Variation in body segment number within and between populations of the centipede Strigamia maritima (Chilopoda: Geophilomorpha)

Although most arthropod species have a fixed number of body segments, one order of centipedes – the Geophilomorpha – provides an unusual opportunity to study the variation and microevolution of segment number. This is because all species in all but one family exhibit variation in the number of leg‐bearing segments (LBS) within and between natural populations. One species in particular, the coastal geophilomorph Strigamia maritima, has become a ‘model system’ for these studies, because of its high population densities and the consequent ease of collecting large samples. Previous studies on this species have examined various aspects of segment number variation. However, most studies have characterized each population by an LBS distribution and a mean LBS number that are based on data from all life‐stages. Here, we dissect the variation within as well as between populations and show that different cohorts within a population often have significantly different LBS number distributions. This is almost certainly due to developmental plasticity, probably related to the prevailing microhabitat temperature within brood chambers, but possibly related to other environmental factors too. Although we found no evidence of selection, the fact that different species of geophilomorphs have different LBS distributions suggests that, in the long term, selection may act on the developmental reaction norm of LBS number. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 107 , 678–685.     

Morphology and phylogeny of Dicellophilus,a centipede genus with a highly disjunct distribution (Chilopoda: Mecistocephalidae)

The centipede genus Dicellophilus Cook, 1896 (Chilopoda: Geophilomorpha: Mecistocephalidae) has been revised by means of a comparative examination of representative specimens of all the species: morphological variation has been documented by means of both light and scanning electronic microscopy, the geographical distribution has been reassessed and updated based on published and new records, and the phyletic relations between the species have been analysed based on morphological evidence. Dicellophilus is confirmed as a highly distinct lineage, supported by synapomorphies in the labrum and in the pattern of coxal organs. Four species are morphologically recognized, each of them occurring in one of three limited, highly disjunct areas in a restricted boreal temperate belt: Dicellophilus carniolensis (C.L. Koch, 1847) is limited to central Europe (central–eastern Alps, Dinarids, Carpathians, and Dobrogea), Dicellophilus pulcher (Kishida, 1928) occurs in Japan (Honshu), and Dicellophilus anomalus (Chamberlin, 1904) and Dicellophilus limatus (Wood, 1862) both occur in the south‐western part of North America (California and Oregon). High support has been found for the following phyletic relationships: (D. carniolensis (D. pulcher (D. anomalus + D. limatus))). Dicellophilus carniolensis is strongly distinct in some autapomorphic traits, including enlarged clypeus and fewer mandibular lamellae, whereas the sister species D. anomalus and D. limatus share some derived features, including an elongated head and associated appendages, longer antennal setae, and stronger forcipular tubercles. The peculiar geographical distribution of Dicellophilus and the historical scenario suggested by the phylogeny are very unusual in respect to the biogeographical patterns known in all other major groups of terrestrial animals. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 501–532.     

On the true identity of Schendylurus (Schendylotyn) integer Chamberlin, 1926, a termitophilous ballophilid centipede (Chilopoda: Geophilomorpha)

Schendylurus (Schendylotyn) integer Chamberlin, 1926, originally described as a member of the Schendylidae, is transferred here to the Ballophilidae as Taeniolinum integer n. comb. and redescribed after the type specimen. Taeniolinum setosum guadeloupensis Demange and Pereira, 1985 is elevated to specific rank.     

A new miniature species of geophilomorph centipede from the Ecuadorian Amazon rainforest (Chilopoda: Geophilomorpha: Ballophilidae)

A new miniature species of geophilomorph centipede, Ityphilus grismadoi sp. nov. (Chilopoda: Geophilomorpha: Ballophilidae) is fully described and illustrated on the basis of specimens collected in Yasuní Scientific Station and Jatun Sacha Biological Station, both located in the Ecuadorian Amazon. The new species is characterized by having the internal edge of the forcipular tarsungulum completely smooth, this trait being shared by six other Neotropical members of the genus Ityphilus Cook, 1899; and another species (I. cifuentesi Cupul Magaña, 2014) from the transition area between the Neotropical and Nearctic regions. Ityphilus grismadoi sp. nov. is distinguished from these seven species by the low number of leg-bearing segments (37, 39), and the very small body size (7–9 mm in length) and for a confident identification it is compared in detail with those having a roughly similar range of leg-bearing segments. This is the first record of the genus Ityphilus from Ecuador and the second report of a ballophilid centipede from the country (the other represented by Zygethmus pantenus Chamberlin, 1957). A key to the Neotropical members of Ityphilus with forcipular tarsungulum smooth (including I. cifuentesi) is also given.

http://zoobank.org/urn:lsid:zoobank.org:pub:32F77890-9DC5-47AC-A794-29C4437C3B93http://zoobank.org/urn:lsid:zoobank.org:act:3EB64970-F159-4C6E-B9FF-AF9D09128553     

An exotic species spreads through Europe: Tygarrup javanicus (Chilopoda: Geophilomorpha: Mecistocephalidae) is reported from the Slovakia and the Czech Republic

Geophilomorph centipedes, due to their soil life style, are frequently transported with plants. This report tries to underline some adaptations that facilitate them being introduced and becoming alien species. Tygarrup javanicus (Attems, 1907), tropical species reported recently from different greenhouses in Central Europe, is used as an example of such a spreading species.     

The sternal pore areas of geophilomorph centipedes (Chilopoda: Geophilomorpha)

Most geophilomorph centipedes have segmental clusters of exocrine glands whose opening pores are arranged in more or less well-defined sternal pore areas. We describe here the cuticular structures forming and/or accompanying the gland openings on the sternites and the shape of the pore areas along the body axis in representatives of most geophilomorph families. The cuticular ring around the pore may exhibit either of two forms. In Himantariidae ( Himantarium ) and in Dignathodontidae ( Henia ) the ring looks like a continuous ribbon with a visible suture, whereas in the representatives of the remaining families no suture is seen. As to the distribution of the pores on ventral surface of the body, we record the presence of pores on the last leg-bearing segment of Clinopodes flavidus , whereas that segment was described as poreless in all geophilomorphs. We also provide a taxonomic survey of shape and distribution of pore areas in the individual families, where the pore areas may take very different shapes that we regard as transformational homologues. As for the segmental distribution of sternal pore areas, there is a considerable amount of complexity along the trunk of geophilomorph centipedes, in contrast to the apparently uniform trunk structure.     

Intraspecific variation in segment number in Pachymerium ferrugineum (C. L. Koch, 1835) (Chilopoda: Geophilomorpha) in the south Aegean Archipelago (north-east Mediterranean, Greece)

Geophilomorph centipedes have numerous leg-bearing segments, always an odd number. Previous research has shown the significant role of latitudinal clines and temperature on intraspecific variation, supporting the view that species of geophilomorphs from cold and temperate regions tend to have fewer segments than those from warmer regions. Here, data are presented on segment numbers of Pachymerium ferrugineum (C. L. Koch, 1835) from the south Aegean Archipelago. Within the framework of a study of the centipede fauna of the south Aegean Islands, three adjacent geographical areas with discrete geological histories were studied (Crete, Cyclades, and Dodecanese). There is no evidence to indicate that a latitudinal trend is present across these three main geographical regions. Apart from Crete, there is no demonstration of a cline along the longitudinal axis of the Aegean. However, the insular characteristics of the central and south-east Cyclades could possibly support higher modal segment numbers. In addition, examination of males and females of P. ferrugineum confirmed the existence of latitudinal clines in certain cases among the islands of Crete, Cyclades, and Dodecanese.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 88 , 533–539.     

Morphology and diversity of the forcipules in Strigamia centipedes (Chilopoda,Geophilomorpha)

The morphology of the venomous limbs (forcipules) of 13 species of Strigamia and of six other geophilomorphs was studied with light microscopy, scanning electron microscopy, and, for a subsample, with confocal laser scanning microscopy. In all Strigamia species a well-distinct denticle is present invariantly on the inner side of the terminal article (tarsungulum), in sub-basal position, just proximal to a faint transverse sulcus and a cuticular introflexion that corresponds to the insertion point of a tendon. Strigamia species differ mainly in size and shape of the denticle and thickness of the distal part of the tarsungulum, suggesting some functional diversity in piercing and handling prey. Anatomical evidence supports the hypothesis that the tarsungulum corresponds to two ancestral articles and a denticle at the basis of the tarsungulum originated multiple times within geophilomorphs, however in different positions corresponding to either the ancestral sub-terminal article (in Strigamia, other Geophiloidea and some Schendylidae) or the ancestral terminal article (in the himantariid Thracophilus).     

Phylogeny of Geophilomorpha (Chilopoda) inferred from new morphological and molecular evidence

To address the phylogenetic relationships of the centipede order Geophilomorpha (more than 1000 species), we have reinterpreted and expanded the knowledge on their morphological disparity, and have doubled the amount of molecular data available. We performed maximum parsimony and maximum likelihood analyses, using 195 phylogenetically informative morphological characters for 80 species, and DNA sequences of 28S, 18S, 16S rRNA and COI for up to 48 species. We found strong support for the monophyly of Geophilomorpha, the basal dichotomy between Adesmata and Placodesmata = Mecistocephalidae, and the basal dichotomy within Adesmata between two clades that are recognized here as superfamilies Himantarioidea and Geophiloidea. With respect to the families currently in use, Himantarioidea comprises three well supported clades corresponding to (i) Oryidae, (ii) Himantariidae, and (iii) Schendylidae s.l. including Ballophilidae; Geophiloidea comprises another three supported clades corresponding to (iv) a new family Zelanophilidae, (v) Gonibregmatidae s.l. including Eriphantidae and Neogeophilidae, and (vi) Geophilidae s.l. including Aphilodontidae, Dignathodontidae, Linotaeniidae, and Macronicophilidae.     

A redescription of the large geophilid centipede Chilenophilus corralinus (Attems, 1903) (Myriapoda: Chilopoda: Geophilomorpha), with new distribution records from southern Chile

The little known geophilomorph centipede Chilenophilus corralinus (Attems, 1903) (Myriapoda: Chilopoda, Geophilidae), a large geophilid species from South America is herein redescribed and illustrated based on new specimens collected in the Andes of Southern Chile. New morphological features of specific value are also given for the taxon. Chilenophilus corralinus is reported for the first time from the following Chilean localities: Region XIV (de Los Ríos region): Valdivia province: Pirihueico; camping “La Herradura”; Mafil. Region X (de Los Lagos region): Chiloé province: Chiloé Island. Llanquihue province: Parque Nacional Alerce Andino. Palena province: Hualaihué; Chaitén; Palena; Futaleufú.     

Taxonomy of the centipede Scolopendra laeta Haase (Chilopoda: Scolopendridae) in Australia

Scolopendra laeta Haase, 1887, which is widespread in the western and southern parts of Australia, is redescribed from the large number of available specimens. Five intraspecific forms are distinguished by their colour patterns, and their distributions are mapped.     

Ityphilus krausi N.Sp., a New Ballophilid Centipede from Peru (Chilopoda: Geophilomorpha: Ballophilidae)

The Amazon rainforest is one of the planet’s biodiversity hotspots, hosting a rich orchid bee fauna. The phoretic cleptoparasites of this bee fauna are largely unknown. We report for the first time the host–cleptoparasite interaction between Eulaema mocsaryi (Friese) (Hymenoptera: Apidae: Euglossini) and the first instar larva (triungulin) of a Tetraonycini meloid beetle. We review the host–cleptoparasite interactions of Tetraonycini with Apid bees in South America and discuss the ecological needs of the cleptoparasite.     

Venom apparatus and toxicity of the centipede Ethmostigmus rubripes (Chilopoda, Scolopendridae)

The venom apparatus of Ethmostigmus rubripes, a generalized predator, consists of the telopodites of the postcephalic segment, the basal article of w which contains the venom gland. Within the gland, venom granules are concentrated in intracellular secretory granules, from which they are discharged into vacuoles in the cytoplasm of the secretory cells and thereafter by exocytosis into the lumen of the gland. A venom duct carries venom to the venom claw, which introduces it into prey via a subterminal pore on the outer curvature of the claw. Pits containing pegs, presumed to be sensory, are concentrated near grooves leading to a cutting ridge proximal to the point of the claw. The venom is toxic both to mammals and insects.     

Molecular-based estimate of species number,phylogenetic relationships and divergence times for the genus Stenotaenia (Chilopoda,Geophilomorpha) in the Italian region

Stenotaenia is one of the largest and most widespread genera of geophilid centipedes in the Western Palearctic, with a very uniform morphology and about fifteen species provisionally recognized. For a better understanding of Stenotaenia species-level taxonomy, we have explored the possibility of using molecular data. As a preliminary assay, we sampled twelve populations, mainly from the Italian region, and analyzed partial sequences of the two genes COI and 28S. We employed a DNA-barcoding approach, complemented by a phylogenetic analysis coupled with divergence time estimation. Assuming a barcoding gap of 10–16% K2P pairwise distances, we found evidence for the presence of at least six Stenotaenia species in the Italian region, which started diverging about 50 million years ago, only partially matching with previously recognized species. We found that small-sized oligopodous species belong to a single clade that originated about 33 million years ago, and obtained some preliminary evidence of the related genus Tuoba being nested within Stenotaenia.     

Effect of urbanization on centipede (Chilopoda) diversity in the Wielkopolska-Kujawy Lowlands of western Poland

Over fifty years of research data from various sources were compiled and analyzed in order to determine the effect of urbanization on centipede diversity in the Wielkopolska-Kujawy Lowlands of western Poland. Urbanization has had a significant effect on species composition and community structures. However, it has not reduced overall species richness and diversity in the centipede fauna. The centipede fauna from built-up areas was found to be rich and varied. The habitats with the highest levels of species richness were the city of Poznań and the beech forests in the surrounding region.     

Tentorial mobility in centipedes (Chilopoda) revisited: 3D reconstruction of the mandibulo-tentorial musculature of Geophilomorpha

Mandibular mechanisms in Geophilomorpha are revised based on three-dimensional reconstructions of the mandibulo-tentorial complex and its muscular equipment in Dicellophilus carniolensis (Placodesmata) and Hydroschendyla submarina (Adesmata). Tentorial structure compares closely in the two species and homologies can be proposed for the 14/17 muscles that attach to the tentorium. Both species retain homologues of muscles that in other Pleurostigmophora are traditionally thought to cause swinging movements of the tentorium that complement the mobility of the mandibles. Although the original set of tentorial muscles is simplified in Geophilomorpha, the arrangement of the preserved homologues conforms to a system of six degrees of freedom of movement, as in non-geophilomorph Pleurostigmophora. A simplification of the mandibular muscles is confirmed for Geophilomorpha, but our results reject absence of muscles that in other Pleurostigmophora primarily support see-saw movements of the mandibles. In the construction of the tentorium, paralabial sclerites seem to be involved in neither Placodesmata nor Adesmata, and we propose their loss in Geophilomorpha as a whole. Current insights on the tentorial skeleton and its musculature permit two alternative conclusions on their transformation in Geophilomorpha: either tentorial mobility is primarily maintained in both Placodesmata and Adesmata (contrary to Manton’s arguments for immobility), or the traditional assumption of the tentorium as being mobile is a misinterpretation for Pleurostigmophora as a whole.     

The importance of looking at small-scale patterns when inferring Gondwanan biogeography: a case study of the centipede Paralamyctes (Chilopoda, Lithobiomorpha, Henicopidae)

Gondwanan biogeography has fascinated zoologists and botanists for over a century, but most biogeographical work has used continent-scale areas as analytical units. More finely resolved patterns, as can be obtained from small invertebrates with limited dispersal abilities, will be obscured in those studies. A common case is treating Australia as a single biogeographical region. In the present study, the necessity of splitting Australia into multiple microareas is demonstrated using centipedes as an example. The lithobiomorph centipede Paralamyctes is distributed on fragments of Gondwana, with species in southern Africa, Madagascar, southern India, Patagonia, eastern Australia, and New Zealand. A cladogram for Paralamyctes is based on morphology and sequences for four molecular markers for 30 terminals that sample 20 of 26 known ingroup species and four outgroups. Analysis with direct optimization across a range of indel costs and transversion : transition cost ratios identifies two main clades: Paralamyctes ( Paralamyctes ) unites species from southern Africa, Madagascar, tropical and warm temperate Australia, and New Zealand. The other group includes the temperate Australian/New Zealand Paralamyctes ( Haasiella ) and Paralamyctes ( Thingathinga ) and a Chilean clade. Subtree analysis finds that different parts of Australia have closest affinities to other Gondwanan fragments, and some of these relationships (such as that between north Queensland and New Zealand) are based on taxonomically stable clades. Area delimitation for large continental fragments should use sufficiently fine resolution to test the 'monophyly' of those fragments and attempt to eliminate spurious geographical paralogy.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 65–78.