Lagenivaginopseudobenedenia is a genus of monopisthocotylean monogenean (a group of ectoparasitic flatworms), included in the family Capsalidae.

[2] The genus includes only 2 species, which are both parasitic on the gills of marine fish of the family Lutjanidae.

Species of the genus Lagenivaginopseudobenedenia are, like most monogeneans of the family Capsalidae, flat with a posterior disc-shaped haptor which attaches to the gill of their host.

Their distinctive feature is a “vagina lageniform, between uterus and right intestinal limb, opening almost midventrally behind cirrus pouch”.

[2] The etymology of this extremely long name involves three steps: Lagenivaginopseudobenedenia, with 27 letters and 17 syllables, is possibly the longest valid generic name of the zoological nomenclature for a non-fossil organism.