Gigantism and the potential for interference competition in the rotifer genus Asplanchna

Summary Laboratory experiments showed that A. bright-welli could outreproduce, or coexist with, A. silvestrii only when the absence of dietary tocopherol prevented the latter from transforming to the giant cruciform and campanulate morphs. When tocopherol permitted polymorphic transformations, as often occurs in nature, the giant morphs of A. silvestrii ingested and rapidly excluded the much smaller, only slightly polymorphic A. brightwelli. Such interference (or encounter) competition from trimorphic Asplanchna species is known to occur in nature and must limit the distribution and abundance of monomorphic or only slightly polymorphic species. The ability to eat congeneric competitors may have provided some selective pressure for the evolution of gigantism in the genus.     

First record of Chinemesa Wygodzinsky (Hemiptera: Heteroptera: Reduviidae: Emesinae) from China,with the description of a new species

Summary

The “Borneo endemic” genus Chinemesa Wygodzinsky, 1966 is recorded from the mainland of Asia for the first time. A new species, Chinemesa chinensis n. sp., is described and illustrated. An updated key to species of Chinemesa is provided. Relationship between Chinemesa and Ocelliemesina Wang, Wang, Cao & Cai, 2015 is discussed, and diagnostic characters of Chinemesa are revised. Distribution of Chinemesa is briefly discussed.     

Revision ofAcanthopsoides Fowler, 1934 (Cypriniformes: Cobitidae), with the description of new species

The genusAcanthopsoides Fowler, 1934 is revised;Neacanthopsis Smith, 1945 is placed in the synonymy ofAcanthopsoides. In addition toAcanthopsoides gracilis Fowler, 1934 andAcanthopsoides gracilentus (Smith, 1945), four new species are described in the genus. These areA. delphax of the Salween, Chao Phraya and Mekong river basins,A. hapalias of the Mekong River basin,A. molobrion from peninsular Thailand, Malaysia and Borneo, andA. robertsi from the Kapuas River basin and adjacent areas, Borneo. The known distribution of the genus includes most of Southeast Asia.Acanthopsoides gracilis, A. gracilentus, and Adelphax are sympatric: Amolobrion and A. robertsi in the Kapuas River basin andA. gracilentus, A. delphax andA. hapalias in the Mekong River basin may be also. The increase in the diversityof Acanthopsoides recognized herein may be indicative of the level of the unknown diversity of the Southeast Asian freshwater fish fauna in general.     

Nest density and distribution of subterranean ants in an evergreen broadleaf forest in Japan with special reference to Amblyopone silvestrii

The density and distributions of nests of the subterranean ants were studied by excavation of thirty 1‐m² quadrats in an evergreen broadleaf forest in central Japan. A total of 20 ant species were collected and the densities of Amblyopone silvestrii and Paratrechina flavipes were highest (both 0.83 nests/m²). The distribution patterns were analyzed by the Standardized Morisita Index (I_p) for the five species that had mean densities of more than 0.5 nests/m². Of them, A. silvestrii and Hypoponera sauteri showed random distributions, while nests of Paratrechina flavipes were significantly overdispersed and those of Carebara yamatonis and Myrmecina nipponica were weakly clumped. These distributional patterns were discussed in connection with the ecology of the ants. In particular, the social organization of A. silvestrii was investigated based on the distributional pattern and the composition of collected colonies.     

Hypergastromyzon eubranchus,a new species of gastromyzontin loach (Homalopteridae) from Sarawak

Hypergastromyzon eubranchus sp. nov. is described from the Lupar basin of Sarawak, Malaysian Borneo. It differs from the only other known species ofHypergastromyzon, H. humilis, from the Kapuas basin of western Borneo, in having a very large gill opening instead of a greatly reduced one, 23–25 instead of 28–30 branched pectoral fin rays, and pelvic fins incompletely rather than completely united to each other posteriorly.     

Larval oophagy in the ant <Emphasis Type="Italic">Amblyopone silvestrii</Emphasis> (Hymenoptera,Formicidae)

Summary Larvae pass through five instars in the temperate, subterranean ponerine ant, Amblyopone silvestrii. Field colonies displayed a large decrease in the number of eggs during mid-summer, despite the fact that queens maintained fully developed ovaries with mature eggs. Observations of laboratory colonies indicate that cannibalism by 1st and 2nd instar larvae caused this decrease in egg number. These instars consumed a total of 66–75% of eggs in the nest, with each larva consuming 2–3 eggs before molting to the 3rd instar. At that time the larvae began to feed on arthropods. The preferred prey of A. silvestrii consists of entire centipedes; the large size of these prey items relative to the size of early instar larvae makes it difficult for the larvae to feed on these prey. Additionally, workers of A. silvestrii do not engage in oral trophallaxis. Consequently, oophagy is a plausible method to feed these very small larvae.     

Ancipirhynchus afossalis n. g., n. sp. (Trypanorhyncha: Otobothriidae), from two species of sharks off Indonesian and Malaysian Borneo

A new genus of trypanorhynch cestode is described from two species of sharks, the sliteye shark Loxodon macrorhinus Müller & Henle and the straight-tooth weasel shark Paragaleus tengi (Chen) collected in the Makassar Strait (off Indonesian Borneo) and Sulu Sea (off Malaysian Borneo). Ancipirhynchus afossalis n. g., n. sp. possesses two bothria and a heteroacanthous, heteromorphous tentacular armature with three distinctive files of hooks on the external tentacle surface but lacks prebulbar organs and gland cells within the tentacular bulbs. The hook arrangement of alternating files on the external surface of the tentacle resembles that seen in the superfamily Otobothrioidea Dollfus, 1942 in the genus Fossobothrium Beveridge & Campbell, 2005. However, the new species lacks the defining characteristic of this group, i.e. the paired bothrial pits. A Bayesian inference (BI) analysis of 37 LSU sequences of trypanorhynchs from three superfamilies provided evidence supporting the taxonomic placement of Ancipirhynchus afossalis n. g., n. sp. within the Otobothrioidea.     

A spectacular new species of Nepenthes L. (Nepenthaceae) pitcher plant from central Palawan,Philippines

A new species of Nepenthes L., N. attenboroughii (Nepenthaceae), from Palawan Island in the Philippines, is described and illustrated. It is restricted to rocky, ultramafic soils that comprise the summit region of Mount Victoria, Municipality of Narra, where it occurs in isolation from other members of the genus. On the basis of the morphological features, this new taxon appears to be related to both N. mira Jebb & Cheek of Palawan and N. rajah Hook.f. of Borneo. Its substantial size places it among the largest of known pitcher plants. The diagnostic morphological characters are discussed and an updated key is provided for a revised complex of Nepenthes species from the Palawan and North Borneo phytogeographical region. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 195–202.     

Araceae of Mulu National Park. I. Four new species of Schismatoglottis (Araceae)

Four new species of Schismatoglottis are described and illustrated from Mulu National Park in Malaysian Borneo: Schismatoglottis fossae (Patentinervia Clade), S. roseopedes and S. serratodentata (Calyptrata Clade) and S. pellucida (currently unplaced but likely in the Multinervia clade). A brief summary is provided of botanical exploration at Mulu, notably where pertinent to aroid botany.     

Endemic to Borneo or the Korean Cheju Island? Mystery of mislabelled land snail solved after 170 years (Gastropoda: Cyclophoroidea: Alycaeidae)

ABSTRACT

The alycaeid Cyclostoma spiracellum Adams & Reeve, 1850 (currently Dicharax spiracellum) was described from Borneo, based on shells from the expedition of HMS Samarang (1843–1846). A comparison with material of nearly all alycaeid species revealed that D. spiracellum is conchologically identical to Alycaeus kurodai Pilsbry & Hirase, 1908, which is described from the Korean Cheju Island. The land operculate snail fauna of Korea and Borneo do not overlap, and D. spiracellum has not been found in Borneo in spite of intensive recent collecting efforts. Therefore, it must be concluded that D. spiracellum does not occur in Borneo and that it was probably obtained when the Samarang visited Cheju Island, and the specimens were most likely mislabelled. As a result, A. kurodai is considered herein as a junior synonym of C. spiracellum, and the type locality of C. spiracellum (Borneo) is corrected to ‘probably Cheju Island, South Korea’. Chamalycaeus kurodai duplicatus Kuroda & Miyanaga, 1943 is treated as Dicharax spiracellum duplicatus (Kuroda & Miyanaga, 1943).     

Hoya peninsularis (Apocynaceae,Asclepiadoideae), a new species from Peninsular Malaysia,and notes on Hoya maingayi and Gongronema wrayi

A new species of Hoya from the western part of Peninsular Malaysia is described and illustrated as H. peninsularis. It has long been confused with Hoya finlaysonii because both have leaves with prominent darker venation, but can be distinguished on the corona lobe size and corolla pubescence. In addition, Hoya maingayi, a species earlier considered ‘doubtful and excluded' is typified and illustrated for the first time, and its distribution is shown to extend to Thailand. Gongronema wrayi is recognised as an earlier name and a new synonym for Hoya omlorii, a species previously considered to occur only in Borneo and Sumatra. The name is typified. An updated checklist of Hoya of Peninsular Malaysia is provided.     

Synanceia quinque,a new species of stonefish (Synanceiidae) from Borneo and Flores

A new species of stonefish, Synanceia quinque (Synanceiidae) is described on the basis of two specimens (61.5–84.4 mm standard length) collected off Sabah (Borneo), Malaysia and Flores, Indonesia. The new species is characterized by 12 pectoral-fin rays, and is most similar to Synanceia alula Eschmeyer and Rama-Rao 1973 (11 pectoral-fin rays in the latter vs. 14 or more in other congeners). Other characters distinguishing S. quinque from S. alula include numbers of pelvic-fin rays [I, 5 in the former vs. I, 3 or 4 (usually I, 4) in the latter], gill rakers (0 + 4 or 5 vs. 0 or 1 + 7), and five preopercular spines/skin flaps (upper three spines relatively well developed, lower two rudimentary) (vs. four preopercle spines, fifth spine or skin flap absent). An updated key to species of Synanceia is provided.

     

Mammalian species richness on islands on the Sunda Shelf,Southeast Asia

Summary A rich mammalian fauna is found on islands that lie on the Sunda Shelf, a continental shelf extending from Vietnam to Borneo and Java that was periodically exposed as dry land during the Pleistocene. The correlation between log of island area and number of species is high (r ²=0.94); the slope of the curve is moderate (z=0.235). Distance from small islands to source areas (=Borneo, Sumatra, and the Malay Peninsula) does not appear to affect species richness, nor does depth of water to source area (a measure of isolation time). A species-area curve for forest reserves of varying sizes on the Malay Peninsula has a low slope (z=0.104); comparison of the mainlaind and island curves indicates that decreasing island area is strongly correlated with increased extinction. Extinction has left reduced but ecologically balanced sets of species on all islands, except that carnivores are under-represented on all but the largest islands. Initial body size and rarity appear to play a significant role in determining the probability of extinction of individual species.     

The genus Pnyxiopalpus gen.n. (Diptera: Sciaridae)

Pnyxiopalpus gen.n. (type-species P. raptor sp.n.), Oriental in distribution, includes the following species: P. acanthipes sp.n. (Malay Peninsula), P. aculeatus sp.n. (Borneo), P. adebratti sp.n. (Borneo), P. aphrodite sp.n. (Sumatra), P. dentaneus sp.n. (Sulawesi), P. fossor sp.n. (Borneo), P. fuscinellus sp.n. (Borneo), P. hamatus sp.n. (Borneo), P. latifalx sp.n. (Borneo), P. macrocellus sp.n. (Malay Peninsula), P. microdon sp.n. (Sumatra), P. nepenthophilus sp.n. (Malay Peninsula), P. noona sp.n. (Palawan), P. raptor sp.n. (Borneo), P. reticulatus sp.n. (Malay Peninsula) and P. simplex sp.n. (Borneo). Males and females are keyed and described. Pnyxiopalpus has a number of characters previously unknown in Sciaridae. In contrast to other Sciaridae, interspecific morphological variation is greater for the females compared to the males. Based on a parsimony analysis of sixty-four morphological characters, Pnyxiopalpus is monophyletic, and its sister group appears to be Spathobdella Frey + {[Peyerimhoffia Kieffer + (Faratsiho Paulian + Pnyxia Johannsen)] + [Hyperlasion Schmitz + (Hermapterosciara Mohrig & Mamaev + Parapnyxia Mohrig & Mamaev)]}. According to the most parsimonious solution, the monophyly of Hyperlasion, Lycoriella Frey and Plastosciara Berg in their current sense is questioned. Aptery and one-segmented maxillary palp, usually regarded as important in sciarid classification, show a lot of homoplasy.     

Subterranean species of the ant genus Crematogaster in Asia (Hymenoptera: Formicidae)

Three Crematogaster ant species, C. (Orthocrema) javanica Menozzi, C. (O.) myops Forel and C. (O.) masukoi sp. nov., share reduced compound eyes which characterizes them among Asian species of the subgenus Orthocrema. The new species is described based on material from Borneo. It can be distinguished from C. javanica and C. myops by its smooth surface of clypeus and acutely produced subpetiolar process. Reduced compound eyes and yellowish body suggest that these three species are subterranean.     

A new genus and species from Borneo and a new species from Java and Sumatra of Cicadini (Hemiptera: Cicadidae)

A new cicada genus and species, Minilomia triquetra, gen. and sp. nov., is described from Borneo. The new genus Minilomia is closely allied to Platylomia Stål and is placed in the subtribe Dundubiina of the tribe Cicadini. Another new cicada species, Pomponia brevicaudata, sp. nov. (subtribe Psithyristriina), is described from Java and Sumatra. The new species belongs to the Pomponia linearis species group and the P. linearis species complex but is distinguished from its congeners by the unusually short male abdomen.     

<Emphasis Type="Italic">Decacotyle cairae</Emphasis> n. sp. (Monogenea: Monocotylidae) from the gills of <Emphasis Type="Italic">Pastinachus</Emphasis> sp. (Elasmobranchii: Dasyatidae) from the South China Sea off Sarawak,Borneo, Malaysia

Decacotyle cairae n. sp. (Monogenea: Monocotylidae) is described from the gills of an unidentified species of Pastinachus collected in the South China Sea off Sematan and Mukah, Sarawak, Borneo, Malaysia. D. cairae can be distinguished from the other six members of the genus by the presence of two simple unsclerotised accessory structures on the dorsal surface of the haptor in combination with a long, narrow, looping male copulatory organ. The host specimens of Pastinachus collected in Borneo also appear to be a new species and the monogenean data support this conclusion. A key to species of Decacotyle is given and their host-specificity is discussed.     

Toxicity of rhizomes of the invasive Hedychium coronarium (Zingiberaceae) on aquatic species

The production and release of chemical compounds by invasive plants can affect competitors and native species overall, destabilizing ecological interactions and harming ecosystem functioning. Hedychium coronarium is an invasive macrophyte common on Brazilian riparian areas that produces a wide variety of allelochemicals, but little is known about their effect on aquatic species. Here, we identified the major chemical compounds of the aqueous extract of H. coronarium rhizomes and assessed its toxicity, evaluating the growth inhibition of one alga (Raphidocelis subcapitata) and one macrophyte (Lemna minor), and the lethality of cladoceran (Ceriodaphnia silvestrii and Daphnia similis) and Chironomidae larvae (Chironomus sancticaroli). The majoritarian compounds of H. coronarium rhizomes were Coronarin D and Coronarin D Ethyl Ether. The aqueous extract was toxic for all tested species. We observed growth inhibition in R. subcapitata, as well as reduction in biomass in L. minor. Chironomus sancticaroli and cladoceran were the most sensible species. The aqueous extract of H. coronarium rhizomes was toxic on tested conditions, suggesting that the rhizome compounds may interfere on aquatic organisms and in the dynamic of trophic webs of aquatic ecosystems on invaded areas.

     

The Stenus of Borneo (Coleoptera: Staphylinidae)*

A key is given to the 21 species of Stenus at present known from Borneo; six of these are described as new. Notes on the species groupings and their geographical distribution are included.