Taxonomic Study of theBurmoniscus ocellatusComplex (Crustacea, Isopoda, Oniscidea) in Japan Shows Genetic Diversification in the Southern Ryukyus, Southwestern Japan

Molecular and taxonomic analyses in troglobiotic Alpioniscus (Illyrionethes) species from the Dinaric Karst (Isopoda: Trichoniscidae)

Species richness of terrestrial isopods is high in caves of the Dinaric Karst, which hosts ~10% of the world’s nominal oniscidean troglobionts. The most widespread taxon is the southern European genus Alpioniscus, which consists of two subgenera: Alpioniscus s.s. and Illyrionethes. Before this study, 14 nominal troglobiotic Illyrionethes taxa were recorded from the Dinaric Karst. Our molecular analyses using two mitochnodrial DNA (16S rRNA and COI) fragments and a nuclear gene (H3) fragment on all known Dinaric taxa identified three distinct lineages: strasseri-, heroldi- and magnus-lineage. Our results confirmed the validity of most nominal species. The exceptions are Alpioniscus balthasari, which consists of two different species including Alpioniscus iapodicus, and Alpioniscus heroldi, which is paraphyletic with respect to Alpioniscus bosniensis. The strasseri-lineage was highly supported by all phylogenetic methods used; therefore, we performed a detailed morphological analysis to distinguish and characterize the species of this group. New morphological characters, such as body part ratios, are proposed for future species identification. In addition, we redescribe three known species (Alpioniscus strasseri, Alpioniscus christiani and Alpioniscus balthasari) and describe two new ones (Alpioniscus hirci sp. nov. and Alpioniscus velebiticus sp. nov.). As a result, 15 nominal species of Illyrionethes are currently known from the Dinaric Karst.

Eleven nominal species of Burmoniscus are junior synonyms of B. kathmandius (Schmalfuss, 1983) (Crustacea, Isopoda, Oniscidea)

Holotypes, paratypes, and specimens newly collected from the type localities (i.e., topotypes) of Burmoniscusaokii (Nunomura, 1986), Burmoniscusboninensis (Nunomura, 1986), Burmoniscusdaitoensis (Nunomura, 1986), Burmoniscushachijoensis Nunomura, 2007, Burmoniscusjaponicus (Nunomura, 1986), Burmoniscuskagoshimaensis Nunomura, 2003, Burmoniscusmurotoensis (Nunomura, 1986), Burmoniscusokinawaensis (Nunomura, 1986), Burmoniscusshibatai (Nunomura, 1986), Burmoniscustanabensis Nunomura, 2003, and Burmoniscuswatanabei (Nunomura, 1986) were examined in order to clarify their taxonomic status. Observation of 13 morphological characters that were purposed to show species-level diagnostic variations in the original descriptions suggests that all eleven nominal species are identical, and molecular analysis based on three gene fragments supports this suggestion. Additionally, the morphology of the carpus of pereopod 1 and of the endo- and exopodites of pleopod 1 of these species are consistent with those of Burmoniscuskathmandius (Schmalfuss, 1983). The eleven above-mentioned species of Burmoniscus described from Japan are therefore relegated to junior synonyms of Burmoniscuskathmandius, originally reported from Nepal.

Phylogeographic Study of Whip Scorpions (Chelicerata: Arachnida: Thelyphonida) in Japan and Taiwan

Whip scorpions (Thelyphonida), comprising an order in the class Arachnida, are distributed from tropical to temperate zones. Two species occur exclusively in Japan and Taiwan, but the border of their distributional ranges is ambiguous in the Central Ryukyus (Japan). We collected new specimens from the Central Ryukyus and revealed that the border of distribution of the two species lies between the Central and Southern Ryukyus, i.e., the Kerama Gap. Moreover, the estimated divergence time (15.8 Mya) of the two species, based on the mitochondrial COI gene, was older than the recently estimated time (1.55 Mya) of formation of the Kerama Gap. These results highlight the risks of a priori assumption solely on the basis of geological data for applying it as a calibration point to some terrestrial animals in this region. Typopeltis stimpsonii was genetically divided into four lineages, two of which turned out to be endemic to the Okinawa Islands. All specimens from the main island of Japan and Shikoku were in one lineage, which was also found in the Amami Islands and Hachijojima Island. This suggests that these specimens may have been dispersed by human activity. Typopeltis crucifer included five genetic lineages. Species collected from Ishigakijima and Iriomotejima Islands were genetically diversified not between the borders of these islands but within Ishigakijima Island. This study also suggests that phylogenetic diversity of the species in the Southern Ryukyus have increased through two times of invasions from Taiwan.

Burmoniscus kitadaitoensis Nunomura, 2009 (Crustacea, Isopoda, Oniscidea) from southern Japan, a junior synonym of B. meeusei (Holthuis, 1947)

Re-examination of the holotype of Burmoniscus kitadaitoensis Nunomura, 2009 from Kitadaitojima Island, southern Japan reveals that this species is a junior synonym of B. meeusei (Holthuis, 1947). Partial regions of mitochondrial COI, 12S and 16S rRNA genes, and nuclear 18S and 28S rRNA genes were detected for species identification in the future.