Zonothrix Todd, 1942

Shah, Manjur, 2011, Nematode parasites of invertebrates from Manipur, North East India (Diagnosis, keys and illustration), Zootaxa 3107, pp. 1-37 : 7-8

Key to all known species of Zonothrix Todd, 1942

1. Body of female C-shaped after fixation.................................................................... 2

- Body of female coiled after fixation.................................................... Z. izecksohni Kloss, 1959

2 ( 1). Posterior end of corpus in female narrower than oesophageal bulb............................................... 3

- Posterior end of corpus in female almost as broad as oesophageal bulb............... Z. hydroi ( Galeb, 1878) Todd, 1942

3 ( 2). Mature female more than 2 mm and less than 5mm long....................................................... 4

- Mature female less than 2 mm long................................................. Z. helocharesae Kloss, 1959

4 ( 3). Swollen annulation present in cephalic extremity of female.................................................... 5

- Swollen annulation absent in cephalic extremity of female................................. Z. tropisterna Todd, 1942

5 ( 4). Cephalic annule in female not inflated..................................................................... 6

- Cephalic annule in female inflated.................................................. Z. alata Shah & Rizvi, 2004

6 ( 5). Female tail narrowing behind anus and not continuing as a spine-like caudal extension.............................. 7

- Female tail not as above............................................................................... 8

7 ( 6). Female tail conical................................................................... Z. gladius Kloss, 1959

- Female tail conically attenuated.......................... Z. mehdii ( Farooqui, 1967) Adamson & Van Waerebeke, 1992

8 ( 6). Caudal extremity of female terminating in a short spine-like structure........................................... 9

- Caudal extremity of female without spine-like structure...................................................... 10

9 ( 8). Caudal spine of female= 26–35 µm long.................................................... Z. galebi Kloss, 1959

- Caudal spine of female less than 10 µm long............................................. Z. paraense Kloss, 1959

10 ( 8). Distance between vulva and anus 20–28 % total body length, tail of female 5–8 % of body length; seven pairs of caudal papillae in male............................................................... Z. columbianus Adamson & Buck, 1990

- Distance between vulva and anus less than 15 % of total body length, tail of female 10 % of body length; six pairs of caudal papillae in male..................................................................... Z. adversa Kloss, 1958