オオユミミズ

　フトミミズ科＞ オオユミミズ 'Pheretima' oyuensis Ohfuchi, 1937

Pheretima oyuensis Ohfuchi, 1937a: 24; 大淵, 1938b: 177; 大淵・山口, 1947: 1367, 1965: 549; 上平, 1973a: 61; Ishizuka, 1999a: 63.

Pheretima cyuensis [sic] Sims & Easton, 1972: 225.

'Pheretima' oyuensis Easton, 1981: 54; Blakemore, 2003: 37, 2008d: 140, 2012b: 20; 伊藤, 2013: 437.

Amynthas oyuensis Tsai et al., 2002: 758.

タイプ標本

基産地：秋田県鹿角市十和田大湯の稲荷山

タイプ標本所在地：不明

形態

＜外部形態＞

　全長 50-55 mm、体幅は第 18 体節で 2.0-2.5 mm、体節数 87-94。

　体色は背面は肉色で、腹面は灰色。

　剛毛は、第 7 体節で 38 本、第 20 体節で 41-42 本。第一背孔は第 13/14 体節に始まる。

　環帯は第 14-16 体節を占め、第 14 体節には雌性孔が一つあり、直径 0.5 mm。受精囊孔や雄性孔、性徴を欠く。

＜内部形態＞

　腸盲嚢は第 27 体節から始まり、長さ 1.5 mm。

　受精囊、摂護腺やその導管を欠く。卵巣は 1 対で大型で、第 12/13 体節間隔膜に付着する。貯精嚢はよく発達し、第 11-12 体節にあり、後縁は砂嚢に接する。

＜原記載（クリックして展開）＞

External characters:

　　Measurements of the body and number of segments of 2 specimens are as follows; body length 50-55 mm, width at male genital region 2.0-2.5 mm, number of segments 87-94.

　　The colour when alive is fresh on the dorsal surface, and grey on the ventral surface.

　　The spermathecal opening are lacking.

　　The female pore is single on XIV, the pore is comparatively very large to the body, its vertical diameter is 0.5 mm.

　　Clitellum very prominent by well developed grandular layer and occupies 3 segments, XIV, XV and XVI, sometimes, extending to the posterior half of segment XIII, without setae, intersegmental furrows and dorsal pores.

　　Setae begnning on segment II.

　　Setal numbers of the worms are as follows; VII 38, XX 41-42.

　　The openings of male pore are not present.

　　The genital papillae are not present on any parts of the body.

　　The first dorsal pore is in XIII/XIV, but are not visible even with higher powers of the binocular.

Internal characters:

　　No spermatheca.

　　Ovisac one pair, it is large compared to the other known species of the same genus, and hangs behind the septum XII/XIII.

　　No prostatic duct and prostate gland, as shown in Text-fig. 4, 2.

　　The saccular intestine begins in XV and a pair of the intestinal coecum or ginates begins in XXVII, about 1.5 mm in length.

　　The coecum is formed a single projection and extends for five segments anteriorly, viz. to XXIII, as is shown in Text-fig. 4, 4.

　　Septa are less developed compared with many other species of the genus Pheretima.

　　Nephridia, moderately tufts in V, VI and VII.

　　The seminal vesicles are well developed and situated in XI, XII, the anterior vesicles extend forward and come into contact with the posterior end of the gizzard, as is shown in Text-fig. 4, 5.

Remarks:

　　The present species differs from Pheretima irregularis (Goto & Hatai), in the body length 125 mm, breadth 6 mm, number of setae in the segments, and the intestine begins in XV, with five pairs of the coeca in XXVI, in the latter.

　　The vas deferens sometimes extend posteriorly to segment XXIII, but usually to segment XVIII. An end of the vas deferens are blind, and without both prostatic ducts and prostate glands. Although, the species without male pore are found in Pheretima vittata and some of Pheretima hilgendorfi, the absence of spermathecae and its openings is the first case in the Japanese species of Pheretima.

　　The present species is the smallest one known among the Japanese species of Pheretima at the present time.

Pheretima oyuensis の形態 (原記載図) (Ohfuchi, 1937a p. 26, fig. 4 より)

生息環境

　日蔭のスギの落葉が厚く堆積した場所によく見られる (Ohfuchi, 1937a)。マツのような針葉樹の落葉の下にも生息する (大淵, 1938b)。

備考

　大淵・山口 (1947) は和名をオホユミミズとした。

シノニムリスト

Pheretima oyuensis Ohfuchi, 1937a: 24. [形態記載]

Pheretima oyuensis 大淵, 1938b: 177. [記述のみ]

Pheretima oyuensis 大淵・山口, 1947: 1367 オホユミミズ (新称). [同定形質のみ]

Pheretima oyuensis 大淵・山口, 1965: 549 オオユミミズ. [同定形質のみ]

Pheretima cyuensis [sic] (Species incertae sedis) Sims & Easton, 1972: 225.

Pheretima oyuensis 上平, 1973a: 61 オオユミミズ. [同定形質のみ] (?, 1973)

'Pheretima' oyuensis Easton, 1981: 54. [同定形質のみ] (Apr 30, 1981)

Pheretima oyuensis Ishizuka, 1999a: 63. [記載のみ]

Amynthas oyuensis Tsai et al., 2002: 758. [同定形質のみ]

'Pheretima' oyuensis Blakemore, 2003: 37. [同定形質のみ] (Apr 30, 1981)

'Pheretima' oyuensis Blakemore, 2008d: 140. [同定形質のみ] (Dec ?, 2008)

'Pheretima' oyuensis Blakemore, 2012b: 20. [記述のみ] (Feb 28, 2012)

’Pheretima' oyuensis 伊藤, 2013: 437. [同定形質のみ]

引用文献

Blakemore, R.J., 2003. Japanese earthworms (Annelida: Oligochaeta): A review and checklist of species. Organisms Diversity and Evolution 11: 1-43.

Blakemore, R.J., 2008d. A review of Japanese earthworms after Blakemore (2003). In: Ito MT, Kaneko N, (eds.), A Series of Searchable Texts on Earthworm Biodiversity, Ecology and Systematics from Various Regions of the World, 2nd Edition (2006) and Supplemental. COE soil Ecology Research Group, Yokohama National University, Japan. CD-ROM Publication.

Blakemore, R.J., 2012b. Japanese earthworms revisited a decade on. Zoology in the Middle East 58 suppl 4: 15-22.

Easton, E.G., 1981. Japanese earthworms: A synopsis of the Megadrile species (Oligochaeta). Bulletin of the British Museum Natural History (Zoology) 40(2): 33-65.

Ishizuka, K., 1999a. A review of the genus Pheretima s. lat. (Megascolecidae) from Japan. Edaphologia (62): 55-80.

伊藤雅道, 2013. 明治神宮の陸生大型ミミズ類. 鎮座百年記念第二次明治神宮境内総合調査報告書 pp. 437-440.

上平幸好, 1973a. 日本産陸棲貧毛類フトミミズ属(Genus Pheretima), 種の検索表. 函館大学論究 7: 53-69.

Ohfuchi, S., 1937a. Descriptions of three new species of the genus Pheretima from North-eastern Honshu, Japan. Saito Ho-on Kai Museum of Natural History, Research Bulletin 12: 13-29.

大淵眞龍, 1938b. 本州東北部に於ける Pheretima 属に就て. 動物学雑誌 50(4): 177-178.

大淵眞龍, 山口英二, 1947. 環形動物貧毛綱. In: 内田清之助 (編), 新日本動物図鑑. 北隆館, 東京. pp. 1352-1371.

大淵真龍, 山口英二, 1965. 環形動物貧毛綱. In: 内田亨 (編), 新日本動物図鑑上. 北隆館、東京 p.533-563.

Sims, R.W., Easton, E.G., 1972. A numerical revision of the earthworm genus Pheretima auct. (Megascolecidae: Oligochaeta) with the recognition of new genera and an appendix on the earthworms collected by the Royal Society North Borneo Expeditions. Biological Journal of the Linnean Society 4: 169-268.

Tsai, C.F., Shen, H.P., Tsai, S.C., 2002. A new athecate earthworm of the genus Amynthas Kinberg (Megascolecidae: Oligochaeta) from Taiwan with discussion on phylogeny and biogeography of the A. illotus species group. Journal of Natural History 36: 757-765.