Synergistic Effects of Dietary Vitamins C and E on Methylmercury-Induced Toxicity in Juvenile Olive Flounder Paralichthys olivaceus

Park, Gunhyun,Yun, Hyeonho,Lee, Seunghan,Taddese, Fasil,Bai, Sungchul C. The Korean Society of Fisheries and Aquatic Scienc 2015 Fisheries and Aquatic Sciences Vol.18 No.2

This experiment was conducted to evaluate the synergistic effects of vitamin C and E on methylmercury (MeHg) toxicity in juvenile olive flounder Paralichthys olivaceus. In a $3{\times}3$ factorial design, 9 experimental diets containing three different vitamin C (0, 200 or 400 mg/kg diet in the form of l-ascorbyl-2-monophosphate) and vitamin E (0, 100 or 200 mg/kg diet in the form of dl-${\alpha}$-tocopheryl acetate) levels with the Hg toxicity level (20 mg/kg diet in the form of MeHg) were formulated. Triplicate groups of fish averaging $2.3{\pm}0.05g(mean{\pm}SD)$ were fed one of the 9 diets in a flow through system for 8 weeks. Fish fed 400 mg vitamin C/kg diet with 100 or 200 mg vitamin E/kg diet showed significantly (P < 0.05) higher weight gain (WG) than did fish fed the other diets. Fish fed 400 mg vitamin C/kg diet at all vitamin E levels and those which fed vitamin C and E equally at a rate of 200 mg/kg diet showed significantly (P < 0.05) higher feed efficiency (FE), specific growth rate (SGR) and protein efficiency ratio (PER) than did fish fed the other diets. Fish fed 200 and 400 mg vitamin C/kg diet exhibited significantly (P < 0.05) lower Hg concentration in their muscle as well as kidney than did fish fed the other diets. Therefore, these results clearly indicated that the synergistic effects of these two vitamins on MeHg toxicity by supplementing dietary vitamin C (200 and 400 mg/kg diet) with vitamin E (100 and 200 mg/kg diet) in juvenile olive flounder.

Original Article : Synergistic Effects of Dietary Vitamins C and E on Methylmercury-Induced Toxicity in Juvenile Olive Flounder Paralichthys olivaceus

( Gunhyun Park ),( Hyeonho Yun ),( Seunghan Lee ),( Fasil Taddese ),( Sungchul C. Bai ) 한국수산과학회(구 한국수산학회) 2015 Fisheries and Aquatic Sciences Vol.18 No.2

This experiment was conducted to evaluate the synergistic effects of vitamin C and E on methylmercury (MeHg) toxicity in juvenile olive flounder Paralichthys olivaceus. In a 3×3 factorial design, 9 experimental diets containing three different vitamin C (0, 200 or 400 mg/kg diet in the form of l-ascorbyl-2-monophosphate) and vitamin E (0, 100 or 200 mg/kg diet in the form of dl-α-tocopheryl acetate) levels with the Hg toxicity level (20 mg/kg diet in the form of MeHg). Triplicate groups of fish averaging 2.3 ± 0.05 g (mean ± SD) were fed one of the 9 diets in a flow through system for 8 weeks. Fish fed 400 mg vitamin C/kg diet with 100 or 200 mg vitamin E/kg diet showed significantly (P < 0.05) higher weight gain (WG) than did fish fed the other diets. Fish fed 400 mg vitamin C/kg diet at all vitamin E levels and those which fed vitamin C and E equally at a rate of 200 mg/kg diet showed significantly (P < 0.05) higher feed efficiency (FE), specific growth rate (SGR) and protein efficiency ratio (PER) than did fish fed the other diets. Fish fed 200 and 400 mg vitamin C/kg diet exhibited significantly (P < 0.05) lower Hg concentration in their muscle as well as kidney than did fish fed the other diets. Therefore, these results clearly indicated that the synergistic effects of these two vitamins on MeHg toxicity by supplementing dietary vitamin C (200 and 400 mg/kg diet) with vitamin E (100 and 200 mg/kg diet) in juvenile olive flounder.

Comparison of the Nutritional Value of Chlorella ellipsoidea and Nannochloris oculata for Rotifers and Artemia Nauplii

Cabrera Tomas,Bae Jean Hee,Bai Sungchul C.,Hur Sung Bum The Korean Society of Fisheries and Aquatic Scienc 2005 Fisheries and Aquatic Sciences Vol.8 No.4

Microalgae are widely used for mass culture of the rotifer Brachionus plicatilis in aquaculture. Since the nutritional value of the rotifer is closely related to its food, the nutritional value of its food should be known in detail. Chlorella ellipsoidea and Nannochloris oculata are re­presentative food organisms for rotifers that are easily cultured. Therefore, the nutritional values of these micro algae were examined for ultrasmall, small, and large rotifers and Artemia nauplii. Chlorella ellipsoidea contained seven times more total fatty acids than N. oculata. The three types of rotifer fed N. oculata contained more amino acids than those fed C. ellipsoidea. However, the total fatty acids of the rotifers fed each microalga species differed according to the type of rotifer. Newly hatched Artemia nauplii contained more protein and had a higher dry weight than those fed microalgae for 6 h. As with the rotifers, the Artemia nauplii fed N. oculata contained more protein and amino acids than those fed C. ellipsoidea, while the reverse was true for the total fatty acid content. Our results suggest that N. oculata is a good supply of protein, while C. ellipsoidea is a good source of lipids as food organisms for rotifers and Artemia nauplii in aquaculture.

Effects of Microalgae and Salinity on the Growth of Three Types of the Rotifer Brachionus plicatilis

Cabrera Tomas,Bae Jean Hee,Bai Sungchul C.,Hur Sung Bum The Korean Society of Fisheries and Aquatic Scienc 2005 Fisheries and Aquatic Sciences Vol.8 No.2

We investigated the effects of salinity and three food species of microalgae on the growth of three types of the rotifer Brachionus plicatilis, with the aim of improving mass culture of rotifers in hatcheries. Three types (large, small, and ultra-small) of the rotifer were cultured at 16 ppt and 32 ppt salinity with the green algae Chlorella ellipsoidea, Nannochloris oculata, or Tetraselmis tetrathele. The maximum density and specific growth rate were compared for each rotifer type. Ultra-small rotifers grew significantly faster at 16 ppt salinity than at 32 ppt, and C. ellipsoidea and T. tetrathele promoted significantly higher growth than did N. oculata. However, small rotifers grew significantly better at 32 ppt salinity than at 16 ppt, and small rotifers fed on N. oculata achieved the highest density at 1,185 individuals/ml. Large rotifers grew faster at 16 ppt salinity than at 32 ppt, with a diet of T. tetrathele resulting in the fastest growth. Each type of rotifer thrived under different regimens of microalgae and salinity.

Species-specific PCR detection of the fish pathogen, Vibrio anguillarum, using the amiB gene, which encodes N-acetylmuramoyl-l-alanine amidase : Species-specific PCR detection of fish pathogen, V. anguillarum

Hong, Gyeong-Eun,Kim, Dong-Gyun,Bae, Ju-Yoon,Ahn, Sun-Hee,Bai, Sungchul C.,Kong, In-Soo Published by Elsevier/North Holland on behalf of t 2007 FEMS microbiology letters Vol.269 No.2

<P>Vibrio anguillarum is the causative agent of the fish disease vibriosis and is the most intensely studied species of Vibrio. In the present study, specific primers and a PCR assay were designed to detect V. anguillarum. The primers were designed to amplify a 429-bp internal region of the V. anguillarum amiB gene, which encodes the peptidoglycan hydrolase N-acetylmuramoyl-L-alanine amidase. PCR specificity was demonstrated by successful amplification of DNA from V. anguillarum and by the absence of a PCR product from 25 other Vibrio strains and various enteric bacteria. The PCR produced a 429-bp amplified fragment from as little as 1 pg of V. anguillarum DNA. The limit of detection for this PCR technique was c. 20 bacterial colonies in 25 mg of infected flounder tissue. These results suggest that this PCR system is a sensitive and species-specific detection method, and is possible to use as a diagnostic tool to detect V. anguillarum.</P>

Original Article : A Review of the Optimum Feeding Rates and Feeding Frequency in Korean Rockfish Sebastes schlegeli Reared at Seven Different Water Temperatures

( Rahman M Mizanur ),( Sungchul C Bai ) 한국수산과학회(구 한국수산학회) 2014 Fisheries and Aquatic Sciences Vol.17 No.2

Seven feeding trials were conducted to determine the effects of feeding rate and frequency in the Korean rockfish Sebastes schlegeli at seven different water temperatures. Two feeding-rate experiments for 5-g Korean rockfish at 17°C and 20°C; three feeding rate experiments for 16-g Korean rockfish at 16°C and 24°C; and finally, two feeding frequency experiments for 93- and 100-g at 15°C and 20°C were conducted. Twenty fish averaging 5.5 ± 0.2 g (mean ± SD) were randomly distributed into 18 indoor tanks containing 40-L seawater from a semi-recirculation system. Fish were fed a commercial diet for 4 weeks at water temperatures of 17°C and 20°C. Two feeding trials were conducted to determine the optimum feeding frequency in growing Korean rockfish reared at temperatures of 15°C and 19°C. Broken line regression analysis of weight gain (WG) indicated that the optimum feeding rates of 5-g growing Korean rockfish were 4.48% (BW/day; BW, body weight) at 17°C and 4.83% (BW/day) at 20°C. Broken line regression analysis of WG showed optimum feeding rates of 16-g juvenile Korean rockfish of 3.41% (BW/day) at 16°C, 3.75% (BW/day) at 20°C, and 3.34% (BW/day) at 24°C. The biological performance, results, along with morphological indices and serological characteristics, suggest that a feeding frequency of 1 meal/day was optimal to improve WG in growing Korean rockfish grown from 93 to 133 g at a water temperature of 15°C, and 100 to 132 g at 19°C.

The Optimum Feeding Frequency in Growing Korean Rockfish (Sebastes schlegeli) Rearing at the Temperature of 15℃ and 19℃

Mizanur, Rahman Md.,Bai, Sungchul C. Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.9

Two feeding trials were conducted to determine the optimum feeding frequency in growing Korean rockfish, (Sebastes schlegeli) reared at the temperatures of $15^{\circ}C$ and $19^{\circ}C$. Fish averaging $92.2{\pm}0.7$ g (mean${\pm}$standard deviation [SD]) at $15.0{\pm}0.5^{\circ}C$ and $100.2{\pm}0.4g$ ($mean{\pm}SD$) at $19.0{\pm}0.5^{\circ}C$ water temperature were randomly distributed into each of 15 indoor tanks containing 250-L sea water from a semi-recirculation system. A total of five feeding frequency groups were set up in three replicates as follows: one meal in a day at 08:00 hour, two meals a day at 08:00 and 17:00 hours, three meals a day at 08:00, 14:00, and 20:00 hours, four meals a day at 08:00, 12:00, 16:00, and 20:00 hours, and one meal every 2 days at 08:00 hour. Fish were fed at the rate of 1.2% body weight (BW)/d at $15^{\circ}C$ and 1.5% BW/d at $19^{\circ}C$. At the end of 8 wks of feeding trial weight gain and specific growth rate were significantly higher at the fish fed groups of one meal a day and two meals a day at $15^{\circ}C$ and fish fed groups of 1 meal every 2 days at $19^{\circ}C$ were significantly lower than those of all other fish fed groups. Glutamic oxaloacetic transaminase and glutamic pyruvic transaminase of fish fed group at 1 meal every 2 days was significantly higher than those of all other fish fed groups in both experiments. Weight gain, specific growth rate and condition factor were gradually decreased as the feeding frequency increased. The results indicate that growing Korean rockfish 92 and 100 g perform better at $15^{\circ}C$ than $19^{\circ}C$ water temperature. As we expected, current results have indicated that a feeding frequency of 1 meal a day is optimal for the improvement of weight gain in growing Korean rockfish grown from 92 g to 133 g at $15^{\circ}C$ and 100 g to 132 g at $19^{\circ}C$ water temperature.

A Review of the Optimum Feeding Rates and Feeding Frequency in Korean Rockfish Sebastes schlegeli Reared at Seven Different Water Temperatures

Mizanur, Rahman M.,Bai, Sungchul C. The Korean Society of Fisheries and Aquatic Scienc 2014 Fisheries and Aquatic Sciences Vol.17 No.2

Seven feeding trials were conducted to determine the effects of feeding rate and frequency in the Korean rockfish Sebastes schlegeli at seven different water temperatures. Two feeding-rate experiments for 5-g Korean rockfish at $17^{\circ}C$ and $20^{\circ}C$; three feeding rate experiments for 16-g Korean rockfish at $16^{\circ}C$ and $24^{\circ}C$; and finally, two feeding frequency experiments for 93- and 100-g at $15^{\circ}C$ and $20^{\circ}C$ were conducted. Twenty fish averaging $5.5{\pm}0.2$ g ($mean{\pm}SD$) were randomly distributed into 18 indoor tanks containing 40-L seawater from a semi-recirculation system. Fish were fed a commercial diet for 4 weeks at water temperatures of $17^{\circ}C$ and $20^{\circ}C$. Two feeding trials were conducted to determine the optimum feeding frequency in growing Korean rockfish reared at temperatures of $15^{\circ}C$ and $19^{\circ}C$. Broken line regression analysis of weight gain (WG) indicated that the optimum feeding rates of 5-g growing Korean rockfish were 4.48% (BW/day; BW, body weight) at $17^{\circ}C$ and 4.83% (BW/day) at $20^{\circ}C$. Broken line regression analysis of WG showed optimum feeding rates of 16-g juvenile Korean rockfish of 3.41% (BW/day) at $16^{\circ}C$, 3.75% (BW/day) at $20^{\circ}C$, and 3.34% (BW/day) at $24^{\circ}C$. The biological performance, results, along with morphological indices and serological characteristics, suggest that a feeding frequency of 1 meal/day was optimal to improve WG in growing Korean rockfish grown from 93 to 133 g at a water temperature of $15^{\circ}C$, and 100 to 132 g at $19^{\circ}C$.

Effects of Feeding Rate and Water Temperature on Growth and Body Composition of Juvenile Korean Rockfish, Sebastes schlegeli (Hilgendorf 1880)

Mizanur, Rahman Md.,Yun, Hyeonho,Moniruzzaman, M.,Ferreira, F.,Kim, Kang-Woong,Bai, Sungchul C. Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.5

Three feeding trials were conducted to evaluate the effects of feeding rate and water temperature on growth and body composition of juvenile Korean rockfish, Sebastes schlegeli rearing at 3 different water temperatures. A total of 270 fish (each experiment) individual body weight (BW) averaging $16{\pm}0.3g$ ($mean{\pm}SD$) were fed a commercial diet for 4 wk at $16^{\circ}C$, $20^{\circ}C$, and $24^{\circ}C$. At each temperature, triplicate tanks were assigned to one of 6 feeding rates: 1.5%, 2.5%, 2.8%, 3.1%, 3.4%, and satiation (3.7% BW/d) at $16^{\circ}C$, 1.9%, 2.9%, 3.2%, 3.5%, 3.8% and satiation (4.1% BW/d) at $20^{\circ}C$ and 1.7%, 2.7%, 3.0%, 3.3%, 3.6%, and satiation (3.9% BW/d) at $24^{\circ}C$ water temperature. Weight gains of fish in satiation and 3.4% groups at $16^{\circ}C$, in satiation and 3.8% groups at $20^{\circ}C$ and in satiation and 3.6% groups at $24^{\circ}C$ were significantly higher than those of fish in the other treatments (p<0.05). A broken line regression analysis of weight gain indicated that optimum feeding rates of juvenile Korean rockfish were 3.41% at $16^{\circ}C$, 3.75% at $20^{\circ}C$ and 3.34% at $24^{\circ}C$ water temperature. Results of the present study indicate that the optimum feeding rate could be >3.1% but <3.41% at $16^{\circ}C$, >3.5% but <3.75% at $20^{\circ}C$ and >3.0% but <3.34% at $24^{\circ}C$. As we expected results suggest that fish performed better at $20^{\circ}C$ than $16^{\circ}C$ or $24^{\circ}C$ water temperature and the optimum feeding rate could be 3.1% BW/d to 3.7% BW/d in 16 g of juvenile Korean rockfish.

Effects of Different Dietary Cadmium Levels on Growth and Tissue Cadmium Content in Juvenile Parrotfish, Oplegnathus fasciatus

Okorie, Okorie E.,Bae, Jun Young,Lee, Jun-Ho,Lee, Seunghyung,Park, Gun-Hyun,Mohseni, Mahmoud,Bai, Sungchul C. Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.1

This feeding trial was carried out to evaluate the effects of different dietary cadmium levels on growth and tissue cadmium content in juvenile parrotfish, Oplegnathus fasciatus, using cadmium chloride ($CdCl_2$) as the cadmium source. Fifteen fish averaging $5.5{\pm}0.06$ g (mean${\pm}$SD) were randomly distributed into each of twenty one rectangular fiber tanks of 30 L capacity. Each tank was then randomly assigned to one of three replicates of seven diets containing 0.30 ($C_0$), 21.0 ($C_{21}$), 40.7 ($C_{41}$), 83.5 ($C_{83}$), 162 ($C_{162}$), 1,387 ($C_{1,387}$) and 2,743 ($C_{2,743}$) mg cadmium/kg diet. At the end of sixteen weeks of feeding trial, weight gain (WG), specific growth rate (SGR) and feed efficiency (FE) of fish fed $C_{21}$ were significantly higher than those of fish fed $C_{83}$, $C_{162}$, $C_{1,387}$ and $C_{2,743}$ (p<0.05). Weight gain, SGR and FE of fish fed $C_0$, $C_{21}$ and $C_{41}$ were significantly higher than those of fish fed $C_{162}$, $C_{1,387}$ and $C_{2,743}$. Protein efficiency ratio of fish fed $C_0$, $C_{21}$ and $C_{41}$ were significantly higher than those of fish fed $C_{1,387}$ and $C_{2,743}$. Average survival of fish fed $C_0$, $C_{21}$, $C_{41}$ and $C_{162}$ were significantly higher than that of fish fed $C_{2,743}$. Tissue cadmium concentrations increased with cadmium content of diets. Cadmium accumulated the most in liver, followed by gill and then muscle. Muscle, gill and liver cadmium concentrations of fish fed $C_0$, $C_{21}$, $C_{41}$ and $C_{83}$ were significantly lower than those of fish fed $C_{162}$, $C_{1,387}$ and $C_{2,743}$. Based on the ANOVA results of growth performance and tissue cadmium concentrations the safe dietary cadmium level could be lower than 40.7 mg Cd/kg diet while the toxic level could be higher than 162 mg Cd/kg diet.