| Summary: | 碩士 === 國立臺灣海洋大學 === 水產養殖學系 === 106 === The objective of the current study on the larval culture of the Amano shrimp (Caridina multidentata) involves in a series of stepwised experiments with three probiotic species. Four experiments have been carried out mentioned as below.
Experiment 1. Probiotic species application trial: There are three species of bacteria Baccilus subtilis, Rhodospirilum rubrum, Shewanella sp. There are four levels of concentration (5x 104, 1x105, 5x 105 and 1x 106) cfu/ml of each of the three species of bacteria applied to the respective larval culture system with backgrounded algae (Tetraselmis chui) density of 2x105 cells/ml. Shrimp larval density sets at 30 ind/L. Results show that B. subtilis at level of 5x105 cfu/ml exhibites the highest post larval survival rate (65.5±3.85) which is significantly better than B. subtilis at 1x106 cfu/ml (59.9±3.33, the 2nd best) compared to that of control (50.3± 3.33)
Experiment 2. Larval density trial; B. subtilis at 5x 105 cfu/ml (Best from experiment 1) was separately applied to triplicately T. chui 2x 105 cells/ml background feeding systems, each holding larval density level at 30, 45, 60 ind./L respectively. Larval density of 30 ind/L, reveals highest post larval survival (76.78±2.55) and shortest maturation duration (15 days), which is significantly better than those for densities at 45 ind/L (71.76±16%, 16 days) and 60 ind/L (70.72±1.62 %, 16 days).
Experiment 3. Effect of B.subtilis application in combination with artificial diets for larval culture: Feeding 9 day-old mysis with B. subtilis at level of 5x105 cfu/ml to algal flour or artificial black grain powder (50mg/L) suspended to water body systems. using T. chui powder suspension without B. subtilis supplementation as control. Only those mysis fed T. chui powder and B. subtilis yielded a survival of 12.22±1.92% of post larval with a required metamorphosis duration of 36 days in comparison to the control (T. chui without B. subtilis 6.67±3.33% in 36 days). The other treatments failed with zero survivals.
Experiment 4. Comparisons of three species of probiotic supplementation in commercial feed on the juvenile growth performance trial. Juveniles (averaged initial body weight 18 mg) were fed fixed level of B. subtilis, S. sp and R. rubrum at 1x108 cfu/g contained in a commercial diet (non-supplementation as control) for each of the respective treatment, rationed at 5% body weight, stocked at a density of 10 ind./L, under conditions without water changes (3 replicates per treatment). Survival rate ranges from 78.3% to 90.8% among the whole treatments. Juveniles of the treatment received dietary supplementation of R. rubrum (2646.9 ± 201%) and B.subtilis (2439±164%) exhibit the highest percent weight gain (with no significant differeces between the two), followed by significant difference on S. sp (2269.9±170%) and control (1259±37%) the lowest.
The author concludes and recommends based upon the above four experiments that applying B.subtilis 5x105 cfu/ml to the Amano shrimp larval culture system holding 2x105cells/ml in concentration of T. chui at temperature 26±1℃, salinity 20‰ and larval stocking density of 60 ind./L.
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