• Journal of Marine Life Science
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• v.6 no.1
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• pp.23-30
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• 2021

The differentiation process of male germ cells and sperm morphology of the abalone Haliotis discus hannai were described in ultrastructure. The differentiation process of sperm was divided into four stages: spermatogonium, spermatocyte, spermatid and sperm. The process of differentiation from spermatogonium to spermatocyte did not show significant morphological changes. However, during the spermiogenesis there were distinct morphological changes such as chromatin condensation, morphological changes of the nucleus, and formation of acrosome, midpiece and flagellum. The sperm of the abalone consisted of head, midpiece and tail. The head of approximately 5.3 ㎛ in length was composed of a nucleus of high electron dense and bullet-shaped acrosome. The midpiece was composed of the basal body and mitochondria, and five mitochondria were arranged in single layer around the basal body. The cross section of the tail showed a "9+2" axonemal structure. These morphological and structural features are the result of showing that the sperm of H. discus hannai is a primitive type.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.363-370
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• 2014

We investigated the survival rate by water temperature and salinity, physiological rhythm and morphological change of live abalone to get to know optimum water temperature and salinity suitable for long-distance transportation of live abalone. At $8^{\circ}C$ and above, 96-100% of survival rate was shown at all experiment groups. At $6^{\circ}C$, 66% of abalones survived in normal seawater but they showed 0% of survival rate at $30{\pm}0.5psu$ and $26{\pm}0.5psu$ of salinity at the same water temperature. There was no significant difference of oxygen consumption rate for a week between the seawater and $30{\pm}0.5psu$. Also, a positive correlation was shown between salinity and water temperature and the oxygen consumption rate was slightly higher at $30{\pm}0.5psu$ than seawater. Thinned epithelial layers and expansion of lymph sinus were observed less than $30{\pm}0.5psu$ or below $6^{\circ}C$ of temperature. This result shows that the optimum level of water temperature and salinity is considered to be $6-8^{\circ}C$ and more than $30{\pm}0.5psu$ respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.181-189
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• 1979

1. 전복, 소라, 북방조개, 가리비의 중요한 인지질은 choline phosphatides, ethanolamine phlosphatides, serine phosphatides, cardiolipin, sphingomyelin 및 lyso choline phosphatides 였다. 2. 이들 plasmalogen은 거의 대부분이 ethanolamine phosphatides에 존재하고, choline phosphatides에는 소량존재하였으며, serine phosphatide에는 전연발견되지 않았다. 3. 전복의 ethanolamine plasmalogen 함량은 1월에 채취한 것에는 $3.5\%$, 7월에 채취한 것에는 $17.2\%$였다. 또, 소라, 북방조개에는 각각 그 함량이 $20.7\%,\;15.1\%$였다. 가리비에는 ethanolamine phosphatides에 plasmalogen이 $18.8\%$ 존재하였다. 4. 전복 및 소라의 중요한 plasmalogen의 aldehyde 조성은 stearyl aldehyde $(C_{18:D})$, palmityl aldehyde $(C_{16:0})$, Palmitoleyl aldehyde $(C_{16:1})$ 및 oleyl aldehyde $(C_{18:1})$ 인데 대하여, 2매패인 북방조개, 가리비에는 eicosamonoenal $(C_{20:1})$이 $14-22\%$ 정도함유 되어 있어 권패와 대조적이였다.

• The Korean Journal of Malacology
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• v.32 no.2
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• pp.111-118
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• 2016

This study was conducted to find out concentration of trace metal, survival rate, falling rate and structural changes of the abalone Haliotis discus hannai exposed to nickel chloride. Experimental groups were composed of one control condition and four nickel chloride exposure conditions (7.0, 12.0, 17.0 and $22.0\;NiCl_2\;mg/L$). The concentration of nickel in abalone was significantly increased all exposure groups. Though the exposure groups had lower survival rate than the control group, falling rate higher than the control group. Histopathological changes in the foot, gill and hepatopancreas of abalone was revealed prominently with exposure group than control group.

• The Korean Journal of Malacology
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• v.31 no.3
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• pp.195-201
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• 2015

This study was conducted to find out concentration of trace metal, survival rate, falling rate and structural changes of abalone, Haliotis discus hannai exposed to zinc chloride. Experimental groups were composed of one control condition and four exposure conditions (0.3, 0.8, 1.3, $1.8\;ZnCl_2\;mg/L$). The accumulation of trace metal (zinc) in abalone was significantly increased all exposure group. Though the exposure groups had lower survival rate than the control group, higher falling rate than the control group. Histopathological changes in the foot, gill and hepatopancreas of abalone revealed obvious with exposure group than control group.

• The Korean Journal of Malacology
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• v.31 no.3
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• pp.165-170
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• 2015

The presence of predators (excluding starfishes) of disk abalone, Haliotis discus hannai was directly investigated by nine SCUBA divings during February-December 2014 at the coastal areas of Yangjeong, Jukjin and Bongpyeong, Uljin, Korea, where the young disk abalone seedlings were artificially released. The results revealed that a total of six individuals of Neptunea cumingii that were feeding on the young disk abalone were observed within the water depth 10m at the coastal area of Jukjin, of which bottom substrate consists of the relatively high composition rate of rocks (60.3%). Though N. cumingii is well known as a carnivorous predator of diverse marine invertebrates such as live mussels (Mytilus spp.) it is the first report that this predator also feeds on the disk abalones. Thus, our results strongly suggest that the future artificial release projects around Korean coasts necessitate extermination works of predators including newly observed N. cumingii in this study as well as previously known starfishes prior to the releases of young Pacific abalone seedlings.

• The Korean Journal of Malacology
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• v.31 no.2
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• pp.143-150
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• 2015

This study was conducted to find out accumulated concentration of nickel, survival rate and falling rate, structural changes of abalone, Haliotis discus hannai exposed to nickel chloride. Experimental groups were composed of one control condition and five nickel chloride exposure conditions (5.9, 8.8, 13.3, 20.0, 30.0 mg/L). The accumulation of nickel in abalone was significantly increased all exposure group. Though the exposure groups had lower survival rate than the control group, higher falling rate than the control group. Histopathological changes in the foot, gill and hepatopancreas of abalone revealed obvious with exposure group than control group.

• The Korean Journal of Malacology
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• v.29 no.4
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• pp.303-311
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• 2013

This study investigated survival, falling and structural changes of foot in Haliotis discus hannai with various water temperature and salinity. Experimental conditions were composed of control with $20^{\circ}C/33.5$ psu, higher temperature group with 23, 26, 29 and $32^{\circ}C$, lower temperature group with 3, 6, 9 and $12^{\circ}C$, and different salinities group with 33.5, 26.8, 20.1, 13.4, 6.7 and 3.3 psu. Experimental period was 7 days. Survival and falling rate of the abalone exposed to 7 days at control and experimental condition of $12^{\circ}C$ and $23^{\circ}C/33.5$ psu were 100% and 0%, respectively. Mortality and falling rate of the abalone exposed to the different temperature and salinity were dose dependent by experimental condition. Histopathological changes in epithelial and muscular layer of foot showed more obvious with experimental condition of salinity decrease than different temperature condition.

• The Korean Journal of Malacology
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• v.32 no.2
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• pp.103-109
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• 2016

The effect of different feeding rate on the growth and survival rate of 3-year-old abalone, Haliotis dicsus hannai were investigated in marine net cage culture. Feeding rate is determined that was fed 5, 10, 15 and 20 percentage to abalone at body weight once daily : 5 daily feeding rate (DFR), 10 DFR, 15 DFR and 20 DFR. After that, it was conducted to reared during thirteen month with two replicates in net cage culture. In the growth performance of reared abalone (initial mean shell length $73.77{\pm}11.27mm$) in net cage culture, that the absolute growth rate (ARG), daily growth rate (DGR) and specific growth rate (SGR) to the shell length and shell breadth, as well as weight gain (WG), daily weight gain (DWG) and specific weight gain (SWG) to body weight of 5 DFR were higher than those of different groups (P < 0.05). Also, survival rate of all feeding rate groups was not significant, but it was showed bellow 30 percents. Therefore, these results is showed that the daily feeding rate for natural feed of 3-year-old abalones reared in net cage culture should be to supply among five to ten percents.

• The Korean Journal of Malacology
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• v.30 no.1
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• pp.87-93
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• 2014

The Morphological characteristics of four species of Korean Abalone species, Nordotis discus hannai, N. discus discus, N. gigantea, N. madaka were compared. then Phenotypic traits were characterized. we collected from coast of samchonpo, sacjon-si, Gyeongsangnam-do and jeju-do of korea 69 individual of Nordotis discus hannai from 2013 December to 2014 January, 180 individual of N. discus, 72 individual of N. gigantea and 54 individual of N. madaka respectively then morphological traits of theses species characteristics were compared. The relationship between Shell length (SL), shell breth (SB), shell height (SH) and total weigh (TW) was expressed by the following equation: SB = 0.6346SL + 3.9082 ($R^2$ = 0.8956), SH = 0.2399SL + 3.2609 ($R^2$ = 0.8024), $TW=0.0009SL^{2.5622}$ ($R^2$ = 0.8088) in the Haliotis discus hannai, SB = 0.7249SL + 1.8035 ($R^2$ = 0.9634), SH = 0.3115SL - 11.223 ($R^2$ = 0.8593), $TW=0.0001SL^{2.9696}$ ($R^2$ = 0.8956) in the H. discus discus, SB = 0.7730SL - 1.1931 ($R^2$ = 0.933), SH = 0.2082SL + 3.2627 ($R^2$ = 0.6927), $TW=0.0002SL^{2.8330}$ ($R^2$ = 0.8431) in the Haliotis gigantea, SB = 0.7513SL - 1.0951 ($R^2$ = 0.913), SH = 0.2618SL - 6.1538 ($R^2$ = 0.6927), $TW=0.0001SL^{2.9614}$ ($R^2$ = 0.9353) in the Haliotis madaka.