61.1 50.8 49.6 46.8 46 46 43.2 44.5 44 50 25.8 29.1 28.8 27.1 31 26.5 28 32 29 13.1 21.6 21.3 24.5 26.9 22 28.8 28.8 26.8 23 nI3 33 11.3 16.8 16.7 16.7 18.7 18 24.4 22.2 17.9 18 Materials and methods
pre-washed in methanol, and then the filter was stored in a clean glass vial with Ž
. chloroformrmethanol qbutyl hydroxyl toluene 2:1 solution. The vials were stored at
y408C. All the glassware used were pre-washed with chloroform to avoid lipid contamina-
tion. The lipids were extracted using a modification of the method of Bligh and Dyer Ž
. 1959 ; fatty acid methyl esters were obtained by methylation with 12 BF
in
3
Ž .
methanol Metcalfe et al., 1966 . A methanolic solution of C was used as an external
23:0
Table 3 Fatty acid content of M. edulis larvae obtained after 2 weeks of feeding on R. reticulata
Ž .
Individual FA are expressed as percentage of total identifiable fatty acids percentage TIFA . SAFA sSaturated fatty acid, MUFA s Monounsaturated fatty acid, PUFA s Polyunsaturated fatty acid. Two individual larval
cultures are code-named as: Con s fed on Control diet, Un sUnfed larvae, HL s High Light, LL s Low Light, fr2 salga cultured under no nutrient limitation, P salga cultures under phosphorus limitations and
Nsalga cultured under nitrogen limitation. Blanks indicate that the fatty acid was below detection levels. Two 20:1 isomers were found. Question mark after the 20:4 ny6 fatty acid indicates that although the fatty
acid could not be identified on the GC trace, the GCrMS analysis suggested an identification. N.I.s fatty acid identified on the GC trace, but not integrated by the instrument. Larval length achieved is taken from
Ž . Ž
. Leonardos and Lucas 2000b
ns60 . Ž
. Ž
. Fatty acid Control
Unfed R. reticulata HL
R. reticulata LL 1
2 1
2 fr2 1 fr2 2 P 1
P 2 N 1
N 2 fr2 1 fr2 2 P 1
P 2 N 1
N 2 14:0
5.3 3.6
5.2 4.4
6.1 5.0
4.8 5.5
4.4 4.0
3.6 3.6
2.4 4.2
5.4 2.7
15:0 2.1
1.3 3.5
4.1 3.9
3.5 2.6
2.7 3.6
2.7 2.3
2.7 2.6
4.1 1.2
1.0 16:0
31 22
30 34
26.1 26.9 24.7 24.5 27 25
22.8 24.3 24 28
23 22.6
18:0 9.8
8.1 10 12
9.4 9.0
9.3 8.4
8.7 10 9.2
9.7 9.8
9.3 7.3
7.3 22:0
4.5 2.6
8.4 5.7
5.4 5.3
5.3 4.9
2.7 1.6
5.3 4.3
5.1 3.8
2.7 3.4
SAFA 52.7 37