Authorship and validity of two flatheads, <Emphasis Type="Italic">Platycephalus japonicus</Emphasis> and <Emphasis Type="Italic">Platycephalus crocodilus</Emphasis> (Teleostei: Platycephalidae)

The authorship of Platycephalus japonicus and Platycephalus crocodilus is researched. Although many authors have considered that the authorship of these flatheads can be attributed to Tilesius (1812), we consider that Cuvier in Cuvier and Valenciennes [ex Tilesius] (1829) has valid authorship of them. Platycephalus isacanthus, Platycephalus borboniensis and Platycephalus guttatus were also established by Cuvier in the same publication. The conspecificity of these three species and the precedence of P. japonicus are reconfirmed in this study. Although many authors have recognized the validity of P. guttatus, its holotype is identical to P. crocodilus. We also establish the precedence of P. crocodilus over P. guttatus.     

Spermatozoal ultrastructure of Penaeus kerathurus and Penaeus japonicus (Crustacea,Dendrobranchiata)

Summary An ultrastructural comparison between the unistellate spermatozoa of the shrimps Penaeus kerathurus and P. japonicus reveals a number of similarities that are common among dendrobranchiates, but also some marked differences which would confirm the validity of a potential use of sperm structure in systematic and phylogenetic studies. Typical morphological features shared by the spermatozoa of P. kerathurus and P. japonicus are: a membrane-bound acrosomal vesicle consisting of a cap and spike; non-membrane-bound filamentous chromatin; a perinuclear cytoplasmic band including degenerative membranous organelles (mostly mitochondria), small vesicles with a dense core and parallel membrane lamellae. Discordant spermatozoal characteristics between both species involve a significantly different size (ca. 5 m in length by ca. 3 m in diameter in P. kerathurus; ca. 8 m in length by ca. 4.7 m in diameter in P. japonicus), the occurrence of intranuclear lipid droplets only in P. kerathurus and the presence of a deeper subacrosomal space in this species as compared to P. japonicus. It is very likely that the most significant difference between both species is, however, the appearance of microtubule bundles in the spermatozoon of P. japonicus. So far, the occurrence of spermatozoal microtubules in decapod crustaceans appears to be restricted to reptantian species, whereby the finding of such elements in sperm of a dendrobranchiate shrimp could be of phylogenetic interest.     

Distribution of two sympatric amphidromous grazing fish Plecoglossus altivelis Temminck & Schlegel and Sicyopterus japonicus (Tanaka) along the course of a temperate river

Densities of two sympatric amphidromous grazing fishes, Plecoglossus altivelis and Sicyopterus japonicus, and gross primary production of benthic algae were investigated at the second, third and fourth-order sites located, respectively, 7.0, 6.7 and 3.6 km from the mouth of the Choshi River, Japan. Gross primary production estimated by multiplying gross photosynthetic rates by hours of insolation on the streambed increased downstream with decreasing canopy cover by valley walls and trees standing along the river. Density of P. altivelis was greatest at the fourth-order site with the higher primary production, while the distribution pattern of S. japonicus differed between adult (> ca. 7 cm in total length) and young individuals. Density of adult of S. japonicus was greater at the third-order site, although the young were more abundant at the fourth-order site. Aggressive acts against conspecifics and different species were observed only by adults of S. japonicus and most frequently observed at the third-order site. The upstream shift in the distribution of the adults of S. japonicus would mitigate interference competition with P. altivelis and contribute to their coexistence in the river. Handling editor: K. Martens     

Taxonomic Study of Korean Chrysochraontini (Orthoptera: Acrididae: Gomphocerinae)

Five species of Korean Chrysochraontini are recognized through the taxonomic investigation. Among them Chrysochraon dispar major Uvarov, 1925 is newly recorded from North Korea, and Euthystira pavlovskii Bey‐Bienko, 1954 is synonymized under Mongolotettix japonicus (Bolívar, 1898). A key is provided, and morphological variations of M. japonicus are discussed.     

Comparative studies on the seasonal occurrence,nymphal development and food menu in two giant water bugs,Diplonychus japonicus vuillefroy andDiplonychus major esaki (Hemiptera: Belostomatidae)

We compared the seasonal changes in population density and nymphal development at different water temperatures and under different food conditions between two giant water bugs, Diplonychus japonicus and D. major, in Okayama, Japan. D. japonicus produced 1–2 generations a year, while D. major was strictly inivoltine. The developmental velocity was higher in D. japonicus than in D. major. The thermal constant of D. japonicus was less than that of D. major. These results suggest that D. japonicus is adapted, to higher water temperature than D. major. In the field, D. japonicus preyed predominately on Lymnaeidae and Physidae snails, while D. major preyed on aquatic insects such as dragonfly nymphs.     

<Emphasis Type="Italic">Humulus japonicus</Emphasis> Accelerates the Decomposition of <Emphasis Type="Italic">Miscanthus sacchariflorus</Emphasis> and <Emphasis Type="Italic">Phragmites australis</Emphasis> in a Floodplain

Humulus japonicus in communities of Miscanthus sacchariflorus and Phragmites australis can grow large enough to overtop other species in the Amsa-dong floodplain. Because of strong winds and the weight of Humulus, plants of M. sacchariflorus and P. australis fell in mid-August and were subject to decomposition under its dense shading. To assess the effects of H. japonicus on nutrient cycling in these communities, we collected fresh samples of M. sacchariflorus and P. australis in litterbags and decomposed them under H. japonicus for 9 months, beginning in August. Biomass and organic contents from M. sacchariflorus during this incubation period were 49–51% and 44–48%, whereas those of P. australis were 49–61% and 32–52%, respectively. Their annual k values were 1.61–1.74 and 1.46–3.54, respectively. Initial N concentrations in M. sacchariflorus and P. australis were 13 and 20 mg g⁻¹, while C:N ratios were 31 and 21, respectively. These results indicate that H. japonicus is responsible for the collapse of M. sacchariflorus and P. australis in August and also accelerates their nutrient cycling through rapid decomposition, thereby increasing nutrient circulation in floodplains.     

Taxonomic identity of caricicolousPuccinia host-alternating onPetasites in Japan

Uredinial-telialPuccinia fungi onCarex shimizuensis in Nagano Pref. and onC. dimorpholepis in Ibaraki Pref. were proven to host-alternate onPetasites japonicus by field observations and inoculation experiments. These fungi from the two localities were morphologically similar and were compared with three describedPuccinia species that host-alternate betwenCarex species andP. japonicus in Japan, i.e.,P. caricis-petasitidis, P. caricis-flabellatae andP. caricis-podogynae. The three previously described species and the newly foundPuccinia fungi were morphologically indistinguishable at all stages of the life cycle; therefore, it was concluded that three species and the two newly found fungi are taxonomically identical, in whichP. caricis-petasitidis has nomenclatural priority.     

Transformation of o-toluate in Pseudomonas putida isolate 1065 and Rhizopus japonicus ATCC 24794

Summary Among various soil microorganisms tested only Pseudomonas putida isolate 1065 and Rhizopus japonicus ATCC 24794 were able to transform o-toluate. In P. putida o-toluate was quantitatively hydroxylated to give 2-hydroxymethyl-benzoate and in R. japonicus it was reduced to 2-hydroxymethyltoluene. Both compounds, which were identified on the basis of their physical properties, accumulated during a one week growth period.     

Type studies of <Emphasis Type="Italic">Pleurotus</Emphasis> reported from Japan

Eight type specimens of Pleurotus reported from Japan were examined. Four new combinations, Marasmius alopecius, Omphalotus guepiniformis, Marasmiellus leiophyllus, and Hohenbuehelia squamula, are proposed. Pleurotus cyatheae is accepted in the original genus. The following species are synonyms: Pleurotus harmandii, a synonym of Omphalotus guepiniformis; P. minutoniger, a synonym of Resupinatus striatulus; and P. pulchellus, a synonym of Hohenbuehelia tremula. Omphalotus japonicus (= Lampteromyces japonicus) is a synonum of O. guepiniformis.     

Cyanogenic glycosides: a case study for evolution and application of cytochromes P450

Cyanogenic glycosides are ancient biomolecules found in more than 2,650 higher plant species as well as in a few arthropod species. Cyanogenic glycosides are amino acid-derived β-glycosides of α-hydroxynitriles. In analogy to cyanogenic plants, cyanogenic arthropods may use cyanogenic glycosides as defence compounds. Many of these arthropod species have been shown to de novo synthesize cyanogenic glycosides by biochemical pathways that involve identical intermediates to those known from plants, while the ability to sequester cyanogenic glycosides appears to be restricted to Lepidopteran species. In plants, two atypical multifunctional cytochromes P450 and a soluble family 1 glycosyltransferase form a metabolon to facilitate channelling of the otherwise toxic and reactive intermediates to the end product in the pathway, the cyanogenic glycoside. The glucosinolate pathway present in Brassicales and the pathway for cyanoalk(en)yl glucoside synthesis such as rhodiocyanosides A and D in Lotus japonicus exemplify how cytochromes P450 in the course of evolution may be recruited for novel pathways. The use of metabolic engineering using cytochromes P450 involved in biosynthesis of cyanogenic glycosides allows for the generation of acyanogenic cassava plants or cyanogenic Arabidopsis thaliana plants as well as L. japonicus and A. thaliana plants with altered cyanogenic, cyanoalkenyl or glucosinolate profiles.     

Lotus japonicus Infested with Herbivorous Mites Emits Volatile Compounds That Attract Predatory Mites

Lotus Japonicus has an indirect defense mechanism against spider mites, Tetranychus urticae, we investigated the responses of predatory mites, Phytoseiulus persimilis, to volatile compounds released from T. urticae-infested L. japonicus in a Y-tube olfactometer. Plants infested with spider mites attracted more P. persimilis than did clean air. Uninfested plants and artificially damaged plants did not attract P. persimilis. When infested by spider mites, L. japonicus plants started emitting (Z)-3-hexenyl acetate, (E)-4,8-dimethyl-1,3,7-nonatriene, germacrene d, 1-octen-3-ol and methyl salicylate (MeSA). These compounds were considered to be T. urticae-induced plant volatile compounds. When three L. japonicus mutants deficient in nodule organogenesis were infested by the spider mites, they all attracted P. persimilis. However, two of the infested mutants emitted blends of induced volatile compounds that were qualitatively different from those emitted from infested wild type L. japonicus. Received 8 August 2000/ Accepted in revised form 12 October 2000     

Life history,distribution and molecular phylogenetics of the Upward-Mouth Spikefish Atrophacanthus japonicus (Teleostei: Tetraodontiformes: Triacanthodidae)

Ninety-six juvenile specimens (37–54 mm standard length; L_S) of the rarely collected Upward-Mouth Spikefish Atrophacanthus japonicus (Triacanthodidae) were obtained from the stomachs of three Yellowfin Tuna Thunnus albacares collected off Guam in the Mariana Islands in the central Pacific Ocean. These specimens extend the range of A. japonicus eastward into Oceania. We review the systematic characters of the monotypic genus Atrophacanthus and present colour photographs of freshly collected specimens. The diet of the juvenile specimens of A. japonicus consisted of thecosome pteropods and foraminiferans. We present a range map of A. japonicus based on all known specimens and show that specimen size is related to whether specimens were collected in the pelagic zone or on the bottom. Our results support that, compared to all other Triacanthodidae, A. japonicus has an unusually extended pelagic larval and juvenile period, up to 54 mm L_S, before settling to the bottom as adults. Lastly, we provide a multilocus phylogeny addressing the phylogenetic placement of Atrophacanthus based on eight of 11 triacanthodid genera and six genetic markers. Our results reveal that Atrophacanthus is the sister group of Macrorhamphosodes and they provide new insights about the evolutionary history of the family.     

Predator and parasitoid attacking ant-attended aphids: effects of predator presence and attending ant species on emerging parasitoid numbers

Interaction between a predator and a parasitoid attacking ant-attended aphids was examined in a system on photinia plants, consisting of the aphid Aphis spiraecola, the two ants Lasius japonicus and Pristomyrmex pungens, the predatory ladybird beetle Scymnus posticalis, and the parasitoid wasp Lysiphlebus japonicus. The ladybird larvae are densely covered with waxy secretion and are never attacked by attending ants. The parasitoid females are often attacked by ants, but successfully oviposit by avoiding ants. The two ants differ in aggressiveness towards aphid enemies. Impacts of the predator larvae and attending ant species on the number of parasitoid adults emerging from mummies per aphid colony were assessed by manipulating the presence of the predator in introduced aphid colonies attended by either ant. The experiment showed a significant negative impact of the predator on emerging parasitoid numbers. This is due to consumption of healthy aphids by the predator and its predation on parasitized aphids containing the parasitoid larvae (intraguild predation). Additionally, attending ant species significantly affected emerging parasitoid numbers, with more parasitoids in P. pungens-attended colonies. This results from the lower extent of interference with parasitoid oviposition by the less aggressive P. pungens. Furthermore, the predator reduced emerging parasitoid numbers more when P. pungens attended aphids. This may be ascribed to larger numbers of the predator and the resulting higher levels of predation on unparasitized and parasitized aphids in P. pungens-attended colonies. In conclusion, a negative effect of the predator on the parasitoid occurs in ant-attended aphid colonies, and the intensity of the interaction is affected by ant species.     

不同生境下川麦冬根围土壤丛枝菌根真菌多样性北大核心CSCD

采用高通量(Illumina Miseq)测序技术对栽培和野生2种生境下川麦冬根围的丛枝菌根(AM)真菌多样性和群落结构进行测定,并结合土壤理化因子进行相关性分析,以明确两种生境下川麦冬根围土壤AM真菌多样性和优势群落的分布特点,探讨AM真菌群落分布差异的驱动因子,为AM真菌应用于麦冬生产提供理论依据和技术支持。结果表明:(1)不同生境下川麦冬根围土壤中共鉴定出AM真菌3属10种,其中野生川麦冬根围土壤鉴定出的AM真菌3属7种,分别隶属于无梗囊霉属(Acaulospora)、多孢囊霉属(Diversispora)和球囊霉属(Glomus),而栽培环境下鉴定出AM真菌1属6种,隶属于球囊霉属。2个生境优势属均为球囊霉属。(2)不同生境下川麦冬根围AM真菌之间存在显著差异,野生生境下川麦冬根围土壤AM真菌多样性指数ACE和Shannon均显著高于人工栽培生境,而Simpson指数则相反。(3)相关性分析表明,AM真菌多样性指数及群落组成结构均与土壤理化因子存在相关性,其中全钾(TK)、全磷(TP)、全氮(TN)对AM真菌多样性指数和群落结构组成均存在显著影响。研究认为,不同生境下川麦冬根围AM真菌群落存在显著差异,球囊霉属为川麦冬互利共生的关键属,TK、TP、TN是不同生境川麦冬根围AM真菌群落差异的主要驱动因子。     

Length‐weight relationships for three zoarcoid fish species from the coastal waters of the northern Yellow Sea,China

Length–weight relationships (LWRs) were determined for three zoarcoid fish species: Zoarces elongatus Kner, 1868, Pholis fangi (Wang & Wang, 1935) and Chirolophis japonicus Herzenstein, 1890. Samples were collected from the coastal waters of the northern Yellow Sea (near Dalian City) using bottom trawl nets (20 mm stretched mesh size in the cod‐end) for Zoarces elongatus and Pholis fangi and set gill nets (mesh size 15.6 mm) for Chirolophis japonicus. Samples were taken from mid‐March to early April 2017. Parameter b values in the fitted LWRs were 3.119, 3.440 and 3.423 for Z. elongatus, P. fangi and C. japonicus, respectively.     

Microbial diversity in the tick Argas japonicus (Acari: Argasidae) with a focus on Rickettsia pathogens

The soft tick Argas japonicus mainly infests birds and can cause human dermatitis; however, no pathogen has been identified from this tick species in China. In the present study, the microbiota in A. japonicus collected from an epidemic community was explored, and some putative Rickettsia pathogens were further characterized. The results obtained indicated that bacteria in A. japonicus were mainly ascribed to the phyla Proteobacteria, Firmicutes and Actinobacteria. At the genus level, the male A. japonicus harboured more diverse bacteria than the females and nymphs. The bacteria Alcaligenes, Pseudomonas, Rickettsia and Staphylococcus were common in nymphs and adults. The abundance of bacteria belonging to the Rickettsia genus in females and males was 7.27% and 10.42%, respectively. Furthermore, the 16S rRNA gene of Rickettsia was amplified and sequenced, and phylogenetic analysis revealed that 13 sequences were clustered with the spotted fever group rickettsiae (Rickettsia heilongjiangensis and Rickettsia japonica) and three were clustered with Rickettsia limoniae, which suggested that the characterized Rickettsia in A. japonicus were novel putative pathogens and also that the residents were at considerable risk for infection by tick‐borne pathogens.     

The effect of bacteria on interspecific relationships between the euryhaline rotifer Brachionus rotundiformis and the harpacticoid copepod Tigriopus japonicus

Inconsistent results have been obtained on the population growth of Brachionus rotundiformis and Tigriopus japonicus, when results from single-species and two-species mixed cultures are compared. Bacteria growth was not regulated in these experiments, which could be the cause for this. In order to test this possibility, we conducted similar experiments under axenic and synxenic (with presence of one species of bacteria) conditions. The population growth of B. rotundiformis was suppressed by the presence of T. japonicus in axenic cultures. T. japonicus could not persist in axenic cultures, but its population increased when grown in synxenic cultures. T. japonicus used RT bacteria strain as a food source, while these bacteria were toxic to B. rotundiformis. These results suggest that bacteria can modify the interspecific relationship between B. rotundiformis and T. japonicus.     

Genetic differences among three species of the genus Trichiurus (Perciformes: Trichiuridae) based on mitochondrial DNA analysis

The mitochondrial DNA segment encoding the 16S ribosomal RNA (16S rRNA) gene sequence (ca. 600 bp) was compared among Trichiurus sp. 2 (sensu Nakabo, 2002) (obtained from various areas of Japan), T. japonicus Temminck and Schlegel (collected from various localities within Japan), and true T. lepturus Linnaeus (caught off the Atlantic coast of the United States and Brazil) of the family Trichiuridae using 10, 10, and 15 specimens, respectively. Based on phylogenetic analysis using a neighbor-joining (NJ) algorithm, the haplotypes of Trichiurus sp. 2, T. japonicus, and T. lepturus indicated three distinct monophyletic lineages, being supported by 100% bootstrap values with no haplotypes overlapping or sharing among the lineages. Trichiurus sp. 2, T. japonicus, and T. lepturus are genetically different from each other, suggesting that they are three distinct species.