Whole-leaf fluorescence imaging to visualize in planta fungal structures of Victory onion leaf rust fungus,Uromyces japonicus,and its taxonomic evaluation

Uromyces japonicus is an autoecious leaf rust of Allium victorialis sensu lato. The rust forms concentric sori on the adaxial surface of host leaves. This fungus is a potential pathogen for economically important Allium plants. Initially, we observed in planta fungal structures using newly developed whole-leaf fluorescent imaging method to evaluate the rust lesion formation process. We then confirmed conspecificity of Japanese and European populations by comparing the morphological characteristics and rDNA sequences. In addition, we estimated phylogenetic relationships among rust fungi on Allium plants. In this study, we designate an epitype of U. japonicus based on fresh specimens from Japan.     

Amylostereum laevigatum associated with the Japanese horntail,Urocerus japonicus

The fungus associated with the Japanese horntail,Urocerus japonicus, in Kochi, Kagawa and Ehime Prefectures was studied. Cultures isolated from the mycangia of 113 adult females of the horntail showed the same cultural characteristics. Four of basidiocarps found on felled logs ofCryptomeria japonica were identifieds asAmylostereum laevigatum based on morphological characteristics. This was the first record ofA. laevigatum from Japan. The cultures isolated from the basidiocarps had the same cultural characteristics as those from the mycangia ofU. japonicus. One mycangial isolate produced basidiocarps on artificially inoculated stem segments ofCr. japonica after a 6-mo incubation and was identified asA. laevigatum. One isolate from the basidiocarps ofA. laevigatum and one from the mycangium ofU. japonicus were artificially inoculated into five trees each ofChamaecyparis obtusa andCr. japonica. The wood of all inoculated trees showed discoloration, with no difference in shape and pattern of discoloration between the two isolates. The inoculated fungi were reisolated from the areas of discoloration in the inoculated trees.     

Revision of the wobbegong genus <Emphasis Type="Italic">Orectolobus</Emphasis> from Japan,with a redescription of <Emphasis Type="Italic">Orectolobus japonicus</Emphasis> (Elasmobranchii: Orectolobiformes)

The wobbegong genus Orectolobus occurring from Japan and its adjacent waters was reviewed, and O. japonicus was redescribed using ten specimens including a syntype. Only one species, O. japonicus, was regarded as valid among three species previously recorded from Japan. Orectolobus maculatus had been erroneously described from Japan because of the past nomenclatural confusion with O. japonicus. The specimen called “Karakusa-oose,” which had been identified with O. ornatus, was regarded as an irregular form of O. japonicus. Orectolobus japonicus was distinguished from the other congeners by having no tubercles on the body, five to eight dermal lobes in the preorbital group, two distally notched lobes in the postspiracular group, no dermal lobes on lower jaw, nasal barbel with a branch, no supraocular knob, relatively high dorsal fins with usually concave posterior margins, a lower number of precaudal vertebrae and intestinal valve turns, saddles on the back without black borders and yellowish and variously shaped blotches, not forming white O-shaped spots.     

Egg parasitoids (Hymenoptera: Mymaridae) of Amrasca biguttula (Ishida) (Hemiptera: Cicadellidae) on Okinawa Island,a pest of okra in Japan

The fairyfly Anagrus (Anagrus) japonicus Sahad (Hymenoptera: Mymaridae) is identified for the first time as an egg parasitoid of the okra leafhopper Amrasca (Sundapteryx) biguttula (Ishida) (Hemiptera: Cicadellidae) on Okinawa Island, Japan. Amrasca biguttula is a serious pest of okra, Abelmoschus esculentus (L.) Moench (Malvaceae), both in Okinawa and Bonin Islands. Female of A. japonicus is redescribed, and its previously unknown male is described, based on the reared specimens from Okinawa. Prior to this study, host associations of A. japonicus were unknown. Another species of Mymaridae, Arescon enocki (Subba Rao and Kaur), also emerged from eggs of A. biguttula on okra in Okinawa, albeit in much smaller numbers.     

A new species of Megoura (Hemiptera,Aphididae) from Japan

A new species of the genus Megoura, M. lathyricola sp. n., was collected from Lathyrus japonicus subsp. japonicus (Leguminosae) in seashore areas of northern and southern Japan. This species is described and illustrated, and a revised key to the identification of the world species of Megoura is presented.     

THE IDENTITY OF PHOTOBIONTS FROM THE LICHENPYRENULA JAPONICA

Nine specimens ofPyrenula japonicaKurokawa were collected from various areas in Japan. Photobionts were isolated from their thalli and studied taxonomically. As a result, only one species of green alga,Trentepohlia lagenifera(Hild.) Wille was identified as the photobiont ofPyrenula japonica. This is the first record of this alga from the lichen genusPyrenula.     

Phylogeography of Rhabdias spp. (Nematoda: Rhabdiasidae) collected from Bufo species in Honshu,Shikoku, and Kyushu,Japan including possible cryptic species

The genus Rhabdias Stiles & Hassall, 1905 comprises lung parasites of amphibians and reptiles worldwide. In Japan, 9 species have been recorded, including Rhabdias incerta Wilkie, 1930 which has been reported only in Bufo species. In this study, to assess the diversity of R. incerta, we performed molecular analyses of Rhabdias species sampled from three species/subspecies of Japanese toads namely Bufo japonicus, B. japonicus formosus, and B. torrenticola, collected in various regions of Honshu, Shikoku, and Kyushu, Japan. DNA sequence divergence was compared using mtDNA (COI) and nuclear DNA (28S) to identify possible cryptic species. Morphological analysis was performed through light microscopy and scanning electron microscopy (SEM). The results revealed that Bufo spp. serve as hosts for at least three Rhabdias species. Morphologically, most samples were identified as R. incerta but with a longer body and larger buccal cavity than originally described. Rhabdias incerta appears to be specific to the genus Bufo and is further subdivided into two or three phylogroups based on subspecies divisions and biogeography of their host. Some Rhabdias specimens collected in this study resemble R. tokyoensis Wilkie, 1930, parasitic in hosts from the order Caudata, which suggests host switching. Both molecular and morphological analyses suggested the presence of undescribed and cryptic Rhabdias species within toads collected in Japan. This study was the first to molecularly characterize Rhabdias species in Japan, including novel sequences of R. incerta and two undescribed species.     

A taxonomic issue of two species of Trissolcus (Hymenoptera: Platygastridae) parasitic on eggs of the brown-winged green bug,Plautia stali (Hemiptera: Pentatomidae): resurrection of T. plautiae,a cryptic species of T. japonicus revealed by morphology,reproductive isolation and molecular evidence

Trissolcus plautiae (Watanabe) is known as a major egg parasitoid of the brown-winged green bug Plautia stali Scott, which is a serious pest of various fruit trees in Japan. Although T. plautiae was synonymized with T. japonicus (Ashmead) in 1981, both scientific names have been used for the same egg parasitoid of P. stali for about the past 30 years because of their taxonomic confusion. To promote an effective IPM program for P. stali using its egg parasitoids, we attempted to resolve the confusion by the use of a variety of methods. On detailed observation of adult morphology, we found that sublateral setae on the T1 are present in T. plautiae and absent in T. japonicus, and that this morphological difference is corroborated by more subtle differences between the two species. This finding supports the view that they are different species. The view was also supported by the results of mating experiments to determine the reproductive isolation of T. plautiae from T. japonicus and DNA analysis of these two species. We conclude that T. plautiae is a cryptic species of T. japonicus and resurrect T. plautiae from T. japonicus stat. rev.     

A taxonomic Study of Species of Bothriocephalus Rudolphi, 1808 (Cestoda: Pseudophyllidea) from Eels in Japan: Morphological and Molecular Evidence for the Occurrence of B. claviceps (Goeze, 1782) and Confirmation of the Validity of B. Japonicus Yamaguti, 1934

A taxonomic study of specimens of Bothriocephalus from eels (Anguilla spp.) in Japan has demonstrated the occurrence of two species, B. claviceps (Goeze, 1782) and B. japonicus Yamaguti, 1934. The former species is a parasite of eels (A. anguilla and A. rostrata) in the Holarctic Region and was recently reported from A. marmorata in Japan. The conspecificity of tapeworms newly found in an eel (A. ? japonica) from Lake Biwa, central Japan, with B. claviceps has been confirmed by the great similarity of their ITS-2 gene sequences (similarity 95.3% and 95.2%). However, the sequences of worms identified as B. claviceps from A. marmorata differed considerably from those of B. claviceps from two populations of A. anguilla from Europe and the above-mentioned one from Japan (similarity 66.3%, 67.1% and 65.1 %, respectively), thus indicating that the former cestodes may have been misidentified. This assumption was confirmed by morphological evaluation of a voucher specimen from A. marmorata. The morphology of this cestode, as well as those from A. japonica from two localities in Japan (Lakes Biwa and Suwa), indicates their conspecificity with B. japonicus. The validity of this taxon has been confirmed on the basis of a re-examination of the type-specimens. The two taxa, B. japonicus and B. claviceps, differ from each other in the shape and length of the scolex (619–730 μm in B. japonicus versus 1,180–2,100 μm in B. claviceps), the relative position of the cirro-vaginal and uterine pores (opposite each other in relation to the median line of the body in B. japonicus versus tandem or slightly offset along the median line in the latter species), and the size of the eggs (41–52 × 28–35 μm in B. japonicus versus 50–70 × 31–43 μm in B. claviceps).

     

Galeus longirostris,a new species of the sawtail catshark from Japan

Galeus longirostris sp. nov. is described based on 46 specimens taken off the southern part of Japan. It is distinguished from all known species ofGaleus in having a considerably longer snout. This species is morphologically close toG. nipponensis, which commonly occurs off the southern part of Japan, but differs in having longer preoral length than the mouth width, a bluntly rounded snout, larger pectoral fins, a shorter interspace between anal and lower caudal fins, and a greater number of monospondylous vertebrae.     

Morphometric Differences between Two Smelt Species, <Emphasis Type="Italic">Hypomesus japonicus</Emphasis> (Brevoort, 1856) and <Emphasis Type="Italic">H. nipponensis</Emphasis> (McAllister, 1963) (Pisces: Osmeridae) from The Northwestern Part of the Sea of Japan

Two smelt species that inhabit the northwest of the Sea of Japan, Hypomesus japonicus and H. nipponensis (family Osmeridae), which are both currently referred to as Japanese smelt, have been studied in order to clarify the taxonomic value of morphometric characters. Variations between individuals of these species have been revealed using a multivariate analysis of their morphometric characters and indices. The results of the analysis show that H. japonicus is distinguished from H. nipponensis both by the previously known characters (the eye diameter is smaller and the vertical through the beginning of the dorsal fin is closer to the head than that through the beginning of the pelvic fins) and by a greater height of the dorsal and adipose fins in the former species as defined in the paper. Within the species H. japonicus, the individuals sampled from Olga Bay are most similar morphologically to those from the coastal waters off the village of Terney. In contrast, the individuals of this species from the coastal waters off Russky Island and from Olga Bay manifest the greatest differences.     

Isolation and development of microsatellite markers for the Japanese dormouse, Glirulus japonicus

Eight microsatellite markers were developed for the Japanese dormouse (Glirulus japonicus), a natural monument and near‐threatened species in Japan. The markers amplify in individuals from all of the mitochondrial lineages detected in a previous study. Numerous polymorphisms were detected in specimens from a local population in central Honshu (11–21 alleles per locus; n = 31) and from the entire distribution range of the species (19–41 alleles per locus; n = 152). These microsatellites will be useful in conservation genetic studies of G. japonicus.     

Length‐weight relationships of four fish species from Visakhapatnam coast,India

Length‐weight relationships (LWRs) were determined for 4 deep water fish species from Visakhapatnam coast, India. Specimens were collected fortnightly between December 2013 and November 2015 from commercial trawls at Visakhapatnam fish landing centre (16.98°N–20.2°N, Long.82.19°–86.53°E). Individuals were captured between 100 and 300 m depth with shrimp trawl net (head rope length: 37–46 m and cod end mesh size: 30–40 mm). Total length (TL) (nearest to 0.1 cm) and body weights (nearest to 0.1 g) were taken each individual. All LWRs were significant with r² values ranged from 0.958 for Uranoscopus bicinctus Temminkc & Schlegel, 1843 to 0.983 for Uranoscopus chinensis Guichenot, 1882 and “b” values ranged from 2.832 for U. bicinctus to 3. 402 Synodus indicus (Day, 1873).This study provides a new maximum length data for three species (Uranoscopus bicinctus Temminkc & Schlegel, 1843; Uranoscopus chinensis Guichenot, 1882 and Uranoscopus marmoratus Cuvier, 1829).     

Seasonal occurrence and food habits of larvae and juveniles of two temperate basses in the Shimanto estuary,Japan

Larvae and juveniles ofLateolabrax japonicus andL. latus occurred from January to May 1986 in the shallow waters of the Shimanto estuary.L. japonicus markedly outnumberedL. latus. Distinct ecological differences were recognized in habitats and food habits between the two species:L. japonicus mainly inhabited eelgrass beds composed ofZostera nana, whileL. latus appeared evenly in both eelgrass beds and non-eelgrass habitats; the former fed on copepods and cladocerans, while the latter fed on copepods and fish larvae. From these habitat and food habit analyses, estuaries were considered to be important as a main habitat forL. japonicus, but not forL. latus. The fact that ecological differences have occurred during the early life stages was inferred to be one of the possible keys to speculate on the speciation of the two species.     

Anisakis spp. in fishery products from Japanese waters: Updated insights on host prevalence and human infection risk factors

The nematodes of the genus Anisakis are among the most relevant parasitic hazards in fishery products since they are responsible for human infection and allergy cases. In a food safety and epidemiological perspective, several marine hosts from different locations around Japan were examined to characterize the parasitism of Anisakis larvae. Chum salmon (Oncorhynchus keta) and Alaska pollock (Gadus chalcogrammus) showed the highest overall prevalence (100%), followed by blue mackerel (Scomber australasicus) (97.5%), Pacific cod (Gadus macrocephalus) (80%), chub mackerel (Scomber japonicus) (60.1%), Japanese flying squid (Todarodes pacificus) (17%) and Japanese pilchard (Sardinops sagax melanostictus) (2%). In Pacific krill (Euphausia pacifica), apart from one Hysterothylacium aduncum larva, no Anisakis specimens were detected. Anisakis simplex sensu stricto was molecularly identified (PCR-RFLP) for the first time in Japanese flying squid and Japanese pilchard distributed in the Northwestern Pacific ocean. That was the most frequent parasitic species detected followed by A. pegreffii, mostly in the western areas of Japan, hybrid genotypes between the two sibling species as well as A. typica and A. berlandi. Surprisingly, A. simplex s.s. was the most abundant species in one batch of chub mackerel from the East China Sea and A. pegreffii was the main species found in one batch from the Pacific coast of Aomori, which seems to indicate that the ranges of these two sibling species might be more variable than previously thought.     

Geographic distribution and environmental control of vertebral count in Ammodytes spp. along the northern Pacific coast of Japan

To examine species composition and population structures in sand lance (Ammodytidae) along the northern Pacific coast of Japan, genetic analysis were carried out for specimens collected in 2014 from Otsuchi Bay, Iwate, Ishinomaki Bay, Miyagi, off Soma, Fukushima and Ise–Mikawa Bays, Aichi. The samples consisted of Ammodytes japonicus and Ammodytes heian, of which the latter is a recently described species. Neither species exhibited significant genetic differences among localities. Only A. japonicus was found in the most southern locality at Aichi, but it decreased northward to <90% in Miyagi and Fukushima and the two species occurred almost evenly in Iwate suggesting a latitudinal cline in their species composition along the northern Pacific coast of Japan, off Tohoku. The vertebral counts differed between A. japonicus and A. heian with modes of 65 and 63, respectively, but this characteristic did not differ significantly within a locality (Iwate). This suggests that the vertebral counts of Ammodytes spp. in Japanese waters are probably strongly determined by the environment than by a species‐specific genetic trait.     

Morphological and genetic characteristics of sea bass,Lateolabrax japonicus, from the Ariake Sea, Japan

Sea bass,Lateolabrax japonicus, from the Ariake Sea, characterized by black dots on the lateral body region as in the Chinese sea bass,L. sp., were examined and compared morphologically and genetically withL. japonicus andL. sp. Some meristic characters of the Ariake form tended to fall midway between values for the two former species. Genetic features, evaluated by isozyme analyses, indicated that the Ariake form as represented a simple Mendelian population, there being no significant differences from a Hardy-Weinberg equilibrium according to chi-square tests. Although some extreme differences in allelic frequencies were found at some loci betweenL. japonicus andL. sp., the Ariake form possessed many heterozygotes at thePROT-1 ^* locus, in addition to allelic frequencies at some loci conforming to those ofL. sp. Average allele numbers per locus, rate of polymorphic loci and average heterozygosity of the Ariake form were higher than for eitherL. japonicus orL. sp., indicating high genetic variation in the former. The results suggested that the Ariake population is genetically independent of other populations ofL. japonicus, but might be genetically influenced byL. sp.     

Larvae of the exotic predatory ladybird <Emphasis Type="Italic">Platynaspidius maculosus</Emphasis> (Coleoptera: Coccinellidae) on citrus trees: prey aphid species and behavioral interactions with aphid-attending ants in Japan

An aphidophagous ladybird, Platynaspidius maculosus (Weise) (Coleoptera: Coccinellidae), is originally distributed in China, Taiwan, and Vietnam. The ladybird has recently intruded into the southern and central parts of Japan. The present study found that the larvae of this ladybird preyed on three aphid species, Aphis spiraecola, Aphis gossypii, and Toxoptera citricidus (all Hemiptera: Aphididae), feeding on young shoots of various Citrus species in August to early October in Shizuoka Prefecture, central Japan. Laboratory rearing of the sampled larvae confirmed that the larvae completed their development (adult emergence) by consuming each of the three aphid species. The ladybird larvae were observed foraging in aphid colonies attended by one of the four ants, Lasius japonicus, Pristomyrmex punctatus, Formica japonica, and Camponotus japonicus (all Hymenoptera: Formicidae). Field observations revealed that the foraging/feeding larvae were almost completely ignored by honeydew-collecting ants even when they physically contacted each other. Thus, in Japan, the larvae of the exotic ladybird exploit colonies of the three aphid species attended by one of the four ant species on many Citrus species. On the basis of the results, I discuss the possibility of the ladybird’s reproduction on citrus trees in Japan, probable adaptations of the ladybird larvae to aphid-attending ants, and potential impacts of the ladybird on native insect enemies attacking ant-attended aphids on citrus.     

Roles of spatial partitioning,competition, and predation in the North American invasion of an exotic mosquito

Invasion success and species coexistence are often mediated by species interactions across patchily distributed habitats and resources. The invasive mosquito Aedes japonicus japonicus has established in the North American range of the competitively superior resident congener, Aedes albopictus, and the predatory native mosquito Toxorhynchites rutilus. We tested predictions for two hypotheses of invasion success and species coexistence: keystone predation and spatial partitioning. We tested competition between A. japonicus japonicus and A. albopictus with or without T. rutilus in laboratory microcosms, and measured abundances of A. japonicus japonicus, A. albopictus, other resident competing mosquito species, and the presence of T. rutilus among tree holes and tires in metropolitan Washington, DC. In laboratory microcosms, A. albopictus was competitively dominant over A. japonicus japonicus, which is consistent with the few prior studies of competition between these two Aedes species. T. rutilus predation severely lowered performances of both Aedes species but more severely lowered A. japonicus japonicus performance than A. albopictus performance when all three species co-occurred, thus yielding no evidence for keystone predation. Consistent with the spatial partitioning hypothesis, A. japonicus japonicus was negatively correlated and independently aggregated with A. albopictus and all combined resident mosquito competitors and was not associated with T. rutilus among field containers. These results suggest that predation from T. rutilus and competition from A. albopictus are barriers to the spread of A. japonicus japonicus, but that A. japonicus japonicus may escape these interspecific effects by utilizing spatially partitioned container habitats.