Dicelis Dujardin, 1845

Ivanova, Elena S. & Hope, Duane, 2009, A new genus and three new species of Drilonematidae (Rhabditida, Drilonematoidea) from earthworms, Zootaxa 2293, pp. 53-67 : 65

Key to the species of Dicelis Dujardin, 1845

1 Egg-shells smooth ........................................................................................................................................................ 3

- Egg-shells ornamented ................................................................................................................................................. 2

2 Caudal organs up to 1/2–2/3 tail diameter, stoma sclerotised ................................................... D. rossica Timm, 1962

- Caudal organs up to 1/4–1/3 tail diameter, stoma not sclerotised ............................................................................... 4

3 Eggs elongated,>60 µm long, 30 µm in diameter ................................................... D. nira Chitwood & Lucker, 1934

- Eggs elliptical, <45–50 µm long, 25–30 µm diameter .......................... D. keimeri Morand, Ivanova & Vaucher, 1996

4 Egg-shells coated with spikes ...................................................................................................................................... 5

- Egg-shells coated with tubercles .................................................................................................................................. 7

5 Tail end gradually tapering, bluntly rounded ............................................................................................................... 6

- Tail end well-tapered with conical terminal tip .................................................................... D. sibirica Ivanova, 1994

6 Eggs broadly elliptical, length 120% of width, <43 µm long; vulva post-median; amphids pore-like ....... D. eiseniae Timm, 1967

- Eggs elongated, length>120% of width,> 62–110 µm long, vulva median; amphids pocket-like ............................... ................................................................................................. D. caledoniensis Spiridonov, Ivanova & Wilson, 2005

7 Caudal organs small, less than 1/4 of tail diameter, situated within posterior third of tail .......................................... 8

- Prominent caudal organs at mid-tail ............................................................................................................................ 9

8 Tip ovary cell near tail tip, no loops of genital tube between anus and spermatheca... D. kimmeriensis Ivanova, 1993

- Tip ovary cell anterior to anus, two loops of genital tube between anus and spermatheca ........................................... ............................................................................................. D. hyrcanus Belostotskaya, Kozodoi & Spiridonov, 1987

9 Tail end well-tapered with conical terminal tip .......................................................................................................... 10

- Tail gradually tapering, bluntly rounded..................................................................................................................... 13

10 Tail broadly conical, fimbriate organs up to 1/3-1/2 of tail diameter ......................................................................... 11

- Tail narrowly conical, fimbriate organs up to 1/4 of tail diameter ....................................................... D. eudrilii sp. n.

11 Egg-shell tubercles 5–12 µm high ............................................... D. ussuriensis Spiridonov, Ivanova & Wilson, 2005

- Egg-shell tubercles 1–6 µm high ................................................................................................................................ 12

12 Chamber of caudal organ twice as large as its external structure; amphids pore-like; caudal papillae enlarged ........... ................................................................................................................................................. D. rubidi Ivanova, 1994

- Chamber of caudal organ smaller than its external structure; amphids pocket-like; caudal papillae small ................... .............................................................................................................................................. D. pereliae Ivanova, 1993

13 Pharynx cylindrical, eggs <50 µm long .................................................................................. D. filaria Dujardin, 1845

- Pharynx with slight basal expansion, eggs> 65 µm long .......................................................................................... 14

14 Lateral fields with 13–15 ridges; spicule body punctated; 9 pairs pre-anal papillae .......... D. lovatiana Ivanova, 1993

- Lateral fields with 5–7 ridges, spicule body smooth, 7 pairs pre-anal papillae ............. D. lumbricicola Ivanova, 1993