Ophidascaris		Contents		Rev 05/28/2025
		Classification		Biology and Ecology
		Morphology and Anatomy		Life Cycle
Return to Ophidascaris menu				Ecosystem Functions and Services
		Distribution		Management
Return to Ascarididae Menu		Feeding		References
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Classification:

Class:    Chromadorea

SubClass: Spiruria

Order:   Ascaridida

Superfamily: Ascaridoidea

Family:  Ascarididae

                          Ophidascaris Baylis 1921

Type species of the genus: Ophidascaris filaria Dujardin, 1845

Synonyms:

Ophidascaris rubicunda Schneider, 1866

Ophidascaris infundibulicola Linstow, 1903

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Morphology and Anatomy:

Nematodes with general characteristics of Ascarididae.

• Relatively large ascaridoids; body of even width or posterior part of body of female wider than anterior.
• Lips oval, square or rectangular, dentigerous ridges present; postlabial grooves present; indented anterior margin and oral groove present; isthmus variable in width; posterior angles of lips rounded, posterior labial pillars absent. Interlabia present. Labial pulp not deeply cleft, with two hammer-shaped anterior prolongations; median lobe of pulp absent.
• Anterior region with or without lateral alae.
• Esophagus gradually widening to its posterior end, without bulb or demarcated ventriculus.
• DEGO behind lips. Ducts of subventral glands at posterior end of oesophagus. Nucleus of dorsal oesophageal gland situated in dorsal sector, nuclei of subventral glands situated in ventral part of subventral sectors.
• Intestinal caecum present or absent.
• Excretory system bilateral; excretory pore a little behind nerve ring; excretory nucleus in commissure or at junction with left lateral filament.
• Cervical papillae level with or slightly behind excretory pore.
• Intestine in living specimens with characteristic folds of internal surface giving iridescent sheen and herringbone, reticulate, or papillate pattern; intestine varying in colour from brownish-red to lemon-yellow.
• Vulva near or behind middle of body; reproductive organs confined to region behind vulva (didelphic-opisthodelphic). Uterus with two branches.
• Female tail with phasmids near tip.
• Male smaller than female; tail curved ventrally, with on each side 30 or more precloacal, two subventral and two subdorsal postcloacal and one double paracloacal papilla; median precloacal papilla or plaque present.
• Phasmids near tip of tail.
• Spicules equal, alate, usually longer than ejaculatory duct. Gubernaculum absent.

Ref: Sprent, 1988

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Distribution:

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Economic Importance:

Primarily intestinal parasites of snakes and amphibians although Ophidascaris robertsi has been reported from a marsupial and has beec recovered from the brain of a human female in Australia.

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Hosts:

Human

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Feeding:

Food Sources and Feeding strategies for the genus Ophidascaris

Intestinal mucosa

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Life Cycle

• Little is known of the life history of Ophidascaris spp.
• Sprent (1988) speculates that species similar to O. filaria have mammals as intermediate hosts. For example, when eggs of O. arndti were fed to mice, larvae became encapsulated in the liver. Within 36 days after infection larvae had grown to 15 mm. Hence it seems likely that pit vipers become infected by O. arndti through feeding on rodents. Similarly, based on feeding preferences, it seems likely that cobras become infected with O. najae from mammalian tissues.
• Further, Sprent (1988)  that species related to O. obtonica have cold blooded intermediate hosts.

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Damage:

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Management:

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References:

Baylis, H.A. 1920. On the classification of the Ascaridae 1. The systematic value of certain characters of the alimentary canal. Parasitology, 12:253-264.

Baylis, H.A. 1921. On the classification of the Ascaridae. II. The Polydelphis group; with some account of other ascarids parasitic in snakes. Parasitology, 12:411-426.

Sprent, J.F.A. 1988. Ascaridoid nematodes of amphibians and reptiles: Ophidascaris Baylis, 1920. Systematic Parasitology 11:165-213.

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