Okudrilus sulcatus Csuzdi & Sherlock & Kouete & Doherty-Bone 2015, sp. n.

Okudrilus sulcatus Csuzdi & Sherlock sp. n.

Figs 9, 10

Etymology: From Latin sulcatus (sulcate), in reference to the long seminal grove connecting the prostatic pores and the single porophore.

Diagnosis: L: 70–81 mm, D: 2–2.5 mm. Colour reddish-brown, paler on ventrum. Head epilobous, setae closely paired. Clitellum annular on 14–17. Prostatic pores in 17/18 a–a, spermathecal pores praesetal on 11 between a–a, female pores on 14 close to 14/ 15 in d. Gizzard in 6, calciferous glands in 12, chylus-sacs in 10, 11. Testes in 11, vesicles in 12 long running back to 33. Ovo-spermathecal apparatus paired, spermathecal ampulla elongated, laterally continues in an ovo-spermathecal duct communicating with the ovarian capsule. The right and left ovo-spermathecal duct interconnected by a small channel. Prostates without copulatory sacs. Simple penial setae 4, 4 mm in length and 0.025 mm in diameter.

Description:

External characters:

Holotype: Preserved length 81 mm diameter after clitellum 2 mm. Segment number: 138. Paratype: (tail truncated) 70 mm in length 2.5 mm in diameter. Segment number: 81. Colour: Preserved reddish-brown, paler on ventrum. Head: Epilobous, ¾. Dorsal pores: Lacking. Setae: Closely paired, setal ratio aa:ab:bc:cd:dd = 5.5:1.5:3.5:1:17. Nephridial pores: Begin on segment 2, somewhat dorsal to setal line d.

Clitellum:Annular on segments 14–17. Prostatic pores: Ventral on two spherical papillae in 17/18, aligned with setal line a–a. The prostatic pores are connected by an invert Y-shaped seminal groove with the single asymmetrically placed porophore on 13/14. Female pores: Small dots on 14, close to the intersegmental furrow 14/15 just below setal line d. Spermathecal pores: paired on 11 near to the intersegmental furrow 10/11 between setae a–a (Fig. 9).

Internal characters:

Muscular gizzard: In 6, large, cylindrical. Septa: 8/9–11/12 slightly thickened. Calciferous glands: Paired in 12, chylus-sacs in 10, 11. Dorsal blood vessel: Simple throughout. Hearts: In 9–11, moniliform. Testes and sperm funnels: In 11 enclosed in a spindle-shaped sperm-reservoir. Seminal vesicles: Long, running alongside the intestine from 12 to 33. Ovo-spermathecal apparatus: Ovaries in 13 enclosed in an ovarian capsule pendant from septum 12/13. This ovarian capsule laterally continuing in an undulating ovarian duct joining the fertilisation chamber bearing a pendant ovisac. From the fertilisation chamber a straight oviduct leads to the female pore. The ovarian capsule medially communicates with a short ovo-spermathecal duct joining laterally to the elongated spermathecal ampulla. The spermathecal ampulla joins a spermathecal duct becoming spindle-shaped before opening into the spermathecal pore. The left and right ovarian ducts communicate by a small interconnecting channel (Fig. 10). Prostates: Long simple tubes without bursa copulatrix or bursa propulsoria. Penial setae: Simple, smooth, 4.4 mm long and 0.025 mm in diameter.

Holotype: CAMEROON: North-West Region, Wum, 1230 m, 2005, L. Norgrove (HNHM AF/5573).

Paratype: CAMEROON: North-West Region, near Elum, 1026 m, 30.v.2012, M. T. Kouete & T. DohertyBone (NHM 2013.444 1 ex.).

Remarks: This species differs from the other two Okudrilus in the position of the spermathecal pores located in segment 11 (12/ 13 in O. monticolus, 12 in O. nyosensis) and furthermore in the structure of the ovo-spermathecal apparatus. The holotype was collected on a Chromolaena odorata two years fallow. The paratype was collected in an area used for subsistence agriculture.