Growth and produc.on performance of tade mullet, Liza tade (Forsskal, 1775) at different
stocking density in .de fed brackishwater pond rearing systems in West Bengal
ICAR-‐ Central Ins.tute of Brackishwater Aquaculture, India
11/4/14 CPWF WORKSHOP-‐DHAKA 1
Subhra Bikash BhaJacharyya,Tapas Kumar Ghoshal Jitendra Kumar Sundaray*
ü Tade mullet-‐ One of the most preferred food fish in India & Bangladesh
ü Grows up to 250 g in one year and about 1 kg in two years in tradi.onal polyculture system ü Informa.on on growth and produc.on performance
in monoculture is scanty ü Scarcity of informa.on on op.mum stocking density
for L. tade monoculture ü System and species diversifica.on is need of hour
Background
11/4/14 2
Objec.ve
ü To op.mize the stocking density for monoculture of Liza tade
q The experiment-‐ Period of 240 days q Experimental farm-‐ Ramkrishnachawk village,
Kakdwip, 24 Pgs (S), West Bengal, India q Tade mullets-‐ Reared at 1 (D1), 2 (D2), and 3 (D3) fish/
m2 stocking densi.es with replica.on q Ponds prepara.on-‐ Following standard procedure for
brackishwater fish culture
Materials and methods
11/4/14 CPWF WORKSHOP-‐DHAKA 3 Contd….
q Stocking-‐Nursery reared tade fingerlings (4.20±0.91 g, 10.30±0.36 cm) q Feed-‐ Formulated floa.ng pellets @ 10-‐2% of
biomass (protein: 29.7%, fat: 4.9%) q Feeding-‐ Twice daily at 0800 and 1630 hrs q Aera.on (2 × 2 HP) was provided in each ponds
as follows: Days of culture Aerator run .me
Morning Evening 1 -‐ 60 0500 -‐ 0530 1500 -‐ 1530 61 -‐120 0500 -‐ 0540 1450 -‐ 1530 121 – 180 0500 -‐ 0550 1440 -‐ 1530 181 -‐ 240 0500 -‐ 0600 1430 -‐ 1530
11/4/14 CPWF WORKSHOP-‐DHAKA 4
q Daily weight gain (DWG) was determined as: 𝑫𝑾𝑮= 𝑾↓𝒇 − 𝑾↓𝒊 /𝒕 q Specific growth rate (SGR) was determined as: 𝑺𝑮𝑹= 𝐥𝐧 𝒘↓𝒇 − 𝒍𝒏𝒘↓𝒊 /𝒕 ×𝟏𝟎𝟎 q Length-‐weight rela.onship was calculated as: 𝑾=𝒂. 𝑻𝑳↑𝒃 q Condi.on factor (K) was determined using Fulton’s
condi.on equa.on as: 𝑲= 𝒘 /( 𝑻𝑳) ↑𝟑 × 𝟏𝟎↑𝟓
𝑊↓𝑓 and 𝑊↓𝑖 are the average final and iniGal weight in Gme t
𝑊↓𝑓 and 𝑊↓𝑖 are the average final and iniGal weight in Gme t
W is fish weight (g), TL is total length (mm), a: proporGonality constant ,b: isometric exponent
𝑤 is the average weight (g) and 𝑇𝐿 is the average total length (mm)
Fish growth parameters
11/4/14 CPWF WORKSHOP-‐DHAKA 5
q Feed conversion ra.o (FCR) was determined as: FCR = total feed intake/ total biomass produc.on q Survival (Sr %) was determined as: Sr (%) = (number of fish harvested/ number of fish stocked) ×100 q Coefficient of varia.on (CVhw) at harvest weight was
determined as: CVhw = mean standard devia.on of final weight/ mean final weight of fish q Fish produc.vity (kg/ ha) was determined as: Pr (kg/ ha) = Stocking no (/ha)× ABW (kg) × Sr (%)
Fish produc.on parameters
11/4/14 CPWF WORKSHOP-‐DHAKA 6
q Physico-‐chemical parameters – (APHA, 1998) o Water temperature (⁰C) o Salinity (ppt) o pH o Dissolved oxygen (DO, mg L-‐l) o Nitrite-‐nitrogen (NO2-‐N, µg L-‐l) o Nitrate-‐nitrogen (NO3-‐N, µg L-‐l) o Ammonia-‐nitrogen (NH3-‐N, µg L-‐l) o Phosphate-‐phosphorus (PO4-‐P, µg L-‐l)
q Plankton samples collected monthly by filtering 50 L of water through bol.ng silk plankton net (mesh size 64 μm).
q Quan.ta.ve & qualita.ve analysis -‐ Direct census method (Jhingran et al., 1969)
Water quality parameters
11/4/14 CPWF WORKSHOP-‐DHAKA 7
Highest growth was observed in D1 (225±10 g) followed by D2 (212±8 g) and D3 (167±10 g)
0
50
100
150
200
250
Feb Mar Apr May Jun Jul Aug Sep Oct
Average Bo
dy W
eight (g)
Months
Growth of tade mullet in 1, 2 and 3 fish/ m2 stocking density
D1 D2 D3
0
50
100
150
200
250
D1 D2 D3
Average bo
dy weight (g)
Stocking density
Average body weight of tade mullet at harvest in1, 2 and 3 fish/
m2 stocking density
Results
11/4/14 CPWF WORKSHOP-‐DHAKA 8
0.50
0.60
0.70
0.80
0.90
1.00
1.10
D1 D2 D3
Daily weight g
ain (g/ da
y)
Daily weight gain (DWG, g/ day) of tade mullet in 1, 2 and 3 fish/ m2
stocking density
1
1.2
1.4
1.6
1.8
2
2.2
2.4
D1 D2 D3
Specific g
rowth ra
te (%
/ da
y)
Specific growth rate (SGR, %/ day) of tade mullet in 1, 2 and 3 fish/ m2
stocking density
Daily weight gain and specific growth rate decreased with increasing stocking density
11/4/14 CPWF WORKSHOP-‐DHAKA 9
TL = 0.0075W3.08 R² = 0.98
0
50
100
150
200
250
300
5 15 25 35
Body weight (g)
Total length (cm)
D1 TL = 0.0056W3.01
R² = 0.96
0
50
100
150
200
250
300
5 15 25 35 Bo
dy weight (g)
Total length (cm)
D2 TL = 0.0085W2.92
R² = 0.97
0
50
100
150
200
250
5 15 25 35
Body weight (g)
Total length (cm)
D3
Tade mullet in D2 showed isometric growth (b=3.01), whereas fishes in D1 and D3 showed posi.ve allometric (b = 3.08) and nega.ve allometric (b=2.92) growth respec.vely Note: when the b parameter is equal to 3 growth is isometric and when it is less than or greater than 3 it is allometric (Enin, 1994). Woo[on (1992) was more specific and stated growth to be posiGve allometric when organism weight increases more than length (b<3), and negaGve allometric when length increases more than weight (b>3).
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
1.4
D1 D2 D3
Cond
i.on
factor (K)
Condi.on factor (K) of tade mullet in 1, 2 and 3 fish/ m2 stocking
density
60
65
70
75
80
85
90
95
100
D1 D2 D3
Survival (%
)
Survival (%) of tade mullet in 1, 2 and 3 fish/ m2 stocking density
Condi.on factor (K) and survival (%) reduced with increasing stocking density
11/4/14 11
1
1.2
1.4
1.6
1.8
2
2.2
D1 D2 D3
Feed
con
version ra.o
(FCR
) Feed conversion ra.o (FCR) of tade mullet reared in 1, 2 and 3 fish/ m2
stocking density
1
1.5
2
2.5
3
3.5
4
4.5
5
D1 D2 D3
Prod
uc.o
n (ton
/ ha
)
Produc.on (ton/ ha) of tade mullet reared in 1, 2 and 3 fish/ m2
stocking density
Feed conversion ra.o (FCR) and produc.on (ton/ ha) increased with increasing stocking density
11/4/14 CPWF WORKSHOP-‐DHAKA 12
Water quality parameters of Tade mullet (Liza tade) rearing ponds at 1 (D1), 2 (D2) and 3 (D3) fish/ m2 stocking density
Water parameters D1 D2 D3 Water temperature (ºC) 29.9±1.7 29.9±1.7 29.7±1.9 pH 8.0±0.2a 7.9±0.2a 7.7±0.3b DO (mg L-‐1) 6.0±0.4a 5.9±0.5a 5.6±0.5b Salinity (ppt) 16.8±5.3 16.7±5.3 16.8±5.1 NO2-‐N (µg L-‐l) 36.7±3.8c 41.6±5.6b 54.7±6.6a NO3-‐N (µg L-‐l) 194.1±15.4c 211.4±11.1b 279.7±8.9a NH4-‐N (µg L-‐l) 175.1±14.6b 179.1±17.9b 254.8±36.2a PO4-‐P (µg L-‐l) 182.6±16.4a 169.1±8.9b 127.6±12.7c Phytoplankton (nos L-‐1 ×103) 17.2±1.2a 15.1±0.9b 12.5±0.7c Zooplankton (nos L-‐1 ×103) 3.7±0.2a 3.1±0.2b 2.8±0.1c Means bearing different superscripts indicate sta.s.cally significant differences in a row
(p<0.05); Values are expressed as mean ± SE of three replicate ponds.
NO3-‐N, NO2-‐N and NH4-‐N increased and DO, pH, PO4-‐P and plankton popula.on decreased with increasing stocking density
11/4/14 CPWF WORKSHOP-‐DHAKA 13
14 Economic analysis revealed higher B: C ra.o in treatment D2
Currency men.oned is Indian Rupee (100 INR=1.67 US$). Item QuanGty/ ha Rate (Rs) D1 D2 D3 Opera.onal cost (OC) T a d e m u l l e t fingerlings
10000, 20000 and 30000 D1, D2 and D3
5 fingerling-‐1 50000 100000 150000
Manure 250 kg 20 kg-‐1 5000 5000 5000 Lime 3000 kg 6 kg-‐1 18000 18000 18000 Feed 2982, 6303 and 7825
kg in D1, D2 and D3 35 kg-‐1 104385 220605 273875
Labour 140, 160 and180 man-‐days in D1, D2 and D3
250 man-‐day-‐1 35000 40000 45000
Sub total 212385 383605 491875 Interest on OC (8 months)
Annual-‐12 % 16991 30695 39350
Total OC 229376 414300 531225 Economic return Tade mullet sale 1977, 3708 and 4309
kg from D1, D2 and D3 210, 200 and 180 from D1, D2 and D3
415170 741600 775620
Gross return 185794 327300 244395 Benefit cost (B:C) ra.o 1.81 1.97 1.46
Comparison of economic parameters among treatments
Conclusion
11/4/14 CPWF WORKSHOP-‐DHAKA 15
• The results demonstrate the feasibility of system diversifica.on with tade mullet farming
• Decrease in growth parameters at higher densi.es is probably due to crowding
• Economic analysis revealed highest benefit cost ra.o of 1.97: 1 with 2 fish/ m2 stocking density
• Stocking density of 3 fish/ m2 resulted a produc.on up to 4 tons/ ha in 8 months
THANK YOU ALL
11/4/14 GROW FISH-‐ GROW WITH FISH 16