Family Amphidelidae

Revised 08/03/20

Classification:

Enoplea
Enoplia
Enoplida
Alaimina
Alaimoidea
Amphidelidae Andrassy, 2002


Amphidelidae (L=1.3 mm); Domes Gardens, UC Davis. Photos by Anna Ruth Crittenden		Amphidelidae; esophageal region and amphid apertures

Amphidelidae:

Length ranging from 0.6 to 4.2 mm.
Somatic setae absent.
Cuticle smooth or with longitudinal strialtions
Labial region rounded, not offset from body contour, sometimes very narrow
Labial papillae minute.
Amphids postlabial, 2 to 5 body widths behind lip region, very distinct.; apertures enlarged.
Stoma minute, inconspicuous.
Nematodes often very slender and internal structures difficult to discern.
Esophagus slightly enlarged posteriorly.
Female may be monovarial or diovarial.
Males monorchic, spiculesshort and plump or long and arcuate
Gubernaculum rarely present.
Tail up to 40 x anal body diameter.

Etymology: refers to conspicuous amphids.

Key to the genera of Amphidelidae:

1	a	Cuticle with conspicuous longitudinal ridges; spicules slender and arcuate; gubernaculum present	Cristamphidelus Siddiqi & Vinciguerra, 1991
1	b	Cuticle without longitudinal ridges; spicules short gubernaculum absent	2
2	a	Amphid apertures large, oval, long axis of aperture longitudinal	Megamphidelus Siddiqi, 1993
2	b	Amphid apertures not enlarged, transverse, oval or slit-like	3
3	a	Vulva open, vagina thick, female generally diovarial	4
3	b	Vulva closed vagina thin, female monovarial	5
4	a	Vaginal walls infolded	Metamphidelus Clausi & Vinciguerra, 1995
4	b	Vaginal walls not infolded	Amphidelus Thorne, 1939
5	a	Head asymmetrical with inner sclerotization; oral opening subterminal	Scleralaimus Siddiqi, 1993
5	b	Head symmetrical without sclerotization; oral opening terminal	6
6	a	Vulval lips sclerotized; spicules simple	Scleramphidelus Clausi & Vinciguerra, 1995
6	b	Vulval lips not sclerotized; spicules with central line	7
7	a	Female monovarial, prodelphic	Etamphidelus Andrássy, 1977
7	b	Female monovarial, opisthodelphic or diovarial, amphidelphic	8
8	a	Amphid apertures large, oval to round, close to head	Laxamphidelus Siddiqi, 1993
8	b	Amphid apertures narrow, slit-like, more than 3 lip widths behind head	9
9	a	Amphids offset from each other, esophagus about 1/3 body length	Postamphidelus Siddiqi, 1993
9	b	Amphids opposite each other, esophagus about 1/4 body length	10
10	a	Female diovarial, amphidelphic; amphids only conspicuous in male	Caviputa Siddiqi, 1993
10	b	Female monovarial, opisthodelphic; amphids conspicuous in both sexes	Paramphidelus Andrássy, 1977

Key modified from Andrássy, 2009, Free-living nematodes of Hungary. Hungarian Natural History Museum, Budapest

References:

Andrássy, 2009, Free-living nematodes of Hungary. Hungarian Natural History Museum, Budapest

Choudhary M., Jairajpuri M.S. (2010) Evolutionary trends in soil-inhabiting alaimid nematodes. In: Sharma V.P. (eds) Nature at Work: Ongoing Saga of Evolution. Springer, New Delhi

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