• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.812-817
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• 2017

This study evaluated the effects of dietary inclusion of soybean (SM) and fermented soybean meal (FSM) on growth promotion in juvenile abalone Haliotis discus. Six hundred and thirty juvenile abalone were distributed into nine plastic containers. Three diets were prepared with 22% fish meal, 2% casein, and either 25% SM or FSM used as the protein sources in the experimental diets, and Undaria was used as a control diet to compare the effects of the experimental diets on the growth performance of abalone. The diets were assigned to three containers each and fed to the abalone once daily to satiation for 16 weeks. Weight gain and specific growth rate (SGR) were higher in abalone fed the SM diet than in those fed the FSM diet. Weight gain and SGR of abalone fed the SM and FSM diets were higher than those of abalone fed Undaria. The crude protein and lipid contents of the edible portions of abalone fed the SM and FSM diets were higher than those of abalone fed Undaria. SM was superior to FSM as a protein source in abalone feed. The SM and FSM diets facilitated greater growth than Undaria.

• Fisheries and Aquatic Sciences
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• v.19 no.5
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• pp.23.1-23.7
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• 2016

The effects of daily feeding frequency (Exp I), water temperature (Exp II), and stocking density (Exp III) on the growth of river puffer, Takifugu obscurus, juvenile fish of 10 and 40 g in body weight were examined to develop effective techniques to produce river puffer in a non-exchange water system. In Exp I, fish were fed commercial floating feed with 45 % protein one to five times per day to apparent satiation each by hand daily for 8 weeks at $25^{\circ}C$. In both the 10- and 40-g size groups, the final body weight, daily feed consumption, and weight gain of fish fed one meal per day were significantly lower than those of fish fed five meals per day (P < 0.05). However, there were no significant differences in the final body weight, daily feed consumption, and weight gain among fish fed two, three, and five meals per day. Feed efficiency showed decreasing tendency with increasing size of fish. In Exp II, fish of 10 and 40 g in initial body weight were reared with the commercial feed at $15-30^{\circ}C$ for 8 weeks. The weight gain of fish increased with raising water temperature up to $25^{\circ}C$ and decreased drastically at $30^{\circ}C$ for both sizes. The Q10 of specific growth rate was decreased with raising water temperature from 5.04 (temperature interval, $15-20^{\circ}C$) to 0.66 ($25-30^{\circ}C$) for the 10-g fish and from 4.98 to 0.31 for the 40-g fish. In Exp III, the effect of stocking density on growth was examined with fish of 10 and 40 g in initial body weight. The final body weight for initial stocking densities of 4, 8, and $12kg/m^3$ was significantly higher than that of $20kg/m^3$ for the 10-g fish, and the final stocking density reached 10.1, 19.2, 28.7, and $39.9kg/m^3$, respectively. For the 40-g fish, the final body weight for initial stocking densities of 3 and $6kg/m^3$ was significantly higher than that of 9 and $15kg/m^3$ and the final stocking density reached 7.38, 13.5, 17.1, and $27.5kg/m^3$, respectively (P < 0.05). In both groups, weight gain tended to decrease with increasing stocking density; however, survival showed no significant difference.

• Fisheries and Aquatic Sciences
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• v.21 no.9
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• pp.26.1-26.8
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• 2018

Inclusion effect of soybean meal (SBM) and fermented SBM (FSM) in extruded pellet for juvenile abalone (Haliotis discus) was compared in abalone farm. Dietary inclusion effect of the combined macroalgae (MA) (Undaria pinnatifida and Hizikia fusiforme) and a single Saccharina japonica on abalone was also compared. Three thousand six hundred juvenile abalone were purchased from a private hatchery and acclimated to the experimental conditions for 2 weeks. Six 5-ton flow-through raceway tanks were used, and abalone were randomly distributed into tanks (n = 600 per tank). Three experimental diets were prepared in duplicate. Fish meal, FSM, corn gluten meal, and shrimp meal and wheat flour and dextrin were used as the protein and carbohydrate sources, respectively, in the FSM diet. MA was also included in the FSM diet. FSM and MA in the FSM diet were substituted with SBM at the expense of wheat flour and S. japonica, referred to as the SBM and SJ diets. The experimental diets were pelletized by an extruded pelleter. Water stability of nutrients in the experimental diets was monitored at 12, 24, and 48 h after seawater immersion. The experimental diets were fed to abalone once a day to satiation with a little leftover for 120 days. The retained crude protein and lipid and ash content of the extruded pellets were changed over all period of time. Weight gain and specific growth rate (SGR) of abalone fed the SBM diet were greater than those of abalone fed the FSM and SJ diets. Weight gain and SGR of abalone fed the SJ diet were also greater than those of abalone fed the FSM diet. The longest shell length, widest shell width, highest shell height, and greatest soft body weight were obtained in abalone fed the SBM diet, followed by the SJ and FSM diets. Proximates of the soft body of abalone were not different among the experimental diets. In conclusion, SBM was a superior protein source to FSM in extruded pellet for growth performance of abalone. Dietary inclusion of a single S. japonica was superior to the combined inclusion of U. pinnatifida and H. fusiforme in the production of abalone.

• Fisheries and Aquatic Sciences
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• v.21 no.4
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• pp.10.1-10.8
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• 2018

Substitution effect of white radish' by-product (WRB) and tunic of sea squirt (TSS) for Undaria in feed on growth and carcass composition of abalone was determined. Eight-hundred forty juveniles were distributed into 12 containers. Three formulated diets were prepared in triplicate. A 15% Undaria was included in the control diet. The 15% Undaria was substituted with a same amount of WRB and TSS, referred to as the DRG and TSS diets, respectively. Finally, dry Undaria was also prepared to compare effect of the formulated diets on performance of abalone. The experimental diets were fed to abalone once a day at a satiation level with a little leftover. The feeding trial lasted for 16 weeks. Crude protein, crude lipid, and ash content of the experimental diets changed over all period of time. Higher crude protein and lipid and ash contents retained in all formulated diets compared to the Undaria were observed at 24 and 48 h after seawater immersion. Survival of abalone was not affected by the experimental diets. Weight gain and specific growth rate (SGR) of abalone fed the TSS diet was greater than all other diets. Weight gain and SGR of abalone fed the control diet was not different from those of abalone fed the WRB diet. Proximates of the soft body of abalone was affected by the diets. In conclusion, WRB and TSS are the promising feed ingredients to replace Undaria in abalone feed; especially, TSS is superior to either Undaria or WRB. The formulated diets produced improved growth performance of abalone over the single Undaria.

• Fisheries and Aquatic Sciences
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• v.23 no.4
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• pp.7.1-7.8
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• 2020

Background: To minimize the use of antibiotics and to obtain a more sustainable fish culture and aquaculture industry, development of alternative natural source of immunostimulant to replace antibiotic in aquafeed is highly needed. Objective: Dietary inclusion effect of yacon (YC), ginger (GG), and blueberry (BB) on growth, body composition, and disease resistance of black rockfish against Vibrio anguillarum was compared to ethoxyquin (EQ). Methods: Four hundred eighty juvenile (an initial weight of 4.2 g) fish were randomly distributed into 12 of 50 L flowthrough tanks (forty fish per tank). Four experimental diets were prepared; the control (Con) diet with 0.01% EQ inclusion, and YC, GG, and BB diets at 1% each additive inclusion. Each additive was included into the experimental diets at the expense of wheat flour. Each diet was assigned to triplicate tanks of fish and hand-fed to satiation twice daily for 8 weeks. At the end of 8-week feeding trial, 20 fish from each tank fish were artificially infected by intraperitoneal injection with 0.1 mL of culture suspension of pathogenic V. anguillarum containing 3.3 × 10⁶ cfu/mL respectively. Fish were monitored for the following 8 days after V. anguillarum infection and dead fish were removed every 6 h for the first 4 days and 12 h for the rest of the study. Results: Weight gain, specific growth rate (SGR), and feed efficiency ratio (FER) of fish fed the YC diet was higher than those of fish fed all other diets. However, feed consumption, protein efficiency ratio, and protein retention was not affected by dietary additive. Moisture, crude protein, and crude lipid content of the whole body of fish were affected by dietary additive. Analysis of the Kaplan-Meier survival curves showed that survival of fish fed the YC, BB, and GG diets was higher than the Con diet. Conclusion: Oral administration of YC can improve not only weight gain, SGR, and FER of black rockfish, but lower mortality of rockfish at occurrence of V. anguillarum.

• Korean Journal of Ichthyology
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• v.21 no.1
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• pp.1-6
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• 2009

The effect of water temperature on fasting and post-prandial total ammonia excretion (TAN) of the starry flounder Platichthys stellatus (mean body weigh : $42.4{\pm}3.4g$) was studied. The fasting and post-prandial TAN excretions were measured under three different water temperatures (10, 15 and $20^{\circ}C$) for 24 hours using a recirculating system. In each treatment three replicates were set up and total 45 fish were used. Fish were taken to the indoor aquarium, acclimated over 10 days at three temperatures, and transferred to TAN measuring system for measurements of TAN excretion at the same temperatures. After 3 days of starvation, fasting TAN excretion was measured at each temperature. To investigate post-prandial TAN excretion, fish were hand-fed to satiation level with a commercial diet containing 50.2% crude protein for 7 days, two times daily 08 : 00 and 16 : 00 h. The fasting and postprandial TAN excretion increased with increased water temperature (p<0.05). Mean fasting TAN excretion rates at 10, 15 and $20^{\circ}C$ were 10.9, 11.2 and $12.2mg\;TAN\;kg\;fish^{-1}\;h^{-1}$, respectively. The value at $20^{\circ}C$ was higher than those at 10 and $15^{\circ}C$ (p<0.05), but there was no significant difference between $10^{\circ}C$ and $15^{\circ}C$. Mean post-prandial TAN excretion rates at 10, 15 and $20^{\circ}C$ were 33.0, 43.4 and $55.3mg\;TAN\;kg\;fish^{-1}\;h^{-1}$, respectively. Two peaks of post-prandial TAN excretions were observed, and the second peak was always greater than the first. The post-prandial TAN excretion rate reached to the maximum after 10 hours from the first feeding at $10^{\circ}C$($45.3mg\;TAN\;kg\;fish^{-1}\;h^{-1}$), $15^{\circ}C$ ($64.5mg\;TAN\;kg\;fish^{-1}\;h^{-1}$) and $20^{\circ}C$ ($83.2mg\;TAN\;kg\;fish^{-1}\;h^{-1}$), respectively. The TAN loss for ingested nitrogen at $20^{\circ}C$ (48.8%) was higher than that for $10^{\circ}C$ (43.0%) and $15^{\circ}C$ (45.7%). This study provides empirical data for estimating ammonia excretion and managing culture management of starry flounder under given temperatures.