Shin-Kwon Kim

Effect of taurine supplemented practical diet on growth performance and taurine contents in whole body and tissues of juvenile Japanese flounder Paralichthys olivaceus

The effect of dietary taurine on juvenile Japanese flounder was determined by feeding three taurine-supplemented experimental diets (TAU) and a commercial diet (CD) to evaluate a practical diet for juvenile Japanese flounder. Juvenile Japanese flounder were reared on the three experimental diets supplemented with taurine at 0, 0.5, 1.0% and CD. These diets were fed to juvenile Japanese flounder of an initial mean body weight of 0.2 g for 6 weeks at 20°C and the taurine contents of the whole body and tissues were analyzed. The final average body weight of juvenile Japanese flounder fed the 1.0% TAU was significantly higher than that of the other groups. Taurine contents in the whole body and tissues increased with the increase in dietary taurine level. These results indicate that juvenile Japanese flounder require at least 15 mg/g taurine in the diet, even though a combined mix of fish, krill and squid meal was the main protein source in the experimental diets.

Comparison of taurine biosynthesis ability between juveniles of Japanese flounder and common carp

Summary.This study was conducted to investigate taurine deficiency and the ability of taurine biosynthesis in both juvenile Japanese flounder (JF) and juvenile common carp (CC) in vivo using low taurine level diets. Three different taurine level diets were prepared by the supplementation of taurine to the basal composition (JF – 0, 0.5 and 1.5% in JF; CC – 0, 1, 3% in CC). The final average body weight and feed efficiency of JF fed the JF – 1.5% was significantly higher than those of fish fed on the JF – 0%. On the other hand, no significant difference was observed in CC fed with CC – 0, 1, and 3% diets. The taurine retention rate was negative in the case of JF-fed with the taurine-free supplement (JF – 0%). On the other hand, the taurine retention rate was about 280% in the case of CC-fed with the taurine-free supplement (CC – 0%). These findings indicate that while taurine is essential for growth of JF, it is not essential for the growth of CC.

Optimum dietary taurine level in casein-based diet for juvenile red sea bream Pagrus major

This study was conducted to investigate the effect of dietary taurine and cholyltaurine (C-tau) on growth and body composition of juvenile red sea Bream Pagrus major. Semi-purified casein-based diets supplemented with 0 (control diet), 0.1, 0.3, 0.5 and 0.7% taurine and 0.5% C-tau were fed to red sea bream (average body weight 4.7g) for 6 weeks at 20°C. The growth and feed efficiency were the lowest in fish fed the control diet. Taurine supplementation improved the growth and feed efficiency of fish dose-dependently, and the taurine requirement was estimated as 0.52% in terms of optimizing growth and 0.48% in terms of optimizing feed efficiency. Taurine content in the whole body and liver increased with the dietary taurine level. Supplemental C-tau at the 0.5% level had limited effects on the growth and no effect on body taurine, biliary bile salt and liver fat contents. From these results it can be inferred that the optimal dietary taurine requirement of juvenile red sea bream is 0.5% on a dry weight basis, and that the supplementation of taurine in the diet not only improves the growth but also increases hepatic lipid levels of red sea bream juveniles.

Effect of dietary taurine and lipid contents on conjugated bile acid composition and growth performance of juvenile Japanese flounder Paralichthys olivaceus

The effects of dietary taurine levels and lipid contents on the conjugated bile acid composition and growth performance of juvenile Japanese flounder Paralichthys olivaceus were investigated. Six types of diet (three different levels of taurine at two different levels of lipid) were fed to juveniles (average body weight, 0.04g). Fishmeal that was washed with 70% ethanol to remove taurine was used as the sole protein source. Feeding experiments were carried out at 20°C for 6 weeks. At the end of the experiments, fish were weighed and analyzed for free amino acids in the body and the composition of the conjugated bile acids. The body weight and percent weight gain of the juveniles were improved by the dietary taurine supplementation. The taurine contents of the whole body and tissues increased with the increase of the dietary taurine contents. The conjugated bile acids in the gall bladder consisted of taurocholic acid and taurochenodeoxycholic acid, which increased with the increase of the dietary taurine level. Taurocholic acid accounted for more than 95% of the total conjugated bile acids. This indicates that taurine is the sole amino acid to conjugate bile acid in Japanese flounder.

State of Aquaculture Management for Optimal Rearing of Eel Anguilla japonica

This study was conducted to investigate the production, elver stocking, rearing facilities and rearing method of eel culture to determine aquaculture management conditions for optimal rearing of eel Anguilla japonica. The production of eel culture was evaluated by the proportion of eels from the mai...

Evaluation of Commercial Extruded Pellets and Raw Fish- Based Moist Pellets for the Growth and Quality of Korean Rockfish Sebastes schlegeli Cultured in Net-Cages

This study was conducted to compare extruded pellets (EP) and soft extruded pellets (SEP) with a raw fish-based moist pellet (MP) diet on the growth and flesh quality of Korean rockfish Sebastes schlegeli. Three groups of 20,000 fish (initial mean weight 133 g) per net-cage (6×12×7 m) were fed commercial EP , SEP or MP for 16 months. The survival of fish fed SEP was higher than those of fish fed EP or MP. The highest growth performances were observed in the mean weight gain, total weight gain, and feed efficiency of fish fed MP , followed by those fed EP and SEP. Among the fish fed on extruded pellets, the total weight gain of fish fed SEP was higher than that of those fed EP, while fish fed EP grew faster than those fed SEP. No notable differences in body composition, sensory scores or textural properties of the dorsal muscle were observed in fish fed on EP , SEP or MP. Thus, it is suggested that extruded pellets, rather than raw fish-based moist pellets, could be fed to Korean rockfish without compromis ing flesh quality.

The Optimal Salinity and Temperature Condition for the Growth of Rotifer, Keratella sp.

Abstract We investigated the optimum salinity and temperature conditions for the mass culture of small rotifer, Keratella sp.. In the salinity experiment ranging from 0-34‰, the population growth of Keratella sp. drastically increased continuously up to 15‰, and then slightly increased over 20‰. Their maximum density reached 1,007 inds./mL at 0‰. A pre-reproductive phase was shorter in low salinity than in high salinity. The highest number of offspring per female (10.2 inds.) and lifespan of the female (10.7 days) were obtained at 0‰, but there were no significant differences compared to those at 5‰. In the temperature experiments ranging from 16-32℃, the highest maximum density (1,766 inds./mL) was shown at 24℃. The number of offspring per female significantly increased with increasing temperature, and the highest number of offspring per female was 10.4 inds. at 24℃. The lifespan of female increased with decreasing temperature and the longest lifespan was 12.8 days at 16℃.Key words : Small rotifer, Keratella sp., Salinity, Temperature Corresponding author : 033-640-2345, telss88@naver.com * 2013 (RP-2013-AQ-169) .

Optimal Food and Concentration for Growth of Small Rotifer, Proales similis

This study determined the optimum microalgae species and concentration for growth of small rotifer Proales similis, in community cultures by feeding it several different foods. Four single trials (Tetraselmis suecica, TET; Isochrysis galbana, ISO; Nannochloropsis oculata, NAN; freshwater Chlorella vulgaris, CHL) were conducted at 5 psu and 25 . The maximum density and specific growth rate (SRG) were ℃ highest for rotifer fed CHL reaching 1,075 individuals (inds.)/mL and 0.83 respectively. By contrast, other foods of ISO, NAN and TET resulted in poor growth rates and maximum density. In the freshwater C. vulgaris experiments examining a range of 0.05 to 8.8 mg/10 4 rotifers, the growth of rotifer tended to decrease with the amount of supplement. The maximum density and SGR of females was highest at 910 inds./mL and 0.55 respectively, at 0.05 mg/10 4 rotifers. These results suggest that the best microalgae species for the culture of P. similis is freshwater C. vulgaris and the optimum concentration is 0.05 mg/10 4 rotifers.

Digestive Physiological Characteristics of the Gobiidae

In this study, we investigated the characteristics of CCK-producing cells and mucus-secreting goblet cells with respect to stomach fish and stomachless fish of the Gobiidae in order to provide a basis for understanding the digestive physiology. Hairychin goby (Sagamia geneionema), which is stomachless fish, the numbers of mucus-secreting goblet cells is highest in the posterior intestine portion (P<0.05), while CCK-producing cells are scattered throughout the intestine. Gluttonous goby (Chasmichthys gulosus), which is stomach fish, mucus-secreting goblet cells are most abundant in the mid intestine portion (P<0.05), whereas CCK-producing cells are observed only in the anterior and mid intestine portion. Trident goby (Tridentiger obscurus) which is stomach fish, mucus-secreting goblet cells were most abundant in the mid intestine portion (P<0.05). CCK-producing cells are found in the anterior and mid intestine portion. Giurine goby, Rhinogobius giurinus which is also stomach fish, the largest number of mucus-secreting goblet cells showed in anterior intestine portion except for esophagus (P<0.05). CCK-producing cells are present only in the anterior and mid intestine portion. In S. geneionema, digestive action occurs in the posterior intestine portion to protect and functions to activate digestion. In contrast, in C. gulosus, T. obscurus and R. giurinus, their digestive action occurs in the anterior and mid intestine portion to protect and functions to activate digestion. Further studies of the modes of food ingestion by these fish, the contents of their digestive tracts, and the staining characteristics of the goblet cells need to be carried out.

Morphological Observation of Pre- and Postovulated Eggs from Artificially Maturated Wild and Feminized Eels

This study about morphological observation of preor post ovulated eggs obtained from artificially maturated female eels. Female eels were divided with two groups as wild eels from nature and feminized eels from farm. Artificial maturation had been conducted with the established methods in this laboratory, and then maturate eggs sampled at fixed 3 times and these were observed with stereomicroscope. Rate of increased body weight (RIW) were measured with 2 times. Egg diameters and development of oil droplets are determined for standardization of egg maturation degree, and the transparency of egg cytoplasm and the homogeneous degrees of egg size were referred to determine of egg quality. Rate of increased body weight (RIW) were good in range about 10 % at final salmon pituitary extracts (SPE) injection time and in range about 20 % at 17 , 20 -dihydroxy-4-pregnen-3-one (DHP) injection time. Good matured egg for α β fertilization had 900-1000 diameter, and they had about 50 oil droplets in size about 100 diameter. μm μm There were not predominant differences at egg size and oil droplet development between wild female and feminized eels