Effects of the swimbladder parasite Anguillicola crassus on the migration of European silver eels Anguilla anguilla in the Baltic Sea

• In a mark–recapture study in 2006, migrating European Anguilla anguilla silver eels were caught,tagged and released in the Baltic Sea and recaptures in commercial pound nets examined for possibleeffects on migration of infection with the swimbladder parasite Anguillicola crassus. The overallrecapture rate was 36%. The prevalence of infection was lowest at the northernmost sampling site.There were no significant differences between infected and uninfected A. anguilla in conditionindices, body fat content and estimated migration speeds. Parasite infection intensity levels weresignificantly negatively correlated with times and distances covered between release and recapture,but did not correlate with migration speed. It appears that more heavily infected A. anguilla wererelatively more vulnerable to recapture in pound nets. It is hypothesized that parasite-induced damageto the swimbladder inhibited vertical migrations and infected A. anguilla tended to migrate inshallower coastal waters, relatively close to the shore.

Ämnesord

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

NATURVETENSKAP  -- Biologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences (hsv//eng)

Nyckelord

parasite incidence

parasite infestation

parasite prevalence

swimming speed

tagging experiment

vertical migration

Marine Ecology

marin ekologi

Terrestrial, freshwater and marine ecology

Biology

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)