Submitted to: Applied Optics
Publication Type: Abstract Only
Publication Acceptance Date: May 30, 1995
Publication Date: N/A
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, Mazmastrongylus odocoilei, Cooperia oncophora and Ostertagia ostertagi, but in Trichostrongylus colubriformis they are slightly anterior to the vulva. Similar hypodermal glands have been found recently in a new lungworm from muskoxen. Postdeirids described previously in Caenorhabditis elegans, Ascaris lumbricoides and Parascarus equorum may be homologs of the perivulval pores. In plant parasitic nematodes of the famiy Tylenchidae similar pores referred to as extra phasmids have been used as a systematic character at the species level. 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 possible source of a female attractant for males.