenes. Although these compounds represent some of the most structurally-intriguing millipede-derived natural products, they are the least studied class of millipede defensive secretions. Here, we describe the chemistry of millipede defensive secretions from three species of Brachycybe: Brachycybe producta, Brachycybe petasata, and Brachycybe rosea. Chemical investigations using mass spectrometry-based metabolomics, chemical synthesis, and 2D NMR led to the identification of five alkaloids, three of which are new to the literature. All identified compounds are monoterpene alkaloids with the new compounds representing indolizidine (i.e. hydrogosodesmine) and quinolizidine alkaloids (i.e. homogosodesmine and homo-hydrogosodesmine). The chemical diversity of these compounds tracks the known species phylogeny of this genus, rather than the geographical proximity of the species. The indolizidines and quinolizidines are produced by non-sympatric sister species, B. producta and B. petasata, while deoxybuzonamine is produced by another set of non-sympatric sister species, B. rosea and Brachycybe lecontii. The fidelity between the chemical diversity and phylogeny strongly suggests that millipedes generate these complex defensive agents de novo and begins to provide insights into the evolution of their biochemical pathways.

Evaluation of the consumption of agricultural and urban waste by the diplopod Trigoniulus corallinus as a strategy for formulating new combinations for the millicomposting process.

This study aimed to measure the consumption of different types of plant waste by the diplopod species Trigoniulus corallinus, in order to determine which would be the most suitable for the millicomposting process. To this end, a waste consumption experiment was carried out in the laboratory, using a completely randomized experimental design with 15 replicates and 13 organic residues from different sources. After 10 days, the following parameters were evaluated: dry mass of the waste used to feed the diplopods, dry mass of the fecal pellets, and diplopod mortality. Significant differences were observed in the consumption rates of the diplopods in the different treatments, with the highest rates being observed for Mimosa caesalpiniifolia, with 44.49%, followed by Gliricidia sepium chips, with 38.24%. The highest values for pellet mass were obtained from the decomposition of Mimosa caesalpiniifolia litter (0.891 g). The treatment with Syngonium auritum shavings showed 93% mortality after consumption, followed by the treatment with Heliconia psittacorum shavings, which showed 53%. Both species are ornamental and widely found in gardens and backyards. The diplopods have a preference for Mimosa caesalpiniifolia litter and Gliricidia sepium shavings. There is limited consumption of ornamental plant waste, with reports of toxicity to other organisms. Based on these results, a mixture of waste will be tested for millicomposting in urban farming areas that excludes toxic plants.

Rapid divergent evolution of internal female genitalia and the coevolution of male genital morphology revealed by micro-computed tomography.

Animal genitalia are thought to evolve rapidly and divergently in response to sexual selection. Studies of genital evolution have focused largely on male genitalia. The paucity of work on female genital morphology is probably due to problems faced in quantifying shape variation, due to their composition and accessibility. Here we use a combination of micro-computed tomography, landmark free shape quantification and phylogenetic analysis to quantify the rate of female genital shape evolution among 29 species of Antichiropus millipedes, and their coevolution with male genitalia. We found significant variation in female and male genital shape among species. Male genital shape showed a stronger phylogenetic signal than female genital shape, although the phylogenetic signal effect sizes did not differ significantly. Male genital shape was found to be evolving 1.2 times faster than female genital shape. Female and male genital shape exhibited strong correlated evolution, indicating that genital shape changes in one sex are associated with corresponding changes in the genital shape of the other sex. This study adds novel insight into our growing understanding of how female genitalia can evolve rapidly and divergently, and highlights the advantages of three-dimensional techniques and multivariate analyses in studies of female genital evolution.

A new species of Lophostreptus Cook, 1895 discovered among syntypes of L.regularis Attems, 1909 (Diplopoda, Spirostreptida, Spirostreptidae).

A new species of the genus Lophostreptus Cook, 1895 is described, based on specimens hidden for over a century among the syntypes of its congener Lophostreptusregularis Attems, 1909 housed in the Naturhistoriska Riksmuseet Stockholm (NRMS) and the Naturhistorisches Museum Wien (NHMW). A lectotype is designated for Lophostreptusregularis Attems, 1909 in order to stabilize its taxonomy. Updates to the millipede fauna of Mt. Kilimanjaro, Tanzania are provided.

Cayenniola albaserrata n. sp., a geographical relict from a Brazilian hotspot of subterranean biodiversity and the first troglobitic Priodesmini (Polydesmida: Chelodesmidae: Chelodesminae)

A new troglobitic species of Chelodesmidae, Cayenniola albaserratan. sp., from the Água Clara cave system, Caatinga Domain, Bahia, Brazil is described. The new species is only the sixth known troglobitic chelodesmid, the first troglobitic species in the Priodesmini, and the first member of the tribe recorded from the state of Bahia. Unique among the Priodesmini, male C. albaserratan. sp. possess greatly elongated pre-gonopodal tarsal claws and differ from the only congener, Cayenniola styliger (Jeekel, 1963),by a combination of gonopodal and somatic characters including classical troglomorphic traits such as a nearly unpigmented body and remarkably long antennae, legs, and tarsal claws. Cayenniola styliger is only known from the type locality in the Amazon rainforest of coastal French Guiana, suggesting that C. albaserratan. sp. may represent a relictual species from the Caatinga Domain of Brazil. We provide ecological notes and evaluate the potential threats to the habitat of C. albaserratan. sp., considering both the subterranean environment and the surrounding areas.

Diversity and taxonomic revision of methanogens and other archaea in the intestinal tract of terrestrial arthropods.

Methane emission by terrestrial invertebrates is restricted to millipedes, termites, cockroaches, and scarab beetles. The arthropod-associated archaea known to date belong to the orders Methanobacteriales, Methanomassiliicoccales, Methanomicrobiales, and Methanosarcinales, and in a few cases also to non-methanogenic Nitrososphaerales and Bathyarchaeales. However, all major host groups are severely undersampled, and the taxonomy of existing lineages is not well developed. Full-length 16S rRNA gene sequences and genomes of arthropod-associated archaea are scarce, reference databases lack resolution, and the names of many taxa are either not validly published or under-classified and require revision. Here, we investigated the diversity of archaea in a wide range of methane-emitting arthropods, combining phylogenomic analysis of isolates and metagenome-assembled genomes (MAGs) with amplicon sequencing of full-length 16S rRNA genes. Our results allowed us to describe numerous new species in hitherto undescribed taxa among the orders Methanobacteriales (Methanacia, Methanarmilla, Methanobaculum, Methanobinarius, Methanocatella, Methanoflexus, Methanorudis, and Methanovirga, all gen. nova), Methanomicrobiales (Methanofilum and Methanorbis, both gen. nova), Methanosarcinales (Methanofrustulum and Methanolapillus, both gen. nova), Methanomassiliicoccales (Methanomethylophilaceae fam. nov., Methanarcanum, Methanogranum, Methanomethylophilus, Methanomicula, Methanoplasma, Methanoprimaticola, all gen. nova), and the new family Bathycorpusculaceae (Bathycorpusculum gen. nov.). Reclassification of amplicon libraries from this and previous studies using this new taxonomic framework revealed that arthropods harbor only CO2 and methyl-reducing hydrogenotrophic methanogens. Numerous genus-level lineages appear to be present exclusively in arthropods, suggesting long evolutionary trajectories with their termite, cockroach, and millipede hosts, and a radiation into various microhabitats and ecological niches provided by their digestive tracts (e.g., hindgut compartments, gut wall, or anaerobic protists). The distribution patterns among the different host groups are often complex, indicating a mixed mode of transmission and a parallel evolution of invertebrate and vertebrate-associated lineages.

Factors affecting the biodiversity of historical landscape elements: detailed analyses from three case studies in Slovakia.

A direct, positive correlation between biodiversity and the traditional agricultural landscape is evident on the national or regional scale. It is mostly conditioned by higher landscape diversity and less intensive farming. We have carried out research on a detailed scale at plot level (productive plots of arable lands, grasslands, vineyards, orchards, and unproductive agrarian landforms (mostly field margins) such as terraced slopes, terraced steps, heaps, mounds, and unconsolidated walls) in three traditional agricultural landscapes: the mountain village Liptovská Teplicka, the vineyard landscape in Svätý Jur, and dispersed settlements in a submontane area in Hrinová. We determined the statistical significance of the impact of the selected landscape ecological factors (a set of factors concerning land use and management, agrarian landforms and relief properties) on the distribution of vegetation and selected invertebrate groups (spiders, millipedes, grasshoppers, and crickets). We also explored whether maintaining traditional land use and traditional management helped to enhance the biodiversity. We found that the management regime is the most important factor determining the species composition of vascular plants and all studied animal groups. Also, present land use and agrarian landforms character (type, skeleton content, continuity) are significant factors. Our expectation of a positive relationship between biodiversity and the maintaining traditional land use and traditional management was, in general, not confirmed: such a relation was only found in Svätý Jur for biodiversity of spiders.

Some Aspects of the Physiology of the Nyctotherus velox, a Commensal Ciliated Protozoon Taken from the Hindgut of the Tropical Millipede Archispirostreptus gigas.

In this paper, the growth requirements, fermentation pattern, and hydrolytic enzymatic activities of anaerobic ciliates collected from the hindgut of the African tropical millipede Archispirostreptus gigas are described. Single-cell molecular analysis showed that ciliates from the millipede hindgut could be assigned to the Nyctotherus velox and a new species named N. archispirostreptae n. sp. The ciliate N. velox can grow in vitro with unspecified prokaryotic populations and various plant polysaccharides (rice starch-RS, xylan, crystalline cellulose20-CC, carboxymethylcellulose-CMC, and inulin) or without polysaccharides (NoPOS) in complex reduced medium with soluble supplements (peptone, glucose, and vitamins). Specific catalytic activity (nkat/g of protein) of α amylase of 300, xylanase of 290, carboxymethylcellulase of 190, and inulinase of 170 was present in the crude protein extract of N. velox. The highest in vitro dry matter digestibility was observed in RS and inulin after 96 h of fermentation. The highest methane concentration was observed in xylan and inulin substrates. The highest short-chain fatty acid concentration was observed in RS, inulin, and xylan. In contrast, the highest ammonia concentration was observed in NoPOS, CMC, and CC. The results indicate that starch is the preferred substrate of the N. velox. Hydrolytic enzyme activities of N. velox showed that the ciliates contribute to the fermentation of plant polysaccharides in the gut of millipedes.