Mite secretions from three traditional mite-ripened cheese types: are ripened French cheeses flavored by the mites (Acari: Astigmata)?

The opisthonotal glands of Astigmata contain monoterpenes, aromatics, aliphatics, and other volatile compounds; some of these compounds act as pheromones and have antifungal effects. This study analyzed volatile compounds secreted by mites on three traditional mite-ripened cheeses from producers (Milbenkäse from Germany, Mimolette and Artisou from France). The mites obtained from various traditional ripened French cheeses (Mimolette, Laguiole, Salers, and Cantal vieux) from stores were also investigated. The gas chromatography (GC) profiles of all their hexane extracts, except the Cantal vieux one, showed almost no differences and were identical to that of Tyrolichus casei Oudemans except for trace components. Based on the GC results, the mites of Cantal vieux were identified as Acarus siro L. For the Artisou and Cantal vieux, not studied before, the influence of the mite secretions on their characteristics was investigated by analyzing the headspace volatiles from the cheeses. According to the results, neral secreted from T. casei is the main compound responsible for the lemon-like flavor of the mite-ripened cheeses, which is, hence, due to a component of the mite secretions rather than the fermentation of the cheese itself. Moreover, the compounds secreted by the mites are not directly added to the cheese through ripening as they were not detected in the odors of the Artisou and Cantal vieux after the mites were removed. However, the consumers of the Artisou usually eat also the cheese rind, and thus, can enjoy its lemon-like flavor fully.

Do 'cheese factory-specific' mites (Acari: Astigmata) exist in the cheese-ripening cabinet?

To determine whether the mites used in the ripening process of traditional cheeses are genetically unique to cheese factories, we investigated mites from three types of traditional cheeses, that use mites in the ripening process: 'Würchwitzer Milbenkäse' from Germany and 'Mimolette' and 'Artisou' from France. In addition, traditional ripened cheeses were purchased from cheese specialty stores in France (Mimolette) and Japan ('Laguiole' from France) as well as stores in temporary markets in France ('Salers' and 'Cantal vieux') and the mites obtained from those cheeses were analyzed in this study. Partial sequences of the 28S rRNA gene (28S) were determined and used to reconstruct a phylogenetic tree. Tyrolichus casei, the dominant cheese mite species from the ripening cabinets of three traditional cheese producers and two cheese specialty stores in France and Japan, had identical partial 28S sequences. All specimens from Cantal vieux from a store in the temporary market in France had an identical sequence with Acarus siro and Acarus immobilis in the determined region of the 28S sequences. Mite individuals from Salers from a store in the temporary markets in France shared the same haplotype as Acotyledon paradoxa. For the T. casei individuals from five different localities (19 individuals in total), the nuclear loci were obtained using MIG-seq. More than several thousand genomic regions are amplified simultaneously by multiplex PCR, and targeting regions surrounded by inter-simple sequence repeats (ISSRs) in the genome were sequenced using the MiSeq system (Illumina). SNPs extracted from this genome-wide analysis showed that no genetic structure existed in the populations from any region. Among the five samples from the three regions, which were more than 500 km apart and from completely different environments, the mites had no geographic bias, but all mite individuals were genetically nearly identical. Thus, we found no evidence to support the existence of 'cheese factory-specific' T. casei mites, at least in terms of genetic analysis.

Geographical parthenogenesis in the brown alga Scytosiphon lomentaria (Scytosiphonaceae): Sexuals in warm waters and parthenogens in cold waters.

Geographical parthenogenesis, a phenomenon where parthenogens and their close sexual relatives inhabit distinct geographical areas, has been considered an interesting topic in evolutionary biology. Reports of geographical parthenogenesis from land and freshwater are numerous, but this occurrence has been rarely reported from the sea. Brown algae are mostly marine and are thought to include numerous obligate parthenogens; still, little is known about the distribution, origin and evolution of parthenogens in this group. Here we report a novel pattern of geographical parthenogenesis in the isogamous brown alga Scytosiphon lomentaria. Sex ratio investigation demonstrated that, in Japan, sexual populations grew in the coast along warm ocean currents, whereas female-dominant parthenogenetic populations grew mainly in the coast along a cold ocean current. In the two localities where sexual and parthenogenetic populations were parapatric, parthenogens grew in more wave-exposed areas than sexuals. Population genetic and phylogenetic analyses, including those based on genome-wide single nucleotide polymorphism data, indicated that parthenogens have initially evolved at least twice and subsequent hybridizations between the parthenogens and sexuals have generated multiple new parthenogenetic lineages. The origin of the initial parthenogens is not clear, except that it would not be interspecies hybridization. Interestingly, we found that the production of sex pheromones, which attract male gametes, has been independently lost in the initial two parthenogenetic lineages. This parallel loss of the sexual trait may represent the direct origin of parthenogens, or the regressive evolution of a useless trait under asexuality.

Two New Species of the Genus Eucorydia (Blattodea: Corydiidae) from the Nansei Islands in Southwest Japan.

Two new species of the cockroach genus Eucorydia Hebard, 1929 from the Nansei Islands in Southwest Japan were compared to two closely related congeners, Eucorydia yasumatsui Asahina, 1971 and Eucorydia dasytoides (Walker, 1868). Eucorydia donanensis Yanagisawa, Sakamaki, and Shimano sp. nov. from Yonaguni-jima Island was characterized by an overall length of 12.5-14.5 mm in males. The dorsal side of the male abdomen was entirely dark purple and there was an obscure orange band running down the middle of the tegmen. Eucorydia tokaraensis Yanagisawa, Sakamaki, and Shimano sp. nov. was characterized by an overall length of 12.0-13.0 mm in males and a distinct orange band running down the middle of the tegmen. Eucorydia yasumatsui, E. donanensis, E. tokaraensis and the zonata population of E. dasytoides were divided into four lineages in a maximum-likelihood tree generated from a dataset concatenated from five (two nuclear, 28S rRNA, histone H3, and three mitochondrial, COII, 12S rRNA, 16S rRNA) genes. We recognized the three Japanese lineages E. yasumatsui, E. donanensis, and E. tokaraensis as distinct species, which were also supported by the pairwise genetic distances (5.4-7.8%, K2P) of the COI sequences. Morphometric analysis was performed on the genitalia. A principal component analysis plot revealed that the sizes of the genitalia in the three Japanese species were similar to each other and smaller than that of the zonata population of E. dasytoides. The analysis also revealed that the three Japanese species were distinguished from each other by combinations of the sizes of L3 and L7 sclerites and the shape of R2 sclerite, with some overlapping exceptions.

Juvenile morphology of seven intertidal mite species (Acari, Oribatida, Ameronothroidea) from the East Asian region.

The present paper provides information on juvenile stages of seven intertidal oribatid mite species from the East Asian region. Larva and nymphs of the fortuyniid species Fortuynia churaumi, F. shibai, F. rotunda and Alismobates reticulatus are described and details about juvenile morphology of the selenoribatid species, Arotrobates granulatus, Indopacifica taiyo and I. tyida are given. Juveniles of the genus Arotrobates are reported for the first time and strong ventral femoral carinae are supposed to be diagnostic characters. Basically, the conservative morphology of immature stages could be confirmed in every studied taxon and its importance for phylogenetic considerations is emphasized.

Diurodrilus kunii sp. nov. (Annelida: Diurodrilidae) and a Molecular Phylogeny of the Genus.

A new species of stygobiontic interstitial annelid, Diurodrilus kunii sp. nov., is described based on material collected from medium sand sediment (ϕ = 1.2-1.7) at groundwater level (40-100 cm in depth; 5-15 m inland from splash zone) in the intertidal beach slope on Ishikari Beach, facing the Sea of Japan, Hokkaido, Japan. The new species differs from six known congeners in the arrangement of the anterior-head ventral ciliophores, the degree of development in the primary and secondary toes, and the shape of the spermatozoa. We inferred the phylogenetic position of the new species among other congeners for which 18S rRNA, 28S rRNA, and COI gene sequences were available in public databases. This is the first representative of the genus from the Northwest Pacific.

First record of the family Ameronothridae (Acari: Oribatida) from Japan - new species, juvenile morphology, ecology and biogeographic remarks.

The Ameronothridae are recorded for the first time from Japanese coasts with the new species Ameronothrus yoichi sp. n. from Hokkaido. The report of this species represents the most southern occurrence of an Ameronothrus species in the Asian Pacific region. Ameronothrus yoichi sp. n. can be easily distinguished from its congeners by the conspicuously pusticulate body surface and the loss of dorsal companion setae d on all genua in the adult stage. Based on adult and juvenile morphology, a close relation to Ameronothrus maculatus and A. schneideri is suggested. Ameronothrus yoichi sp. n. is classified as a lichenivorous inhabitant of sediment-free rocky coastal substrates. Due to a lack of genetic sequence data of nearly all ameronothrid species a molecular genetic comparison is yet unfeasible, but a Bayesian inference tree based on the 18S rRNA gene shows a paraphyletic clustering of the ameronothrid A. yoichi sp. n. and Paraquanothrus grahami. http://www.zoobank.org/urn:lsid:zoobank.org:pub:5B772E2C-7D5E-4C86-9955-AB84A84C50DA.

A preliminary molecular phylogeny shows Japanese and Austrian populations of the red mite Balaustium murorum (Acari: Trombidiformes: Erythraeidae) to be closely related.

The red mite Balaustium murorum (Hermann) inhabits the Western Palaearctic realm and is well adapted to man-made structures. In Japan, B. murorum had been reported more frequently after the 1980s. A molecular phylogeny based on the nuclear 18S rRNA and mitochondrial COI genes, and including B. murorum individuals from Japan and Austria and representatives of related species from Japan showed four Balaustium species-level lineages in Japan (B. murorum, Balaustium sp. 1, Balaustium sp. 2, Balaustium sp. 3). The B. murorum lineage shared identical 18S sequence and COI haplotype with the Austrian population. Balaustium sp. 1 was detected from the Tokyo and Misaki area (Honshu Island) and was the sister group to B. murorum; the other two lineages inhabited coastal environments of Erimo, Hokkaido Island (Balaustium sp. 2) and Ainan, Shikoku Island (Balaustium sp. 3). The high genetic distances among these four lineages indicate that each lineage is a distinct species, with three of the lineages representing undescribed species. Our results are compatible with the conclusion that B. murorum was introduced to Japan from Europe, although our study did not resolve the polarity or timing of migration events.

Molecular Phylogeny of Cypridoid Freshwater Ostracods (Crustacea: Ostracoda), Inferred from 18S and 28S rDNA Sequences.

With the aim of exploring phylogenetic relationships within Cypridoidea, the most species-rich superfamily among the podocopidan ostracods, we sequenced nearly the entire 18S rRNA gene (18S) and part of the 28S rRNA gene (28S) for 22 species in the order Podocopida, with representatives from all the major cypridoid families. We conducted phylogenetic analyses using the methods of maximum likelihood, minimum evolution, and Bayesian analysis. Our analyses showed monophyly for Cyprididae, one of the four families currently recognized in Cypridoidea. Candonidae turned out to be paraphyletic, and included three clades corresponding to the subfamilies Candoninae, Paracypridinae, and Cyclocypridinae. We propose restricting the name Candonidae s. str. to comprise what is now Candoninae, and raising Paracypridinae and Cyclocyprininae to family rank within the superfamily Cypridoidea.

Tubulanus tamias sp. nov. (Nemertea: Palaeonemertea) with Two Different Types of Epidermal Eyes.

Based on specimens collected subtidally (∼10 m in depth) in Tomioka Bay, Japan, we describe the palaeonemertean Tubulanus tamias sp. nov., which differs from all its congeners in body coloration. In molecular phylogenetic analyses based on partial sequences of the nuclear 18S and 28S rRNA genes and histone H3, as well as the mitochondrial 16S rRNA and cytochrome c oxidase subunit I genes, among selected palaeonemerteans, T. tamias nested with part of the congeners in Tubulanus, while the genus as currently diagnosed appears to be non-monophyletic. Molecular cloning detected polymorphism in 28S rDNA sequences in a single individual of T. tamias, indicating incomplete concerted evolution of multiple copies. Tubulanus tamias is peculiar among tubulanids in having 9-10 pigment-cup eyes in the epidermis on either side of the head anterior to the cerebral sensory organs, and remarkably there are two types of eyes. The anterior 8-9 pairs of eyes, becoming larger from anterior to posterior, are completely embedded in the epidermis and proximally abutting the basement membrane; each pigment cup contains bundle of up to seven, rod-shaped structure that resemble a rhabdomeric photoreceptor cell. In contrast, the posterior-most pair of eyes, larger than most of the anterior ones, have an optical cavity filled with long cilia and opening to the exterior, thus appearing to have ciliary-type photoreceptor cells. The size and arrangement of the eyes indicate that the posterior-most pair of eyes are the remnant of the larval (or juvenile) eyes.

Trilobodrilus itoi sp. nov., with a Re-Description of T. nipponicus (Annelida: Dinophilidae) and a Molecular Phylogeny of the Genus.

The marine interstitial annelid Trilobodrilus itoi sp. nov., the sixth member of the genus, is described on the basis of specimens collected intertidally at Ishikari Beach, Hokkaido, Japan; this is the second species in the genus described from the Pacific Rim. In addition, T. nipponicus Uchida and Okuda, 1943 is re-described based on fresh topotypic material from Akkeshi, Hokkaido, Japan. From both species, we determined sequences of the nuclear 18S and 28S rRNA genes, and the mitochondrial cytochrome c oxidase subunit I (COI) gene. Molecular phylogenetic trees based on concatenated sequences of the three genes showed that T. itoi and T. nipponicus form a clade, which was the sister group to a clade containing the two European congeners T. axi Westheide, 1967 and T. heideri Remane, 1925. The Kimura two-parameter distance for COI was 22.5-22.7% between T. itoi and T. nipponicus, comparable with interspecific values in other polychaete genera. We assessed the taxonomic utility of epidermal inclusions and found that the known six species can be classified into three groups.

Two kinorhynch species (Cyclorhagida, Echinoderidae, Echinoderes) show different distribution patterns across Tsugaru Strait, Northern Japan.

We investigated the geographic population structures of two intertidal kinorhynch species, Echinoderes sensibilis and Echinoderes sp. A, in the vicinity of Tsugaru Strait between Honshu and Hokkaido Islands, Japan, to examine whether the distribution or connectivity of populations of either species has been constrained by the strait. For each species, we examined the geographic distribution of COI haplotypes, constructed a median-joining haplotype network, and calculated statistics of genetic variation and connectivity. Tsugaru Strait is the northern range limit for E. sensibilis, which comprises a large, evolutionarily stable metapopulation that appears to have undergone a reduction in size followed by expansion; connectivity is low among most local populations, including across Tsugaru Strait. A divergent haplotype lineage showing no variation occurred only at Horozuki, suggesting recent immigration there from outside the study area. Echinoderes sp. A underwent a severe population bottleneck followed by rapid expansion. It occurred at all sampling sites on both sides of the strait, with high connectivity between populations across the strait. There is a zone of secondary contact between moderately divergent, presumably previously allopatric lineages in eastern Hokkaido. Present-day conditions in the strait have existed only for the past 8000 years, and differences in these species' distributions and apparent connectivity across the strait may relate to conditions existing in the strait when the species underwent population expansions or shifts in range; these historical events were not necessarily concurrent between the species, and occurred more than 8000 years ago. We discuss dispersal mechanisms for kinorhynchs, which could include suspension transport or rafting.

Mitochondrial metagenomics reveal the independent colonization of the world's coasts by intertidal oribatid mites (Acari, Oribatida, Ameronothroidea).

Oribatid mites are an ancient group that already roamed terrestrial ecosystems in the early and middle Devonian. The superfamily of Ameronothroidea, a supposedly monophyletic lineage, represents the only group of oribatid mites that has successfully invaded the marine coastal environment. By using mitogenome data and nucleic ribosomal RNA genes (18S, 5.8S, 28S), we show that Ameronothroidea are a paraphyletic assemblage and that the land-to-sea transition happened three times independently. Common ancestors of the tropical Fortuyniidae and Selenoribatidae were the first to colonize the coasts and molecular calibration of our phylogeny dates this event to a period in the Triassic and Jurassic era (225-146 mya), whereas present-day distribution indicates that this event might have happened early in this period during the Triassic, when the supercontinent Pangaea still existed. The cold temperate northern hemispheric Ameronothridae colonized the marine littoral later in the late Jurassic-Early Cretaceous and had an ancient distribution on Laurasian coasts. The third and final land-to-sea transition happened in the same geological period, but approx. 30 my later when ancestors of Podacaridae invaded coastal marine environments of the Gondwanan landmasses.

Molecular phylogeny of kinorhynchs.

We reconstructed kinorhynch phylogeny using maximum-likelihood and Bayesian analyses of nuclear 18S and 28S rRNA gene sequences from 30 species in 13 genera (18S) and 23 species in 12 genera (28S), representing eight families and both orders (Cyclorhagida and Homalorhagida) currently recognized in the phylum. We analyzed the two genes individually (18S and 28S datasets) and in combination (18S+28S dataset). We detected four main clades (I-IV). Clade I consisted of family Echinoderidae. Clade II contained representatives of Zelinkaderidae, Antygomonidae, Semnoderidae, Centroderes, and Condyloderes, the latter two currently classified in Centroderidae; within Clade II, Zelinkaderidae, Antygomonidae, and Semnoderidae comprised a clade with strong nodal support. Clade III contained only two species in Campyloderes, also currently classified in the Centroderidae, indicating polyphyly for this family. Clades I-III, containing all representatives of Cyclorhagida included in the analysis except for Dracoderes abei, formed a clade with high nodal support in the 28S and 18S+28S trees. Clade IV, resolved in the 18S and 18S+28S trees with high nodal support, contained only species in order Homalorhagida, with the exception of the cyclorhagid Dracoderes abei. Order Cyclorhagida as it currently stands is thus polyphyletic, and order Homalorhagida paraphyletic. Our results indicate that Dracoderidae has been misplaced in Cyclorhagida based on homoplasious characters. Our analyses did not resolve the relationships among Clades I-III within Cyclorhagida. Neither gene alone nor the combined dataset resolved all nodes in trees, indicating that additional markers will be needed to reconstruct kinorhynch phylogeny.

Systematic position of the genus Metacanthocephalus Yamaguti, 1959 (Palaeacanthocephala: Echinorhynchida) inferred from molecular evidence, with a redescription of Metacanthocephalus ovicephalus (Zhukov, 1960).

The familial affiliation of the echinorhynchid palaeacanthocephalan genus Metacanthocephalus has been uncertain, with the three families Echinorhynchidae, Leptorhynchoididae, and Rhadinorhynchidae having been suggested as its parent taxon. In this study, adult individuals of Metacanthocephalus ovicephalus from the intestine of the cresthead flounder Pseudopleuronectes schrenki (new host) and the dark flounder Pseudopleuronectes obscurus in Hokkaido, Japan, were examined. Using three gene markers (mitochondrial cytochrome c oxidase subunit I; nuclear 18S and 28S rRNA genes) determined from two specimens of M. ovicephalus, a molecular phylogenetic analysis was performed along with relevant sequences available in public databases representing 26 species in eight families of the order Echinorhynchida, along with five species from Polymorphida and two from Eoacanthocephala. The resulting phylogram showed that M. ovicephalus was nested within a clade along with nine species in eight genera (Brentisentis yangtzensis, Dentitruncus truttae, Dollfusentis bravoae, Koronacantha mexicana, K. pectinaria, Leptorhynchoides thecatus, Neotegorhynchus cyprini, Pseudoleptorhynchoides lamothei, and Tegorhynchus [= Illiosentis] sp.). In this paper, we propose i) a set of morphological characters to circumscribe members represented by this clade as a Linnaean higher taxon, ii) to place this taxon at the rank of family, iii) to refer to it as Leptorhynchoididae, and iv) to regard Illiosentidae as a junior synonym of Leptorhynchoididae. Our morphological examination revealed a single vaginal sphincter in M. ovicephalus, a character that was not mentioned in any of the previous literature. By this character, along with geographical distribution and host fish, six congeners currently recognized in Metacanthocephalus can be divided into two groups.

Complete mitochondrial genomes of two snail mite: Riccardoella tokyoensis and R. reaumuri (Acariformes, Prostigmata, Ereynetidae).

We determined the mitochondrial genome sequences of two snail mites, Riccardoella tokyoensis and R. reaumuri. The length of the entire mitogenome of these two species is 15,078 bp and 15,148 bp long, respectively. Both of them contain 13 proteins, two rRNAs, and 22 tRNAs for a total of 37 gene products. The gene order of Riccardoella is able to explain by a single rearrangement event from that of other Eupodina species; the whole region, including both rRNA genes and control region (CR), is inverted at the same position. The CR including a tandem repeat region in both of the mitogenomes of Riccardoella species.

Complete mitochondrial genome of a sea cucumber, Euapta godeffroyi (Echinodermata, Holothuroidea, Apodida, Synaptidae).

We determined the complete mitochondrial genome sequence of a holothurian Euapta godeffroyi belonging to the order Apodida. The complete mitogenome of E. godeffroyi was 16,410 bp in length and consisted of 13 protein-coding genes (PCGs), two ribosomal RNA genes, and 22 transfer RNA genes. The orders of PCGs and rRNAs did not match those of any recorded holothurian mitogenomes. The maximum likelihood (ML) phylogenetic tree placed E. godeffroyi as the sister group to chiridotid species and supported the monophyly of the order Apodida.

Molecular systematics of Tanaidacea (Crustacea: Peracarida) based on 18S sequence data, with an amendment of suborder/superfamily-level classification.

Phylogenetic relationships within Tanaidacea were analyzed based on sequence data for the 18S rRNA gene. Our results strongly supported a monophyletic group composed of Neotanaidae, Tanaoidea, and Paratanaoidea, with the first two taxa forming a clade. These results contradict three previously suggested hypotheses of relationships. Based on the molecular results, and considering morphological similarities/differences between Neotanaidomorpha and Tanaidomorpha, we demoted Suborder Neotanaidomorpha to Superfamily Neotanaoidea within Tanaidomorpha; with this change, the classification of extant tanaidaceans becomes a two-suborder, four-superfamily system. This revision required revision of the diagnoses for Tanaidomorpha and its three super-families. The results for Apseudomorpha were ambiguous: this taxon was monophyletic in the maximum likelihood and Bayesian analyses, but paraphyletic in the maximum parsimony and minimum evolution analyses.

Systematics, distribution and morphology of the newt parasitic water mites of the subgenus Lurchibates Goldschmidt amp; Fu, 2011 (Acari, Hydrachnidia, Hygrobatidae, Hygrobates Koch, 1837), including the description of four new species and a key to all so far known species.

Four new water mite species of the genus Hygrobates, subgenus Lurchibates (Acari, Hydrachnidia, Hygrobatidae) are described. Hygrobates (Lurchibates) macrochela sp. nov. Goldschmidt, Nishikawa Shimano is described in male and female; Hygrobates (Lurchibates) malosimilis sp. nov. Goldschmidt, Nishikawa Shimano is described in male, both new water mite species were collected from newts of the species Pachytriton inexpectatus Nishikawa, Jiang, Matsui Mo, 2011; Hygrobates (Lurchibates) incognitus sp. nov. Goldschmidt, Nishikawa Shimano is described in female collected from newts of the species Paramesotriton guangxiensis (Huang, Tang and Tang, 1983); Hygrobates (Lurchibates) fragmentarius sp. nov. Goldschmidt, Nishikawa Shimano is described in a single severely fragmented specimen (sex could not be determined) collected from a newt of the species Paramesotriton yunwuensis Wu, Jiang, and Hanken, 2010. Principal differences between the subgenus Lurchibates and the nominal subgenus Hygrobates s. str. are illustrated and discussed as well as the sexual dimorphism of Lurchibates. Morphometric analyses confirmed the morphological differences of ten out of the eleven so far described species (H. (L.) fragmentarius could not be included in the analysis); two morphological groups became evident mainly based upon the shape of the anterior coxae. These analyses as well provide an idea of possible phylogenetic relationships among the species. A key to all currently known species of the subgenus Lurchibates is given. So far the subgenus is restricted to SE-Asia, a map showing the distribution of all species is presented.

A new amphibious species of the genus emScolopendra/em Linnaeus, 1758 (Scolopendromorpha, Scolopendridae) from the Ryukyu Archipelago and Taiwan.

In Japan and Taiwan, five valid species of the genus Scolopendra Linnaeus, 1758 have been described: S. morsitans Linnaeus, 1758, S. subspinipes Leach, 1816, S. mutilans Koch, 1878, S. japonica Koch, 1878, and S. multidens Newport, 1844. Recently, an undetermined species was found in the Ryukyu Archipelago and Taiwan. Using molecular phylogenetic analyses with mitochondrial COI and 16S rRNA and nuclear 28S rRNA and 18S rRNA genes as well as conventional morphological examination, we successfully discriminated this sixth species as an independent lineage from S. subspinipes, S. mutilans, and other named congeners from East and Southeast Asia. Therefore, the species was described as S. alcyona Tsukamoto Shimano, sp. nov. Several situational evidences suggest that this species prefers streamside environments and exhibits amphibious behavior.