Rev. 10/14/08
| 1 | a | Nematodes with a protrusible stylet (stomatostyle) or spear (odontostyle) | go to 2 | |
| b | Nematodes without protrusible stylet or spear | go to 24 | ||
| 2 | a | Stylet and three-part esophagus with median bulb (metacorpus), males usually with bursa | go to 3 | |
| b | Spear and two-part esophagus with posterior swollen (postcorpus), males usually without bursa but with supplements | go to 16 | ||
| 3 | a | Esophageal glands overlap intestine | go to 4 | |
| b | Esophageal glands enclosed in bulb that abuts intestine | go to 9 | ||
| 4 | a | Cephalic framework well-developed, lip-region high. Females with two gonads | go to 5 | |
| b | Posterior gonad reduced to a post-uterine sac, vulva at 70-90%, lip-region flattened or cephalic framework absent | go to 8 | ||
| 5 | a | Tail tip, anus and vulva in close proximity on posterior of swollen female, male body twisted, male without bursa | go to 6 | |
| b | Anus and vulva anterior to tail tip even when female swollen, male body not twisted, male with bursa | go to 7 | ||
| 6 | Juvenile and female stages are
sedentary endoparasites, female greatly swollen; male without bursa, body twisted,
migratory in soil
i) Body of dead female forms cyst and retains some or all eggs
Heteroderinae
|
Heteroderidae
|
||
| 7 | a |
Stylet 2-3 x stylet body diameter, tail < 2 x anal body diameter, body spiral when heat-killed, vulva
around 60%
i) Mature female remains vermiform Hoplolaiminae ii) Mature female saccate sedentary semi-endoparasite Rotylenchulinae |
Hoplolaimidae | |
| b | Tail > 2.5 x anal body diameter, phasmids
on tail region
i) Long nematodes, stylet > 3 x stylet body diameter
Belonolaiminae
|
Belonolaimidae | ||
| 8 | a |
Lip-region flattened but cephalic framework
well-developed
i) Female remains vermiform Pratylenchinae ii) Female a saccate endoparasite Nacobbinae |
Pratylenchidae | |
| b | Cephalic-framework weak or absent | Anguinidae | ||
| 9 | a | Females with two gonads, males with caudal bursa | Dolichodoridae | |
| b | Posterior female gonad reduced to a post-uterine sac, males with adanal bursa (if present) | go to 10 | ||
| 10 | a | Median bulb large and refractive, stylet knobs absent or small | go to 11 | |
| b | Median bulb not refractive, stylet knobs obvious | go to 12 | ||
| 11 | a | Stylet without knobs, tail rounded, male with bursa | Aphelenchidae | |
| b | Stylet with small knobs, tail pointed, male usually without bursa | Aphelenchoididae | ||
| 12 | a | Stylet short (< stylet body diameter), tail pointed to filiform | go to 13 | |
| b | Stylet long so that knobs are close to median bulb valve, procorpus swollen and fused with metacorpus | go to 14 | ||
| 13 | a | Tail long and filiform (>5 x anal body diameter) | Tylenchidae | |
| b | Tail pointed (<5 x anal body diameter), cephalic framework absent | Anguinidae | ||
| 14 | a | Thick cuticle with coarse striations | go to 15 | |
| b | i) Female swollen, excretory pore
posterior on body, female a saccate sedentary semi-endoparasite Tylenchulinae
ii) Cuticle with fine striations, male often without stylet, body C-shaped Paratylenchinae |
Tylenchulidae | ||
| 15 | a | i) Large body diameter, sausage shape, slow moving,
anchor-shaped stylet knobs
Criconematinae
ii) Extra cuticular sheath, pointed tail, rounded stylet knobs Hemicycliophorinae |
Criconematidae | |
| 16 | a | Spear with complex configuration, loose-fitting cuticle | Diptherophoridae | |
| b | Spear simple, cuticle not loose but may be swollen | go to 17 | ||
| 17 | a | Spear dorsally curved, anus almost terminal | Trichodoridae | |
| b | Spear straight, anus not terminal - tail present | go to 18 | ||
| 18 | a | Long, slender nematodes (1-12 mm), spear > 50 µm, long spear extension (odontophore) | Longidoridae | |
| b | Short spear | go to 19 | ||
| 19 | a | Postcorpus of esophagus with muscular sheath | Belondiridae | |
| b | No muscular sheath around esophagus | go to 20 | ||
| 20 | a | Spear extension (odontophore) thick and curved | Leptonchidae | |
| b | Spear extension not curved | go to 21 | ||
| 21 | a | Plump nematodes, tail rounded | go to 22 | |
| b | Slender nematodes, tail conoid to filiform | go to 23 | ||
| 22 | a | Spear slightly curved, small opening | Nordiidae | |
| b | Spear with large opening, cuticle appears layered at tail | Aporcelaimidae | ||
| 23 | a | Large nematodes (>2 mm), tail filiform (may be rounded in male) | Thornenematidae | |
| b | Medium size (1-2 mm), tail conoid, body generally curved | Qudsianematidae | ||
| 24 | a | Body asymmetrical, caterpillar-like | Bunonematidae | |
| b | Body symmetrical | go to 25 | ||
| 25 | a | Median bulb present, tail filiform | Diplogasteridae | |
| b | Median bulb absent | go to 26 | ||
| 26 | a | Esophagus with terminal bulb or swelling | go to 27 | |
| b | Esophagus cylindrical, no swellings | go to 37 | ||
| 27 | a | Terminal bulb without valves | go to 28 | |
| b | Terminal bulb with valves | go to 29 | ||
| 28 | a | Cuticle not striated | Monhysteridae | |
| b | Cuticle clearly striated | Bastianiidae | ||
| 29 | a | Aquatic forms; cuticle striated and punctated | Chromadoridae | |
| b | Cuticle without punctations | go to 30 | ||
| 30 | a | Stoma cavity with teeth, tail filiform | Diplogasteridae | |
| b | Stoma cavity without teeth | go to 31 | ||
| 31 | a | Head with labial extensions or crown | go to 32 | |
| b | Head without extensions | go to 34 | ||
| 32 | a | Head with lateral cuticular extensions | Plectidae | |
| b | Head with anterior extensions only | go to 33 | ||
| 33 | a | Labial extensions crown-shaped | Teratocephalidae | |
| b | Labial-extensions thorn- or antler-shaped | Cephalobidae | ||
| 34 | a | Tail tip with spinneret, amphids easily visible, males with tubular supplements | Plectidae | |
| b | Tail tip without spinneret | go to 35 | ||
| 35 | a | Stoma cavity cylindrical, cuticular walls, males with bursa | Rhabditidae | |
| b | Stoma cavity funnel-shaped, walls not cuticular, posterior female gonad reduced, anterior gonad reflexed and extending beyond vulva | go to 36 | ||
| 36 | a | Stoma cavity clearly present | Panagrolaimidae | |
| b | Stoma cavity difficult to see, only anterior section open | Cephalobidae | ||
| 37 | a | Cuticle striated | Bastianiidae | |
| b | Cuticle smooth | go to 38 | ||
| 38 | a | Slender nematodes, no obvious stoma cavity or setae | Alaimidae | |
| b | Clear stoma cavity or setae | go to 39 | ||
| 39 | a | Amphids round, clearly visible | Monhysteridae | |
| b | Amphids difficult to see, not round | go to 40 | ||
| 40 | a | Stoma cavity large, walls cuticular walls | go to 41 | |
| b | Stoma cavity funnel-shaped or not obvious, walls not cuticular | go to 42 | ||
| 41 | a | Tail filiform, setae present | Prismatolaimidae | |
| b | Tail not filiform, large stoma cavity with teeth | Mononchidae | ||
| 42 | a | Funnel-shaped stoma with small teeth | Tobrilidae | |
| b | Stoma closed anteriorly, one tooth in lumen | Tripylidae |
March 1996 Howard Ferris Key modified from: Tom Bongers Department of Nematology Wageningen University University of California Wageningen Davis, CA 95616 The Netherlands