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.     

The anal glands of Rhapidostreptus virgator (Diplopoda: Spirostreptidae)

Summary In Rhapidostreptus virgator exocrine gland complexes are found in the anal valves of both sexes. Every gland complex consists of about 200 secretory units, each of which is comprised of four cells: two secretory cells, an intermediary cell, and a canal cell. The amount of secretion produced by these glands varies during the intermoult cycle: it is very small in freshly moulted individuals (postmoult phase), at a medial level during the following intermoult phase, and very large in the premoult phase. The secretion may be used to form the excrement clumps and above all to build the moulting chamber.     

Aggregation in the tropical millipede Alloporus uncinatus (Diplopoda: Spirostreptidae)

Millipedes tend to have a near random dispersion pattern when surface active. Only in a few species do juvenile stadia form dense swarms. This study describes the occurrence and composition of aggregations in an adult population of the tropical spirostreptid millipede Alloporus uncinatus (Attems) inhabiting riparian forest in Zimbabwe. Also presented are the results of a field experiment designed to induce aggregation behaviour in a separate population with the addition of high quality food to the habitat.
Our initial hypothesis that the natural aggregations of between six and 42 individuals observed during the period of surface activity were part of the mating system in this species was refuted. Few mature males were present in aggregates and less than 1%, of copula pairs sampled were taken from aggregates. The composition of aggregates and the results of the experiment suggest that aggregations are associated with the feeding activities of immature individuals and are not related to reproductive activity. We suggest that the aggregations observed in A. uncinatus , although related, may perform different functions to the swarming behaviours observed in other millipede species.     

Thermal Limits in Relation to Acclimation in the Neotropical Millipede Gymnostreptus olivaceus (Diplopoda,Spirostreptidae)

The neotropical millipede, Gymnostreptus olivaceus, lives at ambient temperatures of about 20ºC. Its thermal tolerance was tested after acclimation to lower and higher temperatures as occurs under winter and summer conditions in the south and southeast regions of Brazil. An increase in tolerance to low temperatures was found in adapted specimens. The ecological aspects of this capability are discussed.     

Behavioural thermoregulation of Orthopoms ornatus (Diplopoda: Spirostreptidae) in three desert habitats

Observations on feeding and locomotion of the desert millipede Orthopoms ornatus were made in three separate habitats during the summer feeding season. The habitats were Tornillo Flat in Big Bend National Park, Texas; the Jornada Validation Site of IBP/Desert Biome near Las Cruces, New Mexico; and the base of a volcanic escarpment near Albuquerque, New Mexico.
In each habitat diurnal or diel temperatures were monitored in a typical millipede microsite. Microsites included portions of a Larrea/Opuntia shrub complex (Tornillo Flat), an Ephedra shrub (Jornada Site), and a Salsola shrub (Albuquerque). Adjacent mammal-burrow temperatures were also monitored, as were soil-surface temperatures (two habitats) and air temperatures (one habitat).
Diurnal feeding and locomotion were greatest in early morning and late afternoon; nocturnal activity also occurred. Soil-surface activity generally ceased before surface temperatures reached 35^oC and began again when they cooled to about the same level. In the meantime, movement to burrows, to beneath rocks and vegetation, and to aerial portions of shrubs occurred. Additional behavioural thermoregulation was manifested by horizontal and vertical movements within shrubs, maximum air temperatures encountered being 35.5^oC.
Such behaviour is considered in light of recent studies of water balance and metabolism in this species.     

Genitalia Fitting,Mating Behaviour and Possible Hybridization in Millipedes of the Genus Craspedosoma (Diplopoda,Chordeumatida, Craspedosomatidae)

Abstract The functional anatomy of the extremely complex copulatory organs of the millipede Craspedosoma transsilvanicum Verhoeff, 1897, was investigated by scanning electron microscopy and serial semi-thin sectioning after fixation of the animals by freezing in copula. There is no male organ for sperm transfer which inserts into the receptacula seminis. Sperm secretion is only brushed over the openings of the receptacula by cuticular projections of the anterior gonopods (‘brush’). Other parts of the gonopods (projections of the cheirites, podosternite) bring the brush and the openings of the receptacula in the proper position. Examination of the gonopods from series of Craspedosoma from locations near Vienna showed that there are intermediary specimens between the nominal species C. transsilvanicum and C. alemannicum Verhoeff, 1910. Obviously, a mechanical isolation mechanism, as supposed by Verhoeff, does not exist between these nominal species. At the beginning of a copulation, the male forces the female into the mating position. When touched by males, the females try to evade them by rolling up. The possibilities are discussed that females thereby test the actual fitness of males, and that males use their clasper-like copulatory organs to prevent females from escaping.     

Colonization of Colliery Spoil Heaps by Millipedes (Diplopoda) and Terrestrial Isopods (Oniscidea) in the Sokolov Region, Czech Republic

Successive development of millipede and terrestrial isopod assemblages in colliery spoil heaps in the Sokolov region (northwest Bohemia, Czech Republic) was studied during the years 1993–1998. Younger colliery spoil heaps were characterized by a lower number and low density of millipede species. The millipedes Polydesmus inconstans, Polydesmus testaceus, and Craspedosoma rawlinsii represented the main pioneer species. Alder afforestation proved to be more suitable for the recolonization of millipede populations, especially for the predominant Julus scandinavius. Terrestrial isopods colonized all parts of the heaps, including the youngest open plots. The most frequent isopod, Trachelipus rathkii, is a colonizing species with an apparently high adaptability to different environmental conditions. The isolated character of the extensive heap areas, together with existing extreme soil conditions, resulted in slow recolonization and a successional development of stable populations of these animals. However, the relatively high densities of millipede and isopod assemblages in suitable alder afforestation can represent further potential sources for colonization of other open‐heap areas.     

Anatomy and histology of the alimentary tract of the desert millipede Orthoporus ornatus (Girard) (Diplopoda: Spirostreptidae)

The alimentary tract of the desert millipede Orthoporus ornatus is essentially a straight tube consisting of a histologically distinct foregut, midgut, pylorus, hindgut, and rectum. Common to each region, but often different in regional appearance, are an outer sheath layer, longitudinal and circular muscle layers, a basement membrane, and an inner epithelial layer. Foregut and midgut lumina are lined by a cuticular intima, while a peritrophic membrane occurs in the midgut lumen. Gut structure is considered in the context of the known feeding habits and digestive efficiency of this long-lived, seasonally restricted detritivore.     

Millipedes faced with drought: the life cycle of a Mediterranean population of Ommatoiulus sabulosus (Linnaeus) (Diplopoda,Julida, Julidae)

Growth, development and life-cycle duration of the millipede Ommatoiulussabulosus (f.aimatopodus) were studied in a Mediterranean shrubland of southern France and compared with previous data from northwest Europe. Changes in the proportions of stadia during the course of the year were analysed in several generations. The results show that stadia VII and VIII are consistently reached after the first year of growth, and stadia IX and X after the second year. First reproduction may occur at the age of two years in males reaching maturity at stadium X, but not until the age of three in those reaching maturity at stadia XI and XII. Reproduction cannot occur until at least the age of three in females, which carry mature eggs from stadium XI onwards. In comparison with more northern populations, life-cycle duration is not shorter in the Mediterranean population but there are marked differences in its phenology: the breeding period is in autumn, so that juveniles of stadia II to VI are never faced with the summer drought, and larger individuals are mostly inactive in summer; moreover, all individuals moult once every winter. The results illustrate how julid millipedes of humid temperate regions could respond to higher temperatures and drier summer conditions in the context of climate change.     

Millipedes vs. pathogens: Defensive secretions of some julids (Diplopoda: Julida) as potential antimicrobial agents

In the light of growing interest in discovering new sources of natural antimicrobial agents, we extracted and tested the efficiency of julid defensive secretions in comparison with commercially used antibiotic and antimycotics. This work involved chemical characterization of the defensive secretions of Cylindroiulus boleti (C. L. Koch, 1847), Megaphyllum bosniense (Verhoeff, 1897) and M. unilineatum (C. L. Koch, 1838), as well as in vitro evaluation of their antimicrobial activity against 11 bacteria, one yeast and eight filamentous fungi. Compounds of the analysed defensive secretions included p‐benzoquinones, alkyl esters of fatty acids and ketones. Ketones were recorded for the first time in the order Julida, and they were detected in secretions of both Megaphyllum species. All three analysed defensive secretions showed antibacterial and antifungal potential against all of the tested pathogens. Staphylococcus aureus proved to be the most sensitive bacterial strain to all analysed secretions. Also, defensive secretion of M. unilineatum showed significant antibacterial potential against Bacillus subtilis. The most resistant bacterial strains in this study were Escherichia coli, Erwinia persicina and Pseudomonas syringae pv. tomato. Analysed defensive secretions achieved the strongest antifungal activity against Aspergillus parasiticus (secretions of all three millipede species), Penicillium griseofulvum (secretions of C. boleti and M. bosniense) and Cladosporium oxysporum (secretion of M. unilineatum). The most resistant mycromycetes were A. niger (to all tested defensive secretions), A. flavus (to secretion of M. unilineatum) and P. lanosum (to secretions of C. boleti and M. bosniense). Our results showed a generally lower level of activity compared to antibiotic and a significantly higher level compared to antimycotics. The results of this study elucidate and open opportunities for further research in the field of millipede chemical ecology.     

Recovery of Soybean Cyst Nematodes (Heterodera glycines) from the Digestive Tracts of Blackbirds

Digestive tract contents and feces of blackbirds were examined for cysts of Heterodera glycines, the soybean cyst nematode. Birds fed under laboratory conditions and trapped in naturally-infested fields were checked. Infective larvae were recovered from cysts in the excrement of birds 24 and 48 hr after they were fed cysts. Birds that were force-fed eggs and larvae discharged infective larvae in the excrement. Birds which consumed cysts mixed with feed and cysts in feed mixed with soil discharged numerous cysts containing infective larvae. Seven of 54 starlings, trapped and killed in an infested field, contained cysts in their digestive tracts.     

A revision of the Siphonocryptidae (Diplopoda, Polyzoniida)

Siphonocryptus compactus Pocock, 1894 (Sumatra), is redescribed from type and fresh material. Siphonocryptus latior sp. n. (Malaya) is described. Hirudicryptus gen. n. (monotypic) is erected, type-species Siphonocryptus canariensis Loksa, 1967 (Canary Islands, Madeira). Arguments for monophyly of Siphonocryptidae (= Siphonocryptus + Hirudicryptus ) and for a sister-group relationship between Siphonocryptidae and all other Polyzoniida arc presented. The strongly disjunct distribution area of the family is compared with other disjunct distributions involving the Canary Islands and Madeira.     

Morphology of the mandibles in the millipedes (Diplopoda, Arthropoda)

The mouthparts of seven species from five families of Diplopoda have been investigated with scanning electron microscopy. The distal segment of the mandible, the gnathal lobe, is the most complex structure. Although the biting and crushing parts among the examined genera arc always based on the same general scheme, typical modifications of these structures exist which are regarded to be taxon-specific. The density of the teeth on the pectinate lamellae appears to determine the size of the ingested food particles. A well-developed anterior fringe does not seem to be necessary for the ingestion of food.     

Ecology of Chondromorpha kelaarti (Diplopoda, Polydesmida)

Stadia 11-VII and adults of Chondromorpha kelaarti (Humbert) can be separated by segment number, length, breadth and paired legs. Sexes are distinguished from stadium IV and the sex ratio vaned around SO%, though females were prevalent in May and June.
In females, a positive and significant correlation was found between number ofeggs present and body width at the 17th Segment.
Population density and biomass of C. kelaarti varied from 0.06 to 12.94 and 1.75 mg to 811.24 mg per 0.1 mz, respectively. From May to November, populations of C. kelaartiare aggregated in distribution.
Chondronrorphu keluurti passed the dry season in late stadia (VI, VII and adult) and may complete the life cycle in one or two years.     

两种有鳞类爬行动物消化道微生物的研究

从北草蜥的胃、小肠和大肠中分离出 7个属 8种细菌和 2个属的霉菌 ,从中国石龙子的胃、小肠和大肠中分离到 6个属 7种细菌和 3个属的霉菌 ,酵母菌和放线菌都未发现。北草蜥胃、小肠和大肠中的细菌数量分别为 2 2 7× 1 0 6,2 0 6× 1 0 6和 9 78× 1 0 8个 / g ;霉菌数量为 2 5× 1 0 4 ,2 1 5× 1 0 4 ,1 33× 1 0 4个 /g。细菌在中国石龙子胃、小肠和大肠中的数量分布依次为 3 51× 1 0 6,2 2 5× 1 0 6,1 4 2× 1 0 9个 /g;霉菌分布数量为 2 1 9× 1 0 4 ,1 67× 1 0 4 和 1 61× 1 0 4 个 / g     

Methanogenesis in the hypersaline Solar Lake (Sinai)

Abstract Enrichment studies on microbial mat sediments (potential stromatolites) from the hypersaline Solar Lake (Sinai) indicated high numbers of methanogenic bacteria (up to 10⁵ ml⁻¹ sediment) in spite of the high sulfate reduction rate, sulfate concentration and salinity. Among H₂/CO₂, acetate and monomethylamine, the methylated amine was the preferred substrate. The predominant species enriched was a Methanosarcina sp. The findings indicate that methanogenic bacteria play an important role in hypersaline sulfate-enriched anoxic sediments and stromatolithic microbial mats.