Diomedenema dinarctos

Diomedenema dinarctos	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

Spirurina

Aproctoidea

Desmidocercidae

Diomedenema dinarctos Presswell & Bennett, 2021

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

Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:

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Distribution:

Species described from the South Island of New Zealand

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Economic Importance:

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Feeding:

Parasites of the parabronchi of the lungs of penguin hosts. The host birds were considered sick.

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Hosts:

Fiordland crested penguins Eudyptes pachyrhynchus Gray are thick-billed, crested penguins endemic to New Zealand that breed in small colonies on inaccessible headlands and islets along the coast of Fiordland and Stewart Island, New Zealand. Thebirds are considered Nationally Vulnerable.

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Life Cycle:

For Ecophysiological Parameters for this species, click	If species level data are not available, click for genus level parameters

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Damage:

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Management:

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References:

Johnston, T. H., & Mawson, P. M. (952. 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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