Effect of Salinity on Survival and Growth of Macrobrachium Rosenbergii (De Man)
By: Venugopalan I K.
Contributor(s): Thampy D M (Guide).
Material type:
BookPublisher: Panangad Department of Aquaculture, College of Fisheries 1988DDC classification: 639.2 Online resources: Click here to access online | Click here to access online Dissertation note: MSc Abstract: The effect of salinity on survival and growth of macrobrachium rosenbergii (De Man) was studied with a view to establish the optimum salinity conditions under which it can be cultured. The effect of salinity on survival was assessed by conducting short-term tolerance studies wherein the effect of abrupt transfer and gradual acclimation to the test salinity levels of 5,10,15,20,25,26.5,28.5,30 and 35 ppt was separately studied. In both abrupt transfer and gradual acclimation, no mortality was observed upto 25 ppt within a period of 120 hrs. The LC50 values for 72 hr and 120 hr were 33.3 ppt and 31.6 ppt for gradual acclimation and 29.85 ppt and 28.18 ppt for abrupt transfer respectively. Acclimation prolonged the survival time of the juvenile in the test salinity levels.
The study on the effect of salinity on growth was conducted in cement cisterns, wherein salinity levels from 0-10 ppt with regular increments of 2ppt from treatment to treatment were used. There was no significant difference between treatments upto 6 ppt, but all the levels upto 6ppt differed from 8 and 10 ppt with respect to growth. A field trial to verify the growth pattern in different salinity levels was conducted in one fresh water pond and two brackish water ponds having different salinity levels. The growth rate of the prawns was almost equal in both the fresh water pond (0.119 g/day) and the pond with lower salinity levels (0.126 g/day), whereas it was much lower in the high saline pond (0.063 g/day). The survival rate obtained in the high saline pond (58%) was comparable to fresh water (59%) showing that prawns could survive upto a salinity of 20ppt , although the growth rate is lower in higher salinity levels.
Studies were conducted to evaluate the effect of salinity on oxygen consumption, ammonia excretion and O:N ratios of M.rosenbergii within the test salinity levels of 0-10 ppt. Oxygen consumption and ammonia excretion were found to be strongly influenced by the wet weight of the juveniles, but the influence of salinity on these physiological indices were not significant within the test levels used in this study. However, a trend of an increase in oxygen consumption and decrease in ammonia excretion towards the lower salinity levels was observed. Oxygen to nitrogen ratios were found to be lower in the higher salinity levels indicating an increase in protein catabolism in such salinity levels.
| Item type | Current location | Call number | Status | Date due | Barcode |
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Theses
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KAU Central Library, Thrissur Theses | 639.2 VEN/EF (Browse shelf) | Available | 170572 |
MSc
The effect of salinity on survival and growth of macrobrachium rosenbergii (De Man) was studied with a view to establish the optimum salinity conditions under which it can be cultured. The effect of salinity on survival was assessed by conducting short-term tolerance studies wherein the effect of abrupt transfer and gradual acclimation to the test salinity levels of 5,10,15,20,25,26.5,28.5,30 and 35 ppt was separately studied. In both abrupt transfer and gradual acclimation, no mortality was observed upto 25 ppt within a period of 120 hrs. The LC50 values for 72 hr and 120 hr were 33.3 ppt and 31.6 ppt for gradual acclimation and 29.85 ppt and 28.18 ppt for abrupt transfer respectively. Acclimation prolonged the survival time of the juvenile in the test salinity levels.
The study on the effect of salinity on growth was conducted in cement cisterns, wherein salinity levels from 0-10 ppt with regular increments of 2ppt from treatment to treatment were used. There was no significant difference between treatments upto 6 ppt, but all the levels upto 6ppt differed from 8 and 10 ppt with respect to growth. A field trial to verify the growth pattern in different salinity levels was conducted in one fresh water pond and two brackish water ponds having different salinity levels. The growth rate of the prawns was almost equal in both the fresh water pond (0.119 g/day) and the pond with lower salinity levels (0.126 g/day), whereas it was much lower in the high saline pond (0.063 g/day). The survival rate obtained in the high saline pond (58%) was comparable to fresh water (59%) showing that prawns could survive upto a salinity of 20ppt , although the growth rate is lower in higher salinity levels.
Studies were conducted to evaluate the effect of salinity on oxygen consumption, ammonia excretion and O:N ratios of M.rosenbergii within the test salinity levels of 0-10 ppt. Oxygen consumption and ammonia excretion were found to be strongly influenced by the wet weight of the juveniles, but the influence of salinity on these physiological indices were not significant within the test levels used in this study. However, a trend of an increase in oxygen consumption and decrease in ammonia excretion towards the lower salinity levels was observed. Oxygen to nitrogen ratios were found to be lower in the higher salinity levels indicating an increase in protein catabolism in such salinity levels.
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