Glyphidrilus trangensis 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 : 51-53

34. Glyphidrilus trangensis Chanabun & Panha sp. n. Figs 33 38 Table 1

Type material.

Holotype: CUMZ 3262 ( Fig. 33 ), in muddy swamp near Trang River, Nayong, Trang, Thailand, 09°51'23.0"N, 098°37'38.5"E, 52 m amsl, 14 January 2009. Paratypes: 3 adults and 5 juveniles (CUMZ 3263), 1 adult (ZMH 14571), and 1 adult (NHM), same collection data as holotype.

Etymology.

The name" trangensis " is given to this species as it is the principal name of the type locality of the new species.

Diagnosis.

Glyphidrilus trangensis sp. n. is small sized with distinct expanded tissues of wi in 22, 23-27, 28, with clitellum in 17, 18-30; median unpaired gm on aa in 18-21; he in 8-11; sv in 11-13; ov in 13-14; testis in 10-11; sc sessile, elongated oval or globular in 18-21, two pairs on each side per segment ( Table 1 ).

Description of Holotype.

Dimensions: body length 32.5+ mm, diameter 2.2 mm in segment 8, 2.2 mm before clitellar wi in segment 20, 2.2 mm behind wi in segment 28 in intraclitellar region. Body cylindrical in anterior part, quadrangular in transverse section behind clitellum. 173+ 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 23-27, 2.2 mm in height, and about 0.6 mm in width on both sides. Prostomium zygolobous. Dorsal pores absent. Clitellum annular in 18-30. Four pairs of setae per segment from 2, setal formula aa:ab:bc:cd:dd = 0.6:0.2:0.8:0.3:0.7 in segment 8 and 0.8:0.4:1.2:0.4:0.8 in postclitellar segments. Female pores, male pores, and spermathecal pores are not visible. Median unpaired gm on aa in 18-21.

Septa 5/6-8/9 thicker, 9/10-14/15 thick and 15/16 to the last segment thin. Gi small globular within 8-9. Intestine enlarged from 16. Dorsal blood vessel aborted anterior to 8. He in 8-11. No distinguishable np in first eleven segments. Sv in 11-13. Ov in 13-14. Testis in 10-11. Prostate and accessory glands absent. Sc sessile, elongated oval or globular in 18-21, 0.3-0.5 mm diameter, two on each side per segment.

Variation.

Body length of adult paratypes (5) ranged from 11+-63+mm, with 41+-153+ segments. Wi in 22, 23-27, 28, with clitellum in 17, 18-30; median unpaired gm on aa in 18-21.

Distribution.

The new species is known only from the type locality in a muddy swamp near Trang River, Nayong, Trang, Thailand. Collections in nearby areas have found other Glyphidrilus species but not this species. This new species was found on the shore connected to water of the sandy mud topsoil covered with worm casts and in the water at about 5-8 cm depth.

Remarks.

Glyphidrilus trangensis sp. n. similar to Glyphidrilus horsti from Pulau Berhala, Straits of Malacca in the locations of wi, whereas Glyphidrilus horsti has clitellum in 17, ½18, 18, 19-29, 30, ½31, he in 8, 9-11, 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 however, 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 wi in 21-25, ½26, 26, with clitellum in 18-27, ½28, 29, 30, 31, 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 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, 26, 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, he in 7-11 and lacks sc.

The new species differs from Glyphidrilus wararamensis sp. n. by Glyphidrilus wararamensis sp. n. has larger body size, with different locations of wi in 20, 21-26, 27, longer clitellum in 11, 12, 13-33, 34, 35 and sc in 13/14-17/18. Differs from Glyphidrilus kratuensis sp. n. by Glyphidrilus kratuensis has wi in 23, 24-28, 29, 30, intestine in 14 and sc in 14/15-17/18 ( Table 1 ).

Figures

Figure 33. Morphology of the holotype (CUMZ 3262) of Glyphidrilus trangensis 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.