Glyphidrilus malayanus Michaelsen, 1902

Chanabun, Ratmanee, Bantaowong, Ueangfa, Sutcharit, Chirasak, Tongkerd, Piyoros, James, Samuel W. & Panha, Somsak, 2012, A New Species Of Semi-Aquatic Freshwater Earthworm Of The Genus Glyphidrilus Horst, 1889 From The Mekong River (Oligochaeta: Almidae), Raffles Bulletin of Zoology 60 (2), pp. 265-277 : 268-270

Glyphidrilus malayanus Michaelsen, 1902

( Figs. 3B , 5)

Glyphidrilus malayanus Michaelsen, 1902: 35 . Type locality: Malay Peninsula: Lubock Paku, Pahang River. Michaelsen, 1910: 104. Brinkhurst & Jamieson, 1971: 762, Fig. 15.4E, F.

Material examined. — Holotype from ZMH annelid reference collections ( ZMH V5875, Fig. 5A, B). Additional records: 110

adults and 257 juveniles ( CUMZ 3219 , Fig. 5C), Sungei Kelantan, Kelantan, Malaysia, 6°0'44.1"N, 102° 10'58.2"E, 24 m in elevation (27 May 2011) . 17 adults and 11 juveniles ( CUMZ 3220 , Fig. 5D), Sungei Berkoh , Johor, Malaysia, 2°7'11.1"N, 103°2'24.9"E, 35 m in elevation (21 May 2011) . 65 adults and 41 juveniles ( CUMZ 3218 , Figs. 3B , 5E), Tok Bok Hotspring , Kelantan, Malaysia, 5°50'19.4"N, 102°13'50.3"E, 36 m in elevation (26 May 2011) .

Description. — Dimensions: 52–91 mm body length by 1.4–2.5 mm in the anterior body region, body cylindrical in the anterior part but quadrangular in transverse section after clitellum, with 192–313 segments. The body colour is pale brown. Dorsal surface considerably broader than ventral at the posterior end. The clitellar wings on ventro-lateral part of the clitellum in ¾18, 18–21, ½22, with 2.1–2.6 mm long, and 0.5–1.2 mm wide on both sides. Prostomium zygolobous. Dorsal pores absent. Clitellum annular shape from 15, 16, 17–23, 24, 25. Four pairs of setae per segment from 2. Female pores, male pores, and spermathecal pores not visible. Genital markings: lateral series paired or asymmetrical, between line b and c in 13–15; lateral series paired or asymmetrical, lateral to line b in 16, 17, 22, 23; unpaired median series between aa in 12–16, 22–25.

Septa 4/5–8/9 thick, 9/10–14/15 moderately thick, and extremely thin from 15/16 to the end. Gizzard globular in 8. Intestine enlarged from 16. Hearts from 9–11. No nephridia distinguishable in the first 13 segments. Four pairs of seminal vesicles in 9–12, with the pair in 12 longest, parallel with intestine and extending to 15, 16 or 17. Ovaries in 13. Prostate and accessory glands absent. Spermathecae sessile, globular, 0.2–0.3 mm in diameter, on segments 14/15–16/17, two to three on each side per segment.

Habitat. — Found on the shore but in proximity to the river water, in the sandy mud topsoil and also under the water at a depth of about 10 cm. The river bank soil surface was covered with worm casts at Sungei Berkoh and Tok Bok Hotspring. Also found in the sandy clay in Sungei Kelantan.

Remarks. — Glyphidrilus malayanus from Malay Peninsula: Lubock Paku, Pahang River, Malaysia has clitellum in 15–25, wings in ¾18–½22, and the absence of median genital markings. The specimens collected from Sungei Berkoh, Tok Bok Hotspring, and Sungei Kelantan in this study were slightly different from the type specimen. The positions of the clitellum and wings of the additional specimens are slightly different from the wings location of the type specimen by one or two segments, and median genital markings were present in these specimens. Most of the morphological characteristics are quite similar to the holotype specimen. The smaller size is the only distinct character noticed. We added up our own drawings of the holotype shown in Fig. 5A, B, and of other specimens collected from different localities in Fig.5 C–E, and also the colour picture in Fig. 3B .

Figures

Fig. 3. The colouration of newly collected specimens just after the first step preservation in 30% ethanol:A, Glyphidrilus mekongensis, new species (paratype CUMZ 3216); B, Glyphidrilus malayanus from Tok Bok Hotspring, Kelantan, Malaysia (CUMZ 3218); C, Glyphidrilus singaporensis topotype specimen (CUMZ 3217); D, cocoon characters of Glyphidrilus mekongensis, new species (paratype CUMZ 3216).