Dorylaimopsis, Ditlevsen, 1918

Leduc, Daniel, 2012, Deep-sea nematodes (Comesomatidae) from the Southwest Pacific Ocean: five new species and three new species records, European Journal of Taxonomy 24, pp. 1-42 : 25-26

Dichotomous key to all known species of Dorylaimopsis

(modified from Jensen (1979) and Zhang (1992))

1. Cuticle without lateral longitudinal rows of coarse dots along entire body ........................................ 2 – Cuticle with longitudinal rows of dots along entire length of body .................................................... 4

2. Lateral longitudinal rows of coarse dots present posterior to pharyngeal region only........................ 3 – Lateral longitudinal rows of coarse dots completely absent ................................................................. .......................................................................................... Dorylaimopsis metatypica Chitwood, 1936

3. Lateral differentiation of cuticle consisting of 1-3 longitudinal rows of dots beginning posterior to pharynx, gubernaculum with swollen distal end .......................... D. coomansi Muthumbi et al., 1997

– Lateral differentiation of cuticle consisting of 3-5 longitudinal rows of dots beginning posterior to pharynx, triangular gubernaculum tapering distally ......................................... D. turneri Zhang, 1992

4. Cuticle laterally with two longitudinal rows of coarse dots in middle body region of both sexes...... 5 – Cuticle laterally with more than two longitudinal rows of coarse dots in at least one of the sexes .. 14

5. Lateral differentiation of cuticle <0.2 cbd .......................................................................................... 6 – Lateral differentiation> 0.2 cbd .......................................................................................................... 7

6. Body length 2.5-3.2 mm; spicules with ventral projection ...................... D. punctata Ditlevsen, 1918 – Body length 1.3-1.9 mm; spicules without ventral projection ...................... D. rabalaisi Zhang, 1992

7. Spicules jointed, with ventral projection, or simple ............................................................................ 8 – Spicules jointed and irregularly cuticularised ....................... D. mediterranea Grimaldi-de Zio, 1968

8. Spicules jointed, with two equal segments .................................................... D. perfecta (Cobb, 1920) – Spicules otherwise ............................................................................................................................... 9

9. Spicules without distal hooks or projections ..................................................................................... 10 – Spicules with distal hooks or ventral projections .............................................................................. 13

10.Gubernaculum with irregular base; gubernacular apophyses with blunt distal end ............................ ............................................................................................................................. D. nini (Inglis, 1961) – Gubernaculum with smooth base; gubernacular apophyses with pointed or rounded distal end ......11

11. Gubernaculum with pointed end .......................................................... D. peculiaris Platonova, 1971 – Gubernaculum with rounded end ..................................................................................................... 12

12.Male body length <2100 μm, two equal testes, spicules with poorly developed capitulum, spicule length 1.7-1.9 abd ............................................................................. D. gerardi Muthumbi et al., 1997

– Male body length> 2100 μm, anterior testis larger than posterior testis and with larger sperm, spicules with well-developed capitulum, spicule length 1.8-2.4 abd ......... D. variabilis Muthumbi et al., 1997

13. Spicules with small distal hook; gubernaculum with lateral projections ... D. pellucida (Cobb, 1920)

– Spicules with rounded ventral projection at one third of spicule length from distal end; cuticle laterally with three longitudinal rows in pharyngeal and caudal regions, two rows in middle region ....................................................................................................................... D. nodderi sp. nov.

14. Cuticle with two rows of coarse dots in males and three in females ............................................... 15 – Cuticle with more than two rows of coarse dots in males ............................................................... 16

15. Spicules distally acute ............................................................................... D. poriferum (Cobb, 1920) – Spicules distally with a subterminal hook ........................................................ D. timmi Jensen, 1979

16. Cuticle with three rows of coarse dots in middle body region of males .......................................... 17 – Cuticle with four or five rows of coarse dots in middle body region of males................................. 18

17. Cuticle with 3 rows of coarse dots along entire length of body of both males and females ................................................................................................... D. halongensis Tu et al., 2008

– Cuticle with three rows of coarse dots in middle region of body, four to eight rows elsewhere (males and females).................................................................................................... D. janetae (Inglis, 1963)

18. Spicules without subterminal hook ...................................... D. magellanense Chen and Vincx, 1998 – Spicule with subterminal hook; spicule length 3 abd ................................... D. angelae (Inglis, 1967)