• Journal of Aquaculture
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• v.13 no.1
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• pp.55-62
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• 2000

A 10-week feeding trial was conducted to investigate the effects of several yeasts with or without chemical treatment (protoplasted) in formulated diets on growth and body composition of juvenile abalone(Haliotis discus hanai). There replicate groups of the abalone average weighing 210 mg were fed one of eight isonitrogenous (30%) and isolipidic (4.4%) diets containing 3% Kluyveromyces fragilis protoplasted K. fragilis Candida utilis protoplasted C. utilis, Saccharomyces cerevisiae protoplasted S. cerevisiae or brewer's yeast. In addition these formulated diets were compared with commercial diet. Survival rate and proximate analysis of soft whole body of abalone were not significantly affected by the different dietary yeasts and commercial diet (P>0.05) Body weight gain and soft body weight control diet and diets containing S. cerevisiae or brewer's yeast (P<0.05) Shell length of abalone fed yeast and commercial diet (P<0.05) Th results suggest that protoplasted K. fragilis as an additive in this formulated diet can improve weight gain of abalone.

• Journal of Aquaculture
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• v.11 no.4
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• pp.505-512
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• 1998

This study was conducted to investigate the effects of three different formulated diets and macroalgae(Undaria) on growth and body comoposition among juvenile Haliotis discus, H. sieboldii and H. discus hannail. Three replicate groups among the three species abalones average weighing 0.31g were fed one of one experimental diet, two commercial diets and Undaria for 9 weeks. The three formulated diets produced significantly (P<0.05) greated body and shell growth than Undaria within same abalone species. Survival rates (97~99%) of H. discus and H. sieboldii were higher than that (74~77%) of H. discus hannai. Whereas different diets had no significantly (P>0.05) distincitive effect on survival within each three different abalone species. Moisture of abalone soft body in final stage reduced compared to those of abalone in initial stage in H. discus and H. discus hannai. Regardless of diet, abalone soft body revealed significantly (P<0.05) increased protein and decreased ash at the end of feeding trial in all three abalone species. This study indicate that all three different formulated diets used in this experiment could be a practical diet in three abalone species.

• 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 the Korean Society of Marine Environment & Safety
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• v.14 no.3
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• pp.183-187
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• 2008

Elevated concentrations of suspended solids in the marine enrironment caused by coastal developments have threatened to the marine ecosystem. Effects of suspended solids on the mortality and the modifications of glycogen levels of abalone, Haliotis discus hannai were studied. Abalone were exposed to suspended solids with concentrations of 0 (control), 1,000, 1,500 and 2,000 mg/ L for 96h. These suspended solids had no effect on the mortality of abalone. Significant decreases in the glycogen content of soft tissues were observed over 1,500 mg/ L concentration of suspended solids. These results suggested that abalone could tolerate a high level of suspended solids. However, it is necessary to observe further the long term effects of suspended solids on the physiological responses of abalone.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.391-394
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• 1999

A feeding experiment was conducted using juvenile abalone (Haliotis discus hannai) to investigate the optimum level of supplemental vitamin and/or mineral premixes in a formulated diet for practical feed formulation. Three replicate groups of abalone averaging 100 mg were fed the diets containing different levels of vitamin premix ($0\%,\;0.5\%,\;1.0\%$ and $2\%$) and /or mineral premix($0\%,\;2\%,\;4\%$ and $6\%$) for 4 months. Survival rates of abalone showed no distinctive trend by the levels of dietary vitamin premixes. Weight gain, shell growth and soft body weight of abalone were not significantly affected by the different dietary vitamin and/or mineral premixes (P>0,05). Moisture, protein and lipid contents of soft body were influenced by experimental diets (P<0.05) but these differences also had no definite trends by levels of vitamin and/or mineral premixes. These data indicate that supplemental vitamin or mineral premix is not needed in this formulated diet, therefore price of diet for juvenile abalone could be reduced.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.615-625
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• 2023

This study evaluated the bacteriological safety of seawater and abalone produced in Uisin-myeon, Jindo-gun from September 2020 to December 2022 and calculated the effect of inland pollution sources on seawater and abalone. We surveyed 33 stations for seawater, 4 stations for abalone, and 7 stations for discharge water of major inland pollutants. We analyzed the coliform group, fecal coliform and Escherichia coli (E. coli) as bacteria indicators. In 924 seawater samples, the geometric mean of the coliform group and fecal coliform were <1.8-5.6 MPN/100 mL and <1.8-2.7 MPN/100 mL, respectively. The estimated 90^th percentile range for the coliform group and fecal coliform were <1.8-42 MPN/100 mL and <1.8-8.4 MPN/100 mL, respectively. The fecal coliform and E. coli levels for 107 abalone were <18-460 MPN/100 g and <18-78 MPN/100 g respectively. Moreover, the analyzed standard plate count was <30-7,700 CFU/g. The fecal coliform level and diffusion area in 7 inland pollutants were <1.8-3,300,000 MPN/100 mL and 2-2,500 m, respectively. The bacteriological safety of seawater and abalone in Uisin-myeon, Jindo-gun, was demonstrated to be a designated area according to Korean standards, a conditionally approved area per US standards, and Class A according to EU standards.

• Journal of fish pathology
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• v.29 no.1
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• pp.35-43
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• 2016

In comparison to the numbers of such studies of fish, few studies have been carried out on the immunity, physiology and ecology of abalone, while studies on abalone disease are also extremely rare. Moreover, mass mortality of cultured abalone due to pathogenic bacteria has not been reported in the southern coast of Korea. However, Vibrio-like bacteria have been isolated from dead abalone, which indicates that a review is required in order to determine the cause of abalone mortality. Use of an antimicrobial agent to minimize the damage caused by disease in abalone farms is common, but the therapeutic effects are insignificant. Demand for probiotics has increased, but research on the development of probiotics for use in abalone culture is very rare. Therefore, the present study isolated KC16-2 from fermented kimchi soup and investigated the characteristics of the isolate as a candidate probiotic bacterium in abalone. KC16-2 was identified as Bacillus amyloliquefaciens (B. amyloliquefaciens KC16-2) based on its biochemical properties and 16S rRNA gene sequence. B. amyloliquefaciens KC16-2 showed inhibitory effects against the growth of various vibrios in vitro, and kept the numbers constant until four days after inoculation in marine water at a temperature of $15{\sim}25^{\circ}C$, indicating the possible use of KC16-2 as a probiotic, except in the winter. The growth of KC16-2 was inhibited by bile salt, but the numbers increased over time suggesting the bacteria were still alive in the abalone's digestive tract. Abalone fed with a diet including KC16-2 for 12 weeks showed good growth, but showed no significant differences from the control group. However, the mortality of the abalone supplied the probiotic diet was reduced to half that of the control group in a challenge test with Vibrio tubiashii. Therefore, we suggest that B. amyloliquefaciens KC16-2 could be used as a probiotic bacterium for control of the mortality of abalone caused by opportunistic pathogenic vibrios.

• Journal of fish pathology
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• v.26 no.2
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• pp.117-121
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• 2013

Three commercial exfoliating reagents, product A (main components: citric acid and vitamin C), B (herb) and C (nicotinamide), were used to study their exfoliation effect on abalone, Haliotis discus hannai from the substrate. The exfoliating reagents A, B, C and oxytetracycline (OTC, control) of 6-31.25 g/L and 12-37.5 g/L exfoliated 81.2-84.8% and 90.3-95% of abalone, respectively. Post-treatment recovery time for the abalone was similar for all the reagents except product C. Recovery period for the abalone immersed in OTC for 5-20 second was slightly shorter than the reagents A, B and C; however, no mortality was observed in any group except with the reagents B (concentration: 20 g/L, immersion time: 5 sec) and C (12 g/L, 10 and 20 sec) that showed negligible mortality of 3.3%. Higher concentration and longer treatment with the reagents resulted in longer recovery time of the detached abalone. Although abalone exposed to the reagents needs slightly longer time to recover than that to OTC, the exfoliation effect is much similar. These results indicate that the commercial exfoliating reagents can replace OTC to detach abalone, though they need to be cautiously handled.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.8
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• pp.385-391
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• 2018

Abalone aquacultural industry has been growing rapidly in a short period of time, however, there has been just a few researches related to the forecast of the supply, demand and price. Even the models developed by these researches have problems of low compatibility and reliability. To resolve these problem, a biological supply model needs to be developed that maintains time difference and linkage among the quantity of juvenile abalone into the plots, quantity of cultivation, quantity of shipment, and at the same time juvenile abalone is transplanted into the plot, matured and shipped by the expected market price. This study focus on the development of the model for determining quantity of the abalone cultivation, which is the core part of the entire abalone demand and supply model. Key factors that affect cultivation quantity were identified and verified the causal relationship among these variables and cultivation quantity. It turned out that the quantity of juvenile abalone transplanted and the relative price(the abalone price of the place of produce divided by the brown seaweed price) have a great influence on the cultivation quantity. Also, the similarity of the variation for the cultivation quantity of the observed value and the forecasted value implies that the model developed in this study has a high compatibility.

• Journal of Aquaculture
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• v.11 no.1
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• pp.19-29
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• 1998

An 18-week growth trial was conducted in flow-through aquarium system to evaluate the practical dietary protein sources for juvenile abalone (Haliotis discus hannai). Three replicate groups of the abalone averaging 0.11g were fed one of ten diets containing casein, white fish meal (WFM), meat meal (MM), feather meal (FM), blood meal (BM), soybean meal (SM), corn gluten meal (CGM), cotton seed meal (CSM), Undaria powder (UP), or wheat flour (WF) as a dietary protein source. In addition, these dietary protein sources were cmpared with algae such as raw Undaria or dried Laminaria. Weight gain of abalone fed the diets containing casein, WFM, SM, CSM, or UP was significantly higher (P<0.05) than those of abalone fed other diets, and this value of abalone fed FM, BM, CGM, or algae was lower than other groups. Shell length, shell width, body wt./shell length ratio, and body wt./shell width ratio of abalone fed casein, WFM, SM, CSM, UP, and WF were also highe (P<0.05) than those of other groups. There were no significant difference (P>0.05) in moisture and protein contents of soft body among all diets. The data obtained in this study indicate that each of the casein, WFM, SM, CSM or UP is good dietary protein source for juvenile abalone.