ノハルザキミミズ

　フトミミズ科＞アズマフトミミズ属＞ノハルザキミミズ Amynthas noharuzakiensis (Ohfuchi, 1956)

Pheretima noharuzakiensis Ohfuchi, 1956: 175; Ishizuka, 1999a: 63.

Amynthas noharuzakiensis Sims & Easton, 1972: 237.

Pheretima noharzakiensis [sic] 上平, 1973a: 58.

タイプ標本

基産地：石垣島野原崎？付近（Vicinity of Noharuzaki, Ishigaki Island）

タイプ標本所在地：紛失 (Reynolds & Cook, 1976)

形態

＜外部形態＞

　全長 78-95 mm、体幅 3-4 mm、体節数 85-110。

　体色はフォルマリン液浸標本では、背面は褐色、腹面はより明色。

　剛毛数は第 7 体節で 40-41 本、第 20 体節で 60-65 本。第一背孔は第 12/13 体節間溝。

　環帯は第 14-16 体節の 3 体節を占め、背孔や体節間溝、剛毛を欠く。雄性孔は第 18 体節で、雄性孔の縁は体表よりも盛り上がる。雄性孔間剛毛は 14-16 本。受精囊孔は 3 対で、第 6/7/8/9 体節間溝。性徴を完全に欠く。

＜内部形態＞

　隔膜は第 6/7/8/9 体節間ではずっと厚く、第 9/10 体節間では欠き、第 10/11/12/13 体節間では少し厚い。

　腸管は第 15 体節から始まり、腸盲嚢は突起状型で、第 27 体節から第 24 体節まで伸びる。

　受精囊は 3 対で、第 7-9 体節にあり、主嚢はやや平たく、長さ 1.0 mm、幅 0.5 mm。主嚢の導管は嚢状部の 1/3 の長さ。副嚢は主嚢よりも短く、先端はそれほど広がらずに棍棒状。卵巣は第 14 体節。摂護腺は小さく、長さ 2.5 mm、幅 1.5 mm で、3つの小嚢に別れる。摂護腺の導管は S 字型に折れ曲がる。

＜原記載（クリックして展開）＞

Locality: Vicinity of Noharuzaki, Ishigaki Island. Collected by members, expedition to Riu-kiu Islands organized by Marquis Yamashina, on March 21, 1936.

External characters: The body length from 78 to 95 mm. The greatest diameter from 3-4 mm. The number of segments varies from 85-110.

The colour in formalin, dorsally brownish and ventrally lighter than the dorsal.

The prostomium epilobous or tanylobous. Clitellum is annular and extends from XIV to XVI, without dorsal pores, intersegmental furrows and setae.

The setae bigins on segment II. The setal numbers; 28-32/V, 36-42/VI, 40-41/VII, 47-52/VIII, 60-65/XX, more usual setal number: 30/V, 39/VI, 42/VII, 49/VIII, 63/XX.

The first dorsal pore in XII/XIII.

The spermathecal pores, three pairs in VI/VII, VII/VIII and VIII/IX, ventrolateral in position. No genital papillae are found near this region.

The male pores situated on setal circle close to lateral border of XVIII, separated by 14 or 16 setae. The margin of the porophore is slightly elevated over the body surface.

Internal characters: Septa VI/VII, VII/VIII and VIII/IX much thickened, IX/X absent, X/XI, XI/XII and XII/XIII slightly thickened.

Intestine begins in XV, intestinal caeca simple, originated in XXVII and extending anteriorly into about XXIV.

Spermathecae, three pairs in VII, VIII and IX. Ampulla smooth and slightly flattened dorso-ventrally, about 1 mm in length, 0.5 mm in breadth and continuous to the duct, the duct is about 1/3 of ampulla in length. The spermathecal diverticulum usually arises from the inner face of the spermathecal duct, slightly shorter than the combined length of the duct and ampulla. The spermathecal diverticulum ends in a simple seminal chamber.

The ovisac present in segment XIV.

The prostate gland small about 2.5 mm in length, 1.5 mm in breadth, and divided into three main lobes, muscular duct bends into S-shape.

The seminal vesicles are well developed in moderately sized in XI and XII. Testis sacs in X and XI as in other species of this genus.

備考

　Easton (1981) は疑問符付きで、Blakemore (2003, 2008d) は括弧と疑問符付きで、Blakemore (2012b) は括弧と疑問符なしにコンジキミミズのシノニムとした。ただし、本種は性徴を完全に欠くことから、独立種としておく方が良いと考えられる (南谷, 私見)。タイプ標本は既に紛失したと考えられているため (Reynold & Cook, 1976)、基産地から新たな標本を得て、今後の検証が必要である。

シノニムリスト

Pheretima noharuzakiensis Ohfuchi, 1956: 175. [形態記載]

Amynthas noharuzakiensis Sims & Easton, 1972: 237. [記述のみ]

Pheretima noharzakiensis [sic] 上平, 1973a: 58. [同定形質のみ] (?, 1973)

Pheretima noharuzakiensis Ishizuka, 1999a: 63. [記述のみ]

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.

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., 1956. On a collection of the terrestrial oligochaeta obtained from the various localities in Ryu-Kiu Islands, together with the consideration of their geographical distribution (Part 1). Journal of Agricultural Science, Tokyo Nogyo Daigaku 3(1): 131-176.

Reynolds, J.W., Cook, D.G., 1976. Nomenclatura Oligochaetologica: A Catalogue of Names, Descriptions and Type Specimens of the Oligochaeta. University of New Brunswick, Fredericton, Canada. 217 pp.

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.