Body oboval, slightly asymmetrical, colourless; cross section circular. Oral opening protruding slightly apically. Oral basket wide and long (extending to posterior end), composed of thick nematodesmal rods. Macronucleus ellipsoidal (very likely confused with large food vacuole in original description). About 25 longitudinal somatic kineties. Length 20-90 µm. This species is rather unusual for Holophrya. Instead, body shape and long oral basket distinctly resemble those of Gymnozoum spp. (Gymnozoum viviparum) (Gymnozoum viviparum 2) (Gymnozoum viviparum 3).
This is further corroborated by the fact that several species of Gymnozoum were found further south in Antarctic sea ice (Fenchel and Lee, 1972; Corliss and Snyder, 1986; Petz et al., 1995a). However, the arrangement of a few somatic kineties differs. Not having the advantage of silver impregnation, Lohmann (1920) might have missed the actual course of these rows, which bend anteriorly and almost encircle the mouth. Therefore, Holophrya pelagica very likely belongs to Gymnozoum Meunier, 1910 and is thus tentatively placed in the family Kryoprorodontidae Alekperov and Mamaeva, 1992.
Ref.: Lohmann (1920).