Axonchium
Creators: name: Naz, Tabbasam
name: Ahmad, Wasim
Publisher: name: Zenodo
Year: 2012
Subjects: Biodiversity
Taxonomy
Animalia
Nematoda
Adenophorea
Dorylaimida
Belondiridae
Axonchium

description: Key to species of the genus Axonchium based on females
(modified after Coomans & Nair, 1975)
1 Lips completely amalgamated............................................................................ 2
- Lips incompletely separated or well separated............................................................... 3
2 Body length 1.2–1.4 mm; anterior uterine branch present.............................................. perplexans
- Body length 1.5–1.6 mm; anterior uterine branch absent.............................................. tochigiense
3 The inner portion of the lips deeply offset and appearing as subspherical liplets............................... labiatum
- The inner portion of the lips less offset and marked by depression of the contour....................................4
4 Odontostyle straight and narrow; anterior part of pharynx very narrow; pharyngeal constriction inconspicuous; numerous body pores............................................................................................... 5
- Odontostyle fusiform; anterior part of pharynx quite muscular; pharyngeal constriction very deep or isthmus-like; body pores few................................................................................................. 6
5 Body length 1.8–2.0 mm; odontostyle 8–10 µm; uterus without ‘Z’ organ................................... geminum
- Body length 2.6–3.8 mm; odontostyle 10.5–15 µm; uterus with ‘Z’ organ.................................. variabile
6 Vulva broad, length wise oval; vaginal lumen adjacent to vulva very wide; pharyngeal constriction short isthmus-like.................................................................................................. propinquum
- Vulva transverse, broad or narrow; vaginal lumen narrow; pharyngeal constriction deep or rarely isthmus-like............ 7
7 Intestino-prerectal junction marked by a constriction, surrounded by a sphincter-like structure................. cingulatum
- Constriction or sphincter-like structure at the intestino-prerectal junction absent..................................... 8
8 Anterior genital branch less than three-fourths of the corresponding body width long................................ 9
- Anterior genital branch usually long, very rarely slightly less than the body width long............................. 12
9 Vagina straight, vaginal cuticle wide with rounded or spheroid walls...................................... bulbosum
- Vagina bent posteriad, vaginal cuticle not wide............................................................. 10
10 Body slender (body width 27–35 µm); lips with a shallow notch in the middle separating the outer and inner portion..................................................................................................... nitidum
- Body rather stout (body width 41–58 µm); lips with a deep notch in the middle separating the outer and inner portion..... 11
11 Expanded part 74–80% of total pharyngeal length; anterior uterine branch rudimentary; tail hemispherical with clavate end and three caudal pores on each side................................................................... .. camelliae
- Expanded part 55–73% of total pharyngeal length; anterior uterine branch a simple sac; tail convex-conoid to bluntly rounded and two caudal pores on each side................................................................ amplicolle
12 Posterior genital branch with ‘Z’ organ............................................................ bihariense
- Posterior genital branch without ‘Z’ organ................................................................. 13
13 Vagina with a constriction in the middle................................................................... 14
- Vagina gradually widening towards the uterus.............................................................. 21
14 Vagina wall appears somewhat darker than and offset from the body cuticle................................ saccatum
- Vaginal cuticle not differentiated from the body cuticle....................................................... 15
15 Body length 1.0– 1.6 mm ............................................................................... 16
- Body length 1.8–2.8 mm ............................................................................... 18
16 Vagina straight; anterior uterine branch a simple sac without proximal constriction......................... thoubalicum
- Vagina straight or slightly to completely directed posteriad; anterior uterine branch provided with a proximal constriction.. 17
17 Body almost straight; vaginal wall distinctly thickened than the body cuticle, vaginal sphincter well developed...... phukani
- Body slightly ventrally arcuate; vaginal wall almost of same thickness as the body cuticle, vaginal sphincter weakly developed............................................................................................. neoeletum
18 Vagina straight, anterior uterine sac without a proximal constriction...................................... khasianum
- Vagina bent posteriad; anterior uterine sac with a proximal constriction.......................................... 19
19 Body length 2.1–2.8 mm; middle tubular part of uterus very narrow.......................................... heynsi
- Body length 1.8–2.2 mm; middle tubular part of uterus wide................................................... 20
20 Body almost straight; vaginal lumen becoming cross-shaped within the sphincter; anterior uterine branch 2–3 times body width long................................................................................. transkeiense
- Body curved ventrad; vaginal lumen narrow and straight; prerectum 6–8 times anal body width long; anterior uterine branch 3–4 times body width long................................................................... parasaccatum
21 Lip region distinctly wide (13–15 µm); odontophore relatively long (18–20 µm) more than 1.5 times the odontostyle length............................................................................................... .. sinclairi
- Lip region narrow (less than 12 µm); odontophore less than 1.5 times the odontostyle length......................... 22
22 Body almost straight.................................................................................. 23
- Body ventrally arcuate................................................................................ 24
23 Lip region high, with conoid lips; cardia more or less heart-shaped; tail broadly conoid, shorter than anal body width...................................................................................................... abulum
- Lip region low, with small offset inner portions of the lips; cardia cylindrical; tail cylindroid, longer than the anal body width......................................................................................... latespiculatum
24 Body 2 mm or less; cardia rounded to heart-shaped........................................................... 5
- Body more than 2 mm long; cardia linguiform; posterior uterus with very narrow tubular part................. manalicum
25 Vagina completely directed posteriad.................................................................... 26
- Vagina slightly inclined posteriad....................................................................... 27
26 Lip region with incompletely separated lips and amalgamated inner parts................................... siddiqii
- Lip region with separated lips and well separated inner parts....................................... noreasum n. sp.
27 Anterior part of pharynx slender, separated from the posterior expanded part by an isthmus-like constriction................................................................................................... meghalayense n. sp.
- Anterior part of pharynx moderately to highly muscular, separated from the posterior expanded part by constriction, no isth- mus-like structure.................................................................................... 28
28 Anterior part of pharynx moderately muscular, separated from the posterior expanded part by a weak constriction; tail broadly rounded, distinctly clavate due to expansion of cuticle................................................ cooverkolli
- Anterior part of pharynx quite muscular, separated from the posterior expanded part by a very distinct constriction,; tail not clavate............................................................................................. 29
29 Prerectum 10–13 times anal body width long; tail bluntly rounded, slightly clavate.......................... hosakodii
- Prerectum less than 10 anal body widths long; tail rounded or hemispheroid...................................... 30
30 Expanded part of pharynx 60% or less of total neck length; tail obtusely rounded.............................. elegans
- Expanded part of pharynx more than 60% of total neck length; tail hemispherical or broadly rounded.................. 31
31 Body length 1.3–1.4 mm .......................................................................... shamimi
- Body more than 1.5 mm long........................................................................... 32
32 Body length 1.5–1.6 mm; odontostyle 7–9 µm; anterior genital branch without a proximal constriction.............. eletum
- Body length 1.6–1.9 mm; odontostyle 10.5–12 µm; anterior genital branch with a proximal constriction................ 33
33 Lip region with well separated lips; odontostyle 1.1–1.3 times lip region width long............................. .. metobtusicaudatum
- Lip region with incompletely separated lips; odontostyle one lip region width long............................. vallum
description: Published as part of Naz, Tabbasam & Ahmad, Wasim, 2012, Description of two new and five known species of the genus Axonchium Cobb, 1920 (Nematoda: Dorylamida) from India with diagnostic compendia and keys to species of the genera Axonchium and Syncheilaxonchium Coomans & Nair, 1975, pp. 1-37 in Zootaxa 3264 on pages 32-33, DOI: 10.5281/zenodo.215075