60
40
20
40
20
6. Seasonal Dynamics of Lipids
liS
Stylodrifus heringianus
Tubificidae
Chironomidae
(8)
(5)
Mysis relicta
S6m (1~
1(9)
(9)
(8)1
29m
O~~ __ - L __ ~~~~ __ - L __ L--J __ ~~
M
J J A SON D
Month
FIGURE 6.4. Total lipid content, expressed as a percentage of ash-free dry mass (ash-free
dry mass is approximately 90% of dry mass for oligochaetes and chironomids, and 85% of
dry mass for Mysis relicta; Johnson and Brinkhurst, 1971) in major species of Lake
Michigan macroinvertebrates sampled in southeastern Lake Michigan in 1984. Bars represent standard errors. Numbers in parentheses represent the number of replicate animals
analyzed. (From Gardner et al., 1985a.)
The life cycle of rnysids in the Canadian lakes study was 1 or 2 years in
oligotrophic and mesotrophic lakes, suggesting that lipid accumulation rate was
independent of lake trophic status (Fig. 6.3) (Adare and Lasenby, 1994). However, this situation seems unusual because in other Mysis studies, life cycle length
is considered to be inversely related to lake trophic state (Morgan, 1980), and
40
20
40
20
6. Seasonal Dynamics of Lipids
liS
Stylodrifus heringianus
Tubificidae
Chironomidae
(8)
(5)
Mysis relicta
S6m (1~
1(9)
(9)
(8)1
29m
O~~ __ - L __ ~~~~ __ - L __ L--J __ ~~
M
J J A SON D
Month
FIGURE 6.4. Total lipid content, expressed as a percentage of ash-free dry mass (ash-free
dry mass is approximately 90% of dry mass for oligochaetes and chironomids, and 85% of
dry mass for Mysis relicta; Johnson and Brinkhurst, 1971) in major species of Lake
Michigan macroinvertebrates sampled in southeastern Lake Michigan in 1984. Bars represent standard errors. Numbers in parentheses represent the number of replicate animals
analyzed. (From Gardner et al., 1985a.)
The life cycle of rnysids in the Canadian lakes study was 1 or 2 years in
oligotrophic and mesotrophic lakes, suggesting that lipid accumulation rate was
independent of lake trophic status (Fig. 6.3) (Adare and Lasenby, 1994). However, this situation seems unusual because in other Mysis studies, life cycle length
is considered to be inversely related to lake trophic state (Morgan, 1980), and