Journal of Comparative Physiology B

, Volume 155, Issue 3, pp 357–365 | Cite as

The osmotic response of salmon louse,Lepeophtheirus salmonis (Copepoda: Caligidae), during the transition from sea water to fresh water

  • Lutz Hahnenkamp
  • Hans Jørgen Fyhn


The osmotic changes in haemolymph and body tissues of the ectoparasitic salmon louse,Lepeophtheirus salmonis, have been studied upon transfer from sea water (SW) to dilute sea water (37% SW), and then to fresh water (FW). The parasite shows osmoconformity in SW but hyperosmotic regulation in 37% SW regardless of whether it is attached to the salmon host or free swimming in the water. The same conclusion is reached by haemolymph Cl measurements. In FW, the osmotic tolerance and response of attached and free swimming parasites differ: Attached animals maintain steady haemolymph osmolality and Cl concentration and survive for at least 1 week, while free swimming parasites quickly become diluted and start to die within 8 h.

Acclimation to 37% SW is accompanied by changes in body tissue water content and in the content of ninhydrin positive substances and specific amino acids which suggest the presence of cell volume regulation. Glycine is the dominating free amino acid in the cephalothorax tissues but alanine, proline and taurine also occur in high amounts. Lysine is found to increase significantly during FW acclimation of attached parasites. A breakdown of cell volume regulation is suggested to limit the survival of attached salmon louse in fresh water.


Fresh Water Taurine Free Amino Acid Ninhydrin Specific Amino Acid 
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.



fresh water


ninhydrin positive substances


sea water


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  1. Ashby AB (1951) Sea lice on salmon. Period of survival in fresh water. Salmon Trout Magazine 131:82–85Google Scholar
  2. Bayly IAE (1969) The body fluids of some centropagid copepods: Total concentration and amounts of sodium and magnesium. Comp Biochem Physiol 28:1403–1409Google Scholar
  3. Berland B, Margolis L (1983) The early history of “Lakselus” and some nomenclatural questions relating to copepod parasites of salmon. Sarsia 68:281–288Google Scholar
  4. Brand GW, Bayly IAE (1971) A comparative study of osmotic regulation in four species of calanoid copepod. Comp Biochem Physiol 38B:361–371Google Scholar
  5. Brandal PO, Egidius E, Romslo I (1976) Host blood: A major food component for the parasitic copepodLepeophtheirus salmonis Krøyeri, 1938 (Crustacea: Caligidae). Norw J Zool 24:341–343Google Scholar
  6. Brandal PO, Egidius E (1979) Treatment of salmon lice (Lepeophtheirus salmonis Krøyer, 1838) with Neguvon — Description of method and equipment. Aquaculture 18:183–188Google Scholar
  7. Fugelli K (1980) Amino acid transport coupled to cell volume regulation in anisosmotic media. In: Gilles R (ed) Animals and environmental fitness. Physiological and biochemical aspects of adaptations and ecology. Pergamon Press, Oxford New York Paris Frankfurt, pp 27–41Google Scholar
  8. Fyhn HJ (1976) Holeuryhalinity and its mechanisms in a cirriped crustacean,Balanus improvisus. Comp Biochem Physiol 53A:19–30Google Scholar
  9. Gilles R (1979) Intracellular organic osmotic effectors. In: Gilles R (ed) Mechanisms of osmoregulation in animals. Maintenance of cell volume. John Wiley, Chichester, New York Brisbane Toronto, pp 111–154Google Scholar
  10. Hutton JA (1923) The parasites of salmon. Salmon Trout Magazine 34:302–312Google Scholar
  11. Johannessen A (1974) Lakselus. Fisken og Havet. Rapp meld Fiskeridirektoratets Havforskningsinst. Bergen 2B:21–34 (In Norwegian)Google Scholar
  12. Johannessen A (1975) Lakselus,Lepeophteirus salmonis Krøyer (Copepoda, Caligidae). Frittlevende Larvestadier, vekst og infeksjon på laks (Salmo salar L.) fra oppdrettsanlegg og kommersielle fangster i vestnorske farvann 1973–1974. Cand.real. Thesis, University of Bergen (In Norwegian)Google Scholar
  13. Kabata Z (1974) Mouth and mode of feeding of Caligidae (Copepoda), parasites of fishes, as determined by light and scanning microscopy. J. Fish Res Board Can 31:1583–1588Google Scholar
  14. Kabata Z (1979) Parasitic copepoda of British fishes. The Ray Society, LondonGoogle Scholar
  15. Lance J (1964) Respiration and osmotic behaviour of the copepodAcartia tonsa in diluted sea water. Comp Biochem Physiol 14:155–165Google Scholar
  16. Lange R (1964) The osmotic adjustment in the echinoderm,Strongylocentrotus droebachiensis. Comp Biochem Physiol 13:205–216Google Scholar
  17. Moore S, Stein WH (1948) Photometric ninhydrin method for use in chromatography of amino acids. J Biol Chem 175:376–388Google Scholar
  18. Panikkar NK, Sproston NG (1941) Osmotic relations of some metazoan parasites. Parasitology 33:214–223Google Scholar
  19. Pierce SK (ed) (1981) Cell volume regulation. J Exp Zool 215:235–377Google Scholar
  20. Pierce SK, Greenberg MJ (1972) The nature of cellular volume regulation in marine bivalves. J Exp Biol 57:681–692Google Scholar
  21. Prior DJ, Pierce SK (1981) Adaptation and tolerance of invertebrate nervous systems to osmotic stress. J Exp Zool 215:237–245Google Scholar
  22. Scott A (1901) On the fish parasites,Lepeophtheirus andLernaea. Rep Lancs Sea-Fish Labs 9:63–115Google Scholar
  23. Shields RJ, Sperber RG (1974) Osmotic relationships ofLernaea cyprinacea L. (Copepoda). Crustaceana 26:157–171Google Scholar
  24. Sundnes G (1971)Lernaeocera branchialis (L.) on cod (Gadus morhua L.) in Norwegian waters. Dr Philos thesis, University of BergenGoogle Scholar
  25. Vislie T (1980) Hyper-osmotic cell volume regulation in vivo and in vitro in flounder (Platichthys flesus) heart ventricles. J Comp Physiol 140:185–191Google Scholar
  26. Vislie T (1982) On the role of taurine in the hypo-osmotic cell volume regulation in eel (Anguilla anguilla) heart ventricle. Mar Biol Lett 3:53–63Google Scholar
  27. White HC (1940) Sea lice (Lepeophtheirus) and death of salmon. J Fish Res Bd Can 5:172–175Google Scholar
  28. White HC (1942) Life history ofLepeophtheirus salmonis. J Fish Res Bd Can 6:24–29Google Scholar
  29. Wilson CB (1905) North American parasitic copepods belonging to the family Caligidae. I. The Caliginae. Proc US Natl Mus 28:479–672Google Scholar

Copyright information

© Springer-Verlag 1985

Authors and Affiliations

  • Lutz Hahnenkamp
    • 1
  • Hans Jørgen Fyhn
    • 1
  1. 1.Zoological LaboratoryUniversity of BergenBergenNorway

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