Glyphidrilus vesper Chanabun & Panha, 2013

Chanabun, Ratmanee, Sutcharit, Chirasak, Tongkerd, Piyoros & Panha, Somsak, 2013, The semi-aquatic freshwater earthworms of the genus Glyphidrilus Horst, 1889 from Thailand (Oligochaeta, Almidae) with re-descriptions of several species, ZooKeys 265, pp. 1-76 : 55-59

36. Glyphidrilus vesper Chanabun & Panha sp. n. Figs 35 36 38 Table 1

Type material.

Holotype: CUMZ 3266 ( Fig. 36 ), in muddy swamp near the Thilorsu waterfall, Umphang, Tak, Thailand, 15°15'11.9"N, 098°45'40.5"E, 555 m amsl, 19 January 2011. Paratypes: 79 adults and 11 juveniles (CUMZ 3267), 3 adults (ZMH 14573), and 3 adults (NHM), same collection data as holotype.

Other material examined.

8 adults and 49 juveniles (CUMZ 3268), Nangkruan waterfall, Phopphra, Tak, Thailand, 16°24'36.0"N, 098°41'19.3"E, 369 m amsl, 18 January 2011. 9 adults and 13 juveniles (CUMZ 3269), Phawai waterfall, Phopphra, Tak, Thailand, 16°34'29.6"N, 098°50'3.2"E, 804 m amsl, 20 January 2011. 14 adults and 23 juveniles (CUMZ 3270), Huay Kreangkravia, Sungkhlaburi, Kanchanaburi, Thailand, 14°58'54.8"N, 098°37'2.0"E, 261 m amsl, 18 December 2010. 42 adults and 35 juveniles (CUMZ 3271), Katengcheng waterfall, Khao Lam National Park, Sungkhlaburi, Kanchanaburi, Thailand, 15°01'38.3"N, 098°36'7.5"E, 199 m amsl, 18 December 2010. 50 adults and 27 juveniles (CUMZ 3272), Hindad hot spring, Thongphaphum, Kanchanaburi, Thailand, 14°37'29.9"N, 098°43'27.6"E, 110 m amsl, 8 May 2010. 24 adults and 44 juveniles (CUMZ 3273), Saiyoknoi waterfall, Saiyok, Kanchanaburi, Thailand, 14°14'13.6"N, 099°03'30.2"E, 199 m amsl, 8 May 2010.

Etymology.

The name " vesper " is given to this species for its western distribution, found in Tak and Kanchanaburi, West Thailand.

Diagnosis.

Glyphidrilus vesper sp. n. has unique characters of distinct expanded tissues of wi in 18-24, ½25, 25, with clitellum in 14, 15, 16,17-29, 30, 31, 32; gm: lateral paired or asymmetrical on bc in 12-17, 18, 24, 25-26, 27, median unpaired on aa in 11, 12, 13 and 26, 27; sv in 9-12; he in 7-11; ov in 13-14; sc sessile, elongated oval or globular in 13/14-16/17 ( Table 1 ).

Description of Holotype.

Dimensions: body length 100 mm, diameter 2.8 mm in segment 8, 2.9 mm before clitellar wi in segment 17, 2.8 mm behind wi in segment 25 in intraclitellar region. Body cylindrical in anterior part, quadrangular in transverse section behind clitellum. 194 segments. Body colour pale brown with variations from red to pink at adjacent tissues of wi portion in different individuals of newly collected specimens after placement in 30% ethanol for narcotization. Dorsal surface considerably broader than the ventral at posterior end. Clitellar wi on ventro-lateral part of clitellum in 18-24, 5.4 mm in height, and about 0.6 mm in width on both sides. Prostomium zygolobous. Dorsal pores absent. Clitellum annular in 17-31. Four pairs of setae per segment from 2, setal formula aa:ab:bc:cd:dd = 1.0:0.5:1.0:0.7:1.1 in segment 8 and 0.9:0.6:1.2:0.6:1.1 in postclitellar segments. Female pores, male pores, and spermathecal pores are not visible. Gm: median unpaired on aa in 12-13, 25, lateral paired or asymmetrical on bc in 17.

Septa 5/6-9/10 thick, 10/11 to the last segment thin. Gi small globular within 7-8. Intestine enlarged from 15. Dorsal blood vessel aborted anterior to 7. He in 7-11. No distinguishable np in first twelve segments. Sv in 9-12. Ov in 13-14. Testis in 10-11. Prostate and accessory glands absent. Sc sessile, elongated oval or globular in 13/14-16/17, 0.2-0.3 mm in diameter, three to six on each side per segment.

Variation.

Body length of paratypes (89) and non-types (150) ranged from 46-146 mm (79.6 ± 21.6), with 102-260 segments. Wi in 18-24, ½25, 25, with clitellum in 14, 15, 16, 17-29, 30, 31, 32; gm: lateral paired or asymmetrical on bc in 12-17, 18 and 24, 25-26, 27, median unpaired on aa in 11, 12, 13 and 26, 27.

Distribution.

The new species was found on a waterfall shore in silt topsoil (90% silt and 10% clay, pH 5.9-6.6), covered with worm casts at several locations of West Thailand nearby Burma at Tak and Kanchanaburi.

Remarks.

Glyphidrilus vesper sp. n. similar to Glyphidrilus papillatus from Burma in the locations of wi, whereas Glyphidrilus papillatus has longer clitellum in 14-40, and sc in 14-17. The new species is similar to Glyphidrilus kuekenthali from Barem River, Borneo in the locations of wi however, Glyphidrilus kuekenthali has a bit longer clitellum in ½13 -34, intestinal origin in 15 or 16 and sc in 14-18. Differs from Glyphidrilus spelaeotes from Siju Cave, Garo Hills, Assam by Glyphidrilus spelaeotes has clitellum in 14, 15, 16-30, wi in 18, 19-24, ½25, he in 8-11 and sc in 13/14-15/16.Differs from Glyphidrilus gangeticus from Saharanpur, United Province, India by Glyphidrilus gangeticus has a bit longer clitellum in ½13, 13, 14-34, wi in 17, 18, 19-23, 24, 25, he in 8 or 9-11 and sc in 12/13, 13/14-16/17, 17/18. Differs from Glyphidrilus gatesi from Sungei Kayu, swamp forest near River Sedili, Johor, Malaysia by Glyphidrilus gatesi has shorter clitellum in ½17, 17, 18-25, ½26, 26, intestinal origin in 18, he in 9-11 and sc in 15-17.

The new species differs from Glyphidrilus borealis sp. n. from which has different locations of wi in 21, 22-27, 28, 29, with longer clitellum in 14, 16, 17-31, 32, 33, 34, 35, 36, five pairs of he in 7-11 and sc in 14/15-18/19.It differs from Glyphidrilus vangthongensis sp. n. by Glyphidrilus vangthongensis sp. n. has longer wi in 24, 25, 26-31, 32, and longer clitellum in 12, 13, 14, 15, 16-40, 41, 42, he in 7-11 and sc in 12/13-18/19.

Figures

Figure 35. Photographs showing the A and B type locality of Glyphidrilus vesper sp. n. in a muddy swamp near the Thilorsu Waterfall, Umphang, Tak and C coloration of newly collected paratype CUMZ 3267 just after the first preservation step in 30 % (v / v) ethanol.

Figure 36. Morphology of the holotype (CUMZ 3266) of Glyphidrilus vesper sp. n., showing the A external ventral and B internal dorsal views.

Figure 38. Distribution map of the new Glyphidrilus species from Thailand. Filled hexagon: Glyphidrilus vesper sp. n., Open trapezoid: Glyphidrilus wararamensis sp. n., Filled trapezoid: Glyphidrilus trangensis sp. n., Filled star: Glyphidrilus kratuensis sp. n.