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Influence of salinity and temperature on molting and survival of the Australian freshwater crayfish (Cherax tenuimanus)
Aquaculture, 105 ( 1992) 47-52
47
Elsevier Science Publishers B.V., Amsterdam AQUA 31H
David B. Rouse and Izuddin Kartamulia’ Department of Fisheries and Allied Aquacultures,Auburn University,Auburn, AL, USA
(Accepted 20 November I99 I )
ABSTRACT Rouse, D.B. and Kartamulia, I., 1992. Influence of salinity and temperature on molting and survival of the Australian freshwater crayfish (Cherax tenuimanus). Aquaculture, 105: 47-52. The largest freshwater crayfish in the world are found in Australia. Cherax tenuimanus, or marron, is one of these large freshwater crustaceans which has attracted considerable interest as a potential aquaculture species during the past few years. Experiments to assess the suitability of marron for culture in the Southeastern United States began at Auburn University in 1986. A 6-week bioassay was used to evaluate the effects of three temperature ranges ( I7 f I “C, 24 I I “C and 30 + I “C) and three levels of salinity (0, 50 and 100 mg/l NaCl ) on marron survival and molting. As temperature increased molting frequency increased but survival decreased. Salinity had no effect on number of molts, but it had a positive effect on molting success and survival. Temperatures of 25°C and less and salinity levels of at least 100 mg/l were found to provide the best survival. Because of a need for cool temperatures and low levels of salinity, limited areas in the Southeastern United States will be suitable for marron culture.
INTRODUCTION
Large Australian crayfish belonging to the genus Cherax have attracted considerable interest as aquaculture species during the past few years ( rissy et al., 1990; Rouse et al., 1990). The largest species of this genus is C. tenuimanus, or marron, which is native to south tralia and capable of reaching 2 kg in weight (Morrissy, 1970). began in the late 1960’s. Interest increased dramatically during the 1980’s. Today, several large-scale commercial marron farms and many small farms are in operation (O’Sullivan, 1988 ). Attractive attributes of marron include Correspondence to: Dr. D.B. Rouse, Department of Fisheries and ,111iedAquacultures, Auburn University, Auburn, AL 36849-54 19, USA. ‘Present address: School of Agriculture, University of Sriwijaya, Palembang, Indonesia.
0044-8486/92/$05.00
0 1992 Elsevier Science Publishers B.V. All rights reserved.
48
D.B. ROUSE ANDY. YCARTAMULYA
rapid growth (40-l 20 g/year), a relatively non aggressive and non-burrow-
ing behavior and a simple life cycle in which juvenile crayfish are released from the female, eliminating the need for sophisticated hatcheries for larval rearing (Morrissy, 1976a, 1988; Crook, 198 1). A program to assess the suitability of marron culture in the Southeastern United States began at Auburn University in 1986. Preliminary investigations revealed a more thorough understanding of the effects of temperature and certain water quality parameters were important in determining marrons’ ability to survive and grow in the Southeastern United States. Morrissy ( 1990) described the annual water temperature extremes to range between 8 and 26°C in the central part of their range where abundance is high south of Perth. Low survival of marron after prolonged exposure to temperatures above 27 “C has also been reported (Morrissy, 1976b, 1988, 1990). High temperatures were thought to be a possible cause of marron mortalities reported in Queensland, Australia in 1986 (O’Sullivan, 1988). However, marron farms north of Perth, Australia, regularly record day-time peak temperatures above 30’ C during hot summer months (Gordon Reynolds, personal communications, 1988.). Since water temperatures of 28°C to 30°C are normal for several months of the year in the southern part of the United States, critical upper temperatures need to be clarified. The ability of marron to adjust to water chemistry different from that of its native range is also an important consideration. Morrissy ( 1976a) reported that marron are found in neutral water of low salinity and alkalinity, dominated by sodium and chloride ions. Water in Alabama is also neutral, generally with a low alkalinity but dominated by calcium and magnesium ions rather than sodium and chloride ions ( Arce and Boyd, 1980 ). Earlier studies at Auburn revealed that the addition of sodium chloride to acclimation water was beneficial in improving survival during acclimation following shipments from Australia (Kartamulia, 1989). Upper tolerance limits to salinity of 17 ppt have been reported by Morrissy ( 1978 ), but no minimum requirements have been reported. The following experiment was designed to determine the influence of temperatures that might be experienced during a normal growing season in the Southeastern United States and the influence of sodium chloride concentrations on marron survival and molting, MATERIALS AND METHODS
A bioassay was conducted at the Alabama Agricultural Experiment Station, Fisheries Research Unit, Auburn University, to test the effects of three temperatures and three salinities on molting frequency and success in marron. A 3~ 3 factorial design was used with three replicates per treatment. Culture units were 40-l glass aquaria. Low, medium and high temperature treatments
EFFECTS Ok SALINITY/TEMPERATURE
ON MOLTING
AND SURVIVAL
OF MARRON
49
30 2 1‘C, respectively. Low temperatures were were17~l°C,24+loC,an maintained by pumping chilled water (Sargent cooling bath) through plastic tubes coiled in culture tanks. dium and high temperatures were maintained with aquarium heaters. three salinity levels, 0 mg/l, 50 mg/l and 100 mg/l NaCl, were obtained by adding NaCl to freshwater. Treatment water, before the addition of NaCl, had 75 mg/l total dissolved solids and 3 mg/l chlorides. Twenty-seven aquaria were cleaned, disinfected with 100% alcohol and filled with water of one of the three salinities to a volume of 30 1. Constant aeration and filtration using activated charcoal filters were provided to each aquarium throughout the experiment. Aquaria were siphoned every other day and refilled with treatment water. Replenishment water amounted to about 10% per day. Rigid black plastic netting was formed into 1O-cm-diameter cylinders and placed into each aquarium as shelters. Juvenile marron averaging 1.4 g were shipped from Australia and acclimatized for 3 weeks. When mortalities resulting from shipping had ceased, the marron were stocked into the aquaria at the rate of 10 crayfish/aquarium. All animals were fed ad libitum daily with a 40% protein commercial shrimp ad crayfish were pellet. All aquaria were checked daily for molting activity. recorded and removed. M,olting stage of dead marron w determined and recorded. The experiment was conducted for 6 weeks. Differences among treatments iew 5 12, version 1.03 were determined by analysis of varia,nce usi tosh SE personal com(Abacus Concepts, inc. ) implemented on a puter. Data were normalized using the arcsin RESULTSANDBISCUSSION
Survival in individual aquaria ranged from 0 (0 salinity, 2 temperatures ) to 90% ( 50 mg/l and 100 mg/l salinities, 17“C Average survival among the replicated treatments ranged from 10% in the 0 salinity, 24°C temperature treatment to 80% in the 100 mg/l salinity, 17°C temperature treatment (Table 1) . The total number of molts in individual aquaria ranged from one molt (0 salinity, 17“C and 24°C temperatures) to 11 molts ( 50 mg/l salinity, temperature). Total molts by treatment ranged from 10 molts at 0 an mg/l salinities, with 17°C temperature to 25 molts at 50 mg/l salinity and 24” C temperature (Table 2 Molting success rates in i ividual aquaria were from 0% (at the 0 salinity, 17Oand 30°C temperatures and a; the 50 mg/l salinity, 30°C temperature) to 100% (at all salinities and 17 OC ‘temperature ) . olting success among the replicated treatments ranged from 18.1% at the 50 mg/l salinity, 30°C tem-
D.B. ROUSE AND I. KARTAMULIA
50
TABLE 1 Survival (%) of matron (Cherux tenuimanus) during a 6-week rearing period at three temperatures and three salinities. Values are the means of three replicates &standard errors. Each replicate contained 10 matron Salinity (mg/l)
Temperature ( “C) 17+ 1
2421
30+1
Average
50 100
43.3? 28.3 7O.Ok21.6 80.0* 14.1
lO.Of 8.2 30.0 + 17.0 43.3 & 12.5
13.3+ 9.4 16.7f 9.4 30.0 + 26.2
22.2 + 15.0 38.9 + 22.7 51.1 f21.1
Average
64.42 15.5
27.8f 13.7
20.01 7.2
0
TABLE 2 Number of molts of matron (Cher~ tenuimanus) during a 6-week rearing period at three temperatures and three salinities. Numbers are the total of three replicates. Each replicate contained 10 matron Salinity (mg/l)
Temperature (“C) 17+1
24+1
30fl
Average
0 50 100
10 13 10
23 25 17
22 22 22
18.328.2 20.0 + 4.9 16.3f4.9
Average
11+1.4
21.713.4
22kO.O
TABLE 3 Moltingsuccess (%) of matron (Ckevux Zenuimanus) during a 6-week rearing period at three temperatures and three salinities. Values are the means of three replicates f standard errors. Each replicate contained 10 matron Salinity (mg/l)
Temperature ( “C) 17f 1
24fl
30+1
Average
50 100
44.3541.6 66.73-31.2 83.3 f 23.5
44.1 !I 13.7 52.5+ 15.3 56.0+ 13.8
30.0f 18.9 18.1f 15.3 65.0 + 10.8
39.5f 6.7 45.8 + 20.4 68.lzbll.4
Average
64.8 I 16.0
50.9+ 5.0
37.7 + 20.3
0
perature treatment to 83.3% at the 100 mg/l salinity, 17°C temperature treatment (Table 3 ). There was a highly significant and positive effect of temperature on num-
EFFECTS OF SALINITY/TEMPERATURE
ON MOLTING AND SURVIVAL OF MARRON
51
ber of molts (P< 0.01), but a highly significant and negative effect on surviva1 (P-c 0.01). Low temperature provided the lowest average number of molts ( 11) and highest molting success (64.8%), compared to the 30°C temperature which had an average of 22 molts with a 20% survival rate ( 3). There were no significant differences between 24°C and 30°C temperatures for number of molts or survival (P> 0.05 ), but there was a significant difference between 24 OC and 17 OC temperatures as well as between 30 Oand 17“C temperatures (k 0.05 ). Salinity had no effect on number of molts (P> 0.05 ), but it had a significant and positive effect on molting success and survival (P< 0.05). There was no significant difference between 0 and 50 mg/l salinity for molting success, but there were significant differences between 0 and 100 mg/l, as well as between 50 and 100 mg/l salinities (kO.05). There was no significant interaction effect between salinity and temperature for number of molts, percent molting success or survival (P> 0.05 ). The results of this study in cate that marron are cool-water crayfish, surviving best at temperatures 22” to 25 “C and below, and that they need levels of salinity of at least 100 mg/l for successful molting. These results agree with reports by orrissy ( 1976b, 1988) that marron do not survive well at temperatures e 27 OC. The salinity requirement has not been previously reported. Acclimation studies by Kartamulia ( 1989) indicated that common salt at levels of 100 to 200 mg/l was effective at improv’ survival following shipments between Australia and the United St and Kartamulia ( 1992 ) found that sodiu chloride at 100 mg/l was effective calcium chloride and calcium sulat maintaining good marron su uence. Water samples from marron farms fate, each at 100 mg/l, had no 150 to 250 mg/l, in Australia were found to have salinity levels ranging fr supporting the findings of this study (Kartamulia and use, unpublished data). Morrissy ( 1978) reported that marron tolerate salinities up to 17 g/l. ased on these results, it appears that marron not o ly tolerate varying levels of salinity up to half strength seawater, but they actually require low levels of sodium chloride for successful molting. The need for low levels of salt and cool temperatures will substantially limit the sites suitable for marron culture in the Southeastern United States. These results help explain why many attempts to culture marron outside their native range have not been successful. ACKNOWLEDGMENTS
esearch for this paper was ma e possible through support from the Alament of Indonesia and the bama Agricultural Experiment Stati grant to the Traverse Croup Science Found e Waters Inc. 0
52
D.B. ROUSE AND 1.KARTAMULIA
REFERENCES Arce, R.G. and Boyd, C.E. 1980. Water chemistry of Alabama ponds. Alabama Agricultural Experiment Station, Auburn, AL, Bull. 522,35 pp. Crook, G., 198 1. Marron and marron farming. Department of Fisheries and Wildlife, Western Australia, 40 pp. Kartamulia, I., 1989. The effects of some prophylactic agents, salinity and temperature on survival and growth of marron (Cherux tenuimanus). Ph. D. dissertation, Auburn University, Auburn, AL, 64 pp. Morrissy, N.M., 1970. Spawning of marron, Cherux tenuimanus (Smith) (Decapoda: Parastacidae) in Western Australia. Fisheries Bull., Department of Fisheries and Fauna, Western Australia, 10: l-23. Morrissy, N.M., 1976a. Aquaculture of marron, Cherux fenuimanus (Smith). Part 1. Site selection and the potential of marron for aquaculture. Fish. Res. Bull. Western Australia, 17: l27. Morrissy, N.M., 1976b. Aquaculture of marron Cherax fenuimanus. Part 2. Breeding and early rearing. Fish. Res. Bull. Western Australia, 33 pp. Morrissy, N.M., 1978. The past and present distribution of marron in Western Australia. Fish. Res. Bull. Western Australia, 28 pp. Morrissy, N.M., 1988. Marron Farming - Current industry and research developments in Western Australia. In: Proceedings First Australian Shellfish Aquaculture Conference, 1988. Curtain University of Technology, Perth, Australia. Morrissy, N.M., 1990. Optimum and favourable temperatures for growth of Chevax tenuimanus (Smith 1912) (Decapoda: Parastacidae). Aust. J. Mar. Freshwater Res., 41: 73% 746. Morrissy, N.M,, Evans, L.E. and Huner, J.V., 1990. Australian freshwater crayfish: aquaculture species. World Aquacult., 2 l(2): 113- 122. O’Sullivan, D., 1988. The culture of the marron (Cherax tenuimanus) in Australia. J. World Aquacult. Sot., 19: 55-56 (abstr. ). Rouse, D.B. and Kartamulia, I., 1992. The use of sodium chloride to improve survival in the Australian crayfish, Ckwx tenuimunl~s,Prog. Fish-Cult., 54: in press. Rouse, D.B., Austin, CM. and Medley, P.B., 1990. Progress toward profits? Information on the Australian crayfish. Aquacult. Mag., 17( 3 ): 46-56. Zar, J.H., 1974. Biostatistical Analysis. Prentice-Hall, Englewood Cliffs NJ, 620 pp.
47
Elsevier Science Publishers B.V., Amsterdam AQUA 31H
David B. Rouse and Izuddin Kartamulia’ Department of Fisheries and Allied Aquacultures,Auburn University,Auburn, AL, USA
(Accepted 20 November I99 I )
ABSTRACT Rouse, D.B. and Kartamulia, I., 1992. Influence of salinity and temperature on molting and survival of the Australian freshwater crayfish (Cherax tenuimanus). Aquaculture, 105: 47-52. The largest freshwater crayfish in the world are found in Australia. Cherax tenuimanus, or marron, is one of these large freshwater crustaceans which has attracted considerable interest as a potential aquaculture species during the past few years. Experiments to assess the suitability of marron for culture in the Southeastern United States began at Auburn University in 1986. A 6-week bioassay was used to evaluate the effects of three temperature ranges ( I7 f I “C, 24 I I “C and 30 + I “C) and three levels of salinity (0, 50 and 100 mg/l NaCl ) on marron survival and molting. As temperature increased molting frequency increased but survival decreased. Salinity had no effect on number of molts, but it had a positive effect on molting success and survival. Temperatures of 25°C and less and salinity levels of at least 100 mg/l were found to provide the best survival. Because of a need for cool temperatures and low levels of salinity, limited areas in the Southeastern United States will be suitable for marron culture.
INTRODUCTION
Large Australian crayfish belonging to the genus Cherax have attracted considerable interest as aquaculture species during the past few years ( rissy et al., 1990; Rouse et al., 1990). The largest species of this genus is C. tenuimanus, or marron, which is native to south tralia and capable of reaching 2 kg in weight (Morrissy, 1970). began in the late 1960’s. Interest increased dramatically during the 1980’s. Today, several large-scale commercial marron farms and many small farms are in operation (O’Sullivan, 1988 ). Attractive attributes of marron include Correspondence to: Dr. D.B. Rouse, Department of Fisheries and ,111iedAquacultures, Auburn University, Auburn, AL 36849-54 19, USA. ‘Present address: School of Agriculture, University of Sriwijaya, Palembang, Indonesia.
0044-8486/92/$05.00
0 1992 Elsevier Science Publishers B.V. All rights reserved.
48
D.B. ROUSE ANDY. YCARTAMULYA
rapid growth (40-l 20 g/year), a relatively non aggressive and non-burrow-
ing behavior and a simple life cycle in which juvenile crayfish are released from the female, eliminating the need for sophisticated hatcheries for larval rearing (Morrissy, 1976a, 1988; Crook, 198 1). A program to assess the suitability of marron culture in the Southeastern United States began at Auburn University in 1986. Preliminary investigations revealed a more thorough understanding of the effects of temperature and certain water quality parameters were important in determining marrons’ ability to survive and grow in the Southeastern United States. Morrissy ( 1990) described the annual water temperature extremes to range between 8 and 26°C in the central part of their range where abundance is high south of Perth. Low survival of marron after prolonged exposure to temperatures above 27 “C has also been reported (Morrissy, 1976b, 1988, 1990). High temperatures were thought to be a possible cause of marron mortalities reported in Queensland, Australia in 1986 (O’Sullivan, 1988). However, marron farms north of Perth, Australia, regularly record day-time peak temperatures above 30’ C during hot summer months (Gordon Reynolds, personal communications, 1988.). Since water temperatures of 28°C to 30°C are normal for several months of the year in the southern part of the United States, critical upper temperatures need to be clarified. The ability of marron to adjust to water chemistry different from that of its native range is also an important consideration. Morrissy ( 1976a) reported that marron are found in neutral water of low salinity and alkalinity, dominated by sodium and chloride ions. Water in Alabama is also neutral, generally with a low alkalinity but dominated by calcium and magnesium ions rather than sodium and chloride ions ( Arce and Boyd, 1980 ). Earlier studies at Auburn revealed that the addition of sodium chloride to acclimation water was beneficial in improving survival during acclimation following shipments from Australia (Kartamulia, 1989). Upper tolerance limits to salinity of 17 ppt have been reported by Morrissy ( 1978 ), but no minimum requirements have been reported. The following experiment was designed to determine the influence of temperatures that might be experienced during a normal growing season in the Southeastern United States and the influence of sodium chloride concentrations on marron survival and molting, MATERIALS AND METHODS
A bioassay was conducted at the Alabama Agricultural Experiment Station, Fisheries Research Unit, Auburn University, to test the effects of three temperatures and three salinities on molting frequency and success in marron. A 3~ 3 factorial design was used with three replicates per treatment. Culture units were 40-l glass aquaria. Low, medium and high temperature treatments
EFFECTS Ok SALINITY/TEMPERATURE
ON MOLTING
AND SURVIVAL
OF MARRON
49
30 2 1‘C, respectively. Low temperatures were were17~l°C,24+loC,an maintained by pumping chilled water (Sargent cooling bath) through plastic tubes coiled in culture tanks. dium and high temperatures were maintained with aquarium heaters. three salinity levels, 0 mg/l, 50 mg/l and 100 mg/l NaCl, were obtained by adding NaCl to freshwater. Treatment water, before the addition of NaCl, had 75 mg/l total dissolved solids and 3 mg/l chlorides. Twenty-seven aquaria were cleaned, disinfected with 100% alcohol and filled with water of one of the three salinities to a volume of 30 1. Constant aeration and filtration using activated charcoal filters were provided to each aquarium throughout the experiment. Aquaria were siphoned every other day and refilled with treatment water. Replenishment water amounted to about 10% per day. Rigid black plastic netting was formed into 1O-cm-diameter cylinders and placed into each aquarium as shelters. Juvenile marron averaging 1.4 g were shipped from Australia and acclimatized for 3 weeks. When mortalities resulting from shipping had ceased, the marron were stocked into the aquaria at the rate of 10 crayfish/aquarium. All animals were fed ad libitum daily with a 40% protein commercial shrimp ad crayfish were pellet. All aquaria were checked daily for molting activity. recorded and removed. M,olting stage of dead marron w determined and recorded. The experiment was conducted for 6 weeks. Differences among treatments iew 5 12, version 1.03 were determined by analysis of varia,nce usi tosh SE personal com(Abacus Concepts, inc. ) implemented on a puter. Data were normalized using the arcsin RESULTSANDBISCUSSION
Survival in individual aquaria ranged from 0 (0 salinity, 2 temperatures ) to 90% ( 50 mg/l and 100 mg/l salinities, 17“C Average survival among the replicated treatments ranged from 10% in the 0 salinity, 24°C temperature treatment to 80% in the 100 mg/l salinity, 17°C temperature treatment (Table 1) . The total number of molts in individual aquaria ranged from one molt (0 salinity, 17“C and 24°C temperatures) to 11 molts ( 50 mg/l salinity, temperature). Total molts by treatment ranged from 10 molts at 0 an mg/l salinities, with 17°C temperature to 25 molts at 50 mg/l salinity and 24” C temperature (Table 2 Molting success rates in i ividual aquaria were from 0% (at the 0 salinity, 17Oand 30°C temperatures and a; the 50 mg/l salinity, 30°C temperature) to 100% (at all salinities and 17 OC ‘temperature ) . olting success among the replicated treatments ranged from 18.1% at the 50 mg/l salinity, 30°C tem-
D.B. ROUSE AND I. KARTAMULIA
50
TABLE 1 Survival (%) of matron (Cherux tenuimanus) during a 6-week rearing period at three temperatures and three salinities. Values are the means of three replicates &standard errors. Each replicate contained 10 matron Salinity (mg/l)
Temperature ( “C) 17+ 1
2421
30+1
Average
50 100
43.3? 28.3 7O.Ok21.6 80.0* 14.1
lO.Of 8.2 30.0 + 17.0 43.3 & 12.5
13.3+ 9.4 16.7f 9.4 30.0 + 26.2
22.2 + 15.0 38.9 + 22.7 51.1 f21.1
Average
64.42 15.5
27.8f 13.7
20.01 7.2
0
TABLE 2 Number of molts of matron (Cher~ tenuimanus) during a 6-week rearing period at three temperatures and three salinities. Numbers are the total of three replicates. Each replicate contained 10 matron Salinity (mg/l)
Temperature (“C) 17+1
24+1
30fl
Average
0 50 100
10 13 10
23 25 17
22 22 22
18.328.2 20.0 + 4.9 16.3f4.9
Average
11+1.4
21.713.4
22kO.O
TABLE 3 Moltingsuccess (%) of matron (Ckevux Zenuimanus) during a 6-week rearing period at three temperatures and three salinities. Values are the means of three replicates f standard errors. Each replicate contained 10 matron Salinity (mg/l)
Temperature ( “C) 17f 1
24fl
30+1
Average
50 100
44.3541.6 66.73-31.2 83.3 f 23.5
44.1 !I 13.7 52.5+ 15.3 56.0+ 13.8
30.0f 18.9 18.1f 15.3 65.0 + 10.8
39.5f 6.7 45.8 + 20.4 68.lzbll.4
Average
64.8 I 16.0
50.9+ 5.0
37.7 + 20.3
0
perature treatment to 83.3% at the 100 mg/l salinity, 17°C temperature treatment (Table 3 ). There was a highly significant and positive effect of temperature on num-
EFFECTS OF SALINITY/TEMPERATURE
ON MOLTING AND SURVIVAL OF MARRON
51
ber of molts (P< 0.01), but a highly significant and negative effect on surviva1 (P-c 0.01). Low temperature provided the lowest average number of molts ( 11) and highest molting success (64.8%), compared to the 30°C temperature which had an average of 22 molts with a 20% survival rate ( 3). There were no significant differences between 24°C and 30°C temperatures for number of molts or survival (P> 0.05 ), but there was a significant difference between 24 OC and 17 OC temperatures as well as between 30 Oand 17“C temperatures (k 0.05 ). Salinity had no effect on number of molts (P> 0.05 ), but it had a significant and positive effect on molting success and survival (P< 0.05). There was no significant difference between 0 and 50 mg/l salinity for molting success, but there were significant differences between 0 and 100 mg/l, as well as between 50 and 100 mg/l salinities (kO.05). There was no significant interaction effect between salinity and temperature for number of molts, percent molting success or survival (P> 0.05 ). The results of this study in cate that marron are cool-water crayfish, surviving best at temperatures 22” to 25 “C and below, and that they need levels of salinity of at least 100 mg/l for successful molting. These results agree with reports by orrissy ( 1976b, 1988) that marron do not survive well at temperatures e 27 OC. The salinity requirement has not been previously reported. Acclimation studies by Kartamulia ( 1989) indicated that common salt at levels of 100 to 200 mg/l was effective at improv’ survival following shipments between Australia and the United St and Kartamulia ( 1992 ) found that sodiu chloride at 100 mg/l was effective calcium chloride and calcium sulat maintaining good marron su uence. Water samples from marron farms fate, each at 100 mg/l, had no 150 to 250 mg/l, in Australia were found to have salinity levels ranging fr supporting the findings of this study (Kartamulia and use, unpublished data). Morrissy ( 1978) reported that marron tolerate salinities up to 17 g/l. ased on these results, it appears that marron not o ly tolerate varying levels of salinity up to half strength seawater, but they actually require low levels of sodium chloride for successful molting. The need for low levels of salt and cool temperatures will substantially limit the sites suitable for marron culture in the Southeastern United States. These results help explain why many attempts to culture marron outside their native range have not been successful. ACKNOWLEDGMENTS
esearch for this paper was ma e possible through support from the Alament of Indonesia and the bama Agricultural Experiment Stati grant to the Traverse Croup Science Found e Waters Inc. 0
52
D.B. ROUSE AND 1.KARTAMULIA
REFERENCES Arce, R.G. and Boyd, C.E. 1980. Water chemistry of Alabama ponds. Alabama Agricultural Experiment Station, Auburn, AL, Bull. 522,35 pp. Crook, G., 198 1. Marron and marron farming. Department of Fisheries and Wildlife, Western Australia, 40 pp. Kartamulia, I., 1989. The effects of some prophylactic agents, salinity and temperature on survival and growth of marron (Cherux tenuimanus). Ph. D. dissertation, Auburn University, Auburn, AL, 64 pp. Morrissy, N.M., 1970. Spawning of marron, Cherux tenuimanus (Smith) (Decapoda: Parastacidae) in Western Australia. Fisheries Bull., Department of Fisheries and Fauna, Western Australia, 10: l-23. Morrissy, N.M., 1976a. Aquaculture of marron, Cherux fenuimanus (Smith). Part 1. Site selection and the potential of marron for aquaculture. Fish. Res. Bull. Western Australia, 17: l27. Morrissy, N.M., 1976b. Aquaculture of marron Cherax fenuimanus. Part 2. Breeding and early rearing. Fish. Res. Bull. Western Australia, 33 pp. Morrissy, N.M., 1978. The past and present distribution of marron in Western Australia. Fish. Res. Bull. Western Australia, 28 pp. Morrissy, N.M., 1988. Marron Farming - Current industry and research developments in Western Australia. In: Proceedings First Australian Shellfish Aquaculture Conference, 1988. Curtain University of Technology, Perth, Australia. Morrissy, N.M., 1990. Optimum and favourable temperatures for growth of Chevax tenuimanus (Smith 1912) (Decapoda: Parastacidae). Aust. J. Mar. Freshwater Res., 41: 73% 746. Morrissy, N.M,, Evans, L.E. and Huner, J.V., 1990. Australian freshwater crayfish: aquaculture species. World Aquacult., 2 l(2): 113- 122. O’Sullivan, D., 1988. The culture of the marron (Cherax tenuimanus) in Australia. J. World Aquacult. Sot., 19: 55-56 (abstr. ). Rouse, D.B. and Kartamulia, I., 1992. The use of sodium chloride to improve survival in the Australian crayfish, Ckwx tenuimunl~s,Prog. Fish-Cult., 54: in press. Rouse, D.B., Austin, CM. and Medley, P.B., 1990. Progress toward profits? Information on the Australian crayfish. Aquacult. Mag., 17( 3 ): 46-56. Zar, J.H., 1974. Biostatistical Analysis. Prentice-Hall, Englewood Cliffs NJ, 620 pp.