ロックフェラーミミズ

　フトミミズ科＞アズマフトミミズ属＞ ロックフェラーミミズ Amynthas rockefelleri (Chen, 1933)

Pheretima rockefelleri Chen, 1933: 238, 1935a: 36; Gates, 1935a: 454; Ishizuka, 1999a: 65.

Pheretima rockfelleri [sic] 小林, 1938d: 660, 1938e: 778, 1940a: 120, 1940c: 274, 1940d: 391, 1941d: 376, 1941g: 513; Ishizuka, 1999a: 65.

Pheretima rockffelli [sic] 上平, 1973a: 57.

Amynthas rockefelleri Sims & Easton, 1972: 236; Huang et al., 2006: 14; Tsai et al., 2009: 41.

形態

＜外部形態＞

　全長 85-130 mm、体幅 3.0-4.2 mm、体節数 108-142。第一背孔は第 11/12 体節間溝に開口する。

　剛毛は第 8 体節で 58-75 本、第 25 体節で 52-62 本、第 6 体節の受精囊孔間剛毛は 20-26 本、雄性孔間剛毛は 12-16 本。

　環帯は第 14-16 体節の3体節を占める。雄性孔は第 18 体節に開口し、雄性孔間距離は体周の 1/3。雄性孔は乳首のように突出し、数個の円盤上にある。第 17 体節の剛毛線より後ろに 2-4 個の大きな性徴があり、80 % の個体がこの性徴を 3-4 個持つ。外側のものは雄性孔と同一線上よりやや内側に位置する。内側の 1 対は外側のものよりもやや小さく、剛毛線より後ろではあるが外側のものよりやや前方に位置する。受精囊孔は 3 対で第 5/6/7/8 体節間溝に開口するが通常外部から観察することは困難。受精囊孔間距離は体周の 3/11。性徴は第 8 体節に通常 2 対あり、剛毛線より前の 1 対は後ろ側の対よりも外側に位置する。65 個体中 1 個体のみは第 8 体節の性徴を全く欠いていた。第 8 体節と第 17 体節は他の体節に比べて肥大し、第 17 体節は第 18 体節の 2 倍の長さ。

＜内部形態＞

　腸管は第 16-17 体節から開始し、腸盲嚢は単純状型で、第 27 体節に開口し第 23-24 体節まで伸びる。

　摂護腺はやや大きく、第 17-19 体節の 3 体節分を占める。生殖腺はよく発達し、しばしば摂護腺と見間違えられる。生殖腺の導管は腺体に隠れて見えない。受精囊は小さく、特に第 6 体節のものは小さい。受精囊の副嚢は細く、主嚢の半分ほどの長さもしくは主嚢より長い。第 8 体節の生殖腺は第 17 体節のものに似るが、小さい。

＜原記載（クリックして展開）＞

Description Type no. Ann. 660, Mus. Zool. Cent. Univ. Nanking.

External Characters:

　　Length 112 mm, diameter (around spermathecal region) 3.5 mm, segments 134. Prostomium 1/2-1/3 epilobous, open behind, its width equal to length of 2nd segment. First dorsal pore usually in 11/12, present also on clitellum.

　　Clitellum glandular, in three full segments (XIV-XVI); its glandular layer thick, swollen, smooth and evenly formed on dorsal and lateral sides, but less glandulated or usually roughened on ventral side, often with irregular grooves, extending to latero-ventral side (Fig 17A). Setae slightly enlarged and wider in space on ventral side of three clitellar segments, more numerous posteriorly, 6-8 on XIV, 10-14 on XV, 12-16 on XVI, each seta more straight and blunt at tip, about 425μ in length, slightly longer than those in other segments; such clitellar setae found in all cases.

　　Setae generally short and numerous, closer on preclitellar segments, wider in intervals posteriorly, e.g. ab of preclitellar equal to 1.5 or 1.2 ab of postclitellar segments; no specially longer or widely spaced setae in all segments, ventral ones equal to or a little longer than dorsal but about same in intervals. Setal rings closed on both dorsal and ventral sides, each one from anterior venter about 220-340μ in length, slightly

curved distally or Weekly sigmoid, not modiﬁed in any part, except those on clitellum which are slightly blunt at tips, stouter and more straight. Setal numbers: 36/II, 42/III, 62/VI, 59/VIII, 56/XII, 54/XXV, 32 near posterior end, 16 between spermethecal pores (VI), 12 between male pores.

　　Male pores on ventro-lateral extremities of XVIII, in setal line, about 1/3 of body circumference apart, each pore on an erect teat-like protuberance around which is surrounded by a deep groove and again by several circular wrinklings but rather irregularly wrinkled toward median side; the teat-like protuberance with its surrounding skin always raised (Fig. 17B), setae absent on raised portion. One large papilla situated on each side of posterior half of XVII, in line or slightly medial to ♂ papilla; two smaller ones usually present between the larger ones, parallel or slightly anterior to lateral ones but always behind setae (Fig. 17A), or often coalesced with the latter; about 80% of the specimens having 3-4 papillae on XVII; in some cases either two on one side or median two ones missing. Each papilla circular in shape, with a narrow margin and a large flat glandular center, dark greyish in color, slightly raised from surrounding body wall. Ventral side of XVII greatly lengthened on account of these large papillae, about twice longer than XVIII, but its dorsal side only a little longer than XVIII.

　　Female pore single, on ventral side of XIV, always represented by a depression specially deepened anteriorly in a shape of crescent trench in front of the pore. ♀ pore slightly in front of the normal setal circle on account of sinking in of its anterior portion.

　　Spermathecal pores 3 pairs, in 5/6-7/8, about 3/11 of body circumference apart, usually invisible, sometimes with a minute dark porophore in intersegmental furrow (Fig. 17A); on genital markings around pore. Two pairs of genital papillae usually present on ventral side of VIII, anterior two situated more laterally but ventral to last pair of spermathecal pores in front of setae k or j, posterior two situated more medially than anterior ones behind setae f or g (Fig. 17A), which are absent in some cases. Ventral side of VIII greatly lengthened posteriorly when the latter ones present. Only in one specimen without any papillae on VIII. In three cases, two similar on VII behind setae bc or ef, occasionally one or two in front. Their shape similar to those on XVII but slightly smaller.

　　Color in preservative: pale over whole body except its clitellum light chocholate. In life: pale in general appearance, pinkish at anterior five or six segments, whitish before clitellum, greyish pale behind, pale or greyish pale posteriorly, greenish grey along dorsal pores; clitellum whitish or milky, slightly paler on ventral side.

Internal anatomy:

　　Septum Gizzard, septa 8/9, 9/10 absent, 5/6, 6/7 much thickened and very richly musculated, 7/8, 10/11, 11/12 about equally thickened, 7/8 only slightly less in thickness than preceding two, 12/13 also thick, 13/14 1ess so, 14/15 backward thin.

　　Pharyngeal glands in a thin and compact layer, without acinose glands and other glandular nodules, segmental cavity of V almost filled with ligaments closely connecting pharynx and septum 5/6.

　　Nephridia plectonephridial, very conspicuous in this form. Nephridial tufts on anterior faces of septa 5/6, 6/7 thick, darkish in color, without acinose glands, a moderate amount of similar structures on anterior face of 7/8, very scanty on anterior faces only of 10/11-14/15; 15/16 with a few small nephridial tubules on posterior face, more since 16/17 backward. Septal nephridia remarkably noticeable, their tubes large, about 20μ in thickness, velvety in appearance, more on posterior faces of septa. Integumental nephridia also thick in segments behind XIV.

　　Digestiae tract Gizzard in IX and X, moderate in size, rounded and smooth on surface, whitish, no dilated crop anterior to it. Intestine beginning to swell in XVI or XVII, yellowish fuscous on surface. Caeca simple, horn-shaped, in XXVII-XXIV or XXIII (about three segments), smooth on both edges, or slightly wrinkled on either dorsal or ventral sides, whitish in color.

　　Blood vessels Hearts 4 pairs, in X-XIII, first pair very slender or vestigial, or even absent in some cases. A pair of commissures in X, asymmetrical, one limb vestigial or absent and the other connecting dorsal and ventral vessels. Branches sending out from dorsal vessel over intestine in segments XVI or XVII-XXV rather large. Paired lymph glands small appearing behind septum 26/27 backward.

　　Male organs Seminal vesicles and testis sacs very characteristic in this form. Seminal vesicles very small and inconspicuous, anterior pair closely lying on posterior surface of septum 10/11 wholly covered by second pair of testis sacs, about .6 mm long and .5 mm wide; posterior pair larger, not quite visible from dorsal side, about .8 mm or more long, 1 mm wide. Each with a smooth and pale dorsal lobe, elongate or rather

round which is only a little smaller than main vesicle, the latter tubercular or granular on surface, connected with its respective testis sac at anterior lower part of each septum. Pseudovesicles on 12/13 & 13/14 very small. Testis sacs in X & XI, exceedingly large in size, being many times larger than vesicle, surface smooth and whitish, well-distended; anterior pair elongate, sac-like or sometimes cylindrical, their ventral ends enlarged or rounded for rooming testis and funnel in each sac, widely separated from each other; their slender dorsal ends

usually meeting or overlapping over the dorsal vessel with its opposite sac, closer to septum 10/11; posterior pair large, sometimes ﬂattened closely lying upon posterior surface of septum 10/11, similarly separated on ventral side, overlapping or interfused with its opposite fellow on dorsal side (Fig. 17F). Each testis rather large at anterior lower portion of each sac, greatly folded and whitish. Sperm ducts of each side stout, meeting in XII.

　　Prostate glands Prostatic duct with a deep loop about .2 mm in thickness, gland part usually absent, with ﬁbrous tissue in its stead closely applied to body wall where the prostate gland is otherwise situated; prostates with gland part found only in two or three specimens in the cases examined, but only one side being developed, compact and thick (Fig. 17E), in XVII-XIX, whereas the accessory glands are less developed. Accessory glands very well-developed, easily mistaken for prostates, very compact and greyish in a round mass, situated anteriorly or

medially to prostatic duct. Each gland with many stalks usually concealed under gland leading onto single papilla externally, lumen of stalks being intercellular, with sieve-like longitudinal spaces, leading from gland mass to papilla.

　　Femals organs Ovaries very large reaching upper side of intestine, with elongate lobules of egg strings. Oviduct-funnels also conspicuous, free in front of 13/14, whitish in color.

　　Spermathecae with their diverticula lying in same segments VI, VII & VIII respectively, all very small, first pair smallest, becoming larger one pair after another (Fig. 17C). Ampulla elongate oval or pear-shaped, smooth and pale on surface, greatly tubercular in one specimen, its duct slender or very stout, either very long or very short, not clearly marked off from ampulla; each diverticulum usually slender, half as long as main pouch, or longer (Fig. 17D), with its ental third loosely looped and slightly dilated, its ectal end slender joining main duct near body wall. Accessory glands in VIII similar to those in XVII, but smaller (Fig. 17C, Gl.).

　　Localities: Lin-hai, Tien-tai, Sheng-hsien in Chekiang.

　　Material 35 specimens from Lin-hai, No. Ann. 660; 1 specimen from Tien-tai, No. Ann. 661; 29 specimens from Sheng-hsien, No. Ann. 662, Mus. Zool. Cent. Univ. Nanking.

　　Remarks: This species was first discovered by myself in the mountainous district of Lin-hai inhabiting the hard soil near the hill side. Later on, Mr. Chang collected at random a large number of this species from Sheng-hsien. It is a distinct species.

Pheretima rockefelleri (=Amynthas rockefelleri) の形態 (Chen, 1933, p. 241 fig. 17 より)

分布

　国外では、中国 (Chen, 1933, 1935a; Gates, 1935; Huang et al., 2006)、台湾 (小林, 1938b, e; Huang et al., 2006; Tsai et al., 2009)で記録されている。

備考

A. papulosus は、本種に比べて小型であること、性徴が多いこと、性徴の分布は8体節、17体節に限らずに広がることが挙げられている (Gates, 1935)。

　Gates (1972) はスマトラミミズのシノニムとし、その後の研究者もこの見解に従っているものが多い (Easton, 1981; Blakemore, 2003, 2008d, 2012b)。

シノニムリスト

Pheretima rockefelleri Chen, 1933: 238. [形態記載]

Pheretima rockefelleri Gates, 1935a: 454.

Pheretima rockefelleri Chen, 1935a: 36. [同定形質のみ]

Pheretima rockfelleri [sic] 小林, 1938d: 660. [同定形質のみ]

Pheretima rockfelleri [sic] 小林, 1938e: 778. [記述のみ]

Pheretima rockfelleri [sic] 小林, 1940a: 120. [記述のみ]

Pheretima rockfelleri [sic] 小林, 1940c: 274. [記述のみ]

Pheretima rockfelleri [sic] 小林, 1940d: 391. [記述のみ]

Pheretima rockfelleri [sic] 小林, 1941d: 376. [記述のみ]

Pheretima rockfelleri [sic] 小林, 1941g: 513. [記述のみ]

Amynthas rokefelleri Sims & Easton, 1972: 236. [記述のみ] (Sep ?, 1972)

Pheretima rockffelli [sic] 上平, 1973a: 57 ロックフェリーミミズ（新称？）. [同定形質のみ] (?, 1973)

Pheretima rockefelleri Ishizuka, 1999a: 65.

Amynthas rockefelleri Huang et al., 2006: 14. [記述のみ]

Amynthas rockefelleri Tsai et al., 2009: 41 (hsinpuensis, papulosus Shih et al., 1999 [non Rosa, 1896]).

[要検討]

Tsai, 1964: 8, Kuo, 1995: 187, Shih et al., 1999: 437, Tsai et al., 2000a: 287, Chen & Shih, 1996: 54, Shih et al., 1999: 436+437, Chen et al., 2003: 58, Shen et al., 2003a: 42, Tsai et al., 2004a: 6.

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.

Chen, Y., 1933. A preliminary survey of the earthworms of the lower Yangtze Valley. Contribution from the Biological Laboratory of the Science Society of China, Zoological Series 9(6): 178-296.

Chen, Y., 1935a. On a small collection of earthworms from Hongkong with descriptions of some new species. Bull. Fran. Memo. Inst. Peiping, China, Biol. (Zool.). 6(2): 33-59.

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.

Gates, G.E., 1935. On some Chinese earthworms. Lingnan Science Journal 14(3): 445-457.

Huang, J., Qin, X., Zheng, J.S., Chong, W., Dong, M.Z., 2006. Research on earthworm resources of China: I. Check-list and distribution. Journal of China Agricultural University 11(3): 9-20.

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.

小林新二郎, 1938d. 臺湾新竹の蚯蚓. I. 動物学雑誌 51: 659-660.

小林新二郎, 1938e. 新竹及びその附近の蚯蚓. II. 動物学雑誌 51: 777-779.

小林新二郎, 1940a. 臺湾新竹の蚯蚓. III. 動物学雑誌 52: 120-121.

小林新二郎, 1940c. 臺湾新竹の蚯蚓. IV. 動物学雑誌 52(7): 274.

小林新二郎, 1940d. 臺湾新竹の蚯蚓. V. 動物学雑誌 52(10): 390-391.

小林新二郎, 1941d. 西日本に於ける陸棲貧毛類の分布概況. 動物学雑誌 53(8): 371-384.

小林新二郎, 1941g. 九州地方陸棲貧毛類相の概況. 植物及動物 9(4): 511-518.

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., Lin, K.J., Hsieh, H.L., Yo, S.P., 2009. A checklist of oligochaetes (Annelida) from Taiwan and its adjacent islands. Zootaxa 2133: 33-48.