Nilnaj Chaitanawisuti

Use of tuna-cooking liquid effluent as a dietary protein and lipid source replacing fishmeal in formulated diets for growing hatchery-reared juvenile spotted babylon (Babylonia areolata).

This study presented the first research conducted on the use of tuna by-product from the tuna canning industry for growing hatchery-reared juvenile spotted babylon (Babylonia areolata) to marketable sizes. A feeding trial was conducted to evaluate the effects of five levels of partial to complete replacement of fishmeal by tuna-cooking liquid effluent on growth performance and body composition of snails reared under a flow-through culture system over 150 days. Five experimental diets were formulated to contain 0%, 25%, 50%, 75%, and 100% of tuna-cooking liquid effluent (diets TCLE0, TCLE25, TCLE50, TCLE75, and TCLE100, respectively). Results showed that significant differences (P 0.05) in final survival rate was found among snails fed all experimental diets. Survival rates ranged from 94.2%-94.6%. Moreover, the snails fed diets of 100% replacement of fishmeal by tuna-cooking liquid effluent meal (TCLE100) showed the highest protein content, lowest lipid content, and lowest cholesterol content compared with snails fed all the other diets. The whole body composition of snails fed TCLE50 was significantly higher (P<0.05) in saturated fatty acid, monounsaturated fatty acid, polyunsaturated fatty acid, unsaturated fatty acid, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachinodic acid (ARA), n-6 PUFA, and n-3 PUFA contents than the groups of snails fed all the other diets The results of this study indicated that tuna-cooking liquid effluent meal can completely replace fishmeal protein with positive effects on snail growth performance and whole body composition.

Replacement of Fishmeal by Poultry By-Product Meal in Formulated Diets forGrowing HatcheryâÂÂReared Juvenile Spotted Babylon (Babylonia areolata

A feeding trial was conducted to evaluate the effects of five levels of partial to total replacement of fishmeal by poultry by–product meal on growth performance and body composition of hatchery–reared juvenile spotted babylon (Babylonia areolata) under aflow-through culture system over 150 days. Five experimental diets were formulated to contain 0%, 25% 50%, 75% and 100% of gradient poultry by-product meal (diet PBM0, PBM25, PBM50, PBM75 and PBM100, respectively). Significant differences (P 0.05) while snails fed diets of PBM0 and PBM100 showed poorer specific growth rates of 2.03-2.12% day-1, respectively. Final survival rates of the snails ranged from 92.73% -93.94% and did not differ significantly (P>0.05) between feeding treatments. Significant differences (P<0.05) were detected in proximate composition (protein, ash, fat, moisture, and carbohydrate, cholesterol content, amino acid composition and fatty acid composition of the whole flesh of experimental snails among all feeding treatment groups. Snails fed diets of PBM-50 resulted in the highest protein and fat contents compared with snails fed the PBM0, PBM25, PBM75 and PBM100 replacement diets. Cholesterol was significantly lower (P<0.05) in snails fed diets of PBM75 and PBM100 than in snails fed diets PBM0, PBM25, and PBM50. The whole body composition of snails fed diet of PBM75 was significantly higher (P<0.05) in total non-essential amino acids and total essential amino acids than those of snails fed PBM0, PBM25, PBM100, and PBM75. The whole body composition of snails fed PMB-50 was significantly higher (P<0.05) regarding EPA, DHA, ARA, n-6 PUFA, and n-3 PUFA contents than those of snails fed PBM0, PBM25, PBM100, and PBM75. The results of this study indicated that poultry by-product meal can replace fishmeal protein by 50-75% with no negative effects in snail growth performance. Moreover, the inclusion of up to 75% poultry by-product meal in the diet improved feed efficiency and body composition.

Effects of Water Depth and Water Flow Duration on Growth and Survival of Juvenile Spotted Babylon (Babylonia areolata) Cultured in a Flow-Through System

Eight growth trials of juvenile B. areolata at different water depths (20 and 50 cm) and water flow durations (6, 12, 18, and 24 h) were conducted in a flow-through culture system over 5 months. One-way ANOVA performed on each growth data set showed that there were significant differences among water depth (WD) and water flow duration (WFD) treatments (P < 0.05). The highest weight gain (6.29 g  /snail) was found in snails reared in the treatment of WD50  /WFD24, followed by those from WD50  /WFD18 (6.15 g/snail), WD50/WFD12 (5.90 g/snail), WD50  /WFD6 (5.83 g/snail), WD20  /WFD24 (5.86 g/snail), and WD20  /WFD18 (5.87 g  /snail), while the lowest one was found in WD20  /WFD6 (5.52 g/snail) and WD20  /WFD12 (5.57 g/snail). The relative weight gain (RWG) and individual weight gain (IWG) of the snails showed similar trends as the weight gain. Final survival exceeded 95% for all treatments. Based on all criteria, the best growth performances of juvenile spotted babylon were found in the WD50  /WFD18 and WD50  /WFD24 treatments, followed by the treatments of WD50/WFD12, WD50  /WFD6, WD20  /WFD24, and WD20  /WFD18; the lowest growth was found in WD20  /WFD6 and WD20  /WFD12.

Growth and Water Quality for Grow-out of Hatchery-Reared Juvenile Spotted Babylon (Babylonia areolata) Exposed to Different Water Management Practices in Earthen Ponds

A 180 day growth trial was conducted to determine growth and water quality for grow-out of hatchery-reared juvenile spotted babylon (Babylonia areolata) in experimental earthen ponds (10.0 × 10.0 × 1.2 m) exposed to different water management practices. These practices (T1–T4) consisted of a calcium carbonate addition at 5-day intervals and seawater exchange at 7, 15, and 21 day intervals, respectively. In treatment T4, seawater was exchanged every 7 days without calcium carbonate addition. Results showed that at the end of the experiment, the average body weight gains were 4.41, 3.76, 2.44, and 4.53 g/snail for snails held in the treatments of T1, T2, T3, and T4, respectively, and 0.74, 0.63, 0.41, and 0.76 g mo−1 for those in individual weight gain, respectively. The specific growth rates in body weight were 1.34%, 1.26%, 1.05%, and 1.36% day−1 for snails held in water management treatments of T1, T2, T3, and T4, respectively. Trends similar to those observed in the growth in body weights were observed in those of shell length. No significant difference in final survival was observed among snails held in water management treatments T1, T2, T3, and T4 (range 72.50% to 76.90%). It is recommended to exchange seawater at 7 day intervals either with or without calcium carbonate addition. Both practices provide good results in growth and water quality.

Suitable initial body sizes of juvenile spotted babylon (Babylonia areolata L.) for growing out to marketable sizes in a large-scale flow-through system.

Suitable initial body sizes of juvenile spotted babylon (Babylonia areolata) for growing out to marketable sizes were determined under a large-scale flow-through system. Juveniles were graded by size into six groups of initial body sizes: traditional size (T; 0.29 ± 0.007 g/snail); medium size 1 (M1; 0.16 ± 0.009 g/snail); medium size 2 (M2; 0.13 ± 0.002 g/snail); medium size 3 (M3; 0.12 ± 0.006 g/snail); small size 1 (S1; 0.09 ± 0.007 g/snail); and small size 2 (S2; 0.07 ± 0.005 g/snail). A comparison was performed at the end of the experiment between the growth of small spotted babylon and the other size groups to confirm that the growth performance of small-size groups was better than the others. There were no significant differences in average weight gain between the six size groups (P < 0.05). The average weight gain ranged from 4.13–4.27 g/snail, 4.00–4.25 g/snail, and 3.97 g/snail in the small sizes, medium sizes, and large size, respectively. However, the average specific growth rate in body weight of both small sizes (S1: 2.73% day−1;; S2: 2.59% day−1) was also significantly higher than those of the medium sizes (2.19%–2.39% day−1) and the large size (1.79% day−1). ANOVA of SGR by size groups showed significant differences between the six size groups (P < 0.05). Intergroup comparisons by Tukeys test revealed that SGR differed significantly except S1 vs. S2. The final survival rate was higher than 96% for all growth trials and ranged from 96.40%–97.50%; no significant difference in survival between the six size groups was found. This study shows that juveniles of small size grew faster than the other size groups.