Cobbia zhangi, Uang & Sui, 2024

Uang, Mian & Sui, Xinxin, 2024, Description of Amphimonhystrella sinica sp. nov. and Cobbia zhangi sp. nov. of the family Xyalidae (Nematoda: Monhysterida) from the Yellow Sea, China, Zootaxa 5471 (3), pp. 343-354 : 352

Updated key to valid and the new species of Cobbia zhangi sp. nov. (based on Datta et al. 2018 and Wang et al. 2018)

1. Tail elongated flagelliform.............................................................................. 2

- Tail non-flagelliform................................................................................... 7

2. Buccal cavity with three similar equal-sized teeth............................................................ 3

- Buccal cavity with one large dorsal and two small subventral teeth.............................................. 4

3. Body longer than 2.7 mm, tail with posterior third filiform part, amphidial fovea 20% c.b.d.................. C. triodonta

- Body shorter than 1.6 mm, tail with posterior three fourths filiform part, amphidial fovea 33%–38% c.b.d.. C. zhangi sp. nov.

4. Paired spicules unequal, gubernaculum with dorsal apophyses...................................... C. heterospicula

- Paired spicules equal in length, gubernaculum without dorsal apophyses.......................................... 5

5. Anterior sensilla arrangement 6+10.............................................................. C. kamenevi

- Anterior sensilla arrangement 6+12....................................................................... 6

6. Distance of amphidial fovea from the anterior end is 3.8–4 times amphidial fovea diameter.............. C. trefusiaeformis

- Distance of amphidial fovea from the anterior end is less than three times amphidial fovea diameter............ C. urinator

7. Anterior sensilla arrangement 6+10....................................................................... 8

- Anterior sensilla arrangement 6+12...................................................................... 11

8. Inner labial setae 2.5 µm, amphidial fovea located farther than 30 µm from the anterior end.................................................................................................. C. caledonia Warwick & Platt, 1973

- Inner labial setae 3.5–7 µm, amphidial fovea located less than 30 µm from the anterior end........................... 9

9. Male and female tail conico-cylindrical and of similar length............................................. C. sinica

- Male tail conical, female tail conico-cylindrical and longer than of male......................................... 10

10. Cephalic setae 13–17 µm long, amphidial fovea 5–6 µm wide....................................... C. bengalensis

- Cephalic setae 22–26 µm long, amphidial fovea 10 µm wide............................................ C. dentata

11. Buccal cavity with three equal-sized teeth, gubernaculum with dorsal apophysis........................... C. truncata

- Buccal cavity with one large and two small teeth, gubernaculum without apophysis............................................................................................. C. macrodentata Lo Russo & Pastor de Ward, 2012