Aquatic Parasite Observatory

Posthodiplostomum minimum (Leidy, 1856)

    • Species Name: Posthodiplostomum minimum (Leidy, 1856)
    • Synonyms: None
    • Taxonomy: (Leidy, 1856) Animalia, Platyhelminthes, Trematoda, Strigeidida, Diplostomatidae, Posthodiplostomum minimum
    • Description: "Body distinctly bipartite, forebody flat or concave, oval, sometimes elongate or lanceolate; hindbody oval or claviform to subcylindrical. Pseudosuckers absent; holdfast organ round or almond-shaped, with cavity opening via median slit. Oral and ventral sucker feebly developed; pharynx small.Testes tandem, different in cordiform, sometimes twisted, with large indentation anteriorly. Ovary ellipsoidal, pretesticular, median, lateral or diagonal and tangential to anterior testies. Vitellarium in fore- and hindbody, extending to various levels in relation to ventral sucker region. Copulatory bursa evaginable, with terminal or subterminal opening. Genital cone surrounded by prepuce, encloses hermaphroditic duct, which is formed at its base by union of uterus and ejaculatory duct; ejaculatory pouch absent... Cercariae with rudimentary alimentary system; ventral sucker rudimentary or absent; three pairs of penetration glands in posterior part of body" (Bray et al., 2002).
    • Life Cycle: "First intermediate host are Physa snails (Schleppe and Goater 2004), the second intermediate host are fishes, and the definitive host are piscivorous birds" (Ritossa et al 2013).
    • Sources:Schleppe, J.L. and Goater, C.P. 2004. Comparative life histories of two diplostomid trematodes, Ornithodiplostomum ptychocheilus and Posthodiplostomum minimum. J Parasitol. Vol. 90, No.6, p. 1387-90.
    • Ritossa, L., Flores, V., and Viozzi, G. 2013. Life-Cycle Stages of a Posthodiplostomum Species (Digenea: Diplostomidae) from Patagonia, Argentina. Journal of Parasitology, Vol. 99, No. 5, p. 777-780.
    • Bray, R.A., Gibson D.I., and Jones, A. 2002. Keys to the Trematoda, Vol. 1, p. 196.
    • APO Parasite Records: (by Life Cycle)

Parasite Images:


  • University of Colorado Boulder