• Journal of Aquaculture
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• v.13 no.2
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• pp.153-161
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• 2000

Growth trends of 10 selected species of benthic diatoms, considered essential dietary requirement of the newly settled abalone were monitored. Navicula sp. (B-38), N. incerta and Caloneis schroderi, grew faster than the other tested diatoms. 16 and 32 % abalones fed on Raphoneis sp. and Phaeodactylum settled, respectively; less abalones souled, when fed on Navicula sp., Hantzxchia marina or Nitzschia sp. In the first experiment, survival of the settled abalone was the highest (63 %) and lowest (31 %) for those fed on Rhaphoneis sp. and Navicular sp. respectively. However, in the second and third series of esperiments, abalones fed on Rhaphoneis sp. and Navicula sp. showed the highest (67, 49 %) and lowest (35, 18 %) survival. C. schroderi proved to be the best diet, as the shell length of those fed on the diatoms was 83 ${\mu}$m, as against about 36 ${\mu}$m of those abalones, receiving H. marina or Nitzschia sp., diatoms of the lowest dietary value.

• 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.

• The Korean Journal of Malacology
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• v.28 no.4
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• pp.335-342
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• 2012

This study was conducted to estimation the selection response for growth-related traits in 31-month old of Pacific abalone, Haliotis discus hannai were born in 2008. In overall mean of surveyed traits and standard deviation showed $76.31{\pm}7.247$ mm of shell length, $49.48{\pm}5.307$ mm of shell width and $40.96{\pm}6.80$ g of total weight. The effect of sex and maturity were statistically significant in all traits include out a condition factor (p < 0.01). And In effect of sex, female were higher than male in all traits excepting condition factor, significantly. In correlation between breeding value and phenotypic value by each traits, showed rank correlation coefficient and simple correlation coefficient, which represented low positive correlation. A hopeful genetic improvement to the next generation showed 6.96 mm of shell length, 4.47 mm of shel width and 12.93 g of total weight. Therefor, It is considered that if considering properly selection intensity and selection ratio, efficient improvement could be made.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.3
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• pp.208-214
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• 2008

This study monitored a variety of marine communities during monthly or bimonthly censuses from February 1999 to August 2000. The communities investigated included artificial reefs composed of various substrates, which were placed on an area of sandy bottom at 8, 10, and 13m depths in Muronohana, Ikata, Shikoku, Japan. Economically important shell fishes, such as the turban shell and abalone, appeared on the artificial reefs after 1 month of construction. Shell fishes were recorded at levels of five to 20 individuals per reef. A total of 37 species (4 orders, 19 families) were identified during the experimental period. Apagon semilineatus, Trachurus japonicus, Pteragogus sp., and Pterogobius elapoides accumulated over an average of 100 individuals during the study period. Apagon semilineatus, Pteragogus sp., and P. elapoides accumulated over 1,000 individuals on all artificial reefs in May 1999. Trachurus japonicus reached well over 500 individuals in the artificial iron reef during June and July 2000. Higher monthly variation in fish abundance occurred during periods of high temperature, as compared to periods of low temperature between December 1999 and March 2000. More fish were observed in the artificial iron reef than in the artificial concrete reef, because the former offered a broader inner space and the shadows of the roofs served as a shelter for fish.

• The Korean Journal of Malacology
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• v.23 no.2
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• pp.217-225
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• 2007

This study was conducted to estimate the general genetic parameters, heritabilities, and genetic and phenotypic correlations on growth-related traits by studying multiple trait animal model in two Korean abalone species, Haliotis discus hannai and H. discus discus. The data was collected from the records of 3,795 individuals produced from 54 sires and 74 dams in Haliotis discus hannai and 399 individuals produced from 7 sires and 7 dams in Haliotis discus discus. The data was evaluated by the Genetics and Breeding Research Center, National Fisheries Research & Development Institute (NFRDI). Genetic parameters were estimated for two abalone species raised in Bukjeju branch, NFRDI, from May 20 to November 1, 2004. The heritability estimates for growth traits of shell length, shell width and body weight obtained from restricted maximum likelihood (REML) were ranging from 0.73 to 0.78 in Haliotis discus hannai, and from 0.87 to 0.89 in H. discus discus. The heritabilities for shell shape and condition factor were ranging from 0.17 to 0.20 in Haliotis discus hannai, and from 0.01 to 0.45 in H. discus discus. Genetic and phenotypic correlations were over than 0.96 between shell parameters and weight in both of abalone subspecies, indicating that breeding for weight gains could successfully be achieved by selecting for shell length.

• Journal of Aquaculture
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• v.11 no.3
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• pp.381-390
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• 1998

Three feeding experiments were carried out to evaluate the effects of fatty acids or lipid sources in diets on the survival, growth and body composition of junenile abalone(Haliotis discus hannai). Diets used in this study contained casein or fish meal as a protein source. Three replicate groups of abalone averaging 160 mg were fed with casein diets containing 12:0, 18:1, 18:2n-6, 18:3n-3, n-3HUFA, squid liver oil (SO), corn oil (CO), beef tallow (BT), SO+CO, and SO+BT, or fed fish meal diets containing SO, CO, BT, SO+CO, SO+BT and not supplemental oil for 20 weeks, respectively. Survival rate, weight gain and soft body weight of abalone were not significantly affected by different fatty acids in the casein diets (P>0.05). Weight gain, soft body weight and shell length of abalone fed the casein diets containing SO, SO+CO or SO+BT were significantly higher (P<0.05) than those of abalone fed the casein diets containing CO or BT. Survival rate of abalone fed the fish meal diets was not influenced by different lipid sources (P>0.05). Weight gain and soft body weight of abalone fed the fish meal diets containing beef tallow (BT or SO+BT diet) were lower than those of abalone fed the diet not added oil or diets containing SO, CO and/or SO+CO(P<0.05). These data indicated that SO or SO+CO was good dietary lipid source for juvenile abalone, and that these oil supplement in diet was not necessary when fish meal was used as a protein source.

• Journal of the Korean Ceramic Society
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• v.49 no.5
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• pp.438-441
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• 2012

Abalone shell is a high strength and light weighted ceramic composite material, which is composed of $CaCO_3$ platelet and protein. Microstructure of abalone shell has a matrix structure that is similar to the bricks and mortar. The technology inspired from nature which consumes low energy at low temperature is called bioinspired technology. In this study, to make high strength and light weighted ceramic composite materials using bioinspired technology, porous green body was prepared with $Al_2O_3$ platelet. PMMA was infiltrated into the porous green body, then warm pressed to eliminate pores present in the composite. The microstructure of the composite was observed with FESEM, and the mechanical/thermal properties were measured.

• Fisheries and Aquatic Sciences
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• v.24 no.2
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• pp.89-98
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• 2021

The accumulation of ammonia, a consequence of intensive aquaculture activity, can damage cultured animals. We analyzed the survival rates, growth, antioxidant responses, and immune responses of abalones, Haliotis discus hannai (mean shell length 70.2 ± 4.9 mm; mean body weight 36.9 ± 3.6 g), biweekly for four weeks, to determine the accumulated concentrations of ammonia (0, 0.1, 0.2, 0.4, 0.8, and 1.6 mg/L). In our biweekly measurements, a survival rate of ≥ 95% was observed for all concentrations of ammonia. The specific growth rate (SGR) decreased at ≥ 0.8 mg/L (p < 0.05), but the daily increment in shell length (DISL) showed no significant change (p < 0.05). Regarding antioxidant responses, the superoxide dismutase (SOD) activity of the hepatopancreas was increased at ammonia concentrations over 0.8 and 0.2 mg/L (p < 0.05) at two and four weeks, respectively, and the SOD activity of the gills increased at concentrations over 0.4 and 1.6 mg/L (p < 0.05) at four weeks. The catalase (CAT) activity of the hepatopancreas and gills increased at ammonia concentrations > 0.8 mg/L (p < 0.05). Phenoloxidase (PO) activity increased at ammonia concentrations over 0.8 mg/L (p < 0.05), and Lysozyme (LZM) increased at concentrations over 0.8 and 0.4 mg/L (p < 0.05). Overall, our findings indicated that ammonia concentrations over 0.8 mg/L in seawater might damage the SGR, antioxidant responses, and immune responses in H. discus hannai. Our findings suggest the necessity of improvement or reinstallation for abalone aquaculture systems and can be used to assess the toxic effects of ammonia on H. hannai.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.670-676
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• 2017

Recently, mass mortality of the young abalone Haliotis discus hannai has occurred in commercial seed production farms in Korea. The mortality rate was above 50% of the total cultured organisms in the farm, and the shell length of the moribund organisms was about 3cm. The mortal phenomenon was that the young abalones were weakly scattered on the bottom of the pond from the attachment matrix, or that they could not be moved back to their normal positions. The diseased farmed Pacific abalone had abdominal edema. From the edema in the moribund individuals, three bacterial strains were isolated and all the strains were identified as Vibrio harveyi. These strains were compared with thirty six strains isolated from the fish. The results was that the Vibrio harveyi from the fish were sorted into genogroup A or B; however, the three strains of the diseased farmed Pacific abalone were sorted into genogroup A and the new genogroup C. The identical mortality and pathological symptoms of the naturally infected organisms were reproduced by artificial infection with WA AG-1 and WA CS-5 strains. The $LD_{50}$ of WA AG-1 and WA CS-5 were each $1.0{\times}10^3cfu\;animal^{-1}$ and $1.7{\times}10^4cfu\;animal^{-1}$.

• The Korean Journal of Malacology
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• v.16 no.1_2
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• pp.31-34
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• 2000

A series of rearing experiments have been conducted to determine the growth and survival rate in accordance with body size in closed recirculating sea water system. The abalone, Sulculus aquatilis, spat of 10.24${\pm}$0.85 mm, 0.36${\pm}$0.l g and 24.9${\pm}$1.07 mm 2.07${\pm}$0.57 g in shell length and body weight were used in this study Ranges of water temperature and pH during the rearing period of 90 days were 10.0-24.2$^{\circ}C$ and 7.8-8.2, respectively. Dissolved oxygen during the experiment period was 6.13-7.21 ml/l and inorganic nitrate was 0.68-3.72 $\mu\textrm{m}$ in NH$_4$$\^$+/-N, 0.17-7.79 fm in NO$_2$-N and 0.4-11.52 $\mu\textrm{m}$ in NO $_2$-N, Growth in shell length and body weight of the spat in large group and small group at the end of the experiment were 30.80${\pm}$3.14 mm, 17.98${\pm}$2.61 mm and 3.20${\pm}$0.8 g, 0.36${\pm}$0.1 g, and survival rate of spat in large group and small group at the end of the rearing experiment were 96.0% and 90.0% , respectively.