Glyphidrilus quadratus 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 : 42-45

31. Glyphidrilus quadratus Chanabun & Panha sp. n. Figs 27 28 37 Table 1

Type material.

Holotype: CUMZ 3239 ( Fig. 28 ), in sandy loam in Kang Saphue, Phibunmangsahan, Ubon Ratchathani, Thailand, 15°14'46.8"N, 105°14'33.2"E, 108 m amsl, 12 March 2011. Paratypes: 33 adults and 14 juveniles (CUMZ 3240), 3 adults (ZMH 14567), and 3 adults (NHM) are designated as paratypes, same collection data as for holotype.

Other material examined.

All these collections are in Thailand. 9 adults and 2 juveniles (CUMZ 3241), Tadton waterfall, Khong Chiam, Ubon Ratchathani, 15°15'13.6"N, 105°28'40.8"E, 174 m amsl, 14 May 2011. 5 adults and 2 juveniles (CUMZ 3242), Lamtakong Dam, Pakchong, Nakhon Ratchasima, 14°46'7.4"N, 101°31'4.5"E, 2.7 m amsl, 11 March 2011. 6 adults and 2 juveniles (CUMZ 3243), Mun River near Chai-ngam, Phimai, Nakhon Ratchasima, 15°13'49.1"N, 102°30'16"E, 164 m amsl, 14 March 2011. 24 adults and 4 juveniles (CUMZ 3244), Mun River opposite Phimai Museum, Nakhon Ratchasima, 15°13'28.3"N, 102°29'39.2"E, 150 m amsl, 14 March 2011. 24 adults and 14 juveniles (CUMZ 3245), Rasisalai Dam, Rasisalai, Sisaket, 15°21'7.5"N, 104°05'59.0"E, 126 m amsl, 12 February 2011. 9 adults and 10 juveniles (CUMZ 3246), Lamplaimad River, Lamplaimad, Buriram, 14°59'46.8"N, 102°42'7.7"E, 197 m amsl, 13 March 2011. 9 adults and 20 juveniles (CUMZ 3247), Troknong waterfall, Khlung, Chanthaburi, 12°32'12.5"N, 102°14'39.6"E, 45 m amsl, 9 August 2011. 2 adults and 4 juveniles (CUMZ 3248), Sumrongkeit waterfall, Khunhan, Sisaket, 14°30'35.3"N, 104°29'9.1"E, 218 m amsl, 6 November 2011. 16 adults and 18 juveniles (CUMZ 3249), Klongmanow Lake, Nondindang, Buriram, 14°17'50.6"N, 102°44'39.9"E, 253 m amsl, 15 May 2011. 15 adults and 8 juveniles (CUMZ 3288), stream near Chanthaten waterfall, Mueang, Chonburi, 13°14'13.0"N, 101°01'27.5"E, 52 m amsl, 31 March 2012. 6 adults and 5 juveniles (CUMZ 3289), stream near Tamkhao-hayod, Mueang, Chonburi, 13°08'43.8"N, 101°35'55.7"E, 94 m amsl, 31 March 2012. 1 adult and 15 juveniles (CUMZ 3290), Wattam-neramid, Khaochamao, Rayong, 12°58'14.5"N, 101°39'46.1"E, 41 m amsl, 24 October 2011. 15 adults and 8 juveniles (CUMZ 3291), Angbeng waterfall, Makham, Chanthaburi, 12°51'54.4"N, 102°13'29.3"E, 101 m amsl, 23 May 2012.

Etymology.

The name " quadratu s" is giving to this species for the character of the body that in transverse section is quadrangular in appearance.

Diagnosis.

The unique characters of Glyphidrilus quadratus sp. n. are distinct expanded tissues of wi in 23, 24-28, 29, 30, 31, with clitellum in 15, 16, 17, 18-31, 32, 33, 34, 35, 36; gm: median paired or aa in 11, 12, 13, 14, and 31, 32, 33, 34, lateral paired or asymmetrical on bc in 13, 15, 16, 17, 18, 19-21, 22, 23 and 30, 31; he in 7-11; sv in 9-11; ov in 13-14; sc sessile, elongated oval or globular in 12/13-17/18 ( Table 1 ).

Description of Holotype.

Dimensions: body length 71 mm, diameter 10.0 mm in segment 8, 11.0 mm before clitellar wi in segment 23, 11.0 mm after wi in segment 30 within the clitellum; body cylindrical in anterior part, quadrangular in transverse section behind clitellum. 274 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 24-29, 3.2 mm in height, and about 0.3 mm in width on both sides. Prostomium zygolobous. Dorsal pores absent. Clitellum annular in 15-33. Four pairs of setae per segment from 2, setal formula aa:ab:bc:cd:dd = 1.1:0.5:1.1:0.4:1.8 in segment 8 and 1.2:0.4:1.1:0.6:2.0 in postclitellar segments. Female pores, male pores and spermathecal pores not visible. Gm: median paired on aa in 13-14, lateral paired on bc in 15-23.

Septa 4/5-8/9 thicker, 9/10-12/13 thick and 13/14 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 thirteen segments. Sv in 9-12. Ov in 13-14. Testis in 10-11. Prostate and accessory glands absent. Sc in 12/13-17/18, about 0.1-0.3 mm in diameter, one to fourteen on each side per segment.

Variation.

Body length of paratypes (39) and non-types (141) range from 54-156 mm (103.0 ± 72.1), with 186-378 segments. Wi in 23, 24-28, 29, 30, 31, with clitellum in 15, 16, 17, 18-31, 32, 33, 34, 35, 36; gm: median paired on aa in 11, 12, 13, 14, and 31, 32, 33, 34, lateral paired or asymmetrical on bc in 13, 15, 16, 17, 18, 19-21, 22, 23 and 30, 31.

Distribution.

The new species was found on a canal connected to a waterfall in sandy loam topsoil (79.4% sand, 14.0% silt and 6.5% clay, pH 6.7-7.3). The soil surface was covered with the worm casts. This species was found in several locations within the Mun River drainage area, in the south part of Northeast, Central and East Thailand and it also seems likely that it will be found in nearby areas of the Mun River watershed near Cambodia. This is a large distribution range, from 101o to 105 o E and 12 o to 15 o N.

Remarks.

Glyphidrilus quadratus sp. n. is similar to Glyphidrilus annandalei from India in the locations of wi but Glyphidrilus annandalei has a bit longer wi in 25, 26, 27- ½32, 32, ½33, 33, 35, 36, with a longer clitellum beginning in 13-18 and extending to 35-41 and sc in 13/14-16/17. The new species is similar to Glyphidrilus birmanicus from Burma in the locations of wi however, Glyphidrilus birmanicus has longer clitellum in 12, 13-43, 44 and sc in 13/14-17/18.Differs from Glyphidrilus vangviengensis from Laos by Glyphidrilus vangviengensis has shorter clitellum in 19, 20-35, 36, 37, np from 16, and lacks sc. Differs from Glyphidrilus yunnanensis from China by Glyphidrilus yunnanensis has a bit longer wi in 22-32, np from 16, and lacks sc.

The new species differs from Glyphidrilus vangthongensis sp. n. by Glyphidrilus vangthongensis sp. n. has larger body size, longer clitellum in 12, 13, 14, 15, 16-40, 41, 42, np from 14, gi in 7-8, and sc in 12/13-18/19. It differs from Glyphidrilus chiensis sp. n. by Glyphidrilus chiensis sp. n. has larger body size, wi in 23, 24, 25, 26-29, 30, 31, 32, clitellum in 17, 18-33, 34, 35, 36, 37, 38 and sc in 12/13-18/19. It differs from Glyphidrilus huailuangensis sp. n. by Glyphidrilus huailuangensis sp. n. has smaller size, shorter wi in 25, 26-30, 31, clitellum in 12, 13, 16-32, 33 and lacks sc ( Table 1 ).

Figures

Figure 27. Photographs showing the A type locality of Glyphidrilus quadratus sp. n. on a sandy beach at Kang Saphue, Phibunmangsahan, Ubon Ratchathani, B Glyphidrilus quadratus sp. n. casts and C coloration of newly collected paratype CUMZ 3240 just after the first preservation step in 30 % (v / v) ethanol.

Figure 28. Morphology of the holotype (CUMZ 3239) of Glyphidrilus quadratus sp. n., showing the A external ventral and B internal dorsal views.

Figure 37. Distribution map of the new Glyphidrilus species from Thailand. Open triangle: Glyphidrilus borealis sp. n., Filled triangle: Glyphidrilus vangthongensis sp. n., Filled star: Glyphidrilus chaophraya sp. n., Open square: Glyphidrilus chiensis sp. n., Filled square: Glyphidrilus quadratus sp. n., Open circle: Glyphidrilus huailuangensis sp. n.