Dujardinascaris		Contents		Rev 01/03/2023
		Classification		Biology and Ecology
		Morphology and Anatomy		Life Cycle
Return to Dujardinascaris menu				Ecosystem Functions and Services
		Distribution		Management
Return to Heterocheilidae Menu		Feeding		References
		Go to Nemaplex Main Menu		Go to Dictionary of Terminology

Classification

Chromadorea

       Spiruria

         Ascaridida

          Ascaridoidea

               Heterocheilidae

                          Dujardinascaris Baylis, 1947

The genus Dujardinascaris  includes more than 20 species of reptile and fish parasites. All Dujardinascaris spp. are considered host specific; 18 species parasitize exclusively crocodilians and at least two species parasitize fish.

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Morphology and Anatomy:

• Lips with interlocking processes, dorsal lips with two convex processes, left subventral with two socket, and ventral process.
• Anterior edge of lip with oral plate, bearing rounded teeth on border
• Four anterior prolongations of labial pulp extending into plate; postlabial grooves and interlabia present.
•  Dujardinascaris species differ primarily in the form of the reproductive organs, while other features are considered remarkably uniform.
• An approximate correlation between the relative lengths of spicules and the form of the gubernaculum is considered a constant feature for species differentiation.
• Morphological differentiation is difficult if anly females are present.

Ref. Masova et al., 2014; Sprent, 1977

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Distribution

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Economic Importance:

When feeding causes ulceration of the host digestive system, they are considered of economic importance in crocodile farming (Masova et al., 2014).

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Hosts:

Dujardinascaris spp. are host specific; 18 species parasitize exclusively crocodilians and two species parasitize fish (Sprent 1977; Sprent et al. 1998; Machida et al. 1992, Moravec & Jirku, 2014).

In Africa and Madagascar, five Dujardinascaris spp. ( D. dujardini, D. gedoelsti, D. puylaerti, D. petterae, and D. madagascariensis) are reported in the Nile crocodile (Crocodylus niloticus), African slender snouted crocodile (Mecistops cataphractus) and the African dwarf crocodile (Osteolaemus tetraspis) (Travassos, 1920, Sprent, 1977, Sprent et al., 1998, Chabaud & Caballero, 1966, Masova et al., 2014).

Reported from both the families Crocodilidae and Alligatoridae.

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Feeding

Usually found as parasites in the stomach leading to gastric ulceration

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Life Cycle

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Damage:

Nematode infections in crocodilians are usually conaidered asymptomatic but when they cause ulceration they may reduce host fitness and are considered of economic importance in crocodile farming (Masova et al., 2014).

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Management:

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References:

Chabaud, A.G. & Caballero, R. 1966. Phenomene de subspeciation chez un ascaride parasite de Crocodilus niloticus a Madagascar. Bulletin du Muséum national d'histoire naturelle, 38: 687-689.

Masova, S., Barus, V., Seifertova, M., Malaca, J. 2014. Redescription and molecular characterisation of Dujardinascaris madagascariensis and a note on D. dujardini (Nematoda: Heterocheilidae), parasites of Crocodylus niloticus, with a key to Dujardinascaris spp. in crocodilians. Zootaxa 3893:261-276.

Machida, M., Araki, J., Regoniel, P.A., Pontillas, F.A. & Kurata, Y. 1992. Three species of ascaridoid nematodes from crocodiles in the Philippines. Bulletin of the National Science Museum, Series A (Zoology), 18: 95-102.

Moravec, F & Jirku, M. 2014. Dujardinascaris mormyropsis n. sp. (Nematoda: Anisakidae) from the osteoglossiform fish Mormyrops anguilloides (Linnaeus) (Mormyridae) in Central Africa. Systematic parasitology, 88: 55-62.

Sprent, J.F.A. 1977. Ascaridoid nematodes of amphibians and reptiles: Dujardinascaris. Journal of Helminthology, 51: 253-287.

 Sprent, J.F.A., McKeown, E.A. & Cremin, M. 1998. Dujardinascaris spp. (Nematoda: Ascaridoidea) in Old World crocodilians. Systematic Parasitology, 39: 209-222.

Travassos, L. 1933. Ascarides des crocodiles Sud-Americains. Comptes Rendus des Seances de la Societe de Biologie et des ses Filiales, 114:833-834.

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