Treatments

Parameter

Shrimp pond

NF

FF

FF+NF

FF+NF+S

Mean final weight (g)

3.3 ± 0.88a,b

2.91 ± 0.7a

3.37 ± 0.8a,b

5.02 ± 0.32c

5.43 ± 0.61c

SGR

8-10(9.2)

7-10(8)

9-10(9.5)

10-11(10.5)

11-12(11)

Survival rate (%)

84 ± 6a

90 ± 3a,b

96.7 ± 2c

90 ± 4a,b

93 ± 3b,c

FCR

0.8-1.0

1.2-1.5

0.7-1.0

0.7-0.8

k (d-1)

0.091 ± 0.01a,b

0.087 ± 0.01a

0.09 ± 0.01a,b

0.11 ± 0.02a,b

0.11 ± 0.00b

m (d-1)

0.11 ± 0.03a

0.10 ± 0.02a

0.11 ± 0.03a

0.17 ± 0.01b

0.19 ± 0.02b

t50  (d)

2.9-4.4(3.5)

3.2-4.7(3.8)

2.9-4.2(3.4)

2.1-2.8(2.5)

2.2-2.6(2.4)

δ15N(‰)

7.43 ± 0.54

10.13 ± 0.52

7.31 ± 0.39

7.74 ± 0.16

7.45 ± 0.57

δ15Ng (‰)

7.35 ± 0.41

10.30 ± 0.40

7.22 ± 0.30

7.70 ± 0.12

7.40 ± 0.42

Relative contribution (%)

6-32(26)

100

8-22(15)

27-67(31)

Different superscripts indicate significant differences (a<b<c).
Table 4: Mean final weight, specific growth rate (SGR) and growth parameters (m and k), survival, feed conversion ration (FCR), natural stable isotope value (δ15N) and estimated N half time (t50) in tissue of small shrimp (initial weight, 0.25 ± 0.10 g, δ15N=8.41 ± 0.1‰) L. vannamei reared for 28-days with formulated feed (FF, Micropellets 40%), natural feed (NF) and 50:50 formulated+natural feeds as zooplankton+bioflocs (δ15NNF=8.83 ± 0.54‰) (FF+NF) and plankton+bioflocs+benthos (δ15NNF=8.13 ± 1.42‰) (FF+NF+S) (Trial 2). Relative contribution of natural diet to the growth of specimens reared on FF+NF and FF+NF+S treatments. Isotopic trophic enrichment (Δ15N=δ15Nshrimp–δ15NNF or FF) was estimated in 2.0‰ for NF and 2.49‰ for FF.
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