Zeitschrift für Parasitenkunde

, Volume 71, Issue 6, pp 727–737 | Cite as

Treatment of fish parasites

1. Praziquantel effective against Monogenea (Dactylogyrus vastator, dactylogyrus extensus, diplozoon paradoxum)
  • Günter schmahl
  • Heinz Mehlhorn
Original Investigations


In several experiments it was shown that praziquantel is effective against Monogenea (Dactylogyrus vastator, Dactylogyrus extensus) parasitizing the gills of pond-reared carp (Cyprinus carpio). Also, the effects of praziquantel onDiplozoon paradoxum from chub (Squalius cephalus) were investigated. Infested carp were incubated for 30, 60, 90, 120 or 180 min at 22° C in water containing 0 (control), 1, 5, 10, 100 μg praziquantel/ml. It was found that the drug caused irreversible alterations in the tegument of Monogenea within 30 min after exposure to at least 1 μg praziquantel/ml. The damage found in vitro resulted in vacuolisation of the parasites' teguments. The three species showed little differences in the grade of tegumental alternation:Dactylogyrus vastator showed vacuolisation of its tegument in all regions of its body, which was very marked in the opisthaptor and in the peduncle region. Parasites did not drop from the gills even when killed by treatment with praziquantel. InDactylogyrus extensus the opisthaptor region was especially affected. The worms usually lost their marginal hooklets as well as the large hooks. In contrast toDactylogyrus vastator, treated worms often dropped from gills.Diplozoon paradoxum was lesser sensitive to the drug. After incubation in 1 μg praziquantel/ml for 7 h the worms had a reduced motility. Doses of 10μg/ml and 150 μg/ml for 1.5 h led to severe damage of the tegument, especially in the region of the oral sucker. However, the drug is effective in treatment of this parasite.

It is suggested that therapy againstDactylogyrus vastator andDactylogyrus extensus in carp fingerlings may be done with 10 mg praziquantel/l for 3 h at 22° C during storage in smaller tanks.


Severe Damage Praziquantel Oral Sucker Fish Parasite Small Tank 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Becker B, Mehlhorn H, Andrews P, Thomas H (1980a) Scanning and transmission electron microscope studies on the efficacy of praziquantel onHymenolepis nana (Cestoda) in vitro. Z Parasitenkd 61:121–133PubMedGoogle Scholar
  2. Becker B, Mehlhorn H, Andrews P, Thomas H, Eckert J (1980b) Light and electron microscopic studies on the effect of praziquantel onSchistosoma mansoni, Dicrocoelium dentriticum andFasciola hepatica in vitro. Z Parasitenkd 63:113–128PubMedGoogle Scholar
  3. Bricker CS, Depenbusch JW, Bennett JL (1982) Effects of praziquantel. Am J Trop Med Hyg 72:132–142Google Scholar
  4. Bychowsky BE (1957) Mobogenetic Trematodes; their Systematics and Phylogeny. American ed. W.J. Hargis, Institute of Biological Sciences, Washington D.C.Google Scholar
  5. Gönnert R, Andrews P (1977) Praziquantel, a new broad spectrum anti-schistosomal agent. Z Parasitenkd 52:129–150PubMedGoogle Scholar
  6. Kollmann A (1966)Dactylogyrus extensus Müller et v Cleave, 1932 (Trematoda, Monogenoidea) auf Karpfen (Cyprinus carpio L) zum ersten Male in Westdeutschland nachgewiesen. Zool Anz 177:426–434Google Scholar
  7. Mehlhorn H, Kojima S, Rim HJ, Ruenwongsa P, Andrews P, Thomas H, Bunnag B (1983) Ultrastructural investigations on the effects of praziquantel on human trematodes from Asia:Clonorchis sinensis, Metagonimus yokogawai, Opisthorchis viverrini, Paragonimus westermani andSchistosoma japonicum. Drug Res 33, 1:91–98Google Scholar
  8. Paperna I (1964a) Adaptation ofDactylogyrus extensus (Mueller and Van Cleave, 1932) to ecological conditions of artifical ponds in Israel. J Parasitol 50:90–93Google Scholar
  9. Paperna I (1964b) Competitive exclusion ofDactylogyrus extensus byDactylogyrus vastator (Trematoda, Monogenea) on the gills of reared carp. J Parasitol 50:94–98Google Scholar
  10. Thomas H, Gönnert H (1977) The efficacy of praziquantel against cestodes in animals. Z Parasitenkd 52:117–127PubMedGoogle Scholar
  11. Thomas H, Gönnert R (1978) The efficacy of praziquantel against cestodes in cats, dogs and sheep. Res Vet Sci 24:20–34PubMedGoogle Scholar
  12. Wunder W (1926b)Dactylogyrus vastator (Nybelin) auf den Kiemen der Karpfenbrut. Ein Beitrag zu den Beziehungen zwischen Parasit und Wirt. Biol Ztrbl 46:748–755Google Scholar
  13. Wunder W (1929) DieDactylogyruskrankheit der Karpfenbrut, ihre Ursache und Bekämpfung. Z Fischerei 27:511–545Google Scholar

Copyright information

© Springer-Verlag 1985

Authors and Affiliations

  • Günter schmahl
    • 1
  • Heinz Mehlhorn
    • 1
  1. 1.Lehrstuhl für Spezielle Zoologie und ParasitologieRuhr-Universität BochumBochum 1Federal Republic of Germany

Personalised recommendations