• Journal of Aquaculture
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• v.12 no.3
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• pp.229-236
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• 1999

in the present study, the zinc toxicity to larval development and seed attachment of the abalone, Haliotis discus hannai was obtained under continuous flow through system. The zinc concentration melted from zinc coating pipe for 7 months ranged from $89.00\pm2.55 \mu\textrm{g}/\ell to 15.23\pm2.58\mu\textrm{g}/\ell(Y=0.85M^2-19.71+109.96)$. Treatments were carried out with zinc concentration $0~160 \mu\textrm{g}/\ell$. The maximum and minimum of fertilization rate were $87.7\pm5.3%$ in control, $83.7\pm7.6%$ in zinc concentration $160\mu\textrm{g}/\ell$, respectively. The maximum and minimum of hatching rate were $87.5\pm4.5%$ in zinc concentration $10\mu\textrm{g}/\ell$, $79.3\pm5.6%$ in zinc concentration $160\mu\textrm{g}/\ell$, respectively. Both of the results were not significantly different (P>0.05). But the normality rate, setting rate and survival rate of abalone larvae at over zinc concentration TEX>$20\mu\textrm{g}/\ell$ decreased rapidly and showed significantly different from those of the other group(P<0.05).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.2
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• pp.174-178
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• 2014

In this study, 6-10 clinically healthy farmed abalone, Haliotis discus hannai were obtained from Jeollanam-Do Wando Soan-myeon, Bogil-myeon, and Nohwa-eup monthly for 1 year 7 months and were examined histopathologically. As a result, the adductor muscle had severe cellular swelling and myonecrosis. These lesions were stained with hematoxylin and eosin and Giemsa. The lesions were not caused by infection of bacteria or parasites. We investigated the relationship between lesion frequency and water temperature and discovered that increased water temperature was associated with increasing lesion frequency. As water temperature is related to growth rate, increased growth rate was closely related to increased lesion frequency. We considered that these lesions could be a useful factor in measuring shellfish health.

• Fisheries and Aquatic Sciences
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• v.18 no.2
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• pp.159-164
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• 2015

A feeding experiment was conducted to determine the effect of dietary distillers dried grain (DDG) on the growth and body composition of juvenile abalone, Haliotis discus hannai. Three diets were formulated to contain 0% (DDG0), 30% DDG (DDG1) replacing wheat flour and 30% DDG (DDG2) replacing fish meal and wheat flour. A commercial feed (CF) was also compared with experimental diets. Three replicate groups of abalone averaging $0.6{\pm}0.01g$ were fed one of the four diets for 14 weeks. The highest survival rate was observed in the abalone fed the DDG2 diet, which was higher than that of abalone fed the DDG0 diet. Weight gain, shell length, shell width and soft body weight of the abalone were not affected by dietary DDG and CF diet (P > 0.05). Proximate and amino acid composition of the soft whole body were not affected by dietary DDG and CF diet (P > 0.05). The result of this experiment suggests that DDG is a good ingredient to replace fish meal and wheat flour in the diet and could be used up to 30% in the diet without negative effects on the growth performance of juvenile abalone Haliotis discus hannai.

• The Korean Journal of Malacology
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• v.19 no.2
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• pp.81-87
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• 2003

The digestive system of the abalone, Haliotis discus hannai consists of radula sac, esophagus, crop, stomach, intestine (anterior, mid and posterior intestine) and hepatopancreas. The epithelial layer was composed of ciliated columnar cells, mucous cells and granular cells. And epithelium thickness of the crop was thicker (90.80 ${\mu}$m) than those of other regions. Mucous cells of PAS positive in the esophagus were more advanced than those of other regions. The contents of mucous cell were neutral and acid mucosubstance in the esophagus and the anterior, mid and posterior intestine. And it seem to be lipid in the crop and stomach.

• The Korean Journal of Malacology
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• v.19 no.2
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• pp.89-93
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• 2003

In this study, the food selection of abalone, Haliotis discus hannai, on four various diets, Ulva pertusa, Laminaria japonica, Navicula spp., and artificial diet, was investigated. The abalones in Ulva pertusa and Navicula spp groups had the higher migration rate than the others. The artificial group had the lowest migration rate. As to the growth, Ulva pertusa group had the highest daily increment and the growth rate, which is 120.7 ${\mu}$m and 2.41%. The value of Navicula spp. group is 102.0 ${\mu}$m and 2.04% and that of Laminaria japonica group is 88.7 ${\mu}$m and 1.77%. The lowest one is 81.7 ${\mu}$m and 1.63%, which appeared at the artificial diet group. We suggest that, when breeding Haliotis discus hannai and the diets which is easy to be ingested and digested, as well as contains much nutrient content, should be used. If the artificial diet is used, it should contain low concentration of flesh-eating content.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.4
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• pp.388-395
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• 2017

We investigated the toxicity of zinc and aluminum hot-dip galvanized sheet steel to abalone Haliotis discus hannai via changes in the gill and hepatopancreas using histological and transmission electron microscopy analysis. Experimental groups were composed of one control and four exposure conditions (direct or indirect exposure to zinc and aluminum hot-dip galvanized sheet steel). In the control group, aluminum exposure groups (direct and indirect), and indirect zinc exposure group, abalone mortality was not observed until the end of the experiment, and no histopathological changes were observed in the gill and hepatopancreas. However, the direct zinc exposure group exhibited 100% mortality. Ultrastructural analysis of the cytoplasm of ciliated and microvilli-bearing epithelial cells from gill filaments revealed electron-dense vesicles near the cell membrane and disruption of the nuclear membrane. We also observed swollen mitochondria and a loss of mitochondrial cristae. The hepatopancreas showed similar changes, and we detected highly electron-dense particles within the vesicles. These results suggest that abalone exposed directly to zinc hot-dip galvanized sheet steel experience acute toxicity, causing damage to cell organelles in the gill and hepatopancreas and, finally, inducing mortality.

• Journal of fish pathology
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• v.25 no.2
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• pp.103-109
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• 2012

The objective of this study was to investigate the effects of exposured $Cu^{2+}$ on growth and bioaccumulation of abalone Haliotis discus hannai. Abalone were exposed to various concentration of $Cu^{2+}$ (0, 5, 10, 20, $40{\mu}g/L$). Bioaccumulation of tissues, hepatopancreas, muscles and gills were measured. hepatopancreas and gills $Cu^{2+}$ concentration of abalone increases to extent during the 4 weeks accumulation time. But muscles showed no significant changes, with respect to control. These data indicate that abalone Haliotis discus hannai hepatopancreas and gills can be considered adequate target tissues for waterborne exposured of $Cu^{2+}$. Weight growth rate of abalone exposed to $Cu^{2+}$ was significantly decreased in 20 and $40{\mu}g/L$ groups compared to control. This study revealed that high $Cu^{2+}$ concentration (${\geq}20{\mu}g/{\ell}$) reduced growth of abalone. These data indicate that excessive waterborne $Cu^{2+}$ can affect the toxicity of xenbiotics to abalone through alterations in growth rate. Thus, environmental standard of $Cu^{2+}$ $20{\mu}g/L$, should be considered a potential source of variation in toxicological studies with abalone.

• Development and Reproduction
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• v.15 no.4
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• pp.301-308
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• 2011

The tolerance evaluation for abalone Haliotis discus hannai embryos was performed using different concentrations of cryoprotective agents (CPAs): dimethyl sulfoxide, ethylene glycol and propylene glycol added to 0.2 M sucrose, respectively. 4-cell, trochophore and veliger were exposed in each CPA with different concentration for 10, 20 and 30 minutes of immersion time. Developmental rates were increased with decreased concentration of every CPA and decreased immersion time, and differed from types of CPA. Developmental rates of veliger in all the CPAs were higher than those of 4-cell and trochophore. The developmental rates and larval activity indices in ethylene glycol were comparatively higher than those in other CPAs and the effective CPA and its concentration for the cryopreservation of the abalone embryos was suggested as 2.0 M ethylene glycol with equilibration time of 30 minutes.

• Korean Journal of Environmental Biology
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• v.38 no.2
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• pp.248-253
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• 2020

The level at which analyses of DNA content might contribute more significantly to the genetic mechanisms of evolution lies in the events of speciation. The object of this study was to investigate the DNA content of abalone (Haliotis discus hannai) and determine the optimal tissue samples for measuring the DNA content of abalone by flowcytometry without fixation. The DNA content (pg/nucleus) of gill tissue (2.5±0.08), which was contaminated with protozoa, was significantly lower than that of muscle tissue (3.2±0.02), mantle tissue (3.2±0.02) (p<0.05), and a standard reference standard, while the DNA contents of muscle tissue and mantle tissue were higher than that of the standard reference. Considering the results of this study, DNA content analysis with flowcytometry is an acute and rapid method by which muscle tissue and mantle tissue are the most appropriate sample for measuring the DNA content of abalone without fixation.

• Journal of Aquaculture
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• v.11 no.4
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• pp.465-474
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• 1998

Shell necrosis, which is found in the juvenile stage of Haliotis discus hannai in th culture process, was examine in this study. In the necrosis shell, bacteria of rod type and a blue green algal species with heterocyst were observed. However, it appears to be caused by a boring blue green alga, Mastigocoleus sp., as based on SEM data. At the time of its infection, the shell was discolored from green into bright-grey, and then began to be brittle at the 4th to 6th breathing hole. After 60 days of culture, necrosis occurred in the breathing holes with many brown tiny colony, and continued to 3 years after culture. This shell necrosis was found in the tank culture system in land rather than in the cage culture system in sea, and greatly affected to the growth of Haliotis discus hannai, resulting in very small size of 16mm in 3 year old shell.