Diplopeltidae Filipjev 1918

Key to genera of Diplopeltidae

See Table 4 for additional diagnostic characters.

1. Amphidial fovea a transverse slit; cuticle with ten longitudinal ridges.... Edalonema Andrássy, 2007

– Amphidial fovea double-loop-shaped in male, unispiral in female.................. Belgopeltula gen. nov.

– Amphidial fovea unispiral................................................................................................................ 2

– Amphidial fovea loop-shaped........................................................................................................... 4

2. Basal bulb absent; freshwater or terrestrial........................................ Cylindrolaimus de Man, 1880

– Basal bulb present; marine................................................................................................................ 3

3. Single anterior ovary................................................................ Intasia Tchesunov & Miljutina, 2008

– Two ovaries (anterior and posterior)....................................................... Southerniella Allgén, 1932

4. Oral opening shifted to the ventral body side............................ Morlaxia Vincx & Gourbault, 1988

– Oral opening apical or shifted to the dorsal body side..................................................................... 5

5. Basal pharyngeal bulb present; ovaries antidromously reflexed............... Mudwigglus Leduc, 2013

– Basal pharyngeal bulb absent; ovaries outstretched......................................................................... 6

6. Lateral alae present, in some species fused with the ventral limb of the amphid.................................................................................................................................................. Campylaimus Cobb, 1920

– Lateral alae absent............................................................................................................................ 7

7. Amphid in a shape of rounded loop.................................................................................................. 8

– Amphid in a shape of elongated loop............................................................................................. 10

8. Anterior body region abruptly narrowing; amphid at a distance equal to more than five labial region diameters from the anterior end............................................. Metaraeolaimoides De Coninck, 1936

– Anterior body region cylindrical or subcylindrical; amphid at a distance equal to less than two labial region diameters from the anterior end............................................................................................. 9

9. Buccal cavity cup-shaped; pronounced sexual dimorphism in the amphid size (large in males and small in females).................................................................................. Pararaeolaimus Timm, 1961 – Buccal cavity conical; no sexual dimorphism in the amphid size.......... Araeolaimus de Man, 1888

10. Cervical (paramphideal) setae absent; caudal glands open via three separate pores........................................................................................................................................... Diplopeltula Gerlach, 1950

– Cervical (paramphideal) setae present; caudal glands open via common spinneret........................11

11. Amphid located on a well-developed refractive subcuticular plate.............................................................................................................................................. Diplopeltis Cobb in Stiles & Hassal, 1905

– Refractive subcuticular plate absent.......................................... Pseudaraeolaimus Chitwood, 1951