Trischistoma

Prado-Vera, Ignacio Cid Del, Ferris, Howard & Nadler, Steven A., 2016, Five new species of the family Trischistomatidae (Nematoda: Enoplida) from North and Central America, with keys to the species of Trischistoma and Tripylina, Zootaxa 4109 (2), pp. 173-197 : 183-184

Key to the species of Trischistoma

1. Body a tight spiral shape after death...................................................... T. helicoformis n. sp. Body not spiral-shaped after death........................................................................ 2 2. Post-uterine sac present................................................................................. 3 Post-uterine sac absent................................................................................. 7 3. Body length> 2.0 mm.................................................................................. 4 Body length <2.0 mm.................................................................................. 5 4. Body length 2.9–3.2 mm; tail length 220–242 µm.................................. T. subtillissimum Andrássy, 2011 Body length 4.0– 4.1 mm; tail length 250–260 µm.................................... T. tenuissimum Andrássy, 2011 5. Male absent; V = 75%; tail length 81–98 µm................................................ T. otaika Zhao, 2011 Male present; body length 1.0– 1.9 mm ..................................................................... 6 6. Body length 1.4–1.9 mm; a = 45–77; female tail length 115–150 µm, spicules 25–35 µm long; male tail with one supplement.................................................... T. monohystera (de Man, 1880) Schuurmans-Stekhoven, 1951 Body length 1.4–1.6 mm; a = 38–44; V = 81–83%; female tail length 80–96 µm; spicules 40–44 µm long; male tail with 2–3 supplements................................................................... T. equatoriale Andrássy, 2006 Body length 1.0– 1.3 mm; a = 41–54; female tail length 63–104 long; spicules 29–34 µm long................................................................................ T. veracruzense Cid del Prado-Vera, Ferris & Nadler, 2010 Body length 1.0– 1.1 mm; a = 49–53; c = 12–13, female tail length 82–86 µm; spicules 25–32 µm long................................................................................................... T. gracile Andrássy, 1985

7. Body length <1.0 mm..................................................................................8 Body length> 1.0 mm................................................................................. 10

8. Body length 0.4–0.6 mm; female tail length 40–50 µm.............................. T. minor Tahseen & Nusrat, 2010 Body length 0.6–0.9 mm; V = 73–80%.................................................................... 9

9. Cervical setae absent; pharynx length 155 µm; tail length 50–60 µm; b = 4.4–4.8............... T. pellucidum Cobb, 1913 Single latero-ventral cervical setapresent; pharynx length 171–198 µm; tail length 50–64 µm...... T. waiotama Zhao, 2011 Paired lateral cervical setae present; pharynx length 137–219 µm; tail length 44–72 µm............ T. triregius Zhao, 2011

10. Body length 0.80–1.2 mm; a = 34–45; V = 67–73%; female tail length 51–84 µm.................. T. corticulensis n. sp. Body length 1.0– 1.1 mm; a = 39–59; female tail length 34–92 µm.............................................. 11

11. a = 45–59; c = 17–29; b = 4.1–4.8; V = 67–73%; female tail length 34–57 µm....................... T. ripariana n. sp. a = 39–47; c = 11–15; b = 3.8–4.1; V = 72–76%; female tail length 75–92 µm................... T. tukorehe Zhao, 2011