Table 1
Morpometrics P. paulseni sp. n. and P. yamagatae sp. n.
| P. paulseni RS5918 | P. yamagatae RS5964 | |||
|---|---|---|---|---|
| Character | stenostomatous male | stenostomatous female | stenostomatous male | stenostomatous female |
| n | 10 | 10 | 10 | 10 |
| L | 1208±95.4 (990–1315) | 1560±230 (1222–1895) | 848±42.2 (796–916) | 1162±121.9 (937–1385) |
| L’ | 1032±92.5 (813–1138) | 1298±209.6 (978–1560) | 681±34.7 (616–724) | 908±103.7 (717–1096) |
| a | 14±1,3 (12–16) | 14±0.6 (13–15) | 14±1.4 (13–18) | 14±1.2 (12–17) |
| b | 7.2±0.8 (5.8–9.0) | 8.7±1.0 (7.3–10.1) | 5.8±0.3 (5.3–6.2) | 6.8±0.6 (5.8–7.8) |
| c | 6.9±0.8 (5.6–8.3) | 6.0±0.6 (5.0–6.9) | 5.1±0.4 (4.4–5.9) | 4.6±0.4 (4.1–5.3) |
| c’ | 4.0±0.6 (3.4–4.9) | 6.0±0.5 (5.3–6.8) | 5.1±0.6 (3.9–6) | 7.3±0.7 (6.1–8.2) |
| T or V | 58±2.9 (53–62) | 47±0.9 (45–48) | 51±3.3 (45–54) | 45±1.3 (44–48) |
| Maximum body diam. | 86±4.7 (75–91) | 114±19.3 (84–138) | 60±6.4 (47–70) | 84±9.6 (68–98) |
| Stoma length | 13.0±0.5 (12.0–13.8) | 14.4±0.4 (13.9–15.0) | 11.5±0.7 (10–12.2) | 13.3±0.5 (12.3–14) |
| Stoma diam. | 5.7±0.5 (5.0–6.8) | 6.8±0.4 (6.2–7.5) | 6±0.5 (5.4–6.7) | 7.4±0.5 (6.7–8.3) |
| Pharynx length (head to base of pharynx) | 156±13.8 (122–168) | 169±7.2 (158–178) | 135±5.4 (124–143) | 156±7.3 (146–170) |
| Anterior pharynx (pro- + metacorpus) | 96±8.3 (75–105) | 106±2.9 (102–110) | 83±3.9 (77–88) | 98±4.2 (93–106) |
| Posterior pharynx (isthmus + basal bulb) | 61±6.1 (47–68) | 64±4.8 (56–69) | 52±2.2 (47–55) | 58±3.9 (52–64) |
| Ant/total pharynx % | 61±1.3 (59–63) | 62±1.6 (60–65) | 63±4.2 (59–74) | 63±1.2 (61–65) |
| Median bulb diam. | 28±2.1 (25–31) | 34±2.8 (30–36) | 22±0.7 (21–23) | 30±3.8 (22–36) |
| Terminal bulb diam. | 26±1.8 (23–28) | 30±3.9 (25–34) | 21±1.3 (18–22) | 27±3.7 (20–33) |
| Testis length | 698±69.9 (532–787) | – | 433±37.9 (372–475) | – |
| Ant. end to vulva | – | 730±101.3 (592–860) | – | 527±48.8 (446–610) |
| Vulva to anus distance | – | 570±103.2 (424–710) | – | 380±52.7 (281–470) |
| Cloacal or anal body diam. | 44±3.4 (36–48) | 44±4.3 (37–50) | 33±3.6 (28–40) | 35±1.9 (32–38) |
| Tail length | 176±19.3 (155–220) | 262±69.9 (235–335) | 167±17.5 (140–192) | 255±27.1 (212–289) |
| Spicule length (curve) | 51±2.6 (47–54) | – | 43±1.2 (41–45) | – |
| Spicule length (chord) | 41±2.5 (36–44) | – | 36±0.8 (34–37) | – |
| Gubernaculum length | 14±1.3 (12–16) | – | 14±1.4 (13–18) | – |

Figure 1
Adults of Pristionchus paulseni sp. n. A: female in right lateral view; B: male in right lateral view; C, D: anterior region of stenostomatous female (C) and male (D) in right lateral view showing the variation in body size and deirid position (arrow); E: body surface of female showing the relative position of deirid and lateral gland; F: postdeirid of female in left lateral view; G: phasmid opening of female in right lateral view; H: surface of male lip region in right lateral view; I: stomatal region of stenostomatal male in left lateral view; J, K: stomatal region of stenostomatal female in right lateral view showing the variation in cheilostomatal plates; L, M: stomatal region of eurystomatal female in left lateral view showing the variation in cheilostomatal plates; N: stomatal region of eurystomatal male in right lateral view showing partially split cheilostomatal plates; O: stomatal region of eurystomatal female in right lateral view.

Figure 2
Adults of Pristionchus paulseni sp. n. A: male gonadal system in right lateral view; B; female anterior gonadal system in right lateral view; C, D: male tail region in right lateral view showing the variation in body size; E, F: male tail region in ventral view showing the variation in body size; G, H: spicule and gubernaculum in left lateral view showing the variation in body size; I: female vulval region in ventral view; J: female tail region in right lateral view; K: female anal region in ventral view.

Figure 3
Adults of Pristionchus yamagatae sp. n. A: female in right lateral view; B: male in right lateral view; C, D: anterior region of eurystomatous (C) and stenostomatous (D) females in right and left lateral views, respectively; E: body surface of female showing the relative position of deirid and lateral gland; F: excretory pore opening in ventral view; G: phasmid opening of female in right lateral view; H: surface of male lip region in right lateral view; I: stomatal region of stenostomatal female in left lateral view; J: stomatal region of stenostomatal female in right lateral view; K: stomatal region of eurystomatal female in left lateral view showing partially split cheilostomatal plates; L: stomatal region of eurystomatal female in right lateral view.

Figure 4
Adults of Pristionchus yamagatae sp. n. A: male gonadal system in right lateral view; B: female anterior gonadal system in right lateral view; C: female vulval region in ventral view; D: female tail region in left lateral view; E: female anal region in ventral view; F: surface striation of female anal region in ventral view; G: male tail region in left lateral view; H: male tail region in right lateral view showing the presence of extra v0 papilla (arrow); I: male tail region in ventral view; J: spicule and gubernaculum in right lateral view.

Figure 5
Phylogenetic relationships of the Pristionchus genus. The schematic phylogeny shows the relationship between all species of the Pristionchus genus as inferred from transcriptome data (Rödelsperger et al., 2018), including those described in the two accompanying manuscripts (Yoshida et al., 2018; Kanzaki et al., 2018).