Dichogaster (Diplothecodrilus), 1996

Plisko, Jadwiga D. & Nxele, Thembeka C., 2015, An annotated key separating foreign earthworm species from the indigenous South African taxa (Oligochaeta: Acanthodrilidae, Eudrilidae, Glossoscolecidae, Lumbricidae, Megascolecidae, Microchaetidae, Ocnerodrilidae and Tritogeniidae), African Invertebrates 56 (3), pp. 663-663 : 684

Key to Dichogaster (Diplothecodrilus) introduced to RSA

1 Male reproductive organs acanthodriline................................................................2 Notes: Setae lumbricine. Prostomium epilobous. Female pores paired, in 14. Male pores paired, in 18. Prostatic pores paired, in 17 and 19, respectively. Spermathecal pores paired, in intersegmental furrow 7/8 and 8/9 respectively. Calciferous glands oesophageal in 15–17. Holandric.Excretory system meroic.

– Male reproductive organs in the incomplete microscolecine/balantine state............ ................................................................................ D. (D.) saliens (Beddard, 1893) Description: Male pores paired, in 17; prostatic pores one pair in 17, both open very close to each other, encircled by small papillae. Spermathecal pores paired in intersegmental furrow 7/8 and 8/9 respectively. Body length 25–65 mm. Unpigmented, although alive may be slightly brown. Setae lumbricine. Prostomium epilobous. Female pores paired, median to setae a, in 14. Male pores paired, in 17 within paires of aa setae. Prostatic pore one pair in 17. Spermathecal pores paired in intersegmental furrow 7/8 and 8/9 respectively. Nephropores minute. Clitellum saddle-shaped on 13–19, 20. Genital markings present; a small mid-ventral circular disk in 15/16. Septa 11/12–13/14 somewhat thickened.Two gizzards, in 5 and 6 respectively, slightly externally separated. Typhlosole present, lamellar. Calciferous glands in 15–17 with the anterior pair smallest. Last pair of hearts in 12. Holandric. Excretory system meroic. Seminal vesicles small in 11 and 12; vesicle in 12 may be absent. Prostates single pair in 17 as a long tubular gland. Spermathecae paired, in 8 and 9 respectively, with a mushroom-shaped ampulla with a thin duct half as long as ampulla. Penial setae uniform, 0.7 mm in length. Notes: Widely spread worldwide.Pastures, grasslands, near cow sheds, gardens; noted in natural habitats, protected areas where imported trees or plants were introduced. In RSA recorded from various biotopes in LP and KZN (Plisko 2010). Five unpublished records kept in the NMSA refer to Mkhabati Forest (EC). This species has an incomplete microscolecine arrangement, with two pairs of spermathecae in segment 8 and 9 respectively and only one pair of prostate in segment 17.

2 Female pores paired .................................................................................................3

– Female pore single, medially in 14........................ D. (D.) bolaui (Michaelsen, 1891) Description: Body length 20–40 mm.Unpigmented, sometimes dorsally with brownish tint.Setae lumbricinae.Prostomium epilobous. Male pores paired, in 18. Prostatic pores paired, in 17 and 19, respectively. Spermathecal pores close to setal a lines in intersegmental furrows 7/8 and 8/9. Clitellum annular on 13, 14–18, 19, 20. Genital field oblong. Nephropores minute. Septa 7/8–9/10 slightly thickened. Gizzards muscular in 5–6. Typhlosole small, lamellar. Calciferous glands in 15–17. Hearts in 10–12. Nephridia 3–5 rows in each side of the segment. Holandric. Excretory system meroic. Prostates paired, in 17 and 19 respectively. Spermathecae paired, in 8 and 9 respectively; ampulla subdivided in similar two parts, with small diverticulum ( Fig. 10B ). Penial setae dimorphic, ornamented.

Figures

Fig. 10. Spermathecae: (A) Acanthodrilidae: Udeina adriani; (B) Benhamiinae: Dichogaster (Diplothecodrilus) bolaui, D.(D) modiglianii, D.(D) affinis and D.(D) annae; (C) Microchaetidae:Proandicus pajori; (D) Megascolecidae: Amynthas aeruginosus.