Calanoid Copepods of the Families Diaptomidae, Pseudodiaptomidae, and Centropagidae from Brazil.
Effects of diet mixing on the absorption of ingested organic carbon in marine copepods
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Influence of algal food quality on copepod ingestion and gut absorption efficiency (AE) Peter Thor, Dept. of Marine Ecology, Göteborg University, Kristineberg Marine Research Station, Sweden Marja Koski, Dept. of Marine Ecology, Danish Institute for Fisheries Research Kam W. Tang, Virginia Institute for Marine Sciences Sigrún H. Jónasdóttir, Dept. of Marine Ecology, Danish Institute for Fisheries Research
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Transcript of Effects of diet mixing on the absorption of ingested organic carbon in marine copepods
Influence of algal food quality on copepod ingestion and gut absorption efficiency (AE)
Peter Thor, Dept. of Marine Ecology, Göteborg University, Kristineberg Marine Research Station, Sweden
Marja Koski, Dept. of Marine Ecology, Danish Institute for Fisheries Research
Kam W. Tang, Virginia Institute for Marine Sciences
Sigrún H. Jónasdóttir, Dept. of Marine Ecology, Danish Institute for Fisheries Research
: Low EPR in Acartia tonsa possibly due to unfavourable fatty acid composition (Støttrup and Jensen 1990)
: Incomplete larval development, low somatic growth rates, and low EPR in Pseudocalanus elongatus (Koski et al. 1998)
: Low EPR and egg production efficiency close to zero in Acartia tonsa (Tang et al. 2001)
algal food quality
Dunaliella tertiolecta
Amphidinium carterae
Phaeocystis globosa
Inge
stio
n, µ
gC µ
gC-1
d-1
0.0
0.2
0.4
0.6 Dun = Dunaliella tertiolecta Amp = Amphidinium carterae Pha = Phaeocystis globosa
**
Inge
stio
n, µ
gC µ
gC-1
d-1
0.0
0.2
0.4
0.6
EP
R, µ
gC µ
gC-1
d-1
0.0
0.1
0.2
0.3
Dun = Dunaliella tertiolecta Amp = Amphidinium carterae Pha = Phaeocystis globosa
**
*** ***
GG
E, %
0.0
20
40
60
Dun = Dunaliella tertiolecta Amp = Amphidinium carterae Pha = Phaeocystis globosa
igGGE =
)( erag −−= iraGGE −
=
Increased GGEs or egg production rates are caused either by lower respiration rates, higher absorption rates, or a combination of these, at any given ingestion rate.
Algal concentration, µgC l-1
0 100 200 300 400 500 600
0
1
2
3
4 T. impellucida (high EPR) D. tertiolecta (low EPR)
Respiration
Thor et al. 2000
AE, %
0
20
40
60
80
100
All *** Dun = Dunaliella tertiolecta Amp = Amphidinium carterae Pha = Phaeocystis globosa
0
20
40
60
80
100
Abs
orpt
ion
rate
, d-1
0.0
0.1
0.2
0.3
Dun = Dunaliella tertiolecta Amp = Amphidinium carterae Pha = Phaeocystis globosa All ***
AE, %
Phaeocystis globosa
14:0
14
:1n5
15
:0
16:0
16
:1n1
3 16
:1n7
16
:1n9
16
:2n4
16
:3n4
16
:4n1
16
:4n3
17
:0
17:1
n7
18:0
18
:1n7
18
:1n9
18
:2n4
18
:2n6
18
:3n3
18
:3n4
18
:3n6
18
:4n3
18
:5n3
20
:0
20:1
n9
20:5
n3
22:6
n3
24:0
0
10
20
Amphidinium carterae
perc
ent
0
10
20
Dunaliella tertiolecta
0
10
20
30
Correlations of fatty acid ingestion rates to EPR
r 18:3n3 16:4n3 20:5n3 16:1n7 18:3n6 18:0 14:0 20:0 16:1n13 18:5n3 22:6n3
EPR 0.838 0.821 0.128 0.314 0.847 0.448 0.247 0.392 0.907 0.093 0.021
r 18:3n3 16:4n3 20:5n3 16:1n7 18:3n6 18:0 14:0 20:0 16:1n13 18:5n3 22:6n3
EPR 0.838 0.821 0.128 0.314 0.847 0.448 0.247 0.392 0.907 0.093 0.021
18:3n3 1.000 0.989 -0.255 0.403 0.997 0.146 0.343 0.601 0.957 -0.299 -0.472
16:4n3 1.000 -0.304 0.268 0.996 0.065 0.207 0.495 0.937 -0.325 -0.446
20:5n3 1.000 0.024 -0.239 0.898 -0.002 -0.293 0.035 0.986 -0.088
16:1n7 1.000 0.331 0.373 0.997 0.935 0.385 -0.143 -0.337
18:3n6 1.000 0.144 0.268 0.534 0.961 -0.271 0.6446
18:0 1.000 0.330 0.111 0.410 0.832 -0.358
14:0 1.000 0.928 0.315 -0.170 -0.308
20:0 1.000 0.500 -0.442 0.9481
16:1n13 1.000 -0.009 -0.688
18:5n3 1.000 0.881
Correlations of fatty acid ingestion rates
Intercorrelation: 18:3n3 ~ 16:4n3 ~ 18:3n6 ~ 16:1n13 22:6n3 ~ 20:5n3 ~ 18:5n3 ~ 18:0 16:1n7 ~ 14:0 ~ 20:0
Phaeocystis globosa
14:0
14
:1n5
15
:0
16:0
16
:1n1
3 16
:1n7
16
:1n9
16
:2n4
16
:3n4
16
:4n1
16
:4n3
17
:0
17:1
n7
18:0
18
:1n7
18
:1n9
18
:2n4
18
:2n6
18
:3n3
18
:3n4
18
:3n6
18
:4n3
18
:5n3
20
:0
20:1
n9
20:5
n3
22:6
n3
24:0
0
10
20
Amphidinium carterae
perc
ent
0
10
20
Dunaliella tertiolecta
0
10
20
30
18:3n3
22:6n3
16:1n7
0 0.01 0.02 0.03 0.04 0.0
0.1
0.2
0.3
0.4
0.5
0.6
EPR vs. amount of fatty acids ingested
Fatty acid ingested, µgFA ind-1 d-1
EP
R, µ
gC in
d-1 d
-1
18:3n3
r 2 =0.704
0 0.01 0.02 0.03
22:6n3
r 2 =0.016
0 0.01 0.02 0.03
16:1n7
Fatty acid ingested, µgFA ind-1 d-1
r2=0.099
Intercorrelation: 18:3n3 ~ 16:4n3 ~ 18:3n6 ~ 16:1n13 22:6n3 ~ 20:5n3 ~ 18:5n3 ~ 18:0 16:1n7 ~ 14:0 ~ 20:0
18:3n3
22:6n3
16:1n7
-0.255 0.024
0.403 EPR
U
0.968
0.377
-0.086
0.408
Ingested fatty acids
R2=0.833
Path analysis
Intercorrelation: 18:3n3 ~ 16:4n3 ~ 18:3n6 ~ 16:1n13 22:6n3 ~ 20:5n3 ~ 18:5n3 ~ 18:0 16:1n7 ~ 14:0 ~ 20:0
Phaeocystis globosa
14:0
14
:1n5
15
:0
16:0
16
:1n1
3 16
:1n7
16
:1n9
16
:2n4
16
:3n4
16
:4n1
16
:4n3
17
:0
17:1
n7
18:0
18
:1n7
18
:1n9
18
:2n4
18
:2n6
18
:3n3
18
:3n4
18
:3n6
18
:4n3
18
:5n3
20
:0
20:1
n9
20:5
n3
22:6
n3
24:0
0
10
20
Amphidinium carterae
perc
ent
0
10
20
Dunaliella tertiolecta
0
10
20
30
18:3n3
22:6n3
EPR vs. amount of fatty acids absorbed
18:3n3
r 2 =0.865
Fatty acid absorbed, µgFA ind-1 d-1
0 0.01 0.02 0.0
0.1
0.2
0.3
0.4
0.5
0.6
EP
R, µ
gC in
d-1 d
-1
22:6n3
r 2 =0.057
0 0.01
Fatty acid absorbed, µgFA ind-1 d-1
0 0.01
r 2 =0.062
16:1n7
Intercorrelation: 18:3n3 ~ 16:4n3 ~ 18:3n6 ~ 16:1n13 22:6n3 ~ 20:5n3 ~ 18:5n3 ~ 18:0 16:1n7 ~ 14:0 ~ 20:0
18:3n3
22:6n3
16:1n7
-0.255 0.024
0.403 EPR
U
0.968
0.377
-0.086
0.408
18:3n3
22:6n3
16:1n7
-0.111 0.039
0.116 EPR
U
0.949
0.256
0.194
0.062
Ingested fatty acids Absorbed fatty acids
R2=0.996 R2=0.833
Path analysis
Intercorrelation: 18:3n3 ~ 16:4n3 ~ 18:3n6 ~ 16:1n13 22:6n3 ~ 20:5n3 ~ 18:5n3 ~ 18:0 16:1n7 ~ 14:0 ~ 20:0
Conclusions
• Copepods can obtain optimal algal diets by mixing • Mixing increases carbon AE • Increased AE induces increased EPR • EPR varies significantly with 18:3n3 ingestion • Diet induced variations in EPR can by fully explained by
variations in absorption of the 18:3n3, 22:6n3, and 16:1n7 fatty acid groups
