The peristomatic structures as a source of systematic characters in the genus Lithobius Leach, 1814 (Myriapoda, Chilopoda)

Abstract

Morphological characters have been widely used in centipede systematics. Here, we aim to obtain morphological information from the preoral chamber and peristomatic structures of lithobiomorph centipedes, with taxonomic sampling focused on the species-rich genus Lithobius Leach, 1814. Towards this goal, we (i) examined the epipharynx and hypopharynx of 32 species belonging to four subgenera of the genus Lithobius, viz. Lithobius Leach, 1814, Monotarsobius Verhoeff, 1905, Sigibius Chamberlin, 1913 and Ezembius Chamberlin, 1919 using light and scanning electron microscopy, (ii) searched for phylogenetically informative characters and (iii) described interspecific variation. Three species of the lithobiid genera Eupolybothrus Verhoeff, 1907, Disphaerobius Attems, 1926 and Neolithobius Stuxberg, 1875 were additionally examined and considered as likely outgroups. New characters and character states are proposed as additions to current phylogenetic datasets. Similarities in the peristomatic structures ally Disphaerobius with Lithobius (Ezembius), suggesting that the subfamily Pterygoterginae is nested within Lithobiinae and Lithobius.

Morphology of the mandibles and the first maxillae in the family Lithobiidae (Myriapoda, Chilopoda), with remarks on their phylogenetic significance

“…Phylogenetic analyses using maximum parsimony and maximum likelihood of the newly described characters together with characters from other morphological systems were performed, including characters extracted from other Lithobiidae, Henicopidae, and two representatives of Scutigeromorpha as outgroup. We further compared the mandibular gnathal edge of Disphaerobius loricatus (Sseliwanoff, ) and Lithobius ( Ezembius ) giganteus Sseliwanoff, and, together with the phylogenetic results, verified that it supports previous suggestions on their relationships based on external morphological and peristomatic characters (Farzalieva, Nefediev, & Tuf, ; Ganske et al, ). This is of particular systematic importance because Disphaerobius is usually classified separately from Lithobius , in the subfamilies Pterygoterginae and Lithobiinae, respectively.…”

“…“Bottle‐shaped” glandular shafts at the border between labral and clypeal part of epipharynx: (0) absent; (1) present with one distinct regular row; (2) present with more than one regular or irregular rows. (see Ganske et al, , char. 1; adjusted)…”

“…Number of transverse bulge(s) at border between labral and clypeal parts of epipharynx: (0) absent; (1) one; (2) two. (see Ganske et al, , char. 3)…”

“…Information on the peristomatic structures of the species included in the phylogenetic analysis was obtained from Koch and Edgecombe () and Ganske et al (). Other morphological information was acquired from Koch and Edgecombe (), new observations, or from literature resources.…”

“…The genus Lithobius was hitherto subject to one morphological phylogenetic analysis based on 40 characters resolving it as non‐monophyletic, with a few species being more closely related to the genera Australobius Chamberlin, 1920, Hessebius Verhoeff, 1941 and Pleurolithobius Verhoeff, 1899 (Koch & Edgecombe, ). A more recent study on the peristomatic structures (epipharynx and hypopharynx) of 32 species of the same genus highlighted eight new characters, which could also be systematically useful (Ganske, Edgecombe, & Akkari, ).…”