Glyphidrilus kratuensis 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 : 53-55

35. Glyphidrilus kratuensis Chanabun & Panha sp. n. Figs 34 38 Table 1

Type material.

Holotype: CUMZ 3264 ( Fig. 34 ), in muddy swamp near Kratu waterfall, Kratu, Phuket, Thailand, 07°55'55.5"N, 098°19'23.3"E, 11 m amsl, 11 December 2009. Paratypes: 79 adults and 11 juveniles (CUMZ 3265), 3 adults (ZMH 14572), and 3 adults (NHM), same collection data as holotype.

Etymology.

The name " kratuensis " is given to this species for its type locality in the Kratu waterfall, Kratu, Phuket, Thailand. The locality is a part of this famous waterfall and the first record of this genus in this location.

Diagnosis.

The unique characters Glyphidrilus ofkratuensis sp. n. are its small size, distinct expanded tissues of wi in 23, 24-28, 29, 30, with clitellum in 18-30, 31, 32; gm: lateral paired or asymmetrical on bc in 14, 15, 16, 17, 18, 19, 22, 23, 24, 29, 30, median unpaired on aa in 18, 19-20, 21, 22, 23 and 30-31, 32-34; he in 8-11; sv in 9-12; ov in 13-14; testis in 10-11; sc sessile, elongated oval or globular in 14/15-17/18, two pairs on each side per segment ( Table 1 ).

Description of Holotype.

Dimensions: body length 83 mm, diameter 2.4 mm in segment 8, 2.9 mm before clitellar wi in segment 22, 2.8 mm behind wi in segment 30 in intraclitellar region. Body cylindrical in anterior part, quadrangular in transverse section behind clitellum. 235 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 23-28, 29, 2.4 mm in height, and about 0.6 mm in width on both sides. Prostomium zygolobous. Dorsal pores absent. Clitellum annular in 18-31. Four pairs of setae per segment start from 2, setal formula aa:ab:bc:cd:dd=1.0:0.6:1.7:0.7:1.1 in segment 8 and 0.9:0.4:0.8:0.4:1.0 in postclitellar segments. Female pores, male pores, and spermathecal pores are not visible. Gm: lateral paired or asymmetrical on bc in 15-16, 29, median paired on aa in 19-22 and 30-31.

Septa 5/6-8/9 thicker, 9/10-11/12 thick and 12/13 to the last segment thin. Gi small globular within 8. Intestine enlarged from 14. Dorsal blood vessel aborted ante rior to 8. He in 8-11. 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 14/15-17/18, 0.4-0.5 mm in diameter, two on each side per segment.

Variation.

Body length of adult paratypes (85) ranged from 48-93 mm (156.1 ± 32.6), with 221-282 segments. Wi in 23, 24-28, 29, 30, with clitellum in 18-30, 31, 32; gm: lateral paired or asymmetrical on bc in 14, 15, 16, 17, 18, 19, 22, 23, 24-29, 30, median unpaired on aa in 18, 19-20, 21, 22, 23 and 30-31, 32-34.

Distribution.

Known from the type locality in Kratu waterfall, Kratu, Phuket in South Thailand. The new species was found on the shore connected to a waterfall in sandy mud topsoil covered with worm casts. Collections in nearby areas found other Glyphidrilus species but not this one.

Remarks.

Glyphidrilus kratuensis sp. n. a bit similar to Glyphidrilus horsti from Pulau Berhala, Straits of Malacca, however, Glyphidrilus horsti has smaller body size, shorter wi in 23, ½23-½28, 28, shorter clitellum in 17, ½18, 18, 19-28, 29, 30, ½31, he in 8 or 9-11, np from 13 or 15 or 16, gi in 7-8, and sc in 14-17 or 14/15-17/18.The new species is similar to Glyphidrilus birmanicus from Burma in the locations of wi, whereas Glyphidrilus birmanicus has longer clitellum in 12, 13-43, 44, he in 7-11 and sc in 13/14-17/18.

The new species differs from Glyphidrilus singaporensis which has different locations of wi in 21-25, ½26, 26, intestinal origin in 15 or 16, he in 9-11 and sc in 14-17 or 13/14-16/17.It differs from Glyphidrilus gatesi reported from Johor, Malaysia by Glyphidrilus gatesi has different locations of wi in 18, ½19, 19- ½24, 24, with shorter clitellum in ½17, 17, 18-25, ½26, 26, intestinal origin in 18, he in 9-11 and sc in 15-17.Differs from Glyphidrilus malayanus from Malay Peninsula by Glyphidrilus malayanus has shorter wi in ¾18, 18-21, ½22, and shorter clitellum in 15, 16, 17-23, 24, 25, intestinal origin in 14, he in 9-11 and sc in 14/15-16/17. Differs from Glyphidrilus vangviengensis from Laos by Glyphidrilus vangviengensis has longer wi in 24, 25-31, 32, and longer clitellum in 19, 20-35, 36, 37, 38, five pairs of he in 7-11 and lacks sc.

Differences of further species to Glyphidrilus kratuensis sp. n. are as follows: Glyphidrilus wararamensis sp. n. has a larger size, with wi in 20, 21-26, 27, with longer clitellum in 11, 12, 13-33, 34, 35 and sc in 13/14-17/18.Differs from Glyphidrilus trangensis sp. n. by Glyphidrilus trangensis sp. n. has a bit shorter wi in 22, 23-27, 28, with a bit shorter clitellum in 17, 18-30, and sc in 18-21.

Figures

Figure 34. Morphology of the holotype (CUMZ 3264) of Glyphidrilus kratuensis 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.