Pa. Amundsen et al., INFECTION OF SALMINCOLA-EDWARDSII (COPEPODA, LERNAEOPODIDAE) IN AN AGE-STRUCTURED POPULATION OF ARCTIC CHARR - A LONG-TERM STUDY, Journal of Fish Biology, 51(5), 1997, pp. 1033-1046
The parasite-host relationships between Salmincola edwardsii (Copepoda
: Lernaeopodidae) and Arctic charr Salvelinus alpinus were studied in
lake Takvatn, northern Norway, over an 8-year period. The infection le
vels were modest, with an overall prevalence of 16.1% and an abundance
of 0.5 parasites fish(-1). Most of the infected fish (54.1%) had only
one parasite attached, whilst only 43% had more than 10. In general,
parasite infection increased with increasing age, and hence size of th
e fish. The increase was modest up to age 7, whereafter a steep increm
ent in parasite burdens occurred. Within each age class there was litt
le effect of either fish size, gender, maturation or choice of macroha
bitat upon parasite abundance. There was also little year-to-year vari
ation in infection of the different age classes, indicating a high deg
ree of stability of the parasite-host interactions in this system. The
infection levels exhibited seasonal changes, being lowest in early su
mmer and highest during winter. The infection rates seemed to be relat
ed to seasonal and ontogenetic habitat shifts of the charr. (C) 1997 T
he Fisheries Society of the British Isles.