Onchulus

  

Contents

  

Rev: 03/08/2023

  Classification Biology and Ecology
Morphology and Anatomy Life Cycle
Return to Onchulus Menu Ecosystem Functions and Services
Distribution Management
Return to Onchulidae Menu Feeding  References
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Classification:

Enoplea
  Enoplia
        Enoplida
            Tripylina
                 Tripyloidea
                    Onchulidae
Onchulinae

Onchulus Cobb, 1920

    Synonyms:

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Morphology and Anatomy:

Onchulidae can be recognized from other families of the Tripyloidea (Tripylidae and Trischistomatidae) by the two whorls of cephalic setae, the large buccal tooth, shape of the buccal cavity, the unusual pattern of the esophagus and the lack of a spinneret on the tail.

 
  • Head not offset from body contour; bears two rings of cephalic setae, 6 longer and 4 shorter. There is also a ring of 4 shorter cervical setae.
  • Stoma wide, barrel-shaped with a single strong dorsal tooth and oblique folds posterior to the tooth.
  • Cuticle smooth or finely striated
  • Amphids 2-3 lip widths posterior to head
  • Esophagus cylindrical; with areolated with alternating layers of muscle and gland tissue
  • Cardia large and spheroid
  • Tail filiform in both sexes. 
  • No caudal glands or spinneret but usually with a fine mucron.

 

Females:

  •   Didelphic, amphidelphic. Ovaries reflexed
  • Spermatheca usually devoid of sperm

Ref: Andrassy, 2007

 

 


   

Males:  

  • Rare
  • Diorchic
  • Spicules short and surrounded by a muscular pouch
  • Supplements small, precloacal
Body size range for the species of this genus in the database - Click:
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Distribution:

 

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Feeding:

Classified as predators by Yeates et al (1993)

Biology and Ecology:

 

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Life Cycle:

 
For Ecophysiological Parameters for this genus, click 
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Ecosystem Functions and Services:

Regulation of opportunistic species through predation.

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Management:

 
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References:

 

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Copyright 1999 by Howard Ferris.
Revised: March 08, 2023.