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| Zephronia macula Srisonchai & Wesener, in Srisonchai, Likhitrakarn, Sutcharit et Wesener, 2024. |
Abstract
A large amount of material of the millipede genus Zephronia Gray, 1832 was collected during 2014–2023 from many parts of eastern Thailand. An integrative study of morphological characters and genetic data (COI gene) revealed two new species: Z. chantaburiensis Srisonchai & Wesener, sp. nov. and Z. macula Srisonchai & Wesener, sp. nov. The two new species clearly differ from other congeners by their unique characteristics, especially in their colour pattern and telopod shape. The interspecific genetic distances of the 658 bp COI gene barcoding fragment between these new species and all other species of giant pill-millipede from Thailand, Laos and Cambodia are 12.01–23.49% for Z. chantaburiensis sp. nov. and 17.93–25.13% for Z. macula sp. nov. While relationships among species remain preliminary, the phylogenetic tree shows that species of Zephronia are interspersed with species of Sphaerobelum Verhoeff, 1924 and Prionobelum Verhoeff, 1924. Phylogenetic analyses place both new species in a clade termed Zephronia s.s., which receives support also from morphological data, showing a unique position of the organ of Tömösváry. Z. macula sp. nov. appears to occur over a broad distribution whereas Z. chantaburiensis sp. nov. was found only at the type locality. Given that all known records are in the eastern part of Thailand, we thus regard both species as endemic. Morphological illustrations based on SEM micrographs and a distribution map are also provided.
Key words: Biodiversity, limestone, Myriapoda, Southeast Asia, taxonomy
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| Photograph of live specimens of Zephronia chantaburiensis sp. nov. and habitats A–F paratypes (CUMZ-MYR0014) G coexisting species (Z. macula sp. nov.) H granite habitat at the type locality. Scale bars: 0.5 mm. |
Zephronia chantaburiensis Srisonchai & Wesener, sp. nov.
กิ้งกือกระสุนจันทบุรี ค้นพบที่วัดเขาสุกิม จ.จันทบุรี
Diagnosis: The position of the organ of Tömösváry at the brim and not inside the antennal groove (Fig. 3B) identifies this species as a member of the Zephronia s.s. species group (see Semenyuk et al. 2018), with which it also aligns genetically (Fig. 1). This small brown species (body length ca 20 mm) with short golden hair (Fig. 2A–F) differs from all other Zephronia s.s. species, except for Z. macula sp. nov. found in direct sympatry, described below, in the presence of only a single apical spine on the tarsus of legs 4–21 (2 or 3 in the other species). Midbody endotergum with one row of marginal bristles with longest bristles reaching up to posterior margin, immovable finger (process) of telopoditomere 2 on anterior telopod relatively long and slender. Similar in these respects only to Z. macula sp. nov. but differs from the latter species by the tergite coloration lacking dark or greenish-dark colour spots, the operculum of the female being more slender, the femur of the walking legs being slightly wider than long (slightly longer than wide in Z. macula sp. nov.), and the female subanal plate having a strongly concave margin. Genetically distant from other species by 18.94–26.82% p-distance in the COI barcoding fragment.
Etymology: The name is an adjective referring to the province (Chantaburi) where the type locality is located.
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| Photograph of live specimens of Zephronia macula sp. nov. and habitats A–G paratypes (CUMZ-MYR00016) H habitat at Thaeo Khlong Khlung monastery (granitic rocks) I habitat at Phet Pho Thong cave (limestone). Scale bars: 0.5 mm. |
Zephronia macula Srisonchai & Wesener, sp. nov.
กิ้งกือกระสุนลายด่าง
พบได้ในหลายพื้นที่ในภาคตะวันออกของประเทศไทย
Diagnosis: The position of the organ of Tömösváry in this small Zephronia with an axe-shaped antennomere 6 identifies Z. macula sp. nov. as a member of the Zephronia s.s. species-group (Semenyuk et al. 2018). Z. macula sp. nov. differs from all other known species of the group except for the syntopic Z. chantaburiensis sp. nov., in the presence of only a single apical spine on the tarsi of legs 4–21 (at least 2 or 3 in the other Zephronia). Z. macula sp. nov. differs from Z. chantaburiensis sp. nov. by having a combination of distinct characters, viz. tergite with dark or greenish dark spots, femur of walking legs less strongly widened, slightly longer than wide (wider than long in Z. chantaburiensis sp. nov.), bristles of midbody endotergum reaching to posterior margin, operculum of female vulva not protruding and round, and immovable finger (process) of telopoditomere 2 of the anterior telopod more curved and much longer. Genetically distant from others by a p-distance of the COI barcoding fragment of 17.93–25.13%.
Etymology: The name is a noun referring to the pattern of spots on the body.
Ruttapon Srisonchai, Natdanai Likhitrakarn, Chirasak Sutcharit and Thomas Wesener. 2024. Integrative Taxonomy reveals Two New Giant Pill-millipedes of the Genus Zephronia Gray, 1832 from eastern Thailand (Diplopoda, Sphaerotheriida, Zephroniidae). ZooKeys. 1212: 29-64. DOI: doi.org/10.3897/zookeys.1212.126536
