Instrument, OH, USA), a portable refractometer (ATAGO), and a mercury thermometer. Every morning before ..... College Station, TX, USA, 221 pp. Kinne, 1972.
Aquaculture ELSEWER
Aquaculture 157 (1997) 107-115
The effects of salinity and temperature on the growth and survival rates of juvenile white shrimp, Penaeus vannamei, Boone, 193 1 Jesus Ponce-Palafox
a,b,*, Carlos A. Martinez-Palacios Lindsay G. Ross ’
a,
a Centro de Inuestigacion en Alimentacion y Desarrollo (CIAD), Unidad Mazatlan,P. Box Mazatlan, Sinaloa, Mexico b Uniuersidad Autonoma de1 Estado de Morelos, P. Box 784, Cuemauaca, Morelos, Mexico ’ Institute of Aquaculture, Uniuersity of Stirling, Stirling, FK9 4L.A Scotland, UK
Received 29 May 1996; accepted 8 May 1997
Abstract The growth and survival of Penaeus uannamei postlarvae was measured at temperatures of 20, 25, 30 and 35°C and salinities of 20, 30, 35, 40 and 50%0.Groups of 30 animals were used in each combination of conditions, in triplicate. The results clearly show that juveniles of this species have their best survival between temperatures of 20 and 30°C and salinities above 20%0. Best growth was obtained between temperatures of 25 and 35”C, with little difference being noted among salinities. Survival and growth coincide best at around 28 to 30°C and 33 to 4O%“c0. Calculated overall production was shown to be best in these conditions. The results demonstrate a high coincidence between the experimentally determined optimum conditions for production and the prevailing conditions in the coastal environment from which the animals originated. 0 1997 Elsevier Science B.V. Keywords:
Shrimp; Penaeus cannamei; Growth; Salinity; Temperature
1. Introduction Temperature
influeniing
and salinity
marine
organisms,
are considered to be the most important physical factors and the biological effects of these factors are complex
* Corresponding author. 004.8486/97/$17.00 0 1997 Elsevier PII SOO44-8486(97)00148-E
Science
B.V. All rights reserved.
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157 (1997) 107-115
and wide-ranging (Kinne, 1972). Brett (1979) considered that temperature was the most important modifier of energy flow, and hence growth, in aquatic organisms and that salinity imposed the greatest additional load on the metabolic requirements of an animal. There are numerous studies on the effects of temperature and salinity on the survival of non-penaeid crustacea (Lester and Pante, 199 1). In general, these show survival peaks at salinities and temperatures near those of the natural habitat. However, the little information available on the penaeid shrimp are not always consistent with field observations (Venkataramaiah et al., 1974). Studies frequently focus on the effect of a single variable and, in addition, most studies have used postlarvae with little attention having been paid to the responses of juvenile and adult shrimp. Zein-Eldin and Aldrich (1965) noted short-term survival of 80 to 100% at temperatures of 7 to 35°C in postlarvae of Penaeus aztecus. In trials of 1 month duration, the survival rate increased with temperature, from 65% at 15°C to 98% at 20°C falling again above 25°C to 0% at 35°C (Zein-Eldin and Griffith, 1966). Length and weight increased more rapidly at higher temperatures (25 and 32°C) than at lower temperatures (11 and 18°C) regardless of salinity conditions and average growth rate was higher at 32°C than at 25°C. P. monodon postlarvae and juveniles tolerate a low temperature of 10°C for short periods of time (Motoh, 1981). Survival rate rose to 98% at 39°C but mortality was high at higher temperatures. In aquarium studies, postlarvae of P. stylirostris postlarvae between 18 and 31°C the highest growth was at 31°C and 30%0 (Bassanesi, 1982). Survival rates were greater than 90% between 30%0 and 40%0 and the effect of salinity on survival rate was much more pronounced than the effect of temperature. In a 30-day laboratory trial, Huang (1983) concluded that P. vannamei postlarvae grew best at about 20%0 with poorest results at 5 and 45%0. The white shrimp P. vannumei, Boone, 1931, is very important in semi-intensive and intensive aquaculture in many parts of Latin America (FAO, 1994; Rosenberry, 1993). The natural range of this species extends into brackish and freshwaters where annual rainfall and evaporation cycles can expose the species to wide seasonal variations in temperature and salinity. The inland extension of the species, coupled with its ability to withstand salinity and temperature changes is one of the key factors which make this an attractive species for aquaculture. In order to understand and optimise production conditions, it is necessary to investigate the effects of salinity and temperature on growth, survival and overall production to enable culturists to better manage the husbandry of shrimp in conditions optimised for growth and survival. The aim of the present study was to investigate the effect of salinity and temperature on survival and growth of juvenile P. vunnumei.
2. Materials and methods 2.1. Source of animals Eighteen-day old postlarvae (PL18) of P. uannumei were obtained cial producer in Sinaloa state, Mexico, in three batches of 1800.
from a commer-
J. Ponce-P&fox
2.2. Experimental
et al./Aquaculture
157 (1997) 107-115
109
system
The experimental system consisted of 60 rectangular plastic tanks (50 X 35 X 20 cm), each with an effective water volume of 60 litres. Sea water, pumped from the Mazatlan coast, was filtered through sand and gravel and aerated for 1 day before use. Freshwater was obtained from the city supply and was aerated for at least 5 days before use to avoid any problems with chlorine. Low salinities (20 and 30%0) were obtained by diluting sea water with fresh water. The high salinities (40 and 50%~) were obtained by mixing filtered sea water with sea salt. This concentrated stock was then diluted with sea water to produce the required salinities. Salinity was adjusted daily, as necessary, to keep the variation within f 1.5%0 and changes were effected by replacing portions of water in the test containers with equal volumes of either fresh water or concentrated sea water. Temperature was controlled to within +0.5”C using thermostatted heaters. Each tank was continuously aerated by an air stone and photoperiod was standardised at 12 L: 12 D using timer-controlled lights. Dissolved oxygen, temperature and salinity were measured each morning and afternoon using an oxygen meter (YSI Model 57, Yellow Springs Instrument, OH, USA), a portable refractometer (ATAGO), and a mercury thermometer. Every morning before feeding, faeces and other detritus in each container were siphoned out, and a sufficient quantity of water at the same salinity and temperature was added to maintain levels. 2.3. Experimental
protocol
Survival and growth rate were studied in triplicated combinations of five salinities (20, 30, 35, 40 and 50%0) and four temperatures (20, 25, 30 and 35°C). The location of the treatments were randomised among tanks. Groups of 30 animals were initially distributed into the 60 tanks which contained normal seawater. Salinity was then adjusted at a rate not exceeding S%o/day and temperature was adjusted at a rate of SC/day. Acclimation to all treatments was achieved without problems within 4 days, but acclimation to the highest temperature always resulted in some mortality. The postlarvae were grown under these conditions for 40 days, during which time a 37% protein commercial feed, C.P. Shrimp Feed, was fed twice daily. Unlimited feeding was maintained by observation so that there was always a surplus. Growth and survival were compared every 10 days and at the end of the trial. Specific growth rate (SGR) was calculated at the end of the experimental period using the formula of Ricker (1975): Ln (Final wet body weight) SGR =
2.4. Statistical
- Ln (Initial
wet body weight)
Time (days) analysis
At termination, the total number and weight of shrimp in each tank were determined. Two-way analysis of variance (ANOVA) was used to test the interaction of salinity and temperature and differences between means were compared using Tukey’s test with a 95% confidence interval (P < 0.01).
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3. Results
3.1. Survival
The survival and growth of postlarvae are summarised in Table 1. At all salinities, mean survival was best at 25 and 30°C ranging from 68 to 95% (Fig. l>, with the exception of the group at 40%0 and 25°C probably due to experimental error. Survival was slightly lower at 20°C ranging from 62 to 83%, but was very poor at 35°C ranging only from 11 to 43%. Animals at the lowest salinity of 20%0 had a very low survival at the higher temperatures of 30 and 35°C. Two-way ANOVA performed on final survival data showed that the effect of temperature was statistically significant (P = 0.001) but percent survival was not different within salinities (Table 2). The interaction effect of salinity and temperature was statistically significant (P = 0.005).
3.2. Growth
The final temperatures
weight was greater at higher temperatures (30 and 35°C) than lower (20 and 25°C) regardless of salinity conditions (Table 1). Generally,
Table 1 Survival and growth of P. uannamei postlarvae
grown in different temperature
Salinity
Temperature
Initial weight
Final weight
(%cJ
(“C)
(mg)
20
20 25 30 35 20 25 30 35 20 25 30 35 20 25 30 35 20 25 30 35
19.7 17.0 18.0 24.3 21.0 18.3 21.0 24.3 27.7 22.0 23.3 23.3 17.3 17.7 20.3 10.7 16.3 21.7 19.7 13.0
30
35
40
50
Data are means (P < 0.01).
of three replicates.
Different
and salinity combinations
(mg)
Survival (% f se.)
Specific growth rate (% + s.e.1
70.7 25 1.3 242.0 349.0 80.0 278.3 401.3 378.7 81.7 241.0 469.7 434.0 88.3 162.7 351.7 467.7 100.7 316.0 329.3 513.0
74.4+ 3.94 9O.Ozk4.16 35.2k 12.44 11.1 k2.40 83.3 + 6.83 91.1+0.10 65.6 f 5.94 43.3 + 12.56 71.1 kO.90 73.3 + 6.85 75.653.63 43.3 + 5.66 75.5 t 3.26 51.1 + 11.00 83.3+9.81 28.9 + 6.37 62.2 + 9.06 75.5 + 1.82 67.8+5.51 26.7 f 6.85
3.20*0.228a 6.74 f 0.566b,C 6.50 + 0.208 6.49 + 0.805 3.37 + 0.244a 6.85 k 0.238b,c 7.37 f 0.453b.c.d 6.82 f0.306b,c 2.70+0.110a 6.02 +0.849b 7.45 + 0.280b,c,d 7.30 + 0.093b~‘~d 4.14+0.575a 5.69 * 0.604b 7.17 + 0.346b,‘.d 7.90 f 0.3 15d 4.54 + 0.072= 6.67 +0.335b,c 7.04+0.018s~C 7.60 + 0.044C,d
superscripts
indicate
significant
differences
using
ANOVA
.I. Ponce-Palafox et al. /Aquaculture
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157 (1997) 107-115
111
I
I
/
25
30
35
Temperature ( “C) Fig. 1. Survival of P. uannamei postlarvae
reared at different temperatures
and salinities for 40 days.
specific growth rate was affected more by temperature than salinity and growth rates increased over the temperature range of 20°C to 35°C (Fig. 2). At 20°C growth rates were significantly lower than at the higher temperatures. Above 25”C, growth at 20%0 appeared to be lower than at other salinities but was only significantly lower at 30°C. Although growth was high at 35°C there was a negative effect on survival at this
Table 2 Results of two-way analysis of variance performed on final survival temperatures (20 to 35°C) and five salinities (20 to 50700)
for P. uannamei postlarvae
Source of variance
df
Sum of squares
Mean square
F
P>F
Error Temperature Salinity Temperature
40 3 4 12
5.376 28.661 3.576 3.664
0.134 9.554 0.894 0.305
71.08 6.65 2.72
0.001 0.001 0.026
X
salinity
Table 3 Results of two-way analysis of variance performed on final weight temperatures (20 to 35°C) and five salinities (20 to 50%~)
for P. cjannamei postlarvae
Source of variance
df
Sum of squares
Mean square
F
P>F
Error Temperature Salinity Temperature
40 3 4 12
8627.3 16 19836.821 2383.582 7672.316
215.683 6612.274 595.895 639.365
30.657 2.763 2.964
0.001 0.041 0.005
X salinity
at four
at four
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J. Ponce-Palafox et al. /Aquaculture
157 (1997) 107-115
t
20 %.
t 4
30 %. 35 %.
-t-
40 “I.. 50 “/..
l
25
30
35
Temperature (“C) Fig. 2. Specific days.
growth rate of P. uannamei postlarvae
temperature. The effect of salinity significant (P = 0.001) (Table 3). 3.3. Temperature-salinity
reared at different
and temperature
temperatures
on final weight
and salinities for 40
was statistically
interaction
The interaction between the effects of temperature and salinity on survival are clear from the surface response summarising survival at different temperatures and salinities
50 45 3v
40
.g .-
35
;
30 25
25 Temperature
30 (“C)
Fig. 3. Response surface showing survival of P. uannamei postlarvae salinities for 40 days. The isobars show percentage survival.
reared at different
temperatures
and
.I. Ponce-Palafox et al./Aquaculture
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157 (1997) 107-115
20 22 24 26 26 30 32 34 Temperature Fig. 4. Response surface showing final weight of P. vannamei days. The isobars show final weight in mg.
(“C) at different
temperatures
and salinities for 40
over the 40-day period (Fig. 3). This confirms a generally wide tolerance of P. uannamei postlarvae to salinity and temperature. Generally, good survival (80 to 90%) was obtained below 30°C and below 40%0 salinity. Higher temperatures reduced survival markedly. Higher salinities only had a marked negative effect at the higher temperatures. The surface response summarising final weight at different temperatures and salinities
25 Temperature
i0
35
(“C)
Fig. 5. Response surface showing overall production from 100 P. uannamei at different salinities for 40 days. The isobars show final group weight in grams.
temperatures
and
114
J. Ponce-Palafox et al./Aquaculture
157(1997)
107-115
over the 40-day period shows that temperature is the major influence and that low growth is associated with low temperatures (Fig. 4). Best growth is found at temperatures over 29°C and at salinities greater than 30%0. The optimum temperature and salinity conditions for growth and survival coincide best at around 28 to 30°C and 33 to 40%0. Overall production will thus be best in these conditions and this is illustrated by the response surface calculated for 100 postlarvae shown in Fig. 5.
4. Discussion In general, the growth and survival rates achieved in this work were good and indicated that the laboratory procedures used were in accordance with survival and growth normally obtained in commercial culture. The results clearly show how the survival and growth rate of P. uannamei postlarvae, depends on temperature, salinity and the temperature-salinity interaction. Temperature had a considerable effect on the overall activity, food consumption and growth. Shrimp at 20°C were relatively inactive and exhibited low food consumption compared with hyperactive animals at 35°C. When offered unlimited food, shrimp maintained at 35°C had the highest rate of food consumption. These observations are consistent with those of Zein-Eldin and Aldrich (1965) and Zein-Eldin and Griffith (1966) in P. azfecus. Comparative literature concerning salinity optima for P. vannamei is not conclusive. Bray et al. (1994) showed that 5 and 15%0 treatments produced significantly greater final weights than other levels tested and the hypersaline treatment (49%0) produced significantly less growth than other treatments. Huang (1983) concluded that P. uannamei grew best at about 20%0 and observed poorest results at 5 and 45%0. However, the growth achieved at different salinities in the present study is also consistent with a salinity preference study conducted with P. vannumei postlarvae by Bartlett et al. (1990) who concluded that growth was not reduced within the range of 30 to 45%0 salinity. It is clear that, within the optimum temperature range, the tolerance to salinity is wide, and good growth can be obtained between 25 and 45%0. By contrast, Bassanesi (1982) showed that P. stylirostris was less tolerant to low salinities, again, consistent with its naturally oceanic habit. Lester and Pante (1991) considered that penaeids pass through three stages; larvae adapted to oceanic salinities and surface temperatures, juveniles adapted to estuarine salinities and coastal temperature patterns and adults which are adapted to oceanic salinities and bottom temperatures. Wyban et al. (1995) suggest that temperature optima for fastest growth are size-specific and decrease as shrimp size increases. For small shrimp ( < 5 g), temperature optima may be greater than 30°C while for large shrimp, the temperature optimum is about 27°C. This study has shown that there is a high coincidence between the experimentally determined optimum conditions for production and the prevailing conditions in the coastal environment from which the animals originated. This confirmation of the essentially oceanic preferences of the juveniles of P. vunnamei helps explain why commercial production systems used in much of Latin America perform well when using full strength sea water rather than estuarine waters.
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Acknowledgements The support of CONACyT to CIAD through project CONACyT 4586A-9406 is gratefully acknowledged. LGR and CAMP were supported by a British Council/ODA Higher Education Link programme, Mexico/991/51. The authors wish to thank Bs. Oscar J. Gonzalez Rodriguez for their assistance with the running of the trials.
References Bassanesi, A.T., 1982. Crecimiento y supervivencia de postlarvas de P. stylirostris Stimpson, bajo condiciones controladas de temperatura y salinidad. Tesis de Maestria. Instituto de ciencias de1 Mar y Limnologia. Universidad National Autdnoma de Mexico, 84 pp. Bartlett, P., Bonilla, P., Quiros, L., Takano, M., 1990. Effects of high salinity on the survival and growth of juvenile Penaeus L;annamei, P. stylirostris, and P. monodon. In: Abstracts, World Aquaculture, 90: 121 /CP6. National Research Council, Ottawa, Ontario, Canada. Boone, 193 1. Bray, W.A., Lawrence, A.L., Leung-Trujillo, J.R., 1994. The effect of salinity on growth and survival of Penaeus uanmmei, with observations on the interaction of IHHN virus and salinity. Aquaculture 122, 133-146. Brett, 1979. FAO, 1994. Aquaculture Production 1986-1992. FAO Fisheries Circular 815 (Rev. 6). FAO, Rome. Huang, H.J., 1983. Factors affecting the successful culture of Penaeus stylirostris and Penaeus uannamei at an estuarine power plant site: temperature, salinity, inherent growth variability, damselfly nymph predation, population density and distribution, and polyculture. PhD dissertation. Texas A&M University, College Station, TX, USA, 221 pp. Kinne, 1972. Lester, L.J., Pante, J.R., 1991. Penaeid temperature and salinity responses. In: Fast, A.W., Lester, L.J. (Eds.), Marine Shrimp Culture: Principles and Practices. Vol. 23, pp. 515-534. Motoh, H., 1981. Studies on the fisheries biology of the giant tiger prawn, Penaeus monodon in the Philippines. Tech. Rep. No. 7, SEAFDEC Aquaculture Dept., Iloilo, Philippines. 128 pp. Ricker, W.E., 1975. Computation and interpretation of biological statistics of fish population. Bull. Fisheries Res. Board Can. 191, 382. Rosenberry, R., 1993. World Shrimp Farming 1993. Aquaculture Digest, December 1993, pp. 52. Wyban, J., Walsh, W.A., Godin, D.M., 1995. Temperature effects on growth, feeding rate and feed conversion of the Pacific white shrimp. Aquaculture 138, 267-279. Zein-Eldin, Z.P., Aldrich, D.V., 1965. Growth and survival of postlarvae Penaeus aztecus under controlled conditions of temperature and salinity. Biol. Bull. 129, 199-216. Zein-Eldin, Z.P., Griffith, G.W., 1966. The effect of temperature upon the growth of laboratory-held postlarval Penaeus aztecus. Biol. Bull. 131, 186-196. Venkataramaiah, A., Lakshmi, G.J., Gunter, G., 1974. Studies on the effects of salinity and temperature on the commercial shrimp, Penaeus aztecus, Ives, with special regard to survival limits, growth, oxygen consumption and ionic regulation. Contract report H-74-2. Gulf Coast Research Laboratory, Ocean Springs, MS, USA, pp. 134.
