Seven new Psechrus species are described from South East Asia: P. arietinus sp. nov.(♂♀, Vietnam), P. insulanus sp. nov.(♂, Thailand), P. ampullaceus sp. nov.(♂♀, Vietnam), P. omistes sp. nov.(♂, Indonesia, Sumatra), P. quasillus sp. nov.(♂♀, Malaysia, Borneo), P. huberi sp. nov.(♀, Philippines), and P. wade sp. nov.(♂, Philippines). For the following species, new records are listed and intraspecific variation is discussed and illustrated: P. libelti Kulczyński, 1908, P. norops Bayer, 2012, P. rani Wang & Yin, 2001, P. khammouan Jäger, 2007, P. luangprabang Jäger, 2007, P. jaegeri Bayer, 2012, P. obtectus Bayer, 2012, P. kenting Yoshida, 2009 and P. crepido Bayer, 2012, and Fecenia protensa Thorell, 1891. The latter species is recorded from Vietnam for the first time. P. norops, P. libelti and an unidentified Psechrus species from Baluno, Mindanao are for the first time characterised and illustrated by their pre-epigynes and pre-vulvae.
Scanning electron microscope (SEM) images of dust mites, Suidasia pontifica, is presented to provide an improved visualization of the taxonomic characters of these mites. Suidasia pontifica can easily be identified by its scale-like cuticle, presence of external vertical setae (ve), longer external scapular setae (sce) compared to internal scapular setae (sci) and 3 ventral spines on apex of tarsus I. The differences in morphology of male and female S. pontifica are also discussed.
The Humpback whale tubercles have been studied for more than a decade. Tubercle Leading Edge (TLE) effectively reduces the separation bubble size and helps in delaying stall. They are very effective in case of low Reynolds number flows. The current Computational Fluid Dynamics (CFD) study is on NACA 4415 airfoil, at a Reynolds number 120,000. Two TLE shapes are tested on NACA 4415 airfoil. The tubercle designs implemented on the airfoil are sinusoidal and spherical. A parametric study is also carried out considering three amplitudes (0.025c, 0.05c and 0.075c), the wavelength (0.25c) is fixed. Structured mesh is utilized to generate grid and Transition SST turbulence model is used to capture the flow physics. Results clearly show spherical tubercles outperform sinusoidal tubercles. Furthermore experimental study considering spherical TLE is carried out at Reynolds number 200,000. The experimental results show that spherical TLE improve performance compared to clean airfoil.
A new genus and species of hisponine jumping spider from Sarawak, Jerzego corticicola Maddison sp. nov. are described, representing one of the few hisponine jumping spiders known from Asia, and the only whose male is known. Although similar to the primarily-Madagascan genus Hispo in having an elongate and flat body, sequences of 28s and 16sND1 genes indicate that Jerzego is most closely related to Massagris and Tomomingi, a result consistent with morphology. Females of Jerzego and other genera of Hisponinae were found to have an unusual double copulatory duct, which appears to be a synapomorphy of the subfamily. Two species are transferred from Hispo, Jerzego bipartitus (Simon) comb. nov. and Jerzego alboguttatus (Simon) comb. nov. Diagnostic illustrations and photographs of living spiders are provided.
A new species of Clidicini ant-like stone beetles, Clidicus mawarensis sp. n., is described and illustrated. The holotype male was collected in East Malaysia (Borneo: Sabah); the new species belongs to a group of large-bodied Clidicus, and shows similarities to C. ganglbaueri Reitter; the male has unusually complex structures of the aedeagal apical region.
The monotypic genus Paracyriothasastes Breuning, 1978 was established for Cereopsius marmoreus Pascoe, 1857 from Malaysia. Uraechoides Breuning, 1981 was established for Uraechoides vivesi Breuning, 1981 also from Malaysia, and is currently composed of the type species and U. taomeiae Hayashi, Nara Yu, 1995, the latter from China (Taiwan) (Tavakilian Chevillotte 2020).
Two new species of the genus Stenoloba Staudinger, 1892 (S. mediana, sp. n. and S. fuscobrunnea, sp. n.) are described from Cambodia and Laos respectively, and a new species of the genus Victrix Staudinger, 1879 (V. noloides, sp. n.) from China is described. Stenoloba chlorographa Kononenko Ronkay, 2001 is reported for the first time from China (Xizang), and new distributional data for recently described Stenoloba species from Malaysia are presented.
A preliminary survey of parasitic and infectious hypodermal and haematopoietic necrosis virus (IHHNV) infections in giant freshwater prawn from the Damak Sea of Rejang River, Kuching, Sarawak was conducted. Symptoms of black spots/patches on the rostrum, carapace, pleopods or telson were observed in most of the 107 samples collected. Parasitic examination revealed sessiline peritrichs such as (Zoothamnium sp.), nematode larvae, gregarine stage and cocoon of leech with prevalences of 1.2%, 1.2%, 5% and 17% respectively. Under histopathological examination, changes like accumulation of hemocytes around hepatopancreatic tubules due to vibriosis, basophilic intranuclear inclusions in the epithelium and E-cell of hepatopancreatic tubules as a result of HPV were seen through the section. No positive infection of IHHNV was detected in 78 samples. As such, the wild giant freshwater prawns in Damak Sea of Rejang River in Kuching are IHHNV-free though infections of parvo-like virus and bacteria were seen in histopathology.
The genus Theopea Baly, 1864 is redefined. Seventeen species from Sundaland and the Philippines are recognized and classified into four species groups (including seven new species): T. impressa (Fabricius, 1801), T. longicollis (Jacoby, 1896), T. louwerensi Jolivet, 1951, T. lunduensis Mohamedsaid, 1998, T. chungi sp. nov. in the T. impressa group; T. flavipalpis Laboissère, 1940, T. guoi sp. nov., T. lui sp. nov., T. sabahensis sp. nov. in the T. flavipalpis group; T. elegantula Baly, 1864, T. pulchella Baly, 1864, T. fairmairei Duvivier, 1885, T. kedenburgi Weise, 1922, T. houjayi sp. nov., T. tsoui sp. nov., T. yuae sp. nov. in the T. pulchella group; and T. costata (Allard, 1889) in the T. costata group. The following new synonyms are established: Theopea pulchella Baly, 1864 = T. nigricollis Jacoby, 1892 syn. nov.; Theopea impressa (Fabricius, 1801) = T. impressa flavicornis Laboissère, 1940 syn. nov. and T. impressa malaccana Laboissère, 1940 syn. nov.; T. lunduensis Mohamedsaid, 1998 = T. sepilokensis Mohamedsaid, 2000 syn. nov. Lectotypes are designated for Crioceris impressa Fabricius, 1801, Ozomena longicollis Jacoby, 1896, Theopea elegantula Baly, 1864, T. fairmairei Duvivier, 1885, T. nigricollis Jacoby, 1892, and T. pulchella Baly, 1864. Theopea obliterata Jacoby, 1884, T. variabilis (Jacoby, 1887), T. incostata (Allard, 1889), T. clypeata Jacoby, 1896, T. modiglianii Jacoby, 1896, T. dohrni (Jacoby, 1899), T. viridipennis (Jacoby, 1899), and T. weberi (Weise, 1913) are removed from Theopea and regarded as species incertae sedis.
A new genus and species of the subtribe Batrisina from western Sarawak, Bryantinus matangus gen. et sp. n., is described, illustrated, and compared with related taxa. In addition, examination of a small series of batrisine material from Thailand revealed a new country record for Cerochusa cilioceps Yin & Nomura, which was previously known only from the island of Hainan in southern China.
A new species, Megatyrus femoralis sp. n., is described from the Koshi Zone, East Nepal, with major diagnostic features illustrated. Megatyrus masumotoi Nomura, Sakchoowong & Chanpaisaeng, originally described from southwestern Thailand, is recorded from the Noring Timur Mountain, West Malaysia. The above data extends the known range of Megatyrus about 1,200 km to the west, and 870 km to the south.
Mycomya Rondani specimens from the islands of South-East Asia, i.e. Malaysia, Indonesia and the Philippines, are revised. The paper includes a key to the Mycomya species of the South-East Asian islands. The following six new species are described: M. shimai sp. n. from Java, Indonesia, M. pongo sp. n. from Sabah, Malaysia, and M. apoensis sp. n., M. nakanishii sp. n., M. paraklossi sp. n. and M. yatai sp. n. from Mindanao, the Philippines. The holotypes of M. klossi Edwards from Borneo, Malaysia, and M. minutata Edwards from Sumatra, Indonesia, were examined and their genitalia are described. M. occultans (Winnertz) is recorded from Java, Indonesia.
T. iban sp. nov. is described from the Lanjak Entimau Wildlife Sanctuary in Sarawak, Malaysian Borneo. Both sexes can be distinguished from all other species of Telosticta by the form of the antehumeral markings.
Three new species of Dasyrhicnoessa Hendel, 1934 and one of Pseudorhicnoessa Malloch, 1914 from the Indo-Pacific area are described and the male terminalia illustrated. Among these new species, Dasyrhicnoessa paradoxa sp. nov. and Pseudorhicnoessa longicerca sp. nov. are especially noteworthy for the morphological peculiarities of the male terminalia.
Haemonchus contortus is a highly pathogenic nematode parasite of sheep and goats. This work was conducted to investigate the population and host variations of the parasitic nematode H. contortus of sheep and goats from Malaysia and Yemen. Eight morphological characters were investigated, namely the total body length, cervical papillae, right spicule, left spicule, right barb, left barb, gubernaculum and cuticular ridge (synlophe) pattern. Statistical analysis showed the presence of morphological variation between populations of H. contortus from Malaysia and Yemen, with minor variation in the synlophe pattern of these isolates. Isolates from each country were grouped together in the scatterplots with no host isolation. Body, cervical papillae and spicule lengths were the most important characters that distinguished between populations of the two countries. This variation between Malaysia and Yemen may be attributed to geographical isolation and the possible presence of a different isolate of this worm in each country.
The direction that a snail (Mollusca: Gastropoda) coils, whether dextral (right-handed) or sinistral (left-handed), originates in early development but is most easily observed in the shell form of the adult. Here, we review recent progress in understanding snail chirality from genetic, developmental and ecological perspectives. In the few species that have been characterized, chirality is determined by a single genetic locus with delayed inheritance, which means that the genotype is expressed in the mother's offspring. Although research lags behind the studies of asymmetry in the mouse and nematode, attempts to isolate the loci involved in snail chirality have begun, with the final aim of understanding how the axis of left-right asymmetry is established. In nature, most snail taxa (>90%) are dextral, but sinistrality is known from mutant individuals, populations within dextral species, entirely sinistral species, genera and even families. Ordinarily, it is expected that strong frequency-dependent selection should act against the establishment of new chiral types because the chiral minority have difficulty finding a suitable mating partner (their genitalia are on the 'wrong' side). Mixed populations should therefore not persist. Intriguingly, however, a very few land snail species, notably the subgenus Amphidromus sensu stricto, not only appear to mate randomly between different chiral types, but also have a stable, within-population chiral dimorphism, which suggests the involvement of a balancing factor. At the other end of the spectrum, in many species, different chiral types are unable to mate and so could be reproductively isolated from one another. However, while empirical data, models and simulations have indicated that chiral reversal must sometimes occur, it is rarely likely to lead to so-called 'single-gene' speciation. Nevertheless, chiral reversal could still be a contributing factor to speciation (or to divergence after speciation) when reproductive character displacement is involved. Understanding the establishment of chirality, the preponderance of dextral species and the rare instances of stable dimorphism is an important target for future research. Since the genetics of chirality have been studied in only a few pulmonate species, we also urge that more taxa, especially those from the sea, should be investigated.
Tree snails of the subgenus Amphidromus s. str. are unusual because of the chiral dimorphism that exists in many species, with clockwise (dextrally) and counter-clockwise (sinistrally) coiled individuals co-occurring in the same population. Given that mating in snails is normally impeded when the two partners have opposite coil, positive frequency-dependent selection should prevent such dimorphism from persisting. We test the hypothesis that a strong population structure with little movement between tree-based demes may result in the fixation of coiling morphs at a very small spatial scale, but apparent dimorphism at all larger scales. To do so, we describe the spatial structure in a Malaysian population of A. inversus (Müller, 1774) with 36% dextrals. We marked almost 700 juvenile and adult snails in a piece of forest consisting of 92 separate trees, and recorded dispersal and the proportions of dextrals and sinistrals in all trees over a 7-day period. We observed frequent movement between trees (155 events), and found that no trees had snail populations with proportions of dextrals and sinistrals that were significantly different from random. Upon recapture 1 year later, almost two-thirds of the snails had moved away from their original tree. We conclude that population structure alone cannot stabilise the coil dimorphism in Amphidromus.
The manner in which a gastropod shell coils has long intrigued laypersons and scientists alike. In evolutionary biology, gastropod shells are among the best-studied palaeontological and neontological objects. A gastropod shell generally exhibits logarithmic spiral growth, right-handedness and coils tightly around a single axis. Atypical shell-coiling patterns (e.g. sinistroid growth, uncoiled whorls and multiple coiling axes), however, continue to be uncovered in nature. Here, we report another coiling strategy that is not only puzzling from an evolutionary perspective, but also hitherto unknown among shelled gastropods. The terrestrial gastropod Opisthostoma vermiculum sp. nov. generates a shell with: (i) four discernable coiling axes, (ii) body whorls that thrice detach and twice reattach to preceding whorls without any reference support, and (iii) detached whorls that coil around three secondary axes in addition to their primary teleoconch axis. As the coiling strategies of individuals were found to be generally consistent throughout, this species appears to possess an unorthodox but rigorously defined set of developmental instructions. Although the evolutionary origins of O. vermiculum and its shell's functional significance can be elucidated only once fossil intermediates and live individuals are found, its bewildering morphology suggests that we still lack an understanding of relationships between form and function in certain taxonomic groups.