Effects of seaweeds extract on growth, survival, antibacterial activities, and immune responses of Penaeus monodon against Vibrio parahaemolyticus

Figures & data

Table 1. Composition of the formulated shrimp diets (g kg⁻¹) supplemented with two brown seaweeds extracts.

Ingredients	EA2.5	EA5	E2.5	E5	M2.5	M5	C
Crab meal	80	80	80	80	80	80	80
Meat and bone meal	100	100	100	100	100	100	100
Fish meal	320	320	320	320	32	320	320
Wheat flour	220	220	220	220	220	220	220
Wheat gluten	50	50	50	50	50	50	50
Broken rice	50	50	50	50	50	50	50
Soya bean meal	100	100	100	100	100	100	100
Fish oil	20	20	20	20	20	20	20
Rice bran	20	20	20	20	20	20	20
Vitamin premix	10	10	10	10	10	10	10
Mineral mix	10	10	10	10	10	10	10
Starch	20	20	20	20	20	20	20
*Seaweeds extracts (g)	2.5	5.0	2.5	5.0	2.5	50	Nil

*Seaweeds extract (P. tetrastromatica and S. ilicifolium); EA: Ethyl acetate; E: Ethanol; M: Methanol.

Table 2. Mean (±SE) weight gain, specific growth rate and survival rate of P. monodon juveniles fed on brown seaweeds extract incorporated diets and control group (C).

Treatments
Ingredients	EA2.5	EA5	E2.5	E5	M2.5	M5	C
P. tetrastromatica
Weight gain (g)	5.12 ± 0.17^a	5.87 ± 0.21^b	4.75 ± 0.12^a	6.28 ± 0.14^c	5.81 ± 0.18^b	7.08 ± 0.24^c	4.02 ± 0.08^a
SGR (%)	2.68 ± 0.07^a	3.05 ± 0.11^a	2.56 ± 0.09^a	3.39 ± 0.14^b	2.86 ± 0.11^a	3.32 ± 0.15^b	2.25 ± 0.06^a
Survival (%)	71.25 ± 2.54^a	72.75 ± 1.26^a	72.50 ± 3.35^a	78.45 ± 2.86^b	74.73 ± 3.51^ab	82.45 ± 4.02^b	68.75 ± 4.11^a
S. ilicifolium
Weight gain (g)	4.73 ± 0.18^b	3.96 ± 0.12^a	4.68 ± 0.19^b	5.85 ± 0.22^c	5.18 ± 0.18^b	5.92 ± 0.23^c	4.02 ± 0.09^a
SGR (%)	2.52 ± 0.07^a	2.31 ± 0.09^a	2.99 ± 0.12^b	3.16 ± 0.17^b	2.74 ± 0.20^b	2.95 ± 0.16^b	2.25 ± 0.13^a
Survival (%)	61.31 ± 2.19^a	65.44 ± 2.95^ab	63.25 ± 3.37^a	68.60 ± 2.21^b	61.31 ± 2.56^a	70.74 ± 1.26^b	68.75 ± 2.71^b

EA: ethyl acetate; E: ethanol; M: methanol; C: control; SGR: specific growth rate. Different letters within rows for each parameter indicates significant differences (p < .05).

Table 3. Anti V. parahaemolyticus activity of two brown seaweeds extracted by three different solvents – ethyl acetate, ethanol and methanol.

	Zone of inhibition (mm)
Seaweeds	Ethyl Acetate (250 µg/disc)	Ethanol (250 µg/disc)	Methanol (250 µg/disc)	Ciprofloxacin (5 µg/disc) positive control	Negative control
Padina tetrastromatica	9.75 ± 1.25^a	16.5 ± 1.10^b	22.65 ± 0.57^c	30.55 ± 1.20^d	0.0
Sargassum ilicifolium	10.50 ± 0.75^a	14.8 ± 0.85^b	20.25 ± 1.00^c	31.75 ± 0.65^d	0.0

Figure 1. Percentages of mortality of P. monodon juveniles fed (a) P. tetrastromatica and (b) S. ilicifolium extracted diets and control diets after challenged with V. parahaemolyticus. EA5: ethyl acetate 5 g kg⁻¹; E5: ethanol 5 g kg⁻¹; M5: methanol 5 g kg⁻¹; PC: positive control; BC: blank control; NC: negative control.

Figure 2. Mean haemolymph clotting time of P. monodon with (a) P. tetrastromatica and (b) S. ilicifolium incorporated diet after challenge. Data at the same exposure time with different letters are significantly different (p < .05) among different treatment groups. EA5: ethyl acetate 5 g kg⁻¹; E5: ethanol 5 g kg⁻¹; methanol 5 g kg⁻¹; PC: positive control; BC: blank control; NC: negative control; AD: all died.

Figure 3. Total haemocyte count (THC) of P. monodon with (a) P. tetrastromatica and (b) S. ilicifolium incorporated diet after challenging with V. parahaemolyticus bacteria (1.0 mL of 10⁶ cells) days onward. Data at the same exposure time with different letters are significantly different (p < .05) among different treatment groups. EA5: ethyl acetate 5 g kg⁻¹; E5: ethanol 5 g kg⁻¹; methanol 5 g kg⁻¹; PC: positive control; BC: blank control; NC: negative control; AD: all died.

Figure 4. Phenol oxidase (PO) activity of haemocytes of P. monodon fed (a) P. tetrastromatica and (b) S. ilicifolium extracted immunostimulants diets and control diets after challenged with V. parahaemolyticus. Data at the same exposure time with different letters are significantly different (p < .05) among different treatment groups. EA5: ethyl acetate 5 g kg⁻¹; E5: ethanol 5 g kg⁻¹; methanol 5 g kg⁻¹; PC: positive control; BC: blank control; NC: negative control; AD: all died.

Figure 5. Intra-cellular superoxide (SO) anion production of haemocytes of P. monodon fed (a) P. tetrastromatica and (b) S. ilicifolium extracted immunostimulants diets and control diets after challenged with V. parahaemolyticus. Data at the same exposure time with different letters are significantly different (p < .05) among different treatment groups. EA5: ethyl acetate 5 g kg⁻¹; E5: ethanol 5 g kg⁻¹; methanol 5 g kg⁻¹; PC: positive control; BC: blank control; NC: negative control; AD: all died.