Marine lipids
C16:1 ω07 and C14:0 have been noticed but in lower proportions. The
FA C18:3 ω3 has also been found, but in low proportions. Some variability is observed in the sample compositions but there are no significative differences between samples at low tide on one hand and at high
tide on the other (table 1). Branched FAs were always in low proportions and they represent collectively 1.8 to 2.9% of total FAs. The
C18:l ω7/C18:1 ω9 ratio is superior to 1 but is not very high (table 1).
Long-chain FAs (C26:0- C32:0) were not detected in copepods.
Tabie 1 - Relative abundances of some fatty acids (FAs) in copepods
(fraction >200 µm) at the B26 site in the Seine estuary during high tides (HT)
and low tides (LT).
FA
LT (13 h) LT (1 h)
HT (19 h)
HT (7 h)
C14:0
10.5
7.6
7.9
7.3
C16:0
14.9
10.7
19.4
12.9
C16:1 ω7
10.1
8.4
6.7
7.8
C16:2 ω4
2. i
2.3
1.3
2.1
C16:3 ω4
7.5
7.8
1.6
6.5
08:3 0)3
3.3
3.0
0.9
2.6
C20:5 ω3
19,5
25.2
20.4
23.3
C22:6 ω3
12,1
18.0
22.2
21.2
C18:1 ω7/C18:1 ω9
3.9
1.7
1.9
2.1
Total FAs (mg/g of carbon) 116.4
128.4
98.1
83.0
High proportions of cholesterol (71.9-93.5%) can be noticed (table 2).
However, some phytosterols such as trans-22 deshydrocholesterol, brassicasterol and campesterol are found in lower proportions. β-sitosterol is
in lower proportions in copepods (0.3-1.5%) than in POM (12.9-24.7%
of total STs, data not shown). Except for trans-22 deshydrocholesterol,
all corresponding stanols were found for identified stenols, but in low
proportions. We can notice however that coprostanol was not detected
in copepods but was present in POM (2.9-9.2% of total sterols).
Table 2 - Relative abundances of sterols (STs) in copepods (fraction >200 µm)
at low tides (LT) and at high tides (HT).
ST
LT (13 h) LT (1 h)
HT (19 h)
HT (7 h)
Trans-22 deshydrocholesterol
3,2
1,4
12,0
9,2
Cholesterol
85,5
93,5
71,9
83,0
Brassicasterol
0.6
0.8
5.2
3.2
Campesterol
5.9
2.9
4.9
3.7
Stigmasterol
0.7
0.6
1.3
0.4
β-sitosterol
1.5
0.5
0.3
0.5
Σ Stanols (%)
2.6
0.3
4.4
0.0
Total STs (mg/g of carbon)
2.6
1.5
1.7
0.2
The composition m fatty acids and sterols of the stomachs of Palaemon
longirostris, before incubation, and of faecal pellets, after 24 h of incu82
C16:1 ω07 and C14:0 have been noticed but in lower proportions. The
FA C18:3 ω3 has also been found, but in low proportions. Some variability is observed in the sample compositions but there are no significative differences between samples at low tide on one hand and at high
tide on the other (table 1). Branched FAs were always in low proportions and they represent collectively 1.8 to 2.9% of total FAs. The
C18:l ω7/C18:1 ω9 ratio is superior to 1 but is not very high (table 1).
Long-chain FAs (C26:0- C32:0) were not detected in copepods.
Tabie 1 - Relative abundances of some fatty acids (FAs) in copepods
(fraction >200 µm) at the B26 site in the Seine estuary during high tides (HT)
and low tides (LT).
FA
LT (13 h) LT (1 h)
HT (19 h)
HT (7 h)
C14:0
10.5
7.6
7.9
7.3
C16:0
14.9
10.7
19.4
12.9
C16:1 ω7
10.1
8.4
6.7
7.8
C16:2 ω4
2. i
2.3
1.3
2.1
C16:3 ω4
7.5
7.8
1.6
6.5
08:3 0)3
3.3
3.0
0.9
2.6
C20:5 ω3
19,5
25.2
20.4
23.3
C22:6 ω3
12,1
18.0
22.2
21.2
C18:1 ω7/C18:1 ω9
3.9
1.7
1.9
2.1
Total FAs (mg/g of carbon) 116.4
128.4
98.1
83.0
High proportions of cholesterol (71.9-93.5%) can be noticed (table 2).
However, some phytosterols such as trans-22 deshydrocholesterol, brassicasterol and campesterol are found in lower proportions. β-sitosterol is
in lower proportions in copepods (0.3-1.5%) than in POM (12.9-24.7%
of total STs, data not shown). Except for trans-22 deshydrocholesterol,
all corresponding stanols were found for identified stenols, but in low
proportions. We can notice however that coprostanol was not detected
in copepods but was present in POM (2.9-9.2% of total sterols).
Table 2 - Relative abundances of sterols (STs) in copepods (fraction >200 µm)
at low tides (LT) and at high tides (HT).
ST
LT (13 h) LT (1 h)
HT (19 h)
HT (7 h)
Trans-22 deshydrocholesterol
3,2
1,4
12,0
9,2
Cholesterol
85,5
93,5
71,9
83,0
Brassicasterol
0.6
0.8
5.2
3.2
Campesterol
5.9
2.9
4.9
3.7
Stigmasterol
0.7
0.6
1.3
0.4
β-sitosterol
1.5
0.5
0.3
0.5
Σ Stanols (%)
2.6
0.3
4.4
0.0
Total STs (mg/g of carbon)
2.6
1.5
1.7
0.2
The composition m fatty acids and sterols of the stomachs of Palaemon
longirostris, before incubation, and of faecal pellets, after 24 h of incu82