Tanqua tiara		Contents		Rev 11/01/2022
		Classification		Biology and Ecology
		Morphology and Anatomy		Life Cycle
Return to Tanqua Menu				Ecosystem Functions and Services
		Distribution		Management
Return to Gnathostomatidae Menu		Feeding		References
		Go to Nemaplex Main Menu		Go to Dictionary of Terminology

Classification:

Chromadorea

  Chromadoria

   Rhabditida

Spirurina

              Gnathostomatomorpa

               Gnathostomatidae

Synonyms:

Ascaris tiara von Linstow, 1879

Ctenocephalus tiara von Linstow, 1897; von Linstow, 1904a.

Tetradenos tiara von Linstow, 1897; von Linstow, 1904b.

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Morphology and Anatomy:

• Body elongate with massive cephalic bulb at anterior end.
• Body surface transversally striated.
• Two massive lateral pseudolabia with interlocking distal margins, separated from the cephalic bulb by a groove. Internal surface of the pseudolabia smooth, the distal projections, each with a tooth-like prominence on its margin. Each pseudolabium with a pair of large dome-shaped, submedian papillae. At base of each pseudolabium is a triangular area of pores,
• a small separate median pore representing the external opening of the lateral amphid
•  Cephalic bulb, smooth on its anterior surface, divided into four segments transversally ridged, separated by a groove which narrows posteriorly  Each segment of the cephalic bulb contains a ballonet which is associated with one of four elongate, blindly ending sacs which extend pos teriorly adjacent to the esophagus ,each with one or more swellings along its length. These sacs, referred to as cervical glands or cervical sacs, have a surface with spirally arranged fibrils
• Anterior cervical region deeply invaginated forming a cervical collar. The infolded surfaces of the cuticle in this region are transversally ridged..

Tanqua tiara: 35: Male anterior; 36: Junction of esophagus and intestine, male;  37: femele en face view; 38: :male tail, ventral
Males:   Spicules with pitted surface Two pairs of precloacal caudal papillae, 2 pairs of parallel adcloacal papillae, external pair larger than the internal pair, 4 pairs of post cloaca1 papillae Tail with pointed tip.	Female:    Small vulvar opening without lips or flaps muscular vagina divides distally each branch dividing again to form four uteri; eggs Ref: Gibbons and Keymer, 1991
Reported median body size for this species (Length mm; width micrometers; weight micrograms) - Click:

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Distribution:

Tanqua tiara is widespread among lizard host species

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Feeding:

In a stucy of parasitism of the Nile monitor lizard, Varanus niloticus, bu Tanqua tiara, the adult nematodes attached singly to the host�s stomach wall and penetrated deep into the submucosa.

  Deep pores in the mucosa marked entrance to pit-like formations caused by the deep penetration of nematodes into the submucosa

 Removal of an adult nematode from one of the pit-like formations revealed a �mirror image� of the cephalic region showing a serrated surface of host tissue corresponding to the ridges on the cephalic bulb of the parasite

 The host tissue forms a tight collar around the invaginated cervical region.

The attachment of the parasite to the stomach wall causes severe damage to the mucosa and destruction of gastric epithelium.

The parasite lives in a hostile environment in the alimentary tract of its host and requires a mechanism to retain it in position. The effect of the cephalic bulb of the nematode on the host tissues suggests that the presence of the transverse ridges on the cephalic bulb in addition to the ability to change its shape, and the extendable cervical region, creates an effective holdfast to retain the nematode in the stomach wall of the host (Gibbons and Keymer, 1991)..

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Biology and Ecology:

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Life Cycle:

Ecophysiological Parameters:

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Ecosystem Functions and Services:

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Management:

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References:

Baylis, H. A. 1916. The nematode genus Tanqua, R. B1anchard.-Ann. Mag. nut. Hist. (Ser. 8) 17: 223-232

Gibbons, L. M. & Keymer, I. F. 1991. Redescription of Tanqua tiara (Nematoda, Gnathostomidae), and associated lesions in the stomach of the Nile monitor lizard (Varanus niloticus).Zool. Scr. 20:7-14.

Von Linstow, 0. F. B. 1879.  Helminthologische  Untersuchungen. Jber. Ver. Vaterl. Naturk. Wurtemberg 35:313-342.

Von Linstow, 0. F. B. 1904. Nematoda in the collection of the Colombo Museum.-Spolia Zeylanica 1:1-14.

Von Linstow, 0. F. B. 1904. Beobachtungen  an  Nematoden und Cestoden.-Arch. fur Naturgesch. 70:297-309.

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Copyright © 1999 by Howard Ferris.
Revised: November 01, 2022.