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G . Martınez et al. J. Exp. Mar. Biol. Ecol. 247 2000 29 –49
concentration of the component in a sample of the female and male gonad, and then extrapolated to the total content of that section by assuming that the gonad was equally
divided into male and female sections sections never differed by more than 10 and histological analysis showed a clear separation between them. The effect of diet and
duration of conditioning upon the levels of biochemical components in gonad and muscle, upon enzyme levels in muscle and upon muscle mass and water content was
examined using two-way ANOVAs which considered diet and duration of conditioning as the two factors Systat. When no interactions were observed between the factors,
one-way ANOVAs considering only the effect of duration of conditioning were run for each diet. When significant effects of duration of conditioning were observed, Tukey a
posteriori tests were used to identify significant differences P , 0.05. For each experiment, the data obtained under the two thermal regimes were analysed separately.
3. Results
3.1. Biochemical composition of muscle When recently spawned Argopecten purpuratus, maintained at 16 or 208C, were
supplied with the three experimental diets at 3 or 6 of their dry mass per day, carbohydrate levels in the adductor muscle showed the most pronounced fluctuations.
During experiment I significant initial increases were followed by marked decreases in all treatments Table 2, Tukey a posteriori tests, P , 0.05 Fig. 1. Initial carbohydrate
levels were higher in the second experiment than in the first Student’s test, P , 0.05. Presumably this is why muscle carbohydrates did not rise at the start of the experiment
II.
During conditioning at 3, muscle protein levels showed slight statistical differences between diets at both temperatures Table 2, Fig. 2; slight increases were detected at the
end of conditioning of scallops fed with microalgae plus starch or only microalgae at 168C. At the end of conditioning at 208C, muscle protein levels declined in scallops
conditioned with the mixture microalgae–carbohydrate. In contrast to experiment I, muscle protein levels of animals fed at 6 of their dry mass per day rose at the start of
conditioning, but did not increase further nor fall below initial values in scallops conditioned at either temperature.
In the first experiment, lipid levels in the adductor muscle were higher, particularly on day 32, in the scallops fed microalgae supplemented with lipids or starch than in the
muscle of scallops fed only microalgae P , 0.05 Fig. 3. Initial muscle lipid levels were higher Student’s test, P , 0.05 in the scallops conditioned at the higher level of
food experiment 2 and declined gradually during their conditioning at 168C; at 208C, except with enriched-lipid diet, there was an initial fall on day 10 then initial values
were recovered, followed by a gradual decline during the final maturation of the gonad.
The changes in the biochemical components in muscle during conditioning were not accompanied by shifts in water content nor wet mass ANOVA, P . 0.05.
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. Martınez et al. J. Exp. Mar. Biol. Ecol. 247 2000 29 –49 35
Table 2 Two-factor analysis of variance for adductor muscle biochemical components of Argopecten purpuratus
a
conditioned at 16 and 208C with three diets df
F 168C
208C Experiment I
Carbohydrates Diet
2 3.484
1.112 ns Days of conditioning
4 35.689
46.080 Interaction
8 7.834
17.481 Proteins
Diet 2
2.588 ns 1.147 ns
Days of conditioning 4
9.181 7.151
Interaction 8
1.654 ns 1.270 ns
Lipids Diet
2 1.353 ns
2.146 ns Days of conditioning
4 6.924
8.641 Interaction
8 0.568 ns
2.272 ns Experiment II
Carbohydrates Diet
2 10.867
6.782 Days of conditioning
6 19.103
17.385 Interaction
12 2.631
4.024 Proteins
Diet 2
2.893 ns 1.328 ns
Days of conditioning 6
9.368 14.823
Interaction 12
0.460 ns 1.272 ns
Lipids Diet
2 5.878
7.241 Days of conditioning
6 30.513
22.909 Interaction
12 3.510
3.130
a
Diets and time of conditioning are the main effects considered. ns, not significant; 0.01 , P , 0.05; 0.001 , P , 0.01; P , 0.001.
3.2. Biochemical composition of gonad 3.2.1. Experiment I
Conditioning of the scallops at 168C, at 3 of their dry body mass per day, led to marked fluctuations of the total content of protein and lipid in the female portion of the
gonad Figs. 4 and 5. These changes were most pronounced for scallops fed microalgae supplemented with carbohydrates or lipids. Lipid contents increased at the end of
conditioning relative to levels during the remainder of the experiment two-way ANOVA; P , 0.05. Carbohydrate contents of the female gonad fluctuated little during
conditioning at 168C Fig. 6, but final values were lower during conditioning in the lipid-supplemented diet P , 0.05. Carbohydrate contents of the male portion of the
gonad were low and did not change during conditioning. Lipid levels rose slightly towards the end of conditioning P , 0.05 with lipid-supplemented diet.
At 208C scallops fed microalgae supplemented with lipids showed the most marked
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G . Martınez et al. J. Exp. Mar. Biol. Ecol. 247 2000 29 –49
Fig. 1. Effect of conditioning recently spent Argopecten purpuratus at 16 and 208C with three diets at 3 experiment I and 6 experiment II of their body mass per day, on the concentrations of carbohydrates in
21
adductor muscle mg g dry mass. A Scallops fed with microalgae supplemented with starch, B scallops
fed with microalgae supplemented with a lipid emulsion; C scallops fed only with microalgae. Values represent the mean6S.E. N 5 3. Different letters mean significantly different values Tukey’s P , 0.05; a
single letter means significantly different from the rest of the values of the same treatment and values without letter mean not different from any of the values of the same treatment.
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Fig. 2. Effect of conditioning recently spent Argopecten purpuratus at 16 and 208C with three diets at 3 experiment I and 6 experiment II of their body mass per day, on the concentration of protein in adductor
21
muscle mg g dry mass. A Scallops fed with microalgae supplemented with starch, B scallops fed with
microalgae supplemented with a lipid emulsion; C scallops fed only with microalgae. Values represent the mean6S.E. N 5 3. Different letters mean significantly different values Tukey’s P , 0.05; a single letter
means significantly different from the rest of the values of the same treatment and values without letter mean not different from any of the values of the same treatment.
´ 38
G . Martınez et al. J. Exp. Mar. Biol. Ecol. 247 2000 29 –49
Fig. 3. Effect of conditioning recently spent Argopecten purpuratus at 16 and 208C with three diets at 3 experiment I and 6 experiment II of their body mass per day, on the concentration of lipids in adductor
21
muscle mg g dry mass. A Scallops fed with microalgae supplemented with starch, B scallops fed with
microalgae supplemented with a lipid emulsion; C scallops fed only with microalgae. Values represent the mean6S.E. N 5 3. Different letters mean significantly different values Tukey’s P , 0.05; a single letter
means significantly different from the rest of the values of the same treatment and values without letter mean not different from any of the values of the same treatment.
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Fig. 4. Effect of conditioning recently spent Argopecten purpuratus at 16 and 208C with three diets at 3 experiment I and 6 experiment II of their body mass per day, on the total content of protein in each
21
gonadal portion mg gonad . A Scallops fed with microalgae supplemented with starch; B scallops fed
with microalgae supplemented with a lipid emulsion; C scallops fed only with microalgae. Values represent the mean6S.E. N 5 3. Different letters mean significantly different values Tukey’s P , 0.05; a single letter
means significantly different from the rest of the values of the same treatment and values without letter mean not different from any of the values of the same treatment. Upper-case letters for male gonadal portion and
lower-case letters for female gonadal portion.
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G . Martınez et al. J. Exp. Mar. Biol. Ecol. 247 2000 29 –49
Fig. 5. Effect of conditioning recently spent Argopecten purpuratus at 16 and 208C with three diets at 3 experiment I and 6 experiment II of their body mass per day, on the total content of lipids in each
21
gonadal portion mg gonad . A Scallops fed with microalgae supplemented with starch; B scallops fed
with microalgae supplemented with a lipid emulsion; C scallops fed only with microalgae. Values represent the mean6S.E. N 5 3. Different letters mean significantly different values Tukey’s P , 0.05; a single letter
means significantly different from the rest of the values of the same treatment and values without letter mean not different from any of the values of the same treatment. Upper-case letters for male gonadal portion and
lower-case letters for female gonadal portion.
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Fig. 6. Effect of conditioning recently spent Argopecten purpuratus at 16 and 208C with three diets at 3 experiment I and 6 experiment II of their body mass per day, on the total content of carbohydrate in each
21
gonadal portion mg gonad . A Scallops fed with microalgae supplemented with starch; B scallops fed
with microalgae supplemented with a lipid emulsion; C scallops fed only with microalgae. Values represent the mean6S.E. N 5 3. Different letters mean significantly different values Tukey’s P , 0.05; a single letter
means significantly different from the rest of the values of the same treatment and values without letter mean not different from any of the values of the same treatment. Upper-case letters for male gonadal portion and
lower-case letters for female gonadal portion.
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G . Martınez et al. J. Exp. Mar. Biol. Ecol. 247 2000 29 –49
changes in gonadal contents of carbohydrates and proteins. Diet had a significant effect on the protein content of the female gonad Fig. 4, as well as on the lipid and
carbohydrate content of the male gonad two-way ANOVA; P , 0.05 Figs. 5 and 6. The fluctuations of the levels of biochemical components led the duration of con-
ditioning to significantly affect the contents of proteins and carbohydrates in the female gonad and on all of the components in the male gonad. Inspection of the overall changes
in the gonadal contents of biochemical components indicates that gonadal levels of lipids and proteins rise during final maturation, whereas increases in proteins which are not
accompanied by increases in lipids may occur well before gonadal maturation.
3.2.2. Experiment II The protein content of the female gonad markedly increased at the start of
conditioning with all diets and at both temperatures Fig. 4. Subsequent fluctuations of protein contents occurred under all experimental conditions, but were more pronounced
at 168C. The slight decrease at 70 days was likely to due to a partial spawning. Protein contents of the female gonad were affected by diet and duration of conditioning at 168C
and only by the duration of conditioning at 208C Table 3, two-way ANOVA; P , 0.05. At 168C, lipid contents increased considerably during the last 20 days of the experiment.
Lipid and carbohydrate contents of the female gonad were affected by duration of conditioning and diet at 168C Table 3, Figs. 5 and 6. For each diet, the scallops fed at
208C tended to have lower gonadal protein contents than those fed at 168C. The increase of lipid contents towards the end of conditioning was less pronounced at 20 than at
168C.
Protein contents of the male gonad rose considerably at the start of conditioning, and oscillated before showing their final increase in the scallops conditioned at 168C with the
two supplemented diets Fig. 4. Again these oscillations may reflect partial spawnings. The carbohydrate contents of the male gonad were affected by both duration of
conditioning and diet at both temperatures Table 3, two-way ANOVA; P , 0.05. At 16 and 208C, lipid and protein contents were only affected by duration of conditioning
Table 3. At 208C, a rise in protein contents was noted only for scallops conditioned with the microalgae supplemented with carbohydrates. In contrast to the scallops
conditioned in the first experiment, the lipid contents of the male gonad changed little during the final stages of conditioning.
3.3. Muscle enzyme levels
21
Muscle enzyme levels were expressed as U g wet mass since the water content of
the muscles did not change during conditioning at 168C ANOVA, F 5 0.332,
3,68
P . 0.05. A two-factor ANOVA with time of conditioning and diet as factors indicated that time of conditioning significantly affected GP levels P , 0.001, but that diet did
not. No interaction was found between time and diet. Both diet P 5 0.044 and conditioning time P 5 0.009 significantly affected PK levels. Throughout conditioning,
scallops fed microalgae alone maintained lower levels of PK than those fed microalgae with lipids, whereas those fed microalgae supplemented with carbohydrates showed
decreases followed by an increase at the end of the experiment Fig. 7. ODH levels
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Table 3 Two-factor analysis of variance for gonadal biochemical components of Argopecten purpuratus conditioned at
a
16 and 208C with three diets df
F F
Female portion Male portion
168C 208C
168C 208C
Experiment I Carbohydrates
Diet 2
7.156 7.010
1.097 ns 4.940
Days of conditioning 4
5.256 8.222
3.846 10.184
Interaction 8
6.521 1.520 ns
1.465 ns 2.107 ns
Proteins Diet
2 0.001 ns
4.182 0.371ns
1.083 ns Days of conditioning
4 7.872
10.960 3.054
4.667 Interaction
8 1.060 ns
1.145 ns 0.633 ns
1.619 ns Lipids
Diet 2
3.065 ns 0.859 ns
0.681 ns 4.350
Days of conditioning 4
6.211 1.167 ns
8.256 5.051
Interaction 8
1.486 ns 3.915
0.909 ns 1.315 ns
Experiment II Carbohydrates
Diet 2
4.290 2.631 ns
15.209 6.591
Days of conditioning 6
7.636 12.925
34.483 6.620
Interaction 12
1.164 ns 1.131 ns
3.216 1.784 ns
Proteins Diet
2 3.691
0.674 ns 6.838
0.676 ns Days of conditioning
6 10.963
10.674 21.007
7.034 Interaction
12 2.292
1.024 ns 0.959 ns
1.607 ns Lipids
Diet 2
8.079 2.731 ns
2.382 ns 0.355 ns
Days of conditioning 6
8.410 6.346
16.022 9.452
Interaction 12
1.743 ns 0.680 ns
1.219 ns 1.004 ns
a
Diets and time of conditioning are the main effects considered. ns, not significant; 0.01 , P , 0.05; 0.001 , P , 0.01; P , 0.001.
were significantly reduced after 40 days of conditioning P 5 0.003, but the effect of the diet was not significant P 5 0.478. Time of conditioning P 5 0.096 and diet P 5
0.126 did not significantly affect the activities of CS.
4. Discussion
