• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.2
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• pp.292-298
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• 1999

Myofibril and actomyosin were prepared from red muscle and white muscle of fresh water fish and sea water fish, and their biochemical characteristics and SDS PAGE patterns of myofibril were compared. SDS PAGE analysis showed that electrophoretic patterns of myofibril were similar be tween white muscle and red muscle, while difference of 30kDa component of myofibril was detected between fresh water fish and sea water fish. When myofibril were treated with trypsin, difference in hydrolysis of heavy chain was observed between white muscle and red muscle. In activities of Ca ATPase, Mg ATPase, EDTA ATPase and ATPase activity pH curve, myofibrillar protein from fresh water fish showed higher specific activity than those from sea water fish.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.4
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• pp.574-578
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• 2001

Myofibrillar proteins were prepared from red muscle and white muscle of fresh water fish and sea water fish, and their thermostabilities and effect of temperature on the myofibrillar ATPase activities were compared. Differences in temperature dependency of myofibrillar ATPase activities were found between two species. Thermodynamic data for inactivation of myofibrillar proteins, such as D value, Z value, $\Delta$ $H^{{\neq}}$, $\Delta$ $G^{{\neq}}$ and $\Delta$ $S^{\neq}$ revealed that thermostabilities of myofibrillar proteins from fresh water fish were higher than those from sea water fish, and that myofibrillar proteins from red muscle were more heat labile than those from white muscle.

• The Journal of Fisheries Business Administration
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• v.34 no.2
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• pp.75-90
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• 2003

When we think of fundamental problems of the aquaculture industry, there are several strict conditions, and consequently the aquaculture industry is forced to change. Fish aquaculture has a structural supply surplus in production, aggravation of fishing grounds, stagnant low price due to recent recession, and drastic change of distribution circumstances. It is requested for us to initiate discussion on such issue as “how fish aquaculture establishes its status in the coastal fishery\ulcorner, will fish aquaculture grow in the future\ulcorner, and if so “how it will be restructured\ulcorner” The above issues can be observed in the mariculture of yellow tail, sea scallop and eel. But there have not been studied concerning seabream even though the production is over 30% of the total production of fish aquaculture in resent and it occupied an important status in the fish aquaculture. The objectives of this study is to forecast the future movement of sea bream aquaculture. The first goal of the study is to contribute to managerial and economic studies on the aquaculture industry. The second goal is to identify the factors influencing the competition between production areas and to identify the mechanisms involved. This study will examine the competitive power in individual producing area, its behavior, and its compulsory factors based on case study. Producing areas will be categorized according to following parameters : distance to market and availability of transportation, natural environment, the time of formation of producing areas (leaderㆍfollower), major production items, scale of business and producing areas, degree of organization in production and sales. As a factor in shaping the production area of sea bream aquaculture, natural conditions especially the water temperature is very important. Sea bream shows more active feeding and faster growth in areas located where the water temperature does not go below 13∼14$^{\circ}C$ during the winter. Also fish aquaculture is constrained by the transporting distance. Aquacultured yellowtail is a mass-produced and a mass-distributed item. It is sold a unit of cage and transported by ship. On the other hand, sea bream is sold in small amount in markets and transported by truck; so, the transportation cost is higher than yellow tail. Aquacultured sea bream has different product characteristics due to transport distance. We need to study live fish and fresh fish markets separately. Live fish was the original product form of aquacultured sea bream. Transportation of live fish has more constraints than the transportation of fresh fish. Death rate and distance are highly correlated. In addition, loading capacity of live fish is less than fresh fish. In the case of a 10 ton truck, live fish can only be loaded up to 1.5 tons. But, fresh fish which can be placed in a box can be loaded up to 5 to 6 tons. Because of this characteristics, live fish requires closer location to consumption area than fresh fish. In the consumption markets, the size of fresh fish is mainly 0.8 to 2kg.Live fish usually goes through auction, and quality is graded. Main purchaser comes from many small-sized restaurants, so a relatively small farmer and distributer can sell it. Aquacultured sea bream has been transacted as a fresh fish in GMS ,since 1993 when the price plummeted. Economies of scale works in case of fresh fish. The characteristics of fresh fish is as follows : As a large scale demander, General Merchandise Stores are the main purchasers of sea bream and the size of the fish is around 1.3kg. It mainly goes through negotiation. Aquacultured sea bream has been established as a representative food in General Merchandise Stores. GMS require stable and mass supply, consistent size, and low price. And Distribution of fresh fish is undertook by the large scale distributers, which can satisfy requirements of GMS. The market share in Tokyo Central Wholesale Market shows Mie Pref. is dominating in live fish. And Ehime Pref. is dominating in fresh fish. Ehime Pref. showed remarkable growth in 1990s. At present, the dealings of live fish is decreasing. However, the dealings of fresh fish is increasing in Tokyo Central Wholesale Market. The price of live fish is decreasing more than one of fresh fish. Even though Ehime Pref. has an ideal natural environment for sea bream aquaculture, its entry into sea bream aquaculture was late, because it was located at a further distance to consumers than the competing producing areas. However, Ehime Pref. became the number one producing areas through the sales of fresh fish in the 1990s. The production volume is almost 3 times the production volume of Mie Pref. which is the number two production area. More conversion from yellow tail aquaculture to sea bream aquaculture is taking place in Ehime Pref., because Kagosima Pref. has a better natural environment for yellow tail aquaculture. Transportation is worse than Mie Pref., but this region as a far-flung producing area makes up by increasing the business scale. Ehime Pref. increases the market share for fresh fish by creating demand from GMS. Ehime Pref. has developed market strategies such as a quick return at a small profit, a stable and mass supply and standardization in size. Ehime Pref. increases the market power by the capital of a large scale commission agent. Secondly Mie Pref. is close to markets and composed of small scale farmers. Mie Pref. switched to sea bream aquaculture early, because of the price decrease in aquacultured yellou tail and natural environmental problems. Mie Pref. had not changed until 1993 when the price of the sea bream plummeted. Because it had better natural environment and transportation. Mie Pref. has a suitable water temperature range required for sea bream aquaculture. However, the price of live sea bream continued to decline due to excessive production and economic recession. As a consequence, small scale farmers are faced with a market price below the average production cost in 1993. In such kind of situation, the small-sized and inefficient manager in Mie Pref. was obliged to withdraw from sea bream aquaculture. Kumamoto Pref. is located further from market sites and has an unsuitable nature environmental condition required for sea bream aquaculture. Although Kumamoto Pref. is trying to convert to the puffer fish aquaculture which requires different rearing techniques, aquaculture technique for puffer fish is not established yet.

• Fisheries and Aquatic Sciences
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• v.1 no.1
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• pp.129-146
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• 1998

Fatty acid compositions of seventy-two species of Korean fish muscle, 59 species of sea water fish and 13 species of fresh water fish, were studied. Polyunsaturated fatty acid (PUFA) was the richest fatty acid group in all fish samples, accounting for $38.0\pm10.3\%$ of total fatty acids. Monounsaturated fatty acids $(MUFA,\;31.4\pm9.67\%)$ and saturated fatty acids $(SFA, 30.5\pm3.81\%)$ showed a similar level. There was a positive correlation between the total lipid content and MUFA (r=0.7788, p<0.001) and a negative correlation between the total lipid content and PUFA (r= -0.7786, p<0.001) while there was no correlation between the total lipid content and SFA. The proportion of n-3 PUFA and n-6 PUFA was $29.7\pm8.73\%$ and $6,48\pm3.70\%$, respectively, in all fish samples. The n-3 PUFA was rich in sea water fish while n-6 PUFA was rich in fresh water fish. The migratory fish contained the highest level of the n-3 PUFA $(1.82\pm1.01g/100g\;muscle)$, followed by the fresh water fish $(1.09\pm1.04g/100g\;muscle)$, the reef fish $(0.90\pm0.60g/100g\;muscle)$ and the demersal fish $(0.77\pm0.38g/100g\;muscle)$. There was a positive correlation between the total lipid and n-3 PUFA content, $y=0.2083\times+0.05 (r=0.9352,\;p<0.0010)$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.3
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• pp.276-283
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• 2011

The growth and tolerance for water temperature and salinity were compared among red sea bream Pagrus major (RSB) black sea bream Acanthopagrus schregeli (BSB) and their hybrid ($F_1$), female RSB ${\times}$ male BSB. The growth of the $F_1$ fish did not differ until 27 days after hatching (dAH), after which the most rapid growth was observed until approximately 300 dAH, followed by RSB and BSB. However, the RSB had out grown the $F_1$ fish by approximately 303 dAH. By 480 dAH, the RSB were largest, followed by the $F_1$ and BSB groups. The tolerances for high and low water temperature were significantly different for each species and growth stage. The largest tolerance spectrum was observed in the BSB group, and the tolerance spectrums gradually decreased with increasing final body weight. During the salinity tolerance trials, all of the species started to die following transfer into freshwater (0 psu). BSB showed the highest survival rate when kept in fresh water for an average of 29.9 hours, while the $F_1$ fish were more tolerant than the RSB fish. The fish were increasingly tolerant to fresh water and changes in water temperature as they grew, while the size of the temperature spectrum remained unchanged but shifted to a lower temperature range with growth. Our results demonstrate that $F_1$ performed well in terms of growth compared to parental fish, with higher temperature and salinity tolerances than RSB, and is thus suggested to be a suitable aquaculture species for Korea and northeast China.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.160-167
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• 1998

Proximate composition, cholesterol (CHOL) and $\alpha-tocopherol$ ($\alpha-Toc$) content of seventy-two species of fish muscle (sea water fish, 59 species; fresh water fish, 13 species), which caught off Tongyeong coast of the Southern Sea ( Nam-Hae) and caught Kyeongho river, Sancheong, Korea, were determined. Lipid content was ranked from $0.53\%$ to $20.4\%$ and was high in the following order; mid-surface dwelling and migratory fish ($6.09{\pm}4.25\%$) > fresh water fish ($4.40{\pm}5.90\%$) > coastal and reep dwelling fish ($3.41{\pm}2.68\%$) > demersal fish ($2.12{\pm}2.41\%$). There was a negative correlation between the lipid and moisture content in all fish groups (p< 0.001). Protein was approximately $17\~18\%$ in all fish group, and no correlation was between the protein and moisture content in all but the demersal fish, which there was a negative correlation between both contents. Ash content was almost constant in all fish, accounting for $1\~2\%$, Cholesterol (CHOL) content was shown a great difference according to the fish species from 6.7 mg/100 g muscle (grass fish) to 249 mg/100 g (eel) and there was a positive correlation between the lipid and CHOL content. $\alpha-Toc$ content was less than 3 mg/100 g muscle in all fish, except that of eel (4.1 mg/100 g) and was relatively rich in the fish species contained a large amount of lipid.

• Korean Journal of Ecology and Environment
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• v.34 no.3 s.95
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• pp.251-258
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• 2001

The ichthyofauna and passing efficiency of fish ways were surveyed in the lower and upper regions of the river mouth dam in the lower reaches of the Nakdong river from June to December in 20()0. As the dam built in the river mouth, the brackish area in the estuary disappeared completely and the transitional area did not formed. The fishes collected from survey were classified into 49 species, 45 genera belonging to 29 families. Among them, the fresh water fishes composed of 10 species, peripheral freshwater fishes 11 species and sea water fishes 28 species respectively. Because of the ecological difference between the fresh and sea water, dominant species in the Myeong-ji of sea water area was Acanthogobius flavimanus (39.1%) and in the Sa-sang of fresh water area was Achanthorhodeus macropterus (44.4%). By the video camera records, fishes were identified nine species like as Coilia ectenes, Cyprinus carpio, Hemibarbus labeo, Squalidus gracilis majimae, Plecoglosus altivelis, Lateolabrax japonicus, Anguilla japonica, Mugil cephalus and Pholis nebulosa. Based on total species collected, the efficiency of the fish way for the anadromous fish was 10.1%. Therefore, efficiency evaluation of the fish way in the Nakdong River Mouth Dam was low.

• Journal of the Korean Society of Food Culture
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• v.19 no.3
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• pp.273-284
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• 2004

This study is on the changing pattern of fish-and-shellfish uses during the last two thirds of Chosun period on the premise that they are influenced by development of fishing technology. With a literary approach, this paper researches how fish-and-shellfish production and consumption pattern changed, especially in relation to technological development of fisheries. First, we examine into the changes of fishery production. And next, we analyze the kind and cooking method of fish-and-shellfish in [Eum-sik-di-mi-bang](1670) and [Gyu-hap-chong-seo](1815). The analysis of two books revealed that there were significant differences in fish-and-shellfish uses. Because the two books were written with a gap of 145 years and the development of fishing technology and remarkable changes of fishery production affected on the fish-and-shellfish uses. Due to primitive fishing tools and skills, fresh-water and reverse-river-fish and shellfish had been caught in substantial amount until the middle ages of Chosun period. As a result, the availability of seafood were limited extremely even in the upper classes. These situations are evidenced by the analysis of [Eum-sik-di-mi-bang]. Only 12 kinds of fish-and-shellfish are described in [Eum-sik-di-mi-bang]. Most of the sesfoods is mollusc which is easy to catch. As for the salt-water fish, dried cod and dried herring were mentioned. Mullet, the reverse-water-fish, is used most frequently. Only one kind of 'Hoe', which needs extreme freshness, is described. This means that the use of fresh fish-and-shellfish was very limited to some kinds which could be caught near the village. As the netting fishery began to be developed in the 18th century, the production of some salt-water fishes, such as anchovy, shrimp, yellow corvina, pollack, and herring, had increased remarkably to make marine resources more available. Small fish, such as anchovy and shrimp were preserved as 'Jeot-gal' and sold nationwide. Therefore, 'Jeot-gal' and seafood could be used in Kimchi around this time and had a deep influence on the change of Kimchi in taste and nutrition. In [Gyu-hap-chong-seo], 33 kinds of fish-and-shellfish are described. Including cod and herring, 17 kinds of sea water fish and mollusc are mentioned. Some of these are consumed in fresh state, neither as dried nor as salted. Because the merchants promoted the transport of seafoods to other regions according to the growth of commercial economy. As a result the diet of the people could be enriched by the various seafoods.

• Journal of fish pathology
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• v.34 no.2
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• pp.225-231
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• 2021

In biofloc culture for olive flounder, Paralichthys olivaceus, the possibility of antibiotics treatment was investigated against edwardsiellosis. After inducing edwardsiellosis by immersion in Edwardsiella tarda 1.2 × 10⁵/mL suspension, the survival trends on various biofloc water management and some physiological changes were observed. For biofloc water management, six types of water treatments were carried out, which were no exchange without antibiotics as negative control, the exchange to stored biofloc water, the exchange to stored biofloc water with 20% flow-through, the exchange to fresh biofloc water, half fresh biofloc water and half sea water, and the complete flow-through. There was no significant physicochemical change on water qualities in any type. The exchange to fresh biofloc water was shown the highest survival ratio as 72.3%, and in case of stored biofloc water with 20% flow-through, the survival ratio was also significantly high as 62%. Plasma glucose, cholesterol, total protein, calcium, and magnesium were analyzed as physiological index. Mostly, there was no significant change, but plasma cholesterol showed an initial decrease in low survival group, and an initial increase with high survival group. Consequently, antibiotic treatment against a bacterial disease during biofloc culture is possible as long as the biofloc water management follow along properly.

• Journal of fish pathology
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• v.13 no.2
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• pp.97-102
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• 2000

In order to investigate the effect of chlorine disinfectant against white spot baculovirus (WSBV), 5, 10, or 30 ppm of sodium hypochlorite (NaOCl) was treated to the WSBV-infected shrimp, Penaeus chinensis. In contrast with the non-treated control, no shrimp was dead after of sodium hypochlorite treatment. This result indicated that WSBV was inactivated by chlorine treatment. No inactivation of WSBV was observed by 10, 20, 30 ppm of povidon-iodine treatment. WSBV was also inactivated by 2, 4 hr sunlight exposure and by 1, 2, 3 hr drying. WSBV was inactivated very effectively by addition of fresh water on sea water.