A new species of the earthworm belonging to the genus Metaphire Sims and Easton (Megascolecidae: Oligochaeta) from the Northeastern Taiwan.

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Abstract

This paper describes a new species of the earthworm Metaphire trutina sp. nov. (Megascolecidae: Oligochaeta) from Hsiaochaochi, Ilan of the northeastern Taiwan. It is a large, sexthecal and holandric earthworm, and has a pair of large, round genital papillae with slightly concave centers on narrow male disc in each of the shallow copulatory chambers in XVIII. It belongs to the houlleti species-group of the genus Metaphire Sims and Easton and closely relates to Metaphire tschiliensis (Michaelsen, 1928), Metaphire viridis Feng and Ma, 1987, Metaphire vulgaris (Chen, 1930), and Metaphire praepinguis (Gates, 1935) of China, and Metaphire aggera (Kobayashi, 1934) of Korea and Manchuria.

本文描述產於台灣東北部宜蘭縣小礁溪一新種腔環蚓:Metaphire trutina sp. nov.。其為大型 蚯蚓,第十八體節的交配腔淺裂,內有一對大而圓的生殖突起。M. trutina屬於Metaphire屬之 houlleti種群,與產於中國大陸的Metaphire tschiliensis (Michaelsen, 1928)、Metaphire viridis Feng and Ma, 1987、Metaphire vulgaris (Chen, 1930)、Metaphire praepinguis (Gates, 1935)以及韓國的 Metaphire aggera (Kobayashi, 1934)密切相關。

A New species of the Earthworm Belonging to the Genus

Metaphire Sims and Easton (Megascolecidae:

Oligochaeta) from the Northeastern Taiwan

產 於 台 灣 東 北 部 一 新 種 腔 環 蚓 之 描 述

Chu-Fa Tsai

1

, Jiun-Hong Chen

2

, Su-Chen Tsai

1

and Huei-Ping Shen

1

1 Endemic Species Research Institute, Chichi, Nantou, Taiwan 2 Department of Zoology, National Taiwan University, Taipei, Taiwan

1行政院農業委員會特有生物研究保育中心 南投縣集集鎮民生東路1號 2台灣大學動物學系 台北市羅斯福路四段1號

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Introduction

The genus Metaphire Sims and Easton is a large group of terrestrial earthworms next to the genus Amynthas Kinberg in the family Megascolecidae (Oligochaeta) in Taiwan. They consisted of five endemic species of Metaphire bununa Tsai, Tsai and Liaw, 2000, Metaphire paiwanna Tsai, Tsai and Liaw, 2000 (Tsai et al. 2000a), Metaphire puyuma Tsai, Shen and Tsai, 1999 (Tsai et al. 1999), Metaphire yeni Tsai, Shen and Tsai, 2000 (Tsai et al. 2000b), and Metaphire taiwanensis Tsai, Tsai and Shen, 2003 (Tsai et al. 2003), and four exotic species of Metaphire californica (Kinberg, 1867), Metaphire hesperidum (Beddard, 1892), Metaphire posthuma (Vaillant, 1869), and Metaphire schmardae (Horst, 1883) (Tsai et al. 2000c). This paper describes a new species Metaphire trutina sp. nov. from the northeastern Taiwan. This makes a total of 10 species in the genus Metaphire and 50 nominal species of the terrestrial earthworms in Taiwan. The specimens are preserved at Taiwan Endemic Species Research Institute, Chichi, Nantou, Taiwan.

Metaphire trutina sp. nov.

Type material

Holotype: A mature (clitellate) specimen

(dissected) collected 18, May 2002 in a ditch along a mountain road from Hsien Rd. 192 at an elevation of around 150m, Hsiaochaochi, Ilan County, Taiwan by Y. H. Chen (cat. no. 14-03884).

Paratype: An immature (aclitellate)

specimen (dissected), same collection of holotype (cat. no. 14-03882).

External characters

Length 236 mm for holotype and 305 mm for paratype. Clitellum length 7.89 mm and clitellum width 11.0 mm. Prostomium prolobous. Segment number 96 for holotype and 151 for paratype. Heavy annulets (secondary segmentation) 3 per segment in VI-IX and 5 in X-XIII, setal annulet slightly wider than the adjacent annulets. Setae numerous, 109-118 in VII, 108-128 in XX and 22-28 between male pores. First dorsal pore in 12/13. Clitellum XIV-XVI, dorsal pores absent, setae absent in XIV and XV, but 5 setae on medio-ventrum of XVI.

Spermathecal pores invisible externally due to heavy secondary segmentation, 3 pairs, ventro-lateral in 6/7-8/9, but detected from inside after dissection. No genital papillae in the spermathecal region. Female pore single, medio-ventral in XIV.

Male pores paired in XVIII, ventro-lateral,

Key words: earthworm, new species, Metaphire, Taiwan

關鍵詞:蚯蚓、新種、腔環蚓屬、台灣

Received: March 27, 2003 Accepted: June 2, 2003

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large, C-shape, 2.87 mm in longitudinal length, reaching 17/18 and 18/19 segmental furrows. Porophore, a small tubercle with a small male aperture at the latero-central end of male disc, a narrow longitudinal ridge extending from setal annulet of XVIII. No setae on the male disc. A pair of large, nearly equally sized round-shaped genital papillae located on anterior and posterior ends of the male disc (Fig. 1A, B). Each of the genital papillae 1.0 to 1.1 mm in diameter with a slightly concave center. Lateral wall of the

copulatory chamber smooth externally (laterally) but slightly folliculated internally (medially).

Preserved specimens purplish blue dorsum and around clitellum, and brownish gray ventrum. Setal annulet lighter in color as compared to adjacent annulets.

Internal characters

Septa 8/9/10 absent, 10/11-13/14 very thick. Gizzard large, round in IX and X. Intestine enlarged from XIV. Intestinal caeca paired in

Fig. 1. Metaphire trutina sp. nov. holotype: (A) ventral view of left male pore region with copulatory

chamber closed (gp, genital papilla; md, male disc), (B) ventral view of left male pore region with copulatory chamber (cp) opened (p, porophore), (C) right spermathecae (amp, ampulla; div, diverticulum), (D) right sperm sacs (ss) and seminal vesicles (sv) (dl, dorsal lobe), (E) right prostate gland, and (F) right caecum.

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XXVII extending anteriorly to XXII, each simple with a pointed end, surface wrinkled with vertical lines (Fig. 1F). Esophageal hearts enlarged in XI-XIII.

Spermathecae three pairs in VII-IX, each with an oval or round ampulla with heavily pressed wrinkles at proximal end, and a very short stout stalk. Diverticulum with silver colored and oval shaped seminal chamber and a heavily twisted stalk (Fig. 1C). Ovaries paired in XIII.

Sperm sacs two pairs, medio-ventral in X and XI, each round, white in color, with smooth surface, sperm ducts connected in XIII. Seminal vesicles, two pairs in XI and XII. Anterior pair large, pale in color, surface wrinkled, each with a round brownish, granulated dorsal lobe, filled whole segmental cavity. Posterior pair smaller in size as compared to the anterior ones, granulated surface, each with a large, brown colored, granulated dorsal lobe (Fig. 1D).

Prostate glands paired in XVIII, each lobed, surface folliculated, prostatic duct stout and straight (Fig. 1E). No accessory gland or visible structure associated with the genital papillae in copulatory chambers.

Locality and habitat

The type specimens were collected from the roadside ditch covered with about 10 cm thick sand without vegetation.

Etymology

The name trutina is given to this species with reference to an earthworm possessing a pair of large genital papillae, each with a slightly concave center and connected by narrow male disc with porophore at medio-lateral center, like a balance, in each shallow copulatory chamber.

Remarks

Metaphire trutina sp. nov. is sexthecal with spermathecal pores in 6/7/8/9, and has no genital papillae in 17/18 and 18/19. It belongs to the houlleti species-group of the genus Metaphire (Sims and Easton 1972). It is a large earthworm with a pair of shallow copulatory chambers with C-shaped opening, the characters closely related to Metaphire vulgaris (Chen, 1930) of Nanking, China, Metaphire viridis Feng and Ma, 1987 from Gansu of the northwest China, Metaphire praepinguis (Gates, 1935) of Szichuan (Gates 1935, 1939), Metaphire aggera (Kobayashi, 1934) of Korea and Manchuria (Kobayashi 1934, 1940), and Metaphire tschiliensis (Michaelsen, 1928) of China. The last species consists of three subspecies: 1) M. t. tschiliensis (Michaelsen, 1928) of North and Central China (= Pheretima kiangsuensis Chen, 1930 (Chen 1930, 1931, 1933)), 2) M. t. grahami (Gates, 1935) from Szichuan (Gates 1935, 1939), and 3) M. t. kokoana (Chen and Fong, 1975) of Qinghai and Gansu (Chen et al. 1975).

Metaphire trutina is easily distinguished from the above related species and subspecies of China by possessing higher number of setae, absence of preclitellar genital papillae, absence of wrinkled, swollen lips or crescent ridges bordered anteriorly and posteriorly to each of the spermathecal pores, and the presence of two large genital papillae on both anterior and posterior ends of male disc in each shallow copulatory chamber (Table 1).

Literature Cited

Chen, Y. 1930. On some new earthworms from Nanking, China. Science Reports, National Central University, College of Science,

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Nanking. Series B. 1(1): 11-37.

Chen, Y. 1931. On the terrestrial oligochaeta from Szechuan. Contributions from the Biological Laboratory of the Science Society of China (Zoology) 7: 117-171. Chen, Y. 1933. A preliminary survey of the

earthworms of the lower Yangtze valley. Contributions from the Biological Laboratory of the Science Society of China (Zoology) 9: 177-295.

Chen, Y., C. F. Hsu, T. Yang, and H. Y. Fong. 1975. On some new earthworms from China. Acta Zoologica Sinica 21(1): 89-99. Feng, X. Y., and Z. G. Ma. 1987. Notes on a new

species of the genus Metaphire from Gansu Province, China (Oligochaeta: Mega-scolecidae). Acta Zootaxonomica Sinica 12(3): 248-250.

Gates, G. E. 1935. New earthworms from China, with notes on the synonymy of some Chinese species of Drawida and Pheretima. Smithsonian Miscellaneous Collections 93(3): 1-19.

Gates, G. E. 1939. On some species of Chinese earthworms, with special reference to specimens collected in Szechwan by Dr. D. C. Graham. Proceedings of the United States National Museum 85: 405-507. Kobayashi, S. 1934. Three new Korean

earthworms belonging to the genus Pheretima, together with the wider range of the distribution of Pheretima hilgendorfi (Michaelsen). Journal of the Chosen Natural History Society 19: 1-11.

Kobayashi, S. 1940. Terrestrial Oligochaeta from Manchoukuo. Science Report of the Tohoku University 15: 261-315.

Michaelsen, W. 1928. Miscellanea Oligo-chaetologica. Arkiv för Zoologi 20(2):

1-15.

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

Tsai, C. F., H. P. Shen, and S. C. Tsai. 1999. On some new species of the pheretimoid earthworms (Oligochaeta: Megascolecidae) from Taiwan. Journal of the National Taiwan Museum 52(2): 33-46.

Tsai, C. F., S. C. Tsai, and G. J. Liaw. 2000a. Two new species of protandric pheretimoid earthworms belonging to the genus Metaphire (Megascolecidae: Oligochaeta) from Taiwan. Journal of Natural History 34: 1731-1741.

Tsai, C. F., H. P. Shen, and S. C. Tsai. 2000b. A new pheretimoid earthworm with latero-dorsal genital papillae. Journal of the National Taiwan Museum 53(1): 7-14. Tsai, C. F., H. P. Shen, and S. C. Tsai. 2000c.

Native and exotic species of terrestrial earthworms (Oligochaeta) in Taiwan with reference to Northeast Asia. Zoological Studies 39(4): 285-294.

Tsai, C. F., S. C. Tsai, and H. P. Shen. 2003. A new gigantic earthworm of the genus Metaphire Sims and Easton (Mega-scolecidae: Oligochaeta) from Taiwan with reference to evolutional trends in body sizes and segment numbers of the Pheretima genus-group. Journal of Natural History (in press).

數據

Fig. 1. Metaphire trutina sp. nov. holotype: (A) ventral view of left male pore region with copulatory chamber closed (gp, genital papilla; md, male disc), (B) ventral view of left male pore region with copulatory chamber (cp) opened (p, porophore), (C) ri
Fig. 1. Metaphire trutina sp. nov. holotype: (A) ventral view of left male pore region with copulatory chamber closed (gp, genital papilla; md, male disc), (B) ventral view of left male pore region with copulatory chamber (cp) opened (p, porophore), (C) ri p.3

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