Mysis relicta in Lake Michigan : abundances and relationships with their potential prey, Daphnia

摘要: Mysis relicta were sampled at a 100-m reference staton in southeastern Lake Michigan (43°N 86°40′W) from 1985 to 1989, quantify nighttime water column abundances and compare vertical distributions with those of Daphnia. Diel migration produced maximum concentrations the thermocline night 1 10 mysids∙m−3. Variation among replicates averaged 28% 3-net Tucker trawl 19% Puget Sound closing nets. Mean areal over 5 yr 110 mysids∙m−2 (SE = 20; n = 30; range = 25 645) based on oblique net tows 1–3-wk intervals during summers station. Synoptic cruises 43°N 45°N August indicated that densities considerably greater offshore than inshore, north south. Hypothesized long-term changes mysid not detected. Although is potentially an important predator Daphnia, differences reduce encounters bet...