Japanese Spiders Research Articles

Taxonomic revision of Taiwanese and Japanese <I>Cyrtophora</I> spiders hitherto identified with <I>C</I>. <I>moluccensis</I> (Arachnida: Araneae), using molecular and morphological data

The Taiwanese and Japanese spiders which have been identified with Cyrtophora moluccensis (Doreshall 1857) are taxonomically revised. Three color morphs, yellow-, green-, and red-types, show their own discrete monophyletic clades in the phylogenetic tree inferred by Neighbor Joining method using the partial sequences of mt-16S-rRNA genes. P-distances within group means are 0.2% in the yellow-type, 0.1% in the green-type, and 0% in the red-type. P-distances between group means are 18.8% between yellow- and green-types, 19.4% between yellow- and red-types, 10% between green- and red-types. These three color morphs can be separated also by the shapes of epigynum and male palp. Consequently we recognize them as three independent nominal species and determined the yellow-type as C. cylindroides (Walckenaer 1842), the green-type as C. moluccensis (Doleschall 1857), and the red-type as C. ikomosanensis (Bosenberg & Strand 1906).

A revision of Japanese spiders of the genus Dolomedes (Araneae: Pisauridae) with its phylogeny based on mt-DNA

Japanese spiders of the genus Dolomedes are revised and its phylogeny is inferred by mt-DNA. Dolomedes japonicus Bosenberg & Strand 1906 and D. angustivirgatus Kishida 1936 are removed from the synonymy. Dolomedes fimbriatoides Bosenberg & Strand 1906 and D. hinoi Kayashima 1952 are newly synonymized with D. sulfureus L. Koch 1878, and D. stellatus Kishida 1936 is synonimized with D. japonicus. Two new species, D. fontus and D. silvicola are described. Relative leg length and proportion of male palpal tibia are considered as good keys to indentify Dolomedes spiders, whose genital organs closely resemble one another. Dolomedes sulfureus and D. silvicola, often found on vegetation, have much longer legs and male palpal tibia than their relatives that inhabit near water and run on water surface or hide under water when disturbed. Molecular phylogenetic analysis using mt-COI revealed the following; ((((raptor, yawatai), japonica), orion), (((angustivirgatus, sulfureus), fontus), (silvicola, saganus)), horishanus).

Japanese spiders of the genus Agelena (Araneae: Agelenidae)

The Japanese spiders of the genus Agelena are revised. The occurrence of A. limbata Thorell 1897, A. opulenta Koch 1878, and A. labylinthica (Clerck 1757) are recomfirmed. A. donggukensis Kim 1996 is newly recorded from Japan and the male of the species is described for the first time. A new species, A. babai, is described based on the specimens collected from Amami-oshima Is. of the Ryukyus.

Japanese spiders of the genus Tylorida (Araneae: Tetragnathidae)

The Japanese spiders of the genus Tylorida is revised. T. magniventer Bosenberg & Strand 1906 is newly synonymized with T. striata (Thorell 1877). T. ventralis (Thorell 1877) is a new record for Japan, although whether or not it is an indigenous species remains unclear.

Sparassidae from Japan. II. First Pseudopoda species and new Sinopoda species (Araneae: Sparassidae: Heteropodinae)

The genus Pseudopoda is recorded for the first time from Japan. Pseudopoda kasariana sp. nov. (_??_, _??_) and Pseudopoda spirembolus sp. nov. (_??_, _??_) are described from Amami-oshima Island and Okinawajima Island respectively. Four new Sinopoda species are described: Sinopoda albofasciata (_??_), Sinopoda derivata (_??_, _??_), Sinopoda ogatai (_??_, _??_) and Sinopoda stellatops (_??_, _??_). Sinopoda koreana (Paik 1968) is recorded for the first time from Japan. New records of Sinopoda okinawana Jager & Ono 2000 and S. tanikawai Jager & Ono 2000 are presented. Within the genus Sinopoda Jager 1999 the okinawana species-group is newly diagnosed, which is represented by S. albofasciata sp. nov. (Japan), S. derivata sp. nov. (Japan), S. fasciculata Jager, Gao & Fei 2002 (China), S. hamata (Fox 1937) (China), S. koreana (Paik 1968) (Korea, Japan), S. okinawana Jager & Ono 2000 (Japan), S. tanikawai Jager & Ono 2000 (Japan), S. wangi Song & Zhu 1999 (China). Sinopoda stellata (Schenkel 1963) is deleted from the list of Japanese spiders and considered endemic to central China.

A Revision of the Japanese Spiders of the Genus Neoscona(Araneae: Araneidae).

Japanese spiders of the genus Neoscona are revised. Following eleven species are recognized to be occurring in Japan: Neoscona theisi (Walckenaer, 1841), N. adianta (Walckenaer, 1802), N. amamiensis sp. nov., N. nautica (L. Koch, 1875), N. subpullata (Bosenberg et Strand, 1906), N. mellotteei (Simon, 1895), N. scylloides (Bosenberg et Strand, 1906), N. scylla (Karsch, 1879), N. minoriscylla Yin et al., 1990, N. punctigera (Doleschall, 1857) and N. vigilans (Blackwall, 1865).

Japanese Spiders of the Genus Ordgarius (Araneae: Araneidae).

The Japanese spiders of the genus Ordgarius are revised. The males of Ordgarius hobsoni (O. PICKARD-CAMBRIDGE, 1877) and O. sexspinosus (THORELL, 1894) are described for the first time based on the specimens collected from Kanagawa Pref., Japan.

A Revision of the Japanese Spiders of the Genus Araniella (Araneae: Araneidae).

Japanese spiders of the genus Araniella CHAMBERLIN et IVIE, 1942 are revised. Two species of the genus are recognized from the country. One of these is described as a new species under the name Araniella yaginumai sp. nov., and the other is identified with Araniella displicata (HENTZ, 1847).

A Revision of the Japanese Spiders of the Genus Metleucauge LEVI, 1980 (Araneae: Tetragnathidae).

Japanese spiders of the genus Metleucauge LEVI, 1980 are revised. Two known species, M. yunohamensis (BÖSENBERG et STRAND, 1906) and M. kompirensis (BÖSENBERG et STRAND, 1906) are redescribed. Two new species are described under the names M. yaginumai and M. chikunii.

A Revisional Study of the Japanese Spiders of the Genus Cyclosa MENGE (Araneae: Araneidae).

Japanese spiders of the genus Cyclosa MENGE, 1866, are revised. After an examination of many specimens collected from various parts of Japan, 22 species of the genus occurring in the country were recognized. They are as follows: C. octotuberculata KARSCH, 1879, C. laticauda BOSENBERG et STRAND, 1906, C. monticola BOSENBERG et STRAND, 1906, C. angusta sp. nov., C. onoi sp. nov., C. omonaga sp. nov., C. confusa BOSENBERG et STRAND, 1906, C. japonica BOSENBERG et STRAND, 1906, C. norihisai sp. nov., C. atrata BOSENBERG et STRAND, 1906, C. hamulata sp. nov., C. maritima sp. nov., C. psylla (THORELL, 1887), C. mulmeinensis (THORELL, 1887), C. vallata KEYSERLING, 1886, C. sachikoae sp. nov., C. alba sp. nov., C. argenteoalba BOSENBERG et STRAND, 1906, C. okumae sp. nov., C. ginnaga YAGINUMA, 1959, C. kumadai sp. nov. and C. sedeculata BOSENBERG et STRAND, 1906.

A list of Japanese spiders (revised in 1977)

1. This paper gives a revised, up to date list of the Japanese spiders; 914 species of 280 genera belonging to 48 families have been recorded in Japan.2. The classification follows the YAGINUMA's (1970) system with minor changes recently done.3. The followings are revised in this paper:(a) The Japanese names of three suborders.(b) Spiders of Cybaeinae are transferred from Argyronetidae to Agelenidae.(c) The genus Desis is put in an independent family Desidae.4. Compared with other family groups of spiders, Leptonetidae and Cybaeinae have been split in Japan too finely. Several genera are, therefore, combined into Leptoneta (s. lat.) and Cybaeus. Thus, Falcileptoneta, Masirana and Sarutana into Leptoneta (s. lat.), and Cybaeus (s. str.), Dolichocybaeus and Heterocybaeus into Cybaeus. And those split genera are treated as species groups.5. The many split genera of Araneus (s. lat.) shall be tentatively treated as groups until they are completely revised.

A Historical Review of Studies on Japanese Spiders

A Historical Review of Studies on Japanese Spiders

Revision of Japanese Spiders of Family Argiopidae (2)

No Cyrtophora spider has been recorded till now in Japan. However, according to the writer's examinations, it was found that two species of Cyrtophora actually exist. 1. Cyrtophora ikomosanensis (BOESENBERG et STRAND) 1906 This species was first desdribed as Aranea ikomosnensis by BOESENBERG and STRAND. But it should be undoubtedly Cyrtophora, and has many resemblances to Cyrtophora moluccensis (Dol.) in shape and colour. The web making habit is also similar to the latter, i.e. it makes a large dome-web, about 30-80cm in dia-meter, consisting of many small wide meshes (1.5mm×2mm), which can be con-sidered as a modification of an orb-web. But the spirals have not sticky drops. The radial threads increase towards the edge, so all the meshes are of same size. This web resembles to Linyphiid web at a glance, but in the structure, this is rather nearer to Nephila than to Linyphia. 2. Cyrtophora exanthematica (DOLESCHALL) 1859 This species hitherto been known as Cyclosa bifurcata Kishida (not Walck.) in Japan. But this is not Cyclosa, and its name should be rejected as a secondary homonym on account of existence of Cyrtophora bifurcata (WALCI ENAER) 1841. The writer has identified this species with Cyrtophora exanthematica. Abdomen narrow behind and bifurcated posteriorly. Anterior part of abdomen with weak humps projecting laterally at both sides. Dorsal surface with 6 pairs of muscle-impressions and many small granules scattered exanthematically as its name shows. Two white lines run from shoulder humps to the posterior bifurcated lobes. (no granules seen in male). The web is horizontal and consists of small meshes, like Cyrtophora ikomosanensis, and irregular webs are seen above and below the main web. The spirals are not sticky like the preceding species. The writer recognized the following two types in this genus of Japan. Group I (Euetria type) 1. MOA square, both sides almost parallel. 2. Legs long, patella plus tibia shorter than metatarsus plus tarsus. 3. Posterior eye row almost straight, 4. Pro-tuberances on anterior part of abdomen conical. 5. Web is dome-shaped. Cyrtophora ikomosanensis belongs to this group. Group II (Cyrtophora type) 1. MOA trapezoid, wider in font than behind. 2. Legs snort and stout, patella plus tibia longer than metatarsus plus tarsus 3. Posterior eye row strongly recu-rved. 4. Pretuberances on abdomen poined laterally. 5. Web is horizontal. Cyrtophora exanthematica belongs to this group.

Revision of Japanese Spiders of Family Argiopidae (1)

This paper deals with the revision of Japaneses Meta based upon the writer's collection and the other arachnologists'. In Japan, 10 species of Meta have heretofore been recorded. Of them Meta blanda L. KOCH has already been transferred to Leucauge by E. Strand, M. doenitzi BOESENBERG et STRAND clearly comes under Neoscona according to the writer's re-examination, M. vena DOENITZ et STRAND is nothing but a fleckless type of M. kompirensis BOES. et STR., M. decimpunctata KISHIDA is a synonym of Mangora herbeoides (BOES. et STR.), and M. melanostethi KISHIDA is a species yet undescribed. Accordingly the existence of 5 species and one new (the description of which is given below) is recognized in Japan. 1. Meta segmentata (CLERCK) 1757 2. M. menardi (LATREILLE) 1804 3. M. metanicruciata SAITO 1939 4. M. kompirensis BOESENSERG et STRAND 1906 5. M. yunohamensis BOESENBERG et STRAND 1906 Among the above mentioned species, the latter two have many differences from the other Metas. Owing to their particular characteristics, it may be better that a new subgenus (or genus) is established for them. However, the writer wishes to treat them as one of the groups in Meta in the meantime. Japanese Meta should be divided into two groups. Group I. (Protometa type) 1. Paracymbium not modified. 2. Cymbium projected at the base part. 3. Embolus erect. 4. Epigastric plate with distinct transverse furrows. Meta kompirensis, yunohamensis and melanicruciata (probably) belong to this group. Group II. (Neometa type) 1. Paracymbium much modified, divided into two branches, one bearing hairs, and one well developed and strongly chitinized. 2. Cymbium without any projection. 3. Embolus coiled. 4. Epigastric plate without transverse furrows. Meta segmentata, menardi and reticutoides n. sp. belong to this group. Meta reticutoides sp. nov. Holotype (_??_) 6/XI, 1955, Osaka Pref. (Coll. T. Yaginuma) Cephalothorax longer than wide. Anterior eye row recurved, posterior almost straight. Anterior median eyes separated by their diameter, posterior median eyes separated by less than their diameter. Median eyes of each row closer to each other than to the adjacent laterals. MOA almost square, slightly longer than wide. Lateral eyes contiguous. Cervical, radial and median furrows distinct. Chelicerae well developed and geniculated at the base. Lateral condyle weak. Promargin and retromargin with 3 teeth on each. Sternum triangle in shape, anterior margin slightly procurved. Legs 1. 2. 4. 3. Anterior coxae larger than posteriors. Each leg with spines. Abdomen oval. Epigynum without scape. Total length 7.5 mm. (Deposited in Osaka Municipal Museum of Nat. Hist, ) Allotype (_??_) 24/VIII, 1957, Kumamoto Pref. (Coll. M. Yoshikura) In general appearance, the male resembles female, but it differs in following points. Chelicerae much longer than in female, as long as about 3/4 length of cephalothorax. Labium separated from chelicerae as seen in Arhcaeidae. Distal joint of palp very large and well modified, divided into two branches, one hairly and one hairless and strongly chitinized. Cymbium notched apically along the coiled embolus. Promargin of fang furrow with a tooth, retromargin with 4. Total length 4.6 mm. (Preserved in A. F. Archer's collection) Colour : Both sexes very similar. Cephalothorax yellow with a pair of black flecks along the cervical groove, and with black side margins. Chelicerae, endites, labium and sternum deep brown. Anterior legs with many black spots, but posterior legs annulated by black flecks. Abdomen grey with blackish brown spots scattered on the entire dorsum. Venter black with white lines at both sides

Colour change of Two Species of Japanese Spiders

1. It has been found that there are two species of spiders in Japan that change body colour. i.e. Leucauge subgemmea BOESENBERG et STRAND and Argyria venusta YAGINUMA. 2. Leucauge subgemmea weaves a horizontal orb-web about 30cm in diameter among bushes. The spider itself hides behind a leaf nearby and not in the centre of the web, which habit distinguishes it from other Leucauge. 3. The entire abdomen of Leucauge subgemmea shines golden-green when at rest but it changes colour and numerous scaly flecks appear when picked or shaken strongly. 4. Argyria venusta, when observed at Mt. Myogi (Gunma Prefecture), wove an irregular web on the underside of a leaf of a bush in cliff y ground and from the web hung vertical threads with insects and leaves at their ends. 5. The abdomen of Argyria venusta is of beautiful golden-yellow but when pic-ked or shaken strongly, the colour breaks up into numerous star-like flecks. This change follows the same pattern as in the case of Leucauge subgemmea. 6. The leaves and insects hanging from the Y shaped threads that form the web of Argyria venusta seem to be weights that keep it in shape. 7. The colour change in the abdomen of Leucauge subgemmea and Argyria venusta is probably due to the change in the pigment cells in the golden flecks while expanding and contracting. This change is instantaneous. 8. The flecks on Argyria venusta have been observed to contract by placing the spider in the dark and striking it with the sun's rays. 9. Argyria venusta is a new genus and species belonging to Conopisthinae. Its original description has been made by Mr. T. Yaginuma. (See page 11 in this paper.)

Reports on some Japanese spiders. (2)

Reports on some Japanese spiders. (2)

Reports on some Japanese spiders (1)

Reports on some Japanese spiders (1)

A synopsis of the Japanese spiders of the genus Dolomedes

A synopsis of the Japanese spiders of the genus Dolomedes

A synopsis of the Japanese spiders of the genus Argiope in broad sense

A synopsis of the Japanese spiders of the genus Argiope in broad sense