ACKNOWLEDGEMENT

I am grateful to NACA for providing the opportunity and funding for this study.

I express my sincere gratitude to Dr. Mali Boonyaratpalin, Dr. C. Kwei Lin and Dr. Y.C. Shang for their advice, kindness, helpful guidance and suggestions throughout this experiment.

My sincere thanks are due to Ms. Wipa Chaiwisitkul, Mr. Wech Thongnak, Mr. Pisanu Thongnak who helped me during the field work, and Mr. Warawuch Jakngoen who assisted me for the lab. work. Adknowledgement is also extended to Mr. Nopadol Chotisasitorn, who helped in data processing and Ms. Chujit Thongprapai who typed the report.

Finally, I greatly appreciate my colleague, Ms. S.C. Jayamanne and Mr. Ceno Harimurti for their kind cooperation during our activities and for providing the water quality and biological data.

Table 1. Composition of feed used at the farm.

Ingredients	Percentage (%)
Broken rice	17
Rice bran	7
Soy bean	12
Fresh fish	50
Fish meal	7
Shrimp meal	5
CaPO₄	1
Vitamin	1

Table 2. Production and survival rate of fish and prawn in polyculture system with low and high density of prawn during 7 month grow out period (Dec.'85 – July'86).

Pond No.	Pond Area (sg.m)	species	Stocking rate (Ind/ha)	Initial weight (g)	Total weight of stocking (kg)	Prawn Restocking				Production Daily weight gained		Survival Rate (M
Pond No.	Pond Area (sg.m)	species	Stocking rate (Ind/ha)	Initial weight (g)	Total weight of stocking (kg)	1st number	(2 Mar 86) weight(kg)	2nd number	(28 May 86) weight(kg)	(kg/ha)	(kg/ha/day)	Survival Rate (M
P11	2,744	C.C	792	1.0	0.23					007	1.93	96
P11	2,744	G.G	1,760	6.0	3.00					135	2.12	80
P11	2,744	B.C	1,232	1.4	1.54					270	1.55	70
P11	2,744	S.C	4,400	2.0	2.50					903	6.02	92
P11	2,744	P	21,067	3.5	20.95	825	5.96	666	1	565	2.69	52
P12	2,944	C.C	792	1.0	0.23					010	1.67	88
P12	2,944	G.G	1,760	6.0	3.00					348	1.93	71
P12	2,944	B.C	1,232	4.4	1.54					239	1.33	91
P12	2,944	S.C	4,400	2.0	2.50					660.00	3.67	65
P12	2,944	P	21,092	3.6	21.99	325	2.35	1,944	11.20	877.70	4.18	95
P21	2,744	C.C	792	1.0	0.23					858.40	4.77	90
P21	2,744	G.G	1,760	6.0	3.00					306.60	1.70	80
P21	2,744	B.C	1,232	4.4	1.54					321.60	1.79	87
P21	2,744	S.C	4,400	2.0	2.50					993.30	6.52	85
P21	2,744	P	52,782	4.7	70.63	1,419	10.25	2,440	14.00	830.90	3.99	19
P22	2,744	C.C	792	1.0	0.23					731.90	4.00	93
P22	2,744	G.G	1,760	6.0	3.00					252.70	1.40	66
P22	2,744	B.C	1,232	4.4	1.54					210.00	1.17	98
P22	2,744	S.C	4,400	2.0	2.50					575.60	3.20	71
P22	2,744	P	52,803	4.7	70.50	1,210	8.71	2,703	15.50	900.00	1.67	61

Table 3. Mean weight and weight increament (g) of each species of fish in low densit (L.D) and high density (H.D) of prawn during grow out period (mid January-mid July 1986).

Treatment	Species	Replicate	Initial Weight 13-Jan-86	1st Sampling 04-Feb-86	dif. W1	2nd Sampling 14-Mar-86	dif. W2	3rd Sampling 13-May-86	dif. W3	4th Sampling 15-July-86	dif. W4
Low Density of Prown (2 Prown/sq.m)	Common Carp (C.C)	P11	1.00	26.67	25.67	162.79	136.12	652.50	489.71	1162.29	509.79
		P12	1.00	20.00	19.00	184.77	164.77	673.80	489.03	1011.14	337.34
		Ave.		23.34	22.34	173.78	150.45	663.15	489.37	1086.72	423.57
	Giant gouramy (G.G)	P11	6.00	18.75	12.75	41.82	23.07	149.15	107.33	260.60	111.45
		P12	6.00	16.67	10.67	34.04	17.37	100.36	66.32	256.00	155.64
		Ave.		17.71	11.71	37.93	20.22	124.76	86.83	258.30	133.55
	Big Head (B.C)	P11	4.40	45.56	41.16	106.88	61.32	221.45	114.57	286.17	64.72
		P12	4.40	52.50	48.10	136.88	84.38	190.20	53.32	233.14	42.94
		Ave.		49.03	44.63	121.88	72.85	205.83	83.95	259.66	53.83
	Silver carp (S.C)	P11	2.00	24.44	22.44	97.29	72.85	210.43	113.14	210.70	0.27
		P12	2.00	26.67	24.67	94.53	67.86	160.70	66.17	175.31	14.61
		Ave.		25.56	23.56	95.91	70.36	185.57	89.66	193.01	7.44
High Density of Prown (5 Prown/sq.m)	Common Carp (C.C)	P21	1.00	17.33	16.33	138.20	120.87	697.50	559.30	1202.33	504.83
		P22	1.00	10.00	9.00	89.80	79.80	530.77	440.97	995.33	464.56
		Ave.		13.67	12.67	114.00	100.34	614.14	500.14	1098.83	484.70
	Giant gouramy (G.G)	P21	6.00	13.64	7.64	28.36	14.72	112.69	84.33	214.87	102.18
		P22	6.00	12.50	6.50	23.14	10.64	85.33	62.19	235.48	150.15
		Ave.		13.07	7.07	25.75	12.68	99.01	73.26	225.18	126.17
	Big Head (B.C)	P21	4.40	42.86	38.46	100.69	57.83	227.93	127.24	276.67	48.74
		P22	4.40	51.11	46.71	124.17	73.06	180.67	56.50	207.10	26.43
		Ave.		46.99	42.59	112.43	65.45	204.30	91.87	241.89	37.59
	Silver carp (S.C)	P21	2.00	25.35	23.35	112.65	87.30	232.30	119.65	257.33	25.03
		P22	2.00	26.67	24.67	110.77	84.10	172.84	62.07	183.78	10.94
		Ave.		26.01	24.01	111.71	85.70	202.57	90.86	220.56	17.99

Table 4. Mean length and length increament (cm) of each species of fish in low density (L.D) and high density (H.D) of prawn during grow out period (mid January - mid July 1986).

Treatment	Species	Replicate	Initial Length (cm) 13-Jan-86	1st Sampling 04-Feb-86	dif. L1	2nd Sampling 14-Mar-86	dif. L2	3rd Sampling 13-May-86	dif. L3	4th Sampling 15-July-86	dif. L4
Low Density of Prown Prown/sq.m)	Common Carp (C.C)	P11	3–5	11.30	7.30	20.29	8.99	31.41	11.12	36.49	5.08
		P12		10.45	6.45	20.25	9.80	30.89	10.64	35.99	5.10
		Ave.		10.88	6.88	20.27	9.40	31.15	10.88	36.24	5.09
	Giant gouramy (G.G)	P11	6.4 – 7.7	9.65	2.60	12.92	3.27	19.42	6.50	23.94	4.52
		P12		9.13	2.08	11.72	2.59	16.23	4.51	22.99	6.76
		Ave.		9.39	2.34	12.32	2.93	17.83	5.51	23.47	5.64
	Big Head (B.C)	P11	6.5 – 9.5	15.71	7.71	21.05	5.34	27.38	6.33	29.87	2.49
		P12		16.22	8.22	22.61	6.39	25.77	3.16	28.22	2.45
		Ave.		15.97	7.97	21.83	5.87	26.58	4.75	29.05	2.47
	Silver carp (S.C)	P11	6.0 – 10.8	13.08	4.68	21.72	8.64	27.74	6.02	28.35	0.61
		P12		13.65	5.25	21.37	7.72	25.42	4.05	26.06	0.64
		Ave.		13.37	4.97	21.55	8.18	26.58	5.04	27.21	0.63
High Density of Prawn Prawn/sq.m)	Common Carp (C.C)	P21	3 – 5	10.42	6.42	17.87	7.45	31.52	13.65	36.49	4.97
		P22		8.43	4.43	16.49	8.06	29.54	13.05	34.82	5.28
		Ave.		9.43	5.43	17.18	7.76	30.53	13.35	35.66	5.13
	Giant gouramy (G.G)	P21	6.4 – 7.7	8.88	1.83	11.22	2.34	17.60	6.38	22.15	4.55
		P22		7.71	0.66	10.64	2.93	15.57	4.93	22.15	6.58
		Ave.		8.30	1.25	10.93	2.64	16.59	5.66	22.15	5.57
	Big Head (B.C)	P21	6.5 – 9.5	16.22	8.22	20.98	4.76	27.34	6.36	30.06	2.72
		P22		15.90	7.90	22.20	6.30	25.28	3.08	25.95	0.67
		Ave.		16.06	8.06	21.59	5.53	26.31	4.72	28.01	1.70
	Silver carp (S.C)	P21	6.0 – 10.8	13.09	5.50	22.11	9.02	29.31	7.20	29.60	0.29
		P22		14.33	5.93	22.16	7.83	26.18	4.02	26.39	0.21
		Ave.		13.71	5.72	22.14	8.43	27.75	5.61	28.00	0.25

Table 5. Percentage weight gained (% per day) of each species of fish in low density (L.D) and high density (H.D) of prawn during grow out pond (mid January -mid July 1986).

Treatment	Species	Replicate	1st sampling % day	2nd sampling % day	3rd sampling % day	4th sampling % day
Low Den.	C.C	P11	111.6	349.0	802.8	796.5
		P12	82.6	422.5	801.7	527.7
		Ave.	97.1	385.8	802.2	661.8
	G.G	P11	55.4	59.2	175.9	174.1
		P12	46.4	44.5	108.7	243.2
		Ave.	50.9	51.8	142.3	211.8
	B.C	P11	179.0	157.2	187.8	101.1
		P12	209.1	216.4	87.4	67.1
		Ave.	194.0	186.8	137.6	84.1
	S.C	P11	97.6	186.8	185.5	0.4
		P12	107.3	174.0	108.5	22
		Ave.	102.4	180.4	147.0	11.6
High Den.	C.C	P21	71.0	309.9	916.9	788.8
		P22	39.1	204.6	722.9	725.9
		Ave.	55.1	257.3	819.9	757.3
	G.G	P21	33.2	37.7	138.2	159.7
		P22	28.3	27.3	100.3	234.6
		Ave.	30.7	32.5	120.1	197.1
	B.C	P21	167.2	148.3	208.6	76.2
		P22	203.1	187.3	92.6	41.3
		Ave.	185.2	167.8	150.6	58.7
	B.C	P21	101.5	233.8	196.1	39.1
		P22	107.3	215.6	101.8	17.1
		Ave.	104.4	219.7	148.9	28.1

Table 6, Feed Consumption (kg) by Fish and Prawn and FCR of Fish in Polyculture Ponds (Dec, 1985 - July, 1986).

Pond No.	Dec. (11 days)				Jan. (23 days)				Feb. (24 days)				Mar. (26 days)				Apr. (25 days)				May (27 days)				Jun. (24 days)				Jul. (13 days)				TOTAL (173 days)				FCR
Pond No.	P	F	R	C	P	F	R	C	P	F	R	C	P	F	R	C	P	F	R	C	P	F	R	C	P	F	R	C	P	F	R	C	P	F	R	C
P₁₁	39	6			74.3	11			97.5	19.5			139.5	45	10.5		204.5	25		4	192	11	17		168		7		85				1000	117.5	34.5	4	0.92
P₁₂	39				74.3	11			97.5	19.5			139.5	45	11.5		204.5	20		4	200.5	11	17		168		7		111				1034	112.5	35.5	4	0.78
Daily feeding rate (kg/day)	3.5				3.2				4.1				5.4				8.2				7.3				7
P₂₁	24	5			98.3	13			121.5	20.5			164.5	45	11.5		237.5	25		4	244.5	15	23		240		10		115				1245.5	123.5	44.5	4	1.05
P₂₂	24	5			98.3	13			121.5	20.5			164.5	45	12.5		237.5	20		4	252.5	15	23		240		10		115				1253	118.5	45.5	4	1.20
Daily feeding rate (kg/day)	2.2				4.3				5.1				6.3				9.5				9.2				10

NOTE :
P = Pellet;
F = Chopped Fish (25% dry matter);
R = Broken rice;
C = Corn

Table 7. Prawn yield (kg per pond), average weight (g) in each category and percentage in weight of female and male prawn at each partial harvest during grow out period (mid Dec. 1985 - mid July 1986).

Pond No.	Type	1st Partial Harvest (14 Mar 86)				2nd Partial Harvest (13 May 86)				3rd Partial Harvest (14 July 86)				Total Yield
Pond No.	Type	Yield (kg/pond)	Ave.Weight (g/prawn)	%in Weight	Sex Ratio(%) in weight	Yield (kg/pond)	Ave.Weight (g/prawn)	%in Weight	Sex Ratio(%) in weight	Yield (kg/pond)	Ave.Weight (g/prawn)	%in Weight	Sex Ratio(%) in weight	Yield (kg/pond)	Ave.Weight (g/prawn)	%in Weight	Sex Ratio(%) in weight
P11	F+E	24.4	58.8	25.4	F=51.8	8.95	46.9	21.1	F=49.9	6.7	37.5	13.6	F=37.8	48.1	51	21.4	F=46.5
P11	F-E	22.6	34.5	23.5	M=48.2	18.3	46.1	24.3	M=58.1	5.9	34.5	12	M=62.2	38.8	37	20.7	M=51.5
P11	M#1	18.8	111.1	19.6		6.8	119.1	16.1		5.6	70.8	11.4		31.2	102.2	16.6
P11	M#2	11.5	71.4	12		3.4	75.1	8		6.4	66.7	13		21.3	70.5	11.4
P11	M#3	1.6	52.6	1.7		2.3	53.6	5.4		2.7	46.6	5.5		6.6	50.3	3.5
P11	L.C	11.8	100	12.3		6.8	139.9	16.1		6	98.5	12.2		21.6	108.1	13.1
P11	S.S	5.3	52.6	5.5		3.8	65.4	9		1.3	46.4	2.6		10.4	55.7	5.5
P11	W.M									14.6	15.8	29.7		14.6	15.8	7.8
P11	Total	96				42.4				49.2				187.6
P12	F+E	7.6	38.5	21.5	F=38.3	23.9	37.8	24.2	F=53.3	28.6	35	18	F=44.4	60.1	36.5	20.5	F=48.6
P12	F-E	5.5	34.5	15.5	M=61.7	25.5	36	25.7	M=46.7	19.9	34.2	12.5	M=55.6	50.9	35.1	17.3	M=51.4
P12	M#1	7.6	83.3	21.5		16.1	94.7	16.6		15	83.8	9.4		38.7	87.9	13.1
P12	M#2	2.9	62.5	8.2		10.55	58.6	10.7		14.6	62.3	9.2		28.1	60.9	9.6
P12	M#3	2	40.5	5.6		1.4	48.3	1.4		7.2	47	4.5		10.6	47.4	3.6
P12	L.C	8.6	90.9	24.3		15.2	117.4	15.4		16.3	82.7	10.2		40.1	95.2	13.7
P12	S.S	1.2	62.5	3.4		6.3	66.7	6.4		7.4	43	4.6		14.9	52.1	5.1
P12	W.M									50.3	17.2	31.6		50.3	17.2	17.1
P12	Total	35.4				99				159.3				293.7
P21	F+E	24.8	30.3	21.5	F=38.3	18.2	32.7	18.1	F=54	18.1	34.5	15.1	F=56.2	61.1	32.2	18.6	F=53.2
P21	F-E	25.6	27	15.5	M=61.7	32	28.8	31.9	M=46	22	33	18.3	M=43.8	79.6	29.2	24.3	M=46.8
P21	M#1	6.3	83.3	21.5		11	83.3	10.9		6.4	89.9	5.3		23.7	85	7.2
P21	M#2	17.5	62.5	8.2		13	68.8	13		13	77.9	10.8		43.5	68.4	13.3
P21	M#3	14.8	47.6	5.6		8.7	43.3	8.7		8.5	43.3	7.1		32	45.2	9.8
P21	L.C	8.5	66.7	24.3		10	94.4	10		6.1	101.3	5.1		24.6	83.8	7.5
P21	S.S	9.9	35.7	3.4		7.4	52.1	7.4		8.1	53	6.7		25.4	44.5	7.7
P21	W.M								38	17.7	31.6		38		17.7	11.6
P21	Total	187.4				100.3				128.2				327.9
P22	F+E	26.2	31.3	27	F=50.9	21.5	32.7	17.8	F=51.7	34.5	30.7	28.8	F=54.9	82.2	31.4	21.5	F=53.7
P22	F-E	28	26.3	20.7	M=49.1	35.8	30.8	29.6	M=48.3	27.9	30.3	16.9	M=45.1	83.7	29.5	21.8	M=46.3
P22	M#1	6.8	76.9	7		18.7	87.1	15.5		6.4	85.8	3.9		31.9	84.5	8.3
P22	M#2	16.8	62.5	17.3		17	66.7	14		9.9	66.4	6		43.7	64.9	11.4
P22	M#3	9.8	47.6	10.1		4.4	50	3.6		12.9	43.4	7.8		27.1	45.8	7.1
P22	L.C	11.2	90.9	11.6		13.5	100	11.2		15.5	86.3	9.4		40.2	91.8	10.5
P22	S.S	6.1	45.5	6.3		10.1	53.2	8.3		9.2	58.6	5.6		25.4	58.2	6.6
P22	W.M									49	14	29.6		49	14	12.8
P22	Total	96.9				121				165.3				383.2

Table 8. Prawn number of each category and percentage in number of female and male prawn at each partial harvest during grow out period (mid Dec. 1985 - mid July 1986).

Pond No. Pond No.	Type Type	1st Partial Harvest (14 Mar 86)			2nd Partial Harvest (13 May 86)			3rd Partial Harvest (15 July 86)			Total Harvest
Pond No. Pond No.	Type Type	Number of prawn	% in number	Sex Ratio(%) in number	Number of prawn	% in number	Sex Ratio(%) in number	Number of prawn	% in number	Sex Ratio(%) in number	Number of prawn	% in number	Sex Ratio(%) in number
P11	F+E	414.8	25.4	f=69.1	190.9	28.6	f=68.1	178.9	11.2	f=54.3	784.6	20.1	f=65.5
P11	F-E	655.4	39.7	m=30.9	223.5	33.6	m=31.9	170.9	10.7	m=45.7	1049.8	26.8	m=34.5
P11	M#1	169.2	10.2		57.1	8.6		79.1	5		305.4	7.8
P11	M#2	161	9.7		45.3	6.8		96	6		302.3	7.7
P11	M#3	30.4	1.8		42.9	6.4		58	3.6		131.3	3.4
P11	L.C	118	7.1		48.6	7.3		60.9	3.8		227.5	5.8
P11	S.S	100.7	6.1		58.1	8.7		28	1.8		186.8	4.8
P11	W.M							923.5	57.9		923.5	23.6
P11	Total	1649.5			666.4			1595.3			3911.2	100
P12	F+E	197.6	30.4	f=56.6	632.6	32.5	f=72.5	817	15.5	f=68.3	1647.2	21	f=66.7
P12	F-E	159.5	24.5	m=43.4	708.1	36.4	m=27.5	582.3	11.1	m=31.7	1449.9	18.5	m=33.3
P12	M#1	91.2	14		170	8.7		178.9	3.4		448.1	5.6
P12	M#2	46.4	7.2		180	9.3		234.3	4.5		460.7	5.9
P12	M#3	41.2	6.3		29	1.5		153.3	2.9		233.5	2.8
P12	L.C	94.6	14.6		129.5	6.7		197.2	3.8		421.3	5.4
P12	S.S	19.2	3		94.5	4.9		172.2	3.3		285.9	3.6
P12	W.M							2917.5	55.5		2917.5	37.2
P12	Total	649.7			1943.7			5252.7			7846.1	100
P21	F+E	818.4	28.8	f=69	557.3	22.8	f=72.7	524	13.1	f=73.6	1899.7	20.5	f=70.7
P21	F-E	947.2	33.4	m=31	1113	45.6	m=27.3	664.9	16.7	m=26.4	2725.1	29.4	m=29.3
P21	M#1	75.6	2.7		132	5.4		71.2	1.8		278.8	3
P21	M#2	280	9.9		189	7.7		166.9	4.2		635.9	6.9
P21	M#3	310.8	10.9		200.8	8.3		196.1	4.9		707.7	7.6
P21	L.C	127.5	4.5		105.9	4.4		60.2	1.5		293.6	3.2
P21	S.S	277.2	9.8		141.9	5.8		182	3.8		571.1	6.2
P21	W.M							2149.5	54		2149.5	23.2
P21	Total	2836.7			2439.9			3984.8		9261.4	100
P22	F+E	838.4	34.7	f=70	657	24.3	f=72.4	1123.3	20.8	f=71.8	2618.7	22.6	f=72.4
P22	F-E	760	31.4	m=30	1163.5	43.1	m=27.6	918.1	16.9	m=28.2	2841.6	24.6	m=27.6
P22	M#1	88.4	3.7		214.7	7.9		74.6	3.9		377.7	3.3
P22	M#2	268.8	11.1		255	9.4		149.1	6		672.9	5.8
P22	M#3	205.8	8.5		88	3.3		297.3	7.8		591.1	5.1
P22	L.C	123.2	5.1		135	5		179.7	9.4		437.9	3.8
P22	S.S	134.2	5.5		189.9	7		181.8	5.6		505.9	4.4
P22	W.M							3511.8	29.6		3511.8	30.4
P22	Total	2418.8			2703.1			6435.7			1155.6	188

Table 9 The proportion both in number and weight between marketable and unmarketable size of prawns harvested from polyculture pond

Type	P₁₁		P₁₂		Mean		P₂₁		P₂₂		Mean
Type	No.	%	No.	%	Ave.	%	No.	%	No.	%	Ave.	%
Marketable	2,988	76.4	4,929	62.8	3,958.5	69.6	7,112	76.8	8,046	69.9	7,579	73.2
Unmarketable (U.M)	923	23.6	2,917	37.2	1,920.0	30.4	2,149	23.2	3,512	30.4	2,831	26.8
Total Prawn	3,911	100	7,846	100	5,878.5	100	9,261	100	11,558	100	10,410	100
	Weight(kg)	%	Weight(kg)	%	Ave.	%	Weight(kg)	%	Weight(kg)	%	Ave.	%
Marketable	173.0	92.2	243.4	82.9	200.2	87.6	289.9	88.4	334.2	87.2	312.1	87.8
Unmarketable (U.M)	14.6	7.8	50.3	17.1	32.5	12.4	38.0	11.6	49.0	12.0	43.5	12.2
Total Prawn	187.6	100	293.7	100	240.7	100	327.9	100	383.2	100	355.6	100

Table 10 Accomulated biomass yield (number and weight), survival rate and weight gain of prawns in polyculture ponds during 7 month growout period

Pond	Total count		Total weight (kg)		Survival Weight gained
Pond	Stocking	Harvest	Stocking	Harvest	(%)	Total	Mean
P₁₁	7,476.00	3,911.20	30.71	187.55	52.30	156.80	48.00
P₁₂	8,261.00	7,846.10	35.54	293.65	95.00	258.10	37.40
P₂₁	18,854.00	9,261.40	94.88	327.90	49.10	233.00	35.40
P₂₂	18,914.00	11,557.60	94.74	383.20	61.10	288.50	33.20

Table 11 : Variation in market price (baht per kg)^a) for different prawn categories during culturing period.

Type	15 March 1986	14 May 1986	16 July 1986
Female + Egg	72	72	75
Female - Egg	78.5	77	80
Male no. 1	130	130	150
Male no. 2	110	110	130
Male no. 3	95	95	110
Long claws	90	100	90
Soft shells	86	80	85
Unmarketable size (U.M)			85

a) 1 US$ = 26.3 baht

Table 12. Yields (kg) and revenues of prawn at each partial harvest both in low density and in high density of prawn

	Low Density of prawn (L.D)						High Density of prawn (H.D)
	Partial Harvest						Partial Harvest
	1st harvest		2nd harvest		3rd harvest		1st harvest		2nd harvest		3rd harvest
	Yield	revenues	yield	revenues	yield	revenues	yield	revenues	yield	revenues	yield	revenues
F + E	32	2,304	32.9	2,369	35.3	2,648	51	3,672	39.7	2,858	52.6	3,945
F - E	28.1	2,206	35.8	2,757	25.8	2,064	45.6	3,580	67.8	5,221	49.9	3,992
M # 1	26.4	3,432	22.9	2,977	20.6	3,090	13.1	1,703	29.7	3,861	12.8	1,920
M # 2	14.4	1,584	14.0	1,540	21	2,730	34.3	3,773	30.0	3,300	22.9	2,977
M # 3	3.6	342	3.7	351	9.9	1,089	24.6	2,337	13.1	1,245	21.4	2,354
L.C	20.4	1,836	22	2,200	22.3	2,007	19.7	1,773	23.5	2,350	21.6	1,944
S.S	6.5	559	10.1	808	8.7	740	16.0	1,376	17.5	1,400	17.3	1,471
U.M					64.9	5,516					87	7,395
Total	131.4	12,263	141.4	13,002	208.5	19,884	204.3	18,214	221.3	20.235	285.5	25,998

Table 13 Comparison of total gross revenue of both prawn and fish between in low density and in high density of prawn.

ITEM	Low Density of Prawn			High Density of Prawn
ITEM	Yield (kg)	Price/kg (฿)	Gross Revenues (฿)	Yield (kg)	Price/kg (฿)	Gross Revenues (฿)
PRAWN : F+E	100.2	72–75	7,321	143.3	72–75	10,475
F-E	89.7	77–80	7,027	163.3	77–80	12,793
M#1	69.9	130–150	9,499	55.6	130–150	7,484
M#2	49.4	110–130	5,854	87.2	110–130	10,050
M#3	17.2	95–110	1,782	59.1	95–110	5,936
L.C	64.7	90–100	6,043	64.8	90–100	6,067
S.S	25.3	80–86	2,107	50.8	80–86	4,247
U.M	64.9	85	5,516	87.0	85	7,395
	481.3		45,149	711,1		64,447
FISH : C.C	491	20	9,820	453	20	9,060
G.G	228.5	25	5,713	165	25	4,125
B.C	150	10	1,500	154	10	1,540
S.C	449	10	4,490	450	10	4,500
	1,318.5		21,523	1,222		19,225
	Total Revenues		66,672	Total Revenues		83,672

Table 14. Capital cost and depreciation per pond of polyculture of prawn and ; various species of fish

ITEM	CAPITAL COST (per pond)	YEAR LIFE	FIXED COSTS PER POND (DEPRECIATION)
ITEM	CAPITAL COST (per pond)	YEAR LIFE	(per year)	(per 7 months)
a. Pond construction:	14,850	10	1,485	866
- dykes construction :
- inlet & outlet (concrete pipe) : 1080 ฿/pond (pond size : 50×112 m)
b. Land rent :			2,500	1,458
- 500 ฿/rai/year (pond area : 3.5 rai, it requires 5 rai of land)
c. Water pump & iron pipe:	1,250	6	208	21
- 25,000 ฿/20 ponds
d. Meat grinder + engine + Wooden tray:	750	6	125	73
- 15,000 ฿/20 ponds
e. Storage room + feed drying area:	1,500	20	75	44
- 30,000 ฿/20 ponds
f. Net (Seine) for harvesting:	400	5	80	47
- 8000 ฿/20 ponds (net size : 80 m × 6 m)
g. Bamboo buckets:	40	2	20	12
- 800 ฿/20 ponds
h. Plastic buckets:	75	5	15	9
- 1500 ฿/20 ponds
TOTAL FIXED COSTS	18,865		4,508	2,630

Table 15. Comparison of operating cost in polyculture system, between in low density of prawn (L.D) and high density of prawn (H.D) during 7 months growout period. (in baht)^a)

ITEM		L.D cost per proportion of		H.D cost per proportion of
ITEM		pond^b)	total cost(%)	pond^b)	total cost(%)
1.	FIXED COSTS (DEPRECIATION):
a.	Dykes construction : 1700 ฿/40 m	866	1.9	866	1.5
	pond size: 50×112m) inlet/outlet
	construction : 1080 ฿/pond
b.	Land rent :
	- 500 ฿/rai/year (pond area : 3.5 rai, it requires 5 rai of land)	1,458	3.2	1,458	2.4
c.	Water pump and iron pipe :	121	0.3	121	0.2
	- 25,000 ฿/20 ponds
d.	Meat grinder + engine + wooden tray :	73	0.2	73	0.1
	- 15,000 ฿/20 ponds
e.	Storage room & feed drying area :	44	0.1	44	0.07
	- 30,000 ฿/20 ponds
f.	Seine for harvesting :	47	0.1	47	0.08
	- 8000 ฿/20 ponds ; seine size : 80 m × 6 m
g.	Bamboo buckets :	12	0.03	12	0.02
	- 800 ฿/20 ponds
h.	Plastic buckets :	9	0.02	9	0.01
	- 1500 ฿/20 ponds
i.	Interest :	1,100	2.4	1,100	1.8
	10% of capital cost/year
	Total Fixed Cost	3,730	8.3	3,730	6.2
2.	VARIABLE COSTS
a.	Feed :	21,700	48.2	26,570	44.0
	- amount of feed in L.D = 2170 kg
	- amount of feed H.D = 2657 kg
	- Price : 10 ฿ kg
b.	Labor :	2,600	5.8	2,600	4.3
	- 1 permanent labor ; 200 ฿/month/pond
	- 10 casual labor (for harvesting): 60 ฿/labor/day (4 times harvesting : 1 harvesting/2 ponds/day)
c.	Prawn juveniles (3–4 g) :	5,636	12.5	16,116	26.7
	- stocking weight in L.D = 66.3 kg
	- stocking weight in H.D = 189.6 kg
	- price = 85 ฿/kg
	Fish fingerling :	9,405	20.9	9,405	15.6
	- stocking numbers : CC = 450; GG = 1000; B.C = 700; S.C = 2500 per pond
	- price of CC; GG; BC; SC = (0.3; 6.0; 1.1; 1.0) ฿ each
d.	Manure :	319	0.7	319	0.5
	- Amount : 638 kg chicken manure (Wet state)/pond
	- price = 0.5 ฿/kg
e.	Lime :	200	0.4	200	0.3
	- Amount : 200 kg/pond
	- price = 1 ฿/kg
f.	Fuel :	1,082	2.4	1,082	1.8
	Adding water 10% (seepage) :18 times/7 months (32.5 ฿/times) Pumping in & out the water for harvesting : 3 times/7 months (162.5 ฿/times)
g.	Miscellaneous	350	0.8	350	0.6
	Total Variable Costs	41,292	91.7	56,642	93.8
	Total costs	45,022	100	60,372	100

Table 16. Comparison of profit, rate of return and cost production between in low density and in high density of prawn (in baht)^a)

Treatment	Profit/pond^b)	profit/kg	Production cost per kg	Rate of return on operating cost (%)	Rate of return on initial capital (%)
Low density of prawn (L.D)	21,650	12	25	48	115
High density of prawn (H.D)	23,300	12	31	38	123

a) 1 US$ = 26.3 baht

b) Pond area = 3.5 rai (1 ha = 6.25 rai)

Fig 1. Mean weight of fish (kg) of each species in low L.D and high density (H.D) of prawn during grow out period
(January - July 1986).

Fig 2. Mean length (cm) of fish of each species in L.D and H.D during grow out period (January - July 1986).

Fig 3. The percentage weight gained (% per day) of fish of each species in L.D and H.D during grow out period (Jan. - Jul.86)

Fig 4. Prawn yield (kg) in L.D replicate of each category at each partial harvest during grow out period (mid Dec. 1985 - mid July 1986).

Fig 5. Prawn yield(KG) in H.D replicate of each category at each partial harvest during grow out period (mid Dec. 1985 - mid July 1986).

Fig 6. Average weight (g per prawn) in L.D replicate of each category at each partial harvest during grow out period (mid Dec. 1985 - mid July 1986).

Fig 7. Average weight (f per prawn) in H.D replicate of each category at each partial harvest during grow out period (mid Dec. 1985 - mid July 1986).

Fig 8. Number of prawn in L.D replicate of each category at each partial harvest during grow out period (mid Dec. 1985 - mid July 1986).

Fig 9. Number of prawn in H.D replicate of each category at each partial harvest during grow out period (mid Dec. 1985 - mid July 1986).

Fig. 10. The economical production of prawn in both L.D and H.D at each partial harvest.

Appendix 1. Weekly DO concentration (ppm) and water temperature (°C) between surface and bottom in L.D and H.D pond at the morning measurement (January - July 1986

Appendix 2. Weekly DO concentration (ppm) and water temperature (°C) between surface and bottom at the afternoon measurement (January - July 1986).

Appendix 3. Diurnal DO (ppm) between surface and bottom in L.D and H.D pond on 15 January 1986.

Appendix 4. Diurnal DO (ppm) between surface and bottom in L.D and H.D pond on 4 April 1986.

Appendix 5. Diurnal DO (ppm) between surface and bottom in L.D and H.D pond on 31 May 1986.

Appendix 6. Weekly Ammonia concentration (ug/1) between surface and bottom in L.D and H.D pond (Dec. 1985 - July 1986).

Appendix 7. Weekly pH between surface and bottom in L.D and H.D pond (Dec. 1985 - July 1986).

Appendix 8. Weekly hardness and alkalinity concentration (CaCO₃. eg) between surface and bottom in L.D and H.D pond (Dec. 1985 – July 1986).

Appendix 9. Monthly hydrogen sulfide (ppm) between surface and bottom in L.D and H.D pond (January – June 1986).

Appendix 10. Weekly turbidity (cm) in L.D and H.D pond at the afternoon measurement (January – July 1986).

Pond Number	Stomach Sample of	Mean Bulk Index (MBI)
Pond Number	Stomach Sample of	Aquatic plant	Algae	Pelet	Manure	Benthos	Insect	Zoo	Phyto
P11	Coaaon carp	2.5	4	1	2.5
P12	Coaaon carp	2.5	4	1	2.5	6		6	6
P11	Giant gouraay	2.5	3.5	1	4.5
P12	Giant gouraay	3	1.5	1.5	4.5	6	6.5	6.5	6.5
P11	Big head			1		4	3.5	2.5	4
P12	Big head			1			2	3	4
P11	Silver carp
P12	Silver carp			1				3	2
P11	Prawn	5		1		2.5	2.5	5	5
P12	Prawn			1		2.5	2.5	4	5
P21	Coaaon carp		3.5	1	2	3.5		6	5
P22	Coaaon carp	3		1.5	1.5	4	6	6.5	5.5
P21	Giant gouraay	2		1		4		4.5	3.5
P22	Giant gouraay	2.5		1			2.5	5	4
P21	Big head			1				2	3
P22	Big head			1				2	3
P21	Silver carp			1				3	2
P22	Silver carp			1				2.5	2.5
P21	Prawn			1		2.5		2.5	4
P22	Prawn			1			2	4	3

Appendix 11. Mean bulk index (MBI) of fish and prawn stomach content in L.D and H.D pond (Sample date : 14 March 1986).

Pond Number	Stomach Sample of	Mean Bulk Index (MBI)
Pond Number	Stomach Sample of	Aquatic plant	Algae	Prawn	Pellet	Benthos	Zoo	Phyto
P11	Coaaon carp				1		3	2
P12	Coaaon carp		2.5		1	2.5	5	4
P11	Giant gouraay	1			2		4	3
P12	Giant gouraay	2	3		1			4
P11	Big head				1			2
P12	Big head	2			1		4	3
P11	Silver carp				1			2
P12	Silver carp				1		3	2
P11	Prawn			2	1	3	4.5	4.5
P12	Prawn	3.7		2	1	3.3	5.6	5.3
P21	Coaaon carp	2			1		4	3
P22	Coaaon carp	2.5			1	2.5	5	4
P21	Giant gouraay	1.5			1.5			3
P22	Giant gouraay	1			2			3
P21	Big head				1		3	2
P22	Big head				1		2	3
P21	Silver carp				1			2
P22	Silver carp				1			2
P21	Prawn	4		2	1	3	6	5
P22	Prawn	3		1.5	1.5		5	4

Appendix 12. Mean bulk index (MBI) of fish and prawn stomach content in L.D and H.D pond (Sample date : 15 July 1986).

Appendix 13. Benthos biomass (individuals per sq.m) on biweekly measurement in L.D and H.D pond

Appendix 14. Chlorophyll a (ug/1) on weekly measurement in L.D and H.D pond

Appendix 15. Organic matter (g/128 sq.m) with and without cover on monthly measurement in L.D and H.D ponds.