Diomedenema		Contents		Rev 05/30/2025
		Classification		Hosts
		Morphology and Anatomy		Life Cycle
Return to Diomedenema Menu		Economic Importance		Damage
		Distribution		Management
Return to Desmidocercidae Menu		Feeding		References
		Nemaplex Home Page		Go to Dictionary of Terminology

Classification:

Chromadorea
Chromadoria

           Rhabditida 

                       Spirurina

                          Aproctoidea

                   Desmidocercidae

 

            Diomedenema Johnston & Mawson, 1952

Type species of the genus: Diomedenema diomedeae Johnston & Mawson, 1952

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Morphology and Anatomy:

• Head end laterally compressed.
• Females larger than males.
• Cuticle with punctations arranged in annuli, decreasing in definition towards tail.
• Eight cephalic papillae in two rings,
• An amphid between each outer pair of  four papillae.
• Mouth dorsoventrally elongated, with paired lateral tricuspid teeth.
• Buccal cavity well developed; esophagus 12-13% length of body, not visibly differentiated into two regions but wider posterior to nerve ring.
• Nerve ring anterior to ventral excretory pore.
• Tail short, bluntly pointed in males and females, without alae.

	Females: Vulva located ventrally at the midbody, muscular vagina curving toward posterior. Didelphic, amphidelphic. Oviparous; eggs thick-shelled, embryonated. Posterior end of female with ventrally positioned anus Males: Spicules unequal. Without bursa Ventromedian papillae present Posterior end of male strongly curled ventrally. Ref: Presswell and Bennett, 2021
Diomedenema dinarctos  a) whole body, female  Scale 1mm. b) en-face view of anterior end showing position of papillae, amphids and mouth. Scale 10um. c) anterior end showing position of nerve ring and excretory pore. Scale 100um. d) vulva. Scale 10um. e) posterior end of male showing papillae, phasmid and unequal spicules. Scale 100um

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Distribution:

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Economic Importance:

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Feeding:

Food Sources and Feeding strategies for the genus Diomedenema

  Parasites of lungs and air sacs of fish-eating birds; penguins, gulls, herons and albatrosses.

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Hosts:

Penguins and albatrosses.

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Life Cycle:

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Damage:

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Management:

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References:

Johnston, T. H. and Mawson, P. M. 1952. Some nematodes from Australian birds and mammals. Transactions of the Royal Society of South Australia, 75:30-37.

Presswell. B., Bennett, J. 2021. Diomedenema dinarctos n. sp. (Spiruromorpha: Desmidocercidae), a new species of lung nematode in Fiordland crested penguins (Eudyptes pachyrhynchus;Sphenisciformes), from South Island, New Zealand. Systematic Parasitology 98:285-290.

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Copyright 1999 by Howard Ferris.
Revised: May 30, 2025.