The Mecistocephalidae of the Japanese and Taiwanese islands (Chilopoda: Geophilomorpha)

Abstract

We present a comprehensive taxonomic revision of the Mecistocephalidae occurring in the Japanese main archipelago and in Taiwan, based on both the critical analysis of published information and the comparative morphological examination of representative specimens, including type material. A total of 34 species in 8 genera are recognised. Diagnostic characters, synonyms and geographical distribution are reviewed and discussed for all species, and a detailed redescription is provided for 12 already known species. An identification key to all species is also provided. The following species are described as new: Arrup ishiianus, Arrup lilliputianus, Arrup longicalix, Arrup kyushuensis, Mecistocephalus changi, Mecistocephalus karasawai. The following synonymies are new: Tygarrup monoporus Shinohara, 1961 = Dicellophilus pulcher (Kishida, 1928); Mecistocephalus fenestratus Verhoeff, 1934 = Mecistocephalus japonicus Meinert, 1886; Mecistocephalus insulomontanus Gressitt, 1941 = Mecistocephalus marmoratus Verhoeff, 1934; Mecistocephalus manazurensis Shinohara, 1961 = Mecistocephalus nannocornis Chamberlin, 1920; Mecistocephalus mirandus Pocock, 1895 = Mecistocephalus japonicus Meinert, 1886; Mecistocephalus okinawaensis Takakuwa, 1939 = Mecistocephalus pauroporus Takakuwa, 1936; Mecistocephalus takakuwai Verhoeff, 1934 = Mecistocephalus diversisternus (Silvestri, 1919). Dicellophilus pulcher (Kishida, 1928) new comb. is here recognised as the valid name for the species previously referred to as Dicellophilus latifrons Takakuwa,1934.

Variability in trunk segmentation in the centipede order Scolopendromorpha: a remarkable new species of Scolopendropsis Brandt (Chilopoda: Scolopendridae) from Brazil

“…Elsewhere in the Chilopoda, intraspecific variability in trunk segment numbers is confined to Geophilomorpha, the sister group of Scolopendromorpha (Edgecombe 2007 and references therein) in a clade united by epimorphic development, i.e., hatching from the egg with the complete adult complement of body segments. Indeed, with a few exceptions among the most segment-rich species of the genus Mecistocephalus Newport, 1843 (Bonato et al 2001, Uliana et al 2007, variable segment counts are confined to one of the two basally diverging lineages within the Geophilomorpha, the Adesmata. The other chilopod orders, Scutigeromorpha, Lithobiomorpha, and Craterostigmomorpha, all have a fixed number of 15 trunk segments, the primitive number for Chilopoda as a whole (Minelli et al 2000).…”

Early embryonic determination of the sexual dimorphism in segment number in geophilomorph centipedes

“…In the most speciose suborder of the geophilomorphs, the Adesmata, most if not all species show this pattern of variability. In the basal sister group to the Adesmata, the Mecistocephalidae, only few species show inter-individual variation in segment number, and these may also show sexual dimorphism, although this is not certain [8,19,20]. These observations suggest that there may be a link between the mechanisms underlying individual variation and sexual dimorphism in segment number.…”

Additional morphological information on the holotype of <I>Arrup ishiianus</I> Uliana, Bonato & Minelli 2007 (Chilopoda: Geophilomorpha: Mecistocephalidae)

“…This causes difficulties in differentiating among A. ishiianus and morphologically similar species (Tsukamoto et al 2019). Furthermore, Japanese and other populations of A. hostii might be easily confused with A. ishiianus in some literature (e.g., Takakuwa 1940, Miyosi & Takakuwa 1965) because some of their characteristics such as body length and the number of coxal pores are consistent with the description of A. ishiianus rather than that of A. holstii (see Uliana et al 2007). Very recently we located the holotype of A. ishiianus, which had not yet been deposited unintentionally into the depository designated in the original description, and had opportunity to observe it.…”

“…The mecistocephalid centipede species Arrup ishiianus Uliana, Bonato & Minelli 2007 was described from Japan. Information on mandible and postpedal segments, and photographs of species diagnostic characteristics are not provided in the original description.…”

“…Arrup ishiianus Uliana, Bonato & Minelli 2007 [Japanese name: Ishii-tsumejimukade] (Fig. 1A-E Description of additional morphological characters.…”