Paraxonchium

 

Contents

 

Rev 02/21/2024

  Classification Biology and Ecology
Morphology and Anatomy Life Cycle
Return to Paraxonchium Menu Ecosystem Functions and Services
Distribution Management
Return to Paraxonchiidae Menu Feeding  References
    Go to Nemaplex Main Menu   Go to Dictionary of Terminology

 

Classification:

Enoplea

Paraxonchiidae

Paraxonchiinae

Paraxonchium Krall, 1958

The nominal type species of the genus is P. striatum Krall, 1958 (=Paraxonchium laetificans (Andrassy, 1956) Altherr & Loof, 1969)

Drepanophorus Altherr, 1968, Drepanodorus Altherr, 1954 considered by Andrassy, 2009 to be junior synonyms of Paraxonchium.

      Back to Top

Morphology and Anatomy:

The following characteristics are taken from Heyns' (1988) re description of P. laetificans

.

  • Body posture nearly straight, only slightly ventrally curved.
  •  Body plump, but conspicuously narrowed in anterior part of neck towards the very narrow lip region.
  • Lip region somewhat angular, set off by constriction.
  • Amphid stirrup-shaped, the aperture about half as wide as the lip region.
  • Cuticle thick, especially on tail, and with minute transverse striae
  • Lateral and ventral hypodermal glands and pores conspicuous.
  • Lateral pores and glands in two rows, laterosubventral and laterosubdorsal in position.
  • Odontostyle with large dorsal aperture, comprising 60% (56-63) of the stylet length. Ventral "closed" part of stylet not circular in cross section, but laterally compressed.
  • Base of odontostyle apparently not "forked" (i.e. without basal collar for attachment of odontophore).
  • No guiding ring or plicated guiding sheath visible.
  • Esophagus typically dorylaimoid, gradually widened into basal bulb slightly beyond middle of neck. Basal bulb very granular in appearance.
  • Three oblong cardiac glands at base of oesophagus mostly quite distinct.
  • Esophageal-intestinal junction surrounded by tissue containing several cells, associated with the three cardiac glands. Cardia conspicuous, consisting of a broad hemispherical basal part largely embedded in intestinal tissue, with an elongate-conoid distal part projecting into lumen of intestine.
  • .Prerectum very variable in length,
  • Tail conoid, with rounded terminus, tending to be very slightly subdigitate.
  • Dorsal and other pores conspicuous on the tail.

 Female:

  • Didelphic, vulva transverse, post-equatorial, the vulval lips distinctly sclerotized.
  • Ovejector apparently not strongly demarcated.
  • Uterus short, undifferentiated, distinctly separated from the oviduct by a sphincter.
  • Gravid females with one, two or three uterine eggs.
  • Egg shell thick (up to 6 um) along sides of egg, but mostly very thin (about 1 um) around each end of egg.


    Male:
  • similar to female.
  • Reproductive system typically dorylaimoid.
  • Spicules 63 um long
  • No gubernaculum or lateral guiding pieces.
  • Adanal pair of supplements close to anus, and a ventromedian (more or less contiguous) series of 18, anterior to the cloaca.

From Heyns, 1988

 


Body size range for the species of this genus in the database - Click:
Back to Top

Distribution:

 

Back to Top

Feeding:

     
Back to Top

Biology and Ecology:

   
Back to Top

Life Cycle:

For Ecophysiological Parameters for this genus, click 
Back to Top

Ecosystem Functions and Services:

 

Back to Top

Management:

 

Back to Top

References:

Andrassy, I. 2009. Free-living Nematodes of Hungary III.  Hungarian Natural History Museum, Budapest. 608p.

Heyns, J. 1988. Redescription of Paraxonchium laetificans (Andrassy, 1956) and P. monohystera (Brzeski, 1964) (Nematoda: Dorylaimida). Nematologica

Krall, E. 1958. Paraxonchium striatum gen. n., sp. n.(Nematoda, Belondiridae): a new free-living soil nematode from Estonia.  Eesti NSV Teaduste Akadeemia Toimetised.

Back to Top

For more information about nematodes Go to Nemaplex Main Menu.

Copyright © 1999 by Howard Ferris.
Revised: February 21, 2024.