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United States Department of Agriculture

Agricultural Research Service

Title: Bilateral, Perivulval Cuticular Pores in Haemonchus, Mecistocirrus, Trichostrongylus and Ostertagia (Nematoda: Trichostrongylidae)

Authors
item Lichtenfels J Ra,
item Wergin W P,
item Murphy C,
item Pilitt, Patricia

Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 16, 1994
Publication Date: N/A

Interpretive Summary: Nematodes of the family Trichostrongylidae include numerous species pathogenic to cattle, sheep and goats. Control of the nematode populations depends on drugs. During a study of the nematode cuticle for identification characteristics a new hypodermal gland was observed in apparent association with the vulva of females of several genera of these nematodes. Because of its position and similarity to other secretory hypodermal glands, the newly discovered gland is of interest as a possible source of attractant for males during mating. The new hypodermal gland is described as a first step in an investigation that could lead to a biological control for the economically important parasitic nematodes.

Technical Abstract: A new hypodermal gland was discovered in female nematodes of the family Trichostrongylidae. Because the new structure appears to be associated with the vulva, it was named the perivulval pores. It is similar, based on light and scanning electron microscopy, to phasmids which are located laterally on the tails of nematodes of the Class Secernentea. Like phasmids, perivulval pores are paired and bilateral, with cuticular ducts to the surface in the area of the lateral chords. They are located slightly posterior to the vulva in Haemonchus contortus, H. placei, H. similis, Mecistocirrus digitatus and Ostertagia ostertagi, but in Trichostrongylus colubriformis they are slightly anterior to the vulva. Because of the location near the vulva and the similarity in structure to phasmids which are, at least in part, secretory, the perivulval pores should be considered as a source of a female attractant for males.

Last Modified: 8/29/2014