Glyphidrilus kotatinggi Chanabun & Panha, 2012

Chanabun, Ratmanee, Sutcharit, Chirasak, Tongkerd, Piyoros, Tan, Shau-Hwai Aileen & Panha, Somsak, 2012, Three new species of semi-aquatic freshwater earthworms of the genus Glyphidrilus Horst, 1889 from Malaysia (Clitellata: Oligochaeta: Almidae), Zootaxa 3458, pp. 120-132 : 124-129

Glyphidrilus kotatinggi Chanabun & Panha , sp. n.

( Figs 1, 2B, 4, Table 1)

Type material. Holotype: One clitellate ( CUMZ 3274 ) ( Fig. 4), Kota Tinggi waterfall, Johor, Malaysia, 62 meters in elevation, S. Panha, R. Chanabun, P. Tongkerd and C. Sutcharit leg., 20 May 2011. Four paratypes: 3 clitellates ( CUMZ 3275 ), 1 clitellate ( ZMH 14574), same collection data as for holotype.

Type locality. River banks of Kota Tinggi waterfall, Johor, Malaysia, 01°49'44.5''N, 103°50'4.1"E, 62 m asl .

Etymology. This new species was named after the Kota Tinggi waterfall, a famous waterfall. This is the first record of Glyphidrilus from this place.

Diagnosis. Medium sized limicolous earthworm with distinct expanded tissues of clitellar wing organs on the lateral sides of the body in 20, 21–¼26, 26. Clitellum in 17, 18–28, 29, 30. Female pores, male pores not visible. Inseminated spermathecae visible through body wall in 14/15–16/17. Genital markings post-setal median unpaired without rim on aa in 17, 19, post-setal lateral paired or asymmetrically distributed without rim near b or bc in 11–15, 17, 18, 19, 20 and 26–27. Four pairs of seminal vesicles in 9–12, with the pair in segment 12 largest. Three paired of hearts in 9–11. Intestinal origin in 14. Ovaries in 13–14. Prostate and accessory glands absent. Spermathecae in 13/14–16/17, one to four on each side per segment.

Description of holotype. Dimensions: body length 195 + mm, diameter 3.1 mm in segment 8, 3.1 mm before clitellar wings in segment 20, 3.2 mm behind wings in segment 27 in intraclitellar region. Body cylindrical in anterior part, quadrangular in transverse section behind clitellum. 284 + segments. Body colour pale brown with variations from red to pink at adjacent tissues of wing 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 wings on ventro-lateral part of clitellum in 21–¼26, 5.4 mm long, about 0.6 mm wide on both sides. Prostomium zygolobous. Dorsal pores absent. Clitellum annular in 18–29. Four pairs of setae per segment from 2, setal formula aa:ab:bc:cd:dd = 0.9:0.4:1.6:0.5:1.5 in segment 8. Female pores and male pores not visible. Inseminated spermathecae visible through body wall on b, c, and d line in 14/15–16/17. Genital markings: postsetal median unpaired without rim on aa in 19, post-setal lateral paired without rim near b in 11–15, 20 and 26–27; in 11–13 three genital markings on each side, in 14–15 only one.

Septa 4/5–7/8 thicker, 8/9–11/12 thick and 12/13 to the last segment thin. Gizzard small, globular within 8–9. Intestine enlarged from 14. Dorsal blood vessel aborted anterior to 9. Hearts from 9–11. No nephridia distinguishable in first eleven segments. Four pairs of seminal vesicles in 9–12, with pair in segment 12 larger than the others. Ovaries in 13–14. Prostate and accessory glands absent. Spermathecae in 13/14–16/17, three to four on each side in 14/15–16/17, inseminated, one or two on each side in 13/14, not inseminated. Number of spermathecae on the right side: two in 13/14, three in 14/15, four in 15/16 and in 16/17, on the left side: one in 13/14, three in 14/ 15 and 16/17, and four in 15/16.

Variation. Body length of the four paratypes 151 + – 187 mm, with 221 + –415 segments. Wings in 20, 21–¼26, 26 (covering 6–7 segments), clitellum in 17, 18–28, 29, 30 (covering 11–14 segments). Genital markings: postsetal median unpaired without rim on aa in 17, 19, post-setal lateral paired or asymmetry without rim near b or bc in 11–15, 17, 18, 19, 20 and 26–27.

Habitat. Found on the shore but in proximity to the river water, in the loamy sand topsoil with 82% sand, 14.28% silt and 3.57% clay, with pH 7.54, and also under the water at about 15–25 cm in depth. The river bank near the waterfall was covered with worm casts.

Distribution. The new species is known only from the type locality.

Remarks. Five described species from areas near Malaysia include G. kukenthali , G. malayanus , G. gatesi , G. singaporensis , and G. vangviengensis . They are different from the new species with respect to spermathecae, genital markings, clitellum and wing locations. Glyphidrilus kotatinggi sp. n. is most similar to G. singaporensis Shen & Yeo, 2005 , described from a locality nearby (only 45 km apart). Referring to the original description of the latter, G. kotatinggi differs in larger body size (115 + –195 + mm vs. 112–142 mm), higher segment number (221 + –415 + vs. 163–220), and in the absence of unpaired post-wing genital markings. Further possible differences (clitellum covering 11–14 segments and wings covering 6–7 segments vs. clitellum covering 9–14 segments and wings covering 5–6 segments) are inconclusive due to intraspecific variations in both species that lead to character overlap. For a detailed comparison, we re-investigated the holotype of G. singaporensis and we collected new topotypic material. As a result, we confirm the three above-mentioned differences of G. kotatinggi to G. singaporensis . A comparison of G. kotatinggi with G. singaporensis (specified for holotype, paratypes, and topotypic material) is given in Table 1.

Differences of further species to G. kotatinggi sp. n. are as follows (see also Table 1):

G. kukenthali from Sarawak differs in slightly longer wings in 18, ½18, 19–24, ½24, longer clitellum in ½13–34, hearts in 7–11, and spermathecae in 14–18.

G. malayanus from the Malay Peninsula has a bit shorter wings in 17, ¾18, 18–⅓21, ⅓22, 22, a shorter clitellum in 15–25, 26, intestinal origin in 16, and spermathecae in 14/15–16/17.

G. gatesi from Johor, Malaysia has wings in 18, ½19, 19–½24, 24, a shorter clitellum, in ½17, 17, 18–25, ½26, 26, intestinal origin in 18, and spermathecae in 15–17.

G. vangviengensis reported from the river bank of Song River at Vangvieng, Laos, has longer wings in 24, 25–31, 32, longer clitellum in 19, 20–35, 36, 37, intestinal origin in 16, and spermathecae are absent.

G. bisegmentus sp. n. from Air Banun Pandig, Perak, has shorter wings, shorter clitellum, and genital markings and spermathecae are absent.

G. peninsularis sp. n. from Sungei Bantang, has longer wings, a slighlty longer clitellum, four pairs of hearts in 8–11, and spermathecae in 14/15–17/18.

Material of other species examined for comparison. Glyphidrilus kukenthali Michaelsen, 1896: 195 , pl. 13, Fig. 1; type locality: Borneo, Barem River, Sarawak. Glyphidrilus malayanus Michaelsen, 1902: 35 ; one clitellate (syntype ZMH V 5875); type locality: Malay Peninsula, Lubock Paku, Pahang River. Glyphidrilus gatesi Shen & Yeo, 2005: 16 , Fig. 1; one clitellate (holotype ZRC 1974.12.2.51) and 9 clitellates and 2 aclitellates (paratypes ZRC 1974.12.2.52–62); type locality: Sungei Kayu, swamp forest near River Sedili, Johor, Malaysia. Glyphidrilus singaporensis Shen & Yeo, 2005: 18 , Fig. 3; one clitellate (holotype ZRC) and 2 clitellates and 9 aclitellates (paratypes ZRC) and 10 clitellates and 9 aclitellates (topotypes CUMZ 3273); type locality: Jungle Fall Valley, Bukit Timah, Singapore. Glyphidrilus vangviengensis Panha & Chanabun, 2011: 216 , Figs. 1–3; one clitellate (holotype CUMZ 3221) and 10 clitellates (paratypes CUMZ 3222); type locality: river banks of Song River at Vangvieng, Veintiane Province, Laos.