Deletrocephalus		Contents		Rev 05/28/2025
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		Morphology and Anatomy		Life Cycle
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		Distribution		Management
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Classification:

Phylum:  Nematoda
Class:    Chromadorea

Chromadoria

Order:    Rhabditida 

Superfamily:  Strongyloidea

Family:  Deletrocephalidae

Deletrocephalus Diesing, 1851

Type species of the genus Deletrocephalus dimidiatus Diesing, 1851

Synonyms:

Quasistrongylus

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Morphology and Anatomy:

• Filiform body, white or pale yellow in life.
• Females larger than males (ratio of 1.08:1).
• Cuticle with strong striations, synlophe absent
• Oral aperture with a slight hexagonal shape, bounded by a corona radiata, six external leaves, radially striated
• Four rounded cephalic papillae, a pair of amphids and three pairs of diminute papillae, being one papilla near each cephalic papilla and one near each amphid.
• Subglobular buccal capsule with inner undulated corona radiata, with six protrusions and six depressions with numerous chitinized denticuliform elements.
• Around the bottom of the buccal capsule are 11 lancets and two teeth, larger in size, dorsally located
• A discrete cuticular ring is present at the cephalic end
• Esophagus claviform, widening posteriorly
• Excretory pore near the nerve ring, difficult to visualize, located in the narrow portion of the esophagus
• Esophageal-intestinal valve well developed, formed by three units .

Ref: Ederli and Oliviera, 2017

Deletrocephalus dimidiatus from Rhea americana. (A) Anterior region of a female; esophagus, buccal capsule with teeth and lancets, cervical papilla and esophageal-intestinal junction, scale bar: 125 um; (B) spicules, ventral view, scale bar: 150 um; (C) apical view, lips and distribution of cephalic papillae and amphids, scale bar: 25 um; (D) ovejector in ventral view, scale bar: 150 um; (E) posterior extremity of female showing anus and vulva aperture, scale bar: 150 um; (F) gubernaculum with accessory structure in ventral view; scale bar: 25 um; (G) differential dorsal ray pattern, and the external dorsal ray from the copulatory bursa, ventral view, scale bar: 60 um; (H) copulatory bursa showing the organization of bursal rays, scale bar: 120 um. Drawings from Sederli and Oliviera, 2017
Males: Smaller than females; total body length averaging 8.7mm Spicules slender, well chitinized, similar in length, with proximal end larger and distal end slightly pointed Gubernaculum present Bursa with bursal rays	Females: Didelphic, prodelphic Vulva posterior, near anus Tail conical

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

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Distribution:

Intestinal parasites of birds:  Rhea species.

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Economic Importance:

Deletrocephalus dimidiatus, D. cesarpintoi and Paradeletrocephalus minor are parasites of the gastrointestinal tract of the rhea, Rhea americana. Only D. dimidiatus has been reported to be a parasite of the other rhea species, Darwin's rhea, R. pennata (Ederli and Oliviera, 2017)

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Hosts:

Rhea sp.

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Feeding:

Food Sources and Feeding strategies for the genus Deletrocephalus

Intestinal parasites

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Life Cycle:

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Damage:

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Management:

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References:

Diesing C.M. 1851. Systema Helminthum . Vol. 2 . Vindobonae. Vienna, Austria , Wilhelmum Braumüller 

Ederli, N.N., Oliviera, F.C.R. 2017. Morphology of the nematode Deletrocephalus dimidiatus Diesing, 1851 from the rhea, Rhea americana Linnaeus, 1758, together with a key to species of Deletrocephalinae. J.Helminthology 91:244-254.

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