Phylogeography of Fischer’s blue,Tongeia fischeri,in Japan: Evidence for introgressive hybridization

The widespread lycaenid butterfly Tongeia fischeri is distributed from eastern Europe to northeastern Asia and represented by three geographically isolated populations in Japan. In order to clarify the phylogeographic history of the species, we used sequences of three mitochondrial (COI, Cyt b and ND5) and two nuclear (Rpl5 and Ldh) genes of 207 individuals collected from 55 sites throughout Japan and five sites on the Asian continent. Phylogenetic trees and the median-joining network revealed six evolutionary mitochondrial haplotype clades, which corresponded to the geographic distribution of the species. Common ancestors of Japanese T. fischeri might have come to Japan during the mid-Pleistocene by multiple dispersals of continental populations, probably via a land bridge or narrow channel between western Japan and the Korean Peninsula. The geographical patterns of variation of mitochondrial and nuclear markers are discordant in northeastern Kyushu, possibly as a result of introgressive hybridization during the ancient contact between the Kyushu and Shikoku populations in the last glacial maximum. The phylogeographic pattern of T. fischeri in Japan are probably related to the geological history, Pleistocene climatic oscillations and distribution of the host plant.     

Integrative taxonomy reveals phenotypic plasticity in the freshwater mussel Contradens contradens (Bivalvia: Unionidae) in Thailand,with a description of a new species

The freshwater mussel Contradens contradens (Lea, 1838) occurs in most types of freshwater habitats throughout Thailand. The species shows extensive variation in shell morphology, which has led to the recognition of six different subspecies. In this study, the validity of these six subspecies plus one unknown species was assessed using an integrative taxonomic approach. Geometric morphometric analyses revealed significant differences in shell shapes among these six nominal morphological subspecies, although a considerable degree of overlap was detected in some groups. In contrast, the phylogenetic tree obtained from the concatenated data of mitochondrial COI and nuclear H3 gene sequences and molecular species delimitation analyses revealed only three supported clades. These clades are proposed herein as three distinct species, and strongly corresponded to the biogeographically disjunct drainage systems in Thailand. They consisted of the (i) C. contradens clade found in the Chao Phraya Basin and other rivers that drain into the Gulf of Thailand, (ii) C. crossei clade that is restricted to the Middle Mekong Basin, and (iii) a clade containing only the newly discovered species from Huai Luang River in the north-east of Thailand, which is described herein as Contradens rolfbrandti Jeratthitikul & Panha, sp. nov. Speciation among these congeners was probably caused by the restriction of gene flow due to the past geomorphology of the river systems. The intraspecific variation in the shell shape detected here does not reflect the evolution of the mussel, but rather is evidence of phenotypic plasticity.http://zoobank.org/urn:lsid:zoobank.org:pub:649B6093-E1DD-4FD8-8185-A4696C43AD36; http://zoobank.org/urn:lsid:zoobank.org:act:777DDE86-8397-4FF3-AA78-0BE0F34611F4     

Molecular phylogeny reveals high diversity and endemism in the limestone karst-restricted land snail genus Sophina Benson, 1859 from Myanmar (Eupulmonata: Helicarionidae), with description of four new species

Sophina is a poorly known and neglected genus due to the inaccessibility of the Salween Basin, Southern Myanmar. Taxonomic status, distribution, and phylogeny are being revised based on an integrative analysis of genitalia, radula, and molecular data. Morphological variation in shells and genitalia, together with a phylogenetic tree from concatenated data of mitochondrial and nuclear genes, revealed the existence of ten species/subspecies. Penial morphology and genetic divergence were generally consistent and useful in delimiting species, while shell characters showed little overall taxonomic utility in some species. Taxonomic placement of the previous subspecies “bensoni” shows clear distinction in both genitalia and molecular evidence, and is currently recognized as a distinct species. The nominal species “S. schistostelis” and “S. calias” possess similar genitalia and shell morphology, and molecular evidence suggested that they are sister taxa representing geographically isolated populations. Four new species are additionally described herein as S. furfuracea n. sp., S. pisinna n. sp., S. salweenica n. sp., and S. tonywhitteni n. sp. based on both morphology and molecular evidence. Phylogenetic analyses supported monophyly of Sophina, and further a split into two principal clades. These two clades showed little difference in genitalia, but more clear differences in the umbilical area and allopatric distribution in upper and lower reaches of the Gyaing River. High genetic divergence was revealed and this coincided with remarkable degree of endemism and localization with a pattern of one outcrop for one lineage. These data highlight the importance of the Salween Basin's karst ecosystems as an evolutionary and endemic biodiversity hotspot, and indicate that a focus on conservation and management in this area is urgently required.     

Molecular Evidence for Cryptic Speciation in the Cyclophorus fulguratus (Pfeiffer, 1854) Species Complex (Caenogastropoda: Cyclophoridae) with Description of New Species

A high degree of intraspecific variation, both genetic and in shell morphology, of the operculate land snail Cyclophorus fulguratus (Pfeiffer, 1854) suggests that its classification as a single species warrants reconsideration. We sequenced two nuclear (18S and 28S) and two mitochondrial (16S and COI) genes of 46 C. fulguratus specimens and used them to estimate the phylogeny and to determine the validity of species boundaries. Molecular phylogenetic analyses revealed the presence of three lineages corresponding to three geographically disjunctive populations of C. fulguratus in Thailand. Likelihood tests of topologies significantly supported the non-monophyly of the C. fulguratus–complex and Bayesian species delimitation analysis significantly supported the potential representation as distinct species of these three lineages. Discriminant function analysis based on geometric-morphometrics of shell shape allowed for significant distinction of these three candidate species, although they revealed a considerable degree of overlap of shell shape reflecting their crypsis morphologically. The diagnostic characters are provided by color pattern, pattern of protoconch and pattern of jaw. In conclusion, the results support that the C. fulguratus s.l., as currently recognized, consists of three distinct species in Thailand: C. fulguratus s.s., C. rangunensis and C. abditus sp.nov., which are described herein.     

Systematics of the freshwater leech genus Hirudinaria Whitman, 1886 (Arhynchobdellida,Hirudinidae) from northeastern Thailand

In total, 435 specimens of the Southeast Asian freshwater leech species within the Hirudinidae family were collected from 17 locations of various types of aquatic habitats in northeastern Thailand. They were all morphologically placed within the genus Hirudinaria Whitman, 1886 and there were three distinct species: the common Hirudinaria manillensis, 78.2% of all collected specimens and at all 17 locations, Hirudinaria javanica at 20.3% of collected samples and from five locations and a rarer unidentified morphospecies (Hirudinaria sp.) with six samples from only two locations. The karyotypes of these three species were examined across their range in this study area for 38, 11 and 6 adult specimens of Hirudinaria manillensis, Hirudinaria javanica and Hirudinaria sp., respectively. This revealed different chromosome numbers among all three species, with Hirudinaria javanica having n = 13, 2n = 26, Hirudinaria manillensis lacked one small chromosome pair with n = 12, 2n = 24, and the unknown Hirudinaria sp. differed from any known Hirudinaria karyotypes in exhibiting a higher chromosome number (n = 14, 2n = 28) and a gradual change in size from large to small chromosomes. This suggests that the unknown Hirudinaria sp. is a new biological species. However, phylogenetic analysis based upon a 658 bp fragment of the cytochrome oxidase subunit I gene placed this unknown morphospecies within the Hirudinaria manillensis clade, perhaps then suggesting a recent sympatric speciation, although this requires further confirmation. Regardless, the chromosomes of all three species were asymmetric, most with telocentric elements. A distinct bi-armed chromosome marker was present on the first chromosome pair in Hirudinaria javanica, whilst it was on pairs 1, 2, 3 and 5 in Hirudinaria manillensis, and on pairs 3 and 5 for the unknown Hirudinaria sp.     

Sexual dimorphism and intraspecific variation in wing size and shape of Tongeia fischeri (Lepidoptera: Lycaenidae)

Wing morphological variations are described here for the lycaenid butterfly Tongeia fischeri. A landmark‐based geometric morphometric approach based on wing venation of 197 male and 187 female butterflies collected in Japan was used to quantify wing size and shape variations between sexes and among populations. Sexual dimorphism in wing size and shape was detected. Females had significantly larger wings than males, while males showed a relatively elongated forewing with a longer apex and narrower wing tornus in comparison to females. Intraspecific variations in wing morphology among populations were revealed for the wing shape, but not wing size. Distinct wing shape differences were found in the vein intersections area around the distal part of the discal cell where median veins originated in the forewing and around the origin of the CU1 vein in the hindwing. In addition, phenotypic relationships inferred from wing shape variations grouped T. fischeri populations into three groups, reflecting the subspecies classification of the species. The spatial variability and phenotypic relationships between conspecific populations of T. fischeri detected here are generally in agreement with the previous molecular study based on mitochondrial and nuclear sequences, suggesting the presence of a phylogenetic signal in the wing shape of T. fischeri, and thus having taxonomic implications.     

Genetic analysis of hybridization between white-handed (Hylobates lar) and pileated (Hylobates pileatus) gibbons in a contact zone in Khao Yai National Park,Thailand

Primates - Natural hybridization has played various roles in the evolutionary history of primates. Its consequences range from genetic introgression between taxa, formation of hybrid zones, and...     

Phylogeography of the Asian rice gall midge <Emphasis Type="Italic">Orseolia oryzae</Emphasis> (Wood Mason) (Diptera: Cecidomyiidae) in Thailand

The Asian rice gall midge (RGM) Orseolia oryzae (Wood Mason) (Diptera: Cecidomyiidae) is a major pest of rice, leading to yield losses in Thailand and many Asian countries. Despite an increasing number of reported midge outbreaks and the presence of many susceptible rice varieties, only a few studies have focused on the genetic variation of the midges. Therefore, we analyzed the phylogeography among Thai RGM populations covering north, northeast and central Thailand. Two mitochondrial DNA genes, cytochrome C oxidase I (COI) and 12S, and a non-coding repeat region (RR) situated just before COI were amplified. Overall, the haplotype diversity for COI and 12S genes of the Thai population was high, but the nucleotide diversity was quite low. Altogether, the phylogenetic tree and pairwise F _st values indicated that Thai RGM populations recently expanded and were homogeneously distributed throughout the country, except for some populations in the north, which most likely became recently isolated from the main population. Two non-coding repeat motifs, that were recently observed in the mitogenome of RGM in India, were absent in Thai populations and replaced by an 89 bp non-coding sequence. Tandem nucleotide repeats of the sequence TA were also observed. The repeat copy number varied from 2 to 11 and was not correlated with geographical repartition of the midge. Finally, COI barcoding divergence between Indian and Thai populations was high (6.3% in average), giving insights into the potential existence of an RGM species complex in Asia.