Family Amphidelidae

                                 Revised 01/30/26

Classification:

Phylum Nematoda

 

Class Enoplea
                     Subclass  Enoplia
                       Order  Enoplida
                          Suborder Alaimina
                             Superfamily  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..
  • 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
b Cuticle without longitudinal ridges; spicules short gubernaculum absent 2
2 a Amphid apertures large, oval, long axis of aperture longitudinal Megamphidelus Siddiqi, 1993
b Amphid apertures not enlarged, transverse, oval or slit-like 3
3 a Vulva open, vagina thick, female generally diovarial 4
b Vulva closed vagina thin, female monovarial 5
4 a Vaginal walls infolded Metamphidelus Clausi & Vinciguerra, 1995
b Vaginal walls not infolded Amphidelus Thorne, 1939
5 a Head asymmetrical with inner sclerotization; oral opening subterminal Scleralaimus Siddiqi, 1993
b Head symmetrical without sclerotization; oral opening terminal 6
6 a Vulval lips sclerotized; spicules simple Scleramphidelus Clausi & Vinciguerra, 1995
b Vulval lips not sclerotized; spicules with central line 7
7 a Female monovarial, prodelphic Etamphidelus Andrássy, 1977
b Female monovarial, opisthodelphic or diovarial, amphidelphic 8
8 a Amphid apertures large, oval to round, close to head Laxamphidelus Siddiqi, 1993
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
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
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


    Go To Dictionary of Terminology 

Body size range for the species of this Family in the database - Click:

References

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

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