Pseudosteineria Wieser, 1956

Cidreira, Gabriel, Venekey, Virág, De Souza Alves, Orane F. & Kelmo, Francisco, 2020, Description of Pseudosteineria longisetis sp. n. from northeastern Brazil with a review of the genus Pseudosteineria Wieser, 1956 (Nematoda: Xyalidae), Zootaxa 4763 (3), pp. 354-370 : 366

Dichotomous identification key to valid species of the genus Pseudosteineria Wieser, 1956

(emended after Sun et al., 2019).

1 Six groups of subcephalic setae..................................................... P. longisetis sp. n. ( Fig. 6A)

- Eight groups of subcephalic setae........................................................................ 2

2 Amphideal fovea anterior to or at the level of subcephalic setae groups........................................... 3

- Amphideal fovea posterior to subcephalic setae groups or not visible............................................ 9

3 Males with papilliform precloacal supplements......................................... P. ventropapillata ( Fig. 6B)

- No precloacal supplements in males...................................................................... 4

4 Two small papillae or hillocks on ventral side of the tail in males.............................. P. anteferens ( Fig. 6C)

- No caudal papillae or hillocks in males.................................................................... 5

5 Gubernaculum with dorsal apophysis..................................................................... 6

- Gubernaculum without dorsal apophysis or only with weakly developed apophysis................................. 7

6 Spicules broad and solid; gubernaculum complex with distal hooks............................. P. anticipans ( Fig. 6D)

- Spicules slender; gubernaculum simple without distal hooks..................................... P. zhangi ( Fig. 6E)

7 Groups of subcephalic setae with 5–6 or only 6 setae in each................................................... 8

- Groups of subcephalic setae with 7 setae in each; spicules 32–39 μm long................... P. sagittispiculata ( Fig. 6F)

8 Groups of subcephalic setae with 6 setae in each; body length 1480 μm; spicules 56 μm long............ P. pavo ( Fig. 6G)

- Groups of subcephalic setae with 5–6 setae in each; body length 962–997 μm; spicules 33–34 µm long................................................................................................. P. anteramphida ( Fig. 6H)

9 Somatic setae very long, up to three body diameters....................................... P. paramirabilis ( Fig. 6I)

- Somatic setae small, usually shorter than half body diameter.................................................. 10

10 Amphideal fovea difficult to observe..................................................................... 11

- Amphideal fovea clearly discernible, round or oval......................................................... 12

11 Spicules broad, unequal in length, the longer spicule is jointed.................................... P. sinica ( Fig. 6J)

- Spicules slender, equal in length......................................................... P. coronata ( Fig. 6K)

12 Spicules solid, unequal in length................................................... P. inaequispiculata ( Fig. 6L)

- Spicules slender, equal in length........................................................................ 13

13 Gubernaculum with a prominent dorso-caudal apophysis....................................... P. scopae ( Fig. 6M)

- Gubernaculum apophysis relatively short................................................................. 14

14 Males with three papilliform precloacal supplements.......................................... P. pulchra ( Fig. 6N)

- No precloacal supplements in males....................................................... P. horrida ( Fig. 6O)