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As it is currently defined, Archispirostreptus includes two species groups (the southern African and the east African) with distinct kinds of gonopods. A new genus, Cacuminostreptus Mwabvu, is proposed to accommodate the southern African species which include C. conatus (Attems 1928) comb. n. and three new species, C. vumbaensis Mwabvu, C. triangul...
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... Notes on hosts:—Archispirosteptus gigas is one of the World's largest millipedes, reaching 260 mm in length and 19 mm in diameter. It is widespread in eastern tropical Africa (Mwabvu et al. 2010). 'Spirostreptus' hamatus is a moderate-sized spirostreptid, up to 10 cm long and 5 mm diameter, it occurs in the Tanzanian Eastern Arc mountains (Enghoff et al. in press). ...
Nine new species of the genus Rickia parasitizing Diplopoda are described: R. appendicifera from Iran on Chiraziulus, R. candelabriformis from Australia and New Zealand on several Spirostreptida, R. galatheae from New Zealand on Eumastigonus, R. gigas from Tanzania on ‘Spirostreptus’ and Archispirostreptus, R. lophophora from Tanzania on some genera of Spirostreptidae, R. obelostrepti from Tanzania on Obelostreptus, R. odontopygiidarum from Tanzania on Odontopygidae, R. platessa from Singapore and Thailand on Pachybolidae, and R. rhynchophora from Australia on Trigoniulus. This nearly triples the previously known number of species of Rickia species on millipedes; all 14 species are treated in this study with photomicrographs, additional observations on previously described taxa and comments. A key to these species is also provided.
The Laboulbeniales species were found on millipede specimens preserved mostly at the Natural History Museum of Denmark, from samples collected between 1916 to the present.
... Among them are the genera Archispirostreptus Silvestri, 1895, Doratogonus Attems, 1914, Cacuminostreptus Mwabvu, 2010, Spirostreptus Brandt, 1833, Plagiotaphrus Attems, 1914, and Bicoxidens Attems, 1928, which contain large-bodied species. Although male genitalia are central in spirostreptid millipede taxonomy (see Hoffman 2008; Hamer 2009; Mwabvu et al. 2010) because they are divergent and species specific (Bond et al. 2003), morphology-based classifications may be too inclusive (Adams et al. 2009; Ács et al. 2010) and may hide considerable variation. Molecular data have demon strated in many arthropod groups that molecular divergence may not reflect divergence in morphology, thus resulting in an underestimation of diversity (Brewer et al. 2012). ...
... At this stage, it is premature to question relationships based on genital morphology because of poor taxon sampling and, according to Sole-Cava and Wörheide (2007), possible identification errors in the Genbank database, because sequences are not from holotypes. Archispirostreptus gigas and A. tumuliporus do not form a subclade within the Spirostreptidae clade, even though based on gonopod morphology they are congeneric (Mwabvu et al. 2010); this was unexpected. Whether A. gigas and A. tumuliporus belong in different genera requires further scrutiny; possibly these taxonomic assignments are incorrect. ...
The aim of this study was to use cytochrome c oxidase 1 (CO1) sequences to recover a phylogeny for seven morphologically described spirostreptid millipede taxa from southern Africa, and to evaluate the correspondence between morphological and molecular phylogenies. Genetic p-distance generally increased with taxonomic divergence: inter-specific mean 15.33 % (14.09 % –17.02 %), inter-generic mean 18.43 % (6.83 %–26.81 %) and inter-order mean 24.16 % (range 18.56 %–30.77 %). Congruent Bayesian, maximum parsimony and neighbour-joining analyses of 520 nucleotides of the CO1 gene resolved the orders Spirostreptida, Julida and Callipodida. Members of genera within the Spirostreptidae (Archispirostreptus, Bicoxidens, Cacuminostreptus, Doratogonus, Orthoporoides, Plagiotaphrus and Spirostreptus) formed a single clade within which a sample of Thyropygus (family Harpagophoridae) was paraphyletically nested. Phylogenetic analyses failed to recover support for the genera Doratogonus, Bicoxidens, Archispirostreptus and Spirostreptus, as representatives of these genera were not monophyletic. Samples morphologically identified as the same species (Bicoxidens flavicollis) were part of two different clades, one of which was well supported and otherwise contained members of Doratogonus. This high level of divergence (mean 12.64 %) between morphologically identified spirostreptid millipede sister species could indicate that changes in genital morphology occur rather slowly relative to CO1 sequence substitution, and may underestimate species diversity.
... As noted earlier, the tropical species E. pulchripes and A. gigas were obtained from a pet shop and from individual breeders. Species determination of A. gigas was verified based on gonopod morphology after Mwabvu et al. [35]. The tropical species were kept at about 25uC on horticultural substrate plus hardwood leaf litter. ...
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.
... Pfenninger et al. 2007;Burns et al. 2008), gonopod morphology is still central to spirostreptid millipede taxonomy (e.g . Hoffman 2008;Hamer 2009;Mwabvu et al. 2010), because it has been mooted that the divergent male genitalia suggest reproductive isolation (Bond et al. 2003). ...
The structure of the male gonopods of millipedes has been considered to be species-specific. As such, gonopods—which aid in copulation and sperm transfer—are used in the taxonomic diagnosis and description of species. However, it was recently demonstrated that gonopod morphology is not always characteristic of species. Diagnoses based on gonopod morphology can therefore result in underestimation of taxonomic diversity amongst millipedes. On the basis of this observation, we examined genetic variation in two populations (approximately 250 km apart) of a widely distributed and colour-polymorphic southern African millipede, namely Bicoxidens flavicollis Attems, 1928. An analysis of genetic divergence based on 520 nucleotides of the mitochondrial cytochrome oxidase 1 gene, and 684 nucleotides of the mitochondrial 16S rRNA gene, demonstrated high levels of divergence (19.09% for cytochrome oxidase 1 and 6.66% for 16S rRNA) between the two populations. These results suggest the presence of cryptic species in B. flavicollis and, furthermore, corroborate observations that taxonomy based on gonopod morphology may be too inclusive.
Physicochemical characterization of new chitin isolates can provide valuable insights into designing of biomimetic materials. Chitin isolates with a definite three-dimensional (3D) structure can exhibit characteristics that distinguish them from other chitin specimens that are in form of powder or flakes without a definite and uniform shape. Herein, 3D chitin rings were produced from body segments of a diplopod (Archispirostreptus gigas) inhabiting tropical regions. This organism is cultured easily and can reach 38 cm in length, which makes it a suitable source for isolation of chitin. The chitin rings were characterized via TGA, FT-IR, SEM and XRD analyses. Enzymatic digestion test with chitinase demonstrated that chitin isolates had high purity (digestion rate: 97.4%). The source organism had high chitin content; 21.02 ± 2.23% on dry weight. Interactions of the chitin rings with bovine serum albumin (BSA) protein were studied under different conditions (pH: 4.0-8.0, chitin amount: 6-14 mg, contact time: 30-360 min, protein concentration: 0.2-1 mg/mL). The highest BSA adsorption was observed at pH 5.0 at 20°C. The adsorption equilibrium data exhibited a better fit to Langmuir adsorption and the pseudo-first order kinetic models. The findings presented here can be useful for further studies aiming to develop biocompatible and nontoxic biomaterials.
The midgut epithelia of the millipedes Polyxenus lagurus, Archispirostreptus gigas and Julus scandinavius were analyzed under light and transmission electron microscopies. In order to detect the proliferation of regenerative cells, labeling with BrdU and antibodies against phosphohistone H3 were employed. A tube-shaped midgut of three millipedes examined spreads along the entire length of the middle region of the body. The epithelium is composed of digestive, secretory and regenerative cells. The digestive cells are responsible for the accumulation of metals and the reserve material as well as the synthesis of substances, which are then secreted into the midgut lumen. The secretions are of three types - merocrine, apocrine and microapocrine. The oval or pear-like shaped secretory cells do not come into contact with the midgut lumen and represent the closed type of secretory cells. They possess many electron-dense granules (J. scandinavus) or electron-dense granules and electron-lucent vesicles (A. gigas, P. lagurus), which are accompanied by cisterns of the rough endoplasmic reticulum. The regenerative cells are distributed individually among the basal regions of the digestive cells. The proliferation and differentiation of regenerative cells into the digestive cells occurred in J. scandinavius and A. gigas, while these processes were not observed in P. lagurus. As a results of the mitotic division of regenerative cells, one of the newly formed cells fulfills the role of a regenerative cell, while the second one differentiates into a digestive cell. We concluded that regenerative cells play the role of unipotent midgut stem cells.
