• Korean Journal of Fisheries and Aquatic Sciences
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• v.40 no.3
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• pp.133-140
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• 2007

In 2006, we studied herbivore consumption rate and preference for algal species using laboratory experiments. In the no-choice feeding experiment, three herbivores (two sea urchins, Stronglyocentrotus nudus and Stronglyocentrotus intermedius and an abalone, Haliotis discus hannai) showed significantly (P<0.05) distinct preferences for four algae (Laminaria japonica, Undaria pinnatifida, Costaria costata and Ecklonia stolonifera). The alga preferred by S. nudus was L. japonica followed by U. pinnatifida, C. costata and E. stolonifera with respective daily feeding rates of $5.7{\pm}:0.85\;g,\;4.4{\pm}0.89\;g,\;3.1{\pm}0.39\;g\;and\;2.1{\pm}0.32\;g(mean{\pm}SE)$. A similar trend was found for S. intermedius. Interestingly, the herbivore consumption rates for the algae differed with or without competition. The competition stimulated the feeding activity for S. nudus, but lowered the activity for S. intermedius. The multi-choice feeding experiment confirmed that L. japonica was significantly preferred by two herbivores: S. nudus and H. discus hannai (Duncan's multiple range test, ANOVA, p<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.5
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• pp.565-570
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• 2013

Physiological studies on the salinity tolerance with respect to survival rate and body composition changes of the abalone Haliotis discus hannai were conducted by rapidly changing the salinity in an indoor rearing system. The survival rate of the control (35 psu), 30 and 25 psu groups at $15^{\circ}C$ was 100%. The survival rate of the 20 psu group was $35{\pm}5.0%$. Survival rate of the 15 psu group was 0%. At $15^{\circ}C$ and 35, 30, 25, 20, 15 psu, the moisture contents of abalone muscle were $82.1{\pm}0.7$, $82.5{\pm}0.7$, $84.9{\pm}0.5$, $86.9{\pm}0.3$ and $86.6{\pm}0.4%$, respectively. Crude lipid contents were $0.47{\pm}0.03$, $0.47{\pm}0.03$, $0.47{\pm}0.09$, $0.77{\pm}0.09$ and $0.63{\pm}0.03%$, respectively and crude ash contents were $1.30{\pm}0.12$, $1.33{\pm}0.15$, $1.13{\pm}0.23$, $1.87{\pm}0.15$ and $1.40{\pm}0.31%$, respectively. At salinity below 20 psu, these values increased compared with the control. The general components of abalone muscles significantly increased below 20 psu, while amino acid composition showed no significant difference with salinity and water temperature.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.5
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• pp.560-564
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• 2011

Two feeding experiments were conducted to investigate the effects of dietary inclusion of genetically modified (GM) soybean and corn on the growth performance, feed utilization and body composition of juvenile abalone Haliotis discus hannai. Four isonitrogenous (31% crude protein) and isolipidic (6% crude lipid) diets (designated as nGM-soya, GM-soya, nGM-corn and GM-corn) were formulated to contain 20% non-GM (nGM) and GM soya and corn. Fifty juvenile abalone (initial body weight, 2.0 g) were distributed in each 50 L tank in a flow-through system. Each experimental diet was fed to duplicate groups of abalone to satiation once a day for 10 weeks. No effects of GM feedstuffs on survival were observed. Dietary inclusion of GM feedstuffs did not affect either growth performance or feed utilization of abalone. Body composition was not altered by the inclusion of GM feedstuffs. These results indicate that dietary inclusion of GM soybean and corn could have no effect on the growth performance and body composition of juvenile abalone. Further studies to investigate the effects of GM feedstuffs on transgenic fragment residues in ambient environments and in animals are necessary for the safe use of such ingredients in aquaculture.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.3
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• pp.238-247
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• 2018

This study investigated survival rates and physiological responses in Pacific abalone (Haliotis discus hannai) to 18 days of containment in live fish containers ($8^{\circ}C$, 34 psu). The investigation was divided into three periods: before, during, and recovery after transportation. The overall survival rate was greater than 99%. Glucose, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) rose immediately on the first day of containment, but then gradually returned to normal levels. $NH_3$ continued to rise after the first day, but during the recovery period it decreased to a level not significantly different from that of the control group. $Na^+$ and osmolality did not show any abnormal changes. After recovery, superoxide dismutase (SOD) was not significantly different from control. Abalone in the experimental group had lower glutathione reductase (GR) than control. The hyalinocyte ratio fell immediately after confinement, but then gradually increased until it reached a normal level. The ratios of apoptotic and necrotic cells indicated no specific variations in hemocyte viability. Histological changes in the epidermal layer and muscle layer of the foot were not significantly different from those seen in the control group. The experimental data obtained in this study suggest that live fish containers may be used for transport of Pacific abalone without significantly impacting their physiology or survival rates.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.586-590
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• 2003

The effect of water temperature and feed on the growth, survival, and body composition of juvenile abalone (Haliotis discus hannai) fed an artificial formulated diet and a macroalgae (Laminaria japonica) for 12 weeks was investigated. Rearing temperature was maintained at $13{\circ}C,\;16{\circ}C,\;19{\circ}C$ by heated and natural sea water temperatures $(7.5-10.2{\circ}C).$ Shell growth, weight gain, and survival rate of the abalone were affected by water temperature and diet (P<0.05). Survival and growth rate of the abalone fed with the formulated diet and Laminaria at $19{\circ}C$ was significantly higher than those of the abalone fed the formulated diet or Laminaria at $13{\circ}C,\;16{\circ}C,$ and ambient temperatures (P<0.05). Moisture, crude protein, crude lipid, and ash contents of the soft whole body were affected mainly by diet than rearing water temperature (P<0.05). These indicate that a mixture of formulated diet and macroalgae could improve the growth of the abalone independent of water temperature and heated water could improve the growth of abalone during the winter season.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.6
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• pp.591-595
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• 2003

Settlement of larvae, growth, and survival of juvenile abalone (Haliotis discus hannai) were examined after feding of 5 species of benthic diatoms (Cocconeis suctellum, Navicula sp Nitzschia longissima Bacillavia paxillifera, Licmophora flabellata). All of the benthic diatoms were isolated from natural populations on plastic plates for the abalone. The settlement of larvae, shell growth, and survival rate of juvenile abalone varied by diatoms species. The highest settlement rate of larvae was $43.1\%$ with the Cocconeis suctellum diet. Daliy growth rate reached a maximum at 64.1 ${\mu}m/day$ with the Navicula sp. diet and a minimum at 22.4 ${\mu}m/day$ with the Licmophora flabellata diet. Survival rate of the juvenile abalone was highest at $62.0\%$ with the Navicula sp., Cocconeis suctellum , and Nitzschia longissima diets. Survival rate of the Juvenile abalone was significantly higher than the control group with mixed diatom population diets (P<0.05). Therefore, diatom . species composition in diets can be a controling factor for the settlement, growth, and survival rates of Juvenile abalone.

• Journal of Aquaculture
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• v.13 no.2
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• pp.163-168
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• 2000

Dietary value of eight species of benthic diatoms, considered as essential live food for larvae and spat of abalone, was assessed on the retarded spat (ca 4.4 m shell length). Survival of the spat, fed on Caloneis schroderi, Phaeodactylum tricornutum and Raphoneis sp. was over 93 % and significantly higher than that of others; spat fed on C かwがwi gained the highest daily growth of 112.6 mm, which was two times faster than that fed on Undaria pinnatifida Spat fed on natural or cultured diatoms of C. schroderi grew at rates, that were not significantly different. C. schroderi is recommended to restore the retarded growth of abalone spat.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.6
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• pp.640-646
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• 2018

To determine whether there are differences in the food component characteristics of the cultured recessive small-sized abalone Haliotis discus hannai (SA; 30-40 each/kg) and middle-sized abalone (MA; 10-15 each/kg), the proximate compositions, fatty acid and total amino acid compositions of these two species were evaluated. Additionally, extraction methods were performed on the SA to asses the quality characteristics of the resulting. In terms of proximate composition, MA had lower moisture and carbohydrate levels and higher crude protein contents than SA. The total amino acid contents of MA and SA were 15,734.4 and 11,379.1 mg/100 g, respectively, the major amino acids were glutamic acid, aspartic acid, serine, glycine, alanine, leucine, arginine and lysine, and the major fatty acids were 16:0, 18:0, 18:1n-9, 18:1n-7, 20:4n-6, 20:5n-3, and 22:5n-3. The pH levels and total nitrogen and amino nitrogen contents of the hot-water extract (WE) and scrap enzyme hydrolysate (SE) samples from the SA were 6.32 and 6.05, 1.36% and 1.52%, and 342.1 and 403.1 mg/100 g, respectively. The extraction yields and free amino acid contents from SA were 1,317 and 440 mL/kg, and 8,721.1 and 9,070.7 mg/100 g, respectively, and the concentrations of major components were as follows: arginine, glycine, glutamic acid, alanine and lysine. Additionally, the complex extract (WE+SE) was superior to the traditional extract (WE) in terms of extraction yield, amino-nitrogen content, and organoleptic qualities but not odor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.6
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• pp.621-627
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• 2009

In order to standardize the juvenile abalone rearing technique, we selected sample farms by region in East, West and South coasts of Korea and Jeju island. We also have reviewed previous literature and visited farms to survey on the management of abalone juvenile production, spawning, hatching and so forth. Results of investigation are as follows: The light colors of tanks for larvae breeding are good for a frequent examination of larvae behaviour changes during the breeding period. The tank for the abalone juvenile production is a rectangular form in general and its size should amount to 3.5 m in length and 1.2 m width. It also should be built with proper drainage. The best age and size of adult for juvenile production are 3-6 years old individuals, with 9-12 cm separate burial and 125-150 g average weight. To induce spawning, the use of the exposure on air and ultraviolet ray together was the most effective. The density of larvae by plate should be 150-300 individuals and the proper stocking density was est imated and amount to 10-30 individuals. It has been shown that a correlation between water surface size($X_1$) and number of plates ($Y_1$), when producing abalone juveniles, is quite high and it is described by equation $Y_1=138.88X_1-5,736.8\;(R^2=0.9028)$. In addition, it has also been shown that a correlation between production of abalone juveniles ($Y_2$) and number of plates ($X_2$) is high and it is described by equation $Y_2=4.554X_2+12,493\;(R^2=0.8818)$. In Jindo region where a mass production of juveniles abalone has been done, it was shown, that a correlation between rearing water surface size ($X_3$) and production of juveniles abalone ($Y_3$) is very high and this relationship was described by the equation $Y_3=747.03X_2+94,359(R^2=0.9809)$. It has also been shown that a correlation between water surface size ($X_4$) and production of abalone juveniles ($Y_4$) in nationwide is high and the relationship between this variables was described by equation $Y_4=635.85X_4+99,923\;(R^2=0.9020)$.

• Journal of Aquaculture
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• v.9 no.4
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• pp.445-452
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• 1996

Endogeneous activities of ${\beta}-galactosidase$-like enzyme in various tissues from several finfishes and shellfishes were examined by histochemical analysis based on X-gal staining and by fluorimetric measurement using 4-methylumbelliferyl-${\beta}$-D-galactoside (4-MUG). Species used in this study were 3 freshwater fishes, mud loach (Misgurnus mizolepis), common carp (Cyprinus carpio) and tilapia (Oreochromis niloticus) ; 3 marine fishes, olive flounder (Paralichthys olivaceus), stone flounder (Kareius bicoloratus) and marbled sole (Limanda yokohamae) ; and 4 shellfishes, abalone (Haliotis discus hannai), Pacific oyster (Crassoskra gigas), pearl oyster (Pinctada fucata martensii) and ark shell (Anadara broughtonii). The activities of ${\beta}-galactosidase$-like enzyme in all finfishes examined were significantly different among species, with the wide variations between tissues in a species. In general, the tissues such as kidney, intestine and liver were ones which showed the significantly higher values in 4-MUG fluorimetry and deeper staining patterns in X-gal analysis compared to other tissues. On the other hand, serum and muscle revealed the significantly lower activities than others did, regardless of species. Shellfishes were also found to have endogenous activities of ${\beta}-galactosidase$-like enzyme which were significantly varied depending on both species and organs in a species. Hepatopancreas from all shellfishes examined showed the deepest pattern in X-gal staining and also the highest value in 4-MUG analysis, while activities of ${\beta}-galactosidase$-like enzyme in adductor muscles and mantle muscles from all shellfish species in this study except Pacific oyster were negligible : Pacific oyster had the significant activity of this enzyme in muscle tissues. Putative endogenous lacZ fragment was amplified from both finfishes and shellfishes by polymerase chain reaction (PCR). The molecular size of PCR products was about 510 bp, and there was no difference in size among species examined.