Local differences in immunocompetence reflect resistance of sticklebacks against the eye fluke Diplostomum pseudospathaceum

M. KALBE a1c1 and J. KURTZ a1p1
a1 Max Planck Institute for Limnology, Department of Evolutionary Ecology, August-Thienemann-Strasse 2, D-24306 Plön, Germany

Article author query
kalbe m   [PubMed][Google Scholar] 
kurtz j   [PubMed][Google Scholar] 


We investigated population differences in immunological adaptation of three-spined sticklebacks (Gasterosteus aculeatus) to one of their most abundant macroparasites, the eye fluke Diplostomum pseudospathaceum. We compared infection success in lab-bred fish of 2 populations in northern Germany, from a lake, where eye flukes are prevalent, and a river, where these parasites do not occur. In order to discriminate between protection through innate and acquired immunity, we exposed fish either only once or repeatedly. Lake fish were significantly less susceptible than river sticklebacks already after a single exposure, indicating that in sympatric hosts innate immunity plays the major role in the defence against this helminth infection. In both habitat types, previous exposures only marginally decreased infection rates within 12 weeks. Lake fish showed higher immunocompentence by means of respiratory burst activity and spleen size, regardless of the infection status. Furthermore, they were in a better energy status than river fish, as indicated by a higher hepatosomatic index and haematocrit value. Interestingly, F1 hybrid fish of both populations ranged between the pure habitat types in parasite susceptibility as well as in immunological and condition parameters. Our results suggest that sticklebacks from lakes are better adapted to cope with higher parasite abundance in this habitat.

(Received May 24 2005)
(Revised June 28 2005)
(Accepted June 29 2005)
(September 13 2005)

Key Words: parasite-host coevolution; local adaptation; fish; innate immunity; respiratory burst; acquired immunity; hybrid; habitat.

c1 Tel: +49 4522 763 256. Fax: +49 4522 763 310. E-mail:
p1 Present address: Experimental Ecology, Universitätsstrasse 16, ETH-Zentrum, CHN JR.1, CH-8092 Zürich, Switzerland.