• Journal of the Korean Chemical Society
• /
• v.41 no.2
• /
• pp.105-112
• /
• 1997

The smelly nitro compounds were extracted from dried fishes by simultanous distillation and extraction, then were analyzed by GC-MS. Carbon number and order of an amine could be predicted by using retention time and equivalent chain length. Anchovy, codfish, imitation crab meat, cuttle fish, file fish, pollack, shrimp, octopus, harvest fish, and hard-shelled mussel were used for this investigation. Various smelly nitro compounds such as methylamine, acetamide, thiazole, 2-hydroxy isopropylamine, N-methyl pyrroline, piperidine, cyclohexylamine were identified, however, dimethylamine, trimethylamine, diethylamine were not detected. Principal components analysis was applied to GC-MS profiles for pattern recognition of smelly nitro compounds in dried fishes. Multivariate aspects using principal components analysis were very useful for pattern recognition of smelly components, category similarity.

• Korean Journal of Environment and Ecology
• /
• v.30 no.4
• /
• pp.730-744
• /
• 2016

In this study, fish fauna and stream characteristics were surveyed from June to October of 2014 in 31 sites of 23 small streams of Namhae Island. During the study period, 38 species belonging to 30 genera under 13 families were collected. Cyprinidae and Gobiidae fish occupied 28.9% (11 species) and Cobitidae fish accounted for 10.5% (4 species). The dominant family was Cyprinidae, and the most dominant species was Zacco koreanus with 30.3% (1,089 individuals) of the total. Eight species (33.8%) such as Zacco koreanus, Squalidus gracilis majimae, Coreoleuciscus splendidus, Pseudobagrus koreanus, Iksookimia hugowolfeld, Iksookimia longicorpa, Silurus microdorsalis and Liobagrus mediadiposalis were Korean endemic and one species of Micropterus salmoides was exotic. According to the analysis of the community based on the diversity, evenness and richness indices, fish community seems to be more stable in the S7. The small streams were classified into three types of steep mountainous, mountainous-flatland, and flat land streams, and their types were categorized by their features of stream width, water depth, bottom substrate, riparian vegetation, and land use patterns. Principal component analysis based on species abundance classified fish communities into three main groups according to human impact and land-use pattern change. These results suggest that fish community structures were primary affected by the longitudinal environmental changes and these were modified by the habitat condition in accordance with the land use pattern change in the small streams.

• The Korean Journal of Food And Nutrition
• /
• v.21 no.4
• /
• pp.518-523
• /
• 2008

Experiments were conducted to assess the quality properties of steamed fish paste by addition level, along with a fish meat replacement(dried bovine plasma). The moisture, crude protein, crude fat and ash contents evidenced partially significant difference among the controls, DBP1, DBP2 and DBP3 groups(p<0.05). The pH values of the steamed samples were higher than those of the non-steamed samples, and when the content of the dried bovine plasma as meat replacement agent was increased, the pH was increased. The water holding capacity of the steamed fish past samples, along with the replacement levels were significantly higher than in the samples without the meat replacer(p<0.05). The range of cooking loss was $5.19{\sim}5.38%$. Structural weakening of the boiled samples was significantly higher than that observed in the fried sample. Hardness and chewiness were increased slightly by the addition of bovine plasma, but gel strength evidenced a pattern of decreased in DBP1, DBP2 and DBP3 groups. The result of our sensory evaluation on taste, texture, color and overall acceptance evidenced significant differences among the controls, DBP1, DBP2 and DBP3 groups, and the sensory score of color was the highest.

• Journal of fish pathology
• /
• v.25 no.1
• /
• pp.59-65
• /
• 2012

Overinflation of cardiac stomach occurred in farmed sterlet sturgeon (Acipenser ruthenus) fingerlings. Affected fish congregated and swam upside-down near the edges of the tanks with abdominal distension. When pressed the dilated abdomen, the fish often exhibited a normal swimming pattern for some time, then resumed their characteristic upside-down swimming patterns. Internally, the fish showed abdominal dropsy and dilated stomach filled with yellowish granular contents. When the contents in the stomach, fish feed, water and excrement in the farm inoculated on Sabouraud destrose agar (SDA) at $25^{\circ}C$ for 48 hr. Candida sp. were isolated except from the feed. Candida sp. in excrement or water in the farm may enter into the stomach with feed and then produce gases in the metabolic process, which in turn may cause the stomach overinflation.

• Journal of Life Science
• /
• v.26 no.8
• /
• pp.955-962
• /
• 2016

Fish-meat gel is an intermediate product used in a variety of surimi-based seafood. One of the most-used raw materials of fish-meat gel is Alaska Pollock due to its high-quality meat in terms of gel strength and texture. However, increasing demand for fish-meat gel, along with overexploitation of the wild catch Alaska Pollock, has put the industry in need of low-cost sustainable alternative sources for fish-meat gel. Pagrus major (PM) is a widely aquacultured fish known for having white meat that is low in fat. The current study compares the quality of fish-meat gel prepared from aquacultured PM to that of high and mid-grade Alaska Pollock fish-meat gel. Gels were compared in terms of gel strength, texture, color, and protein pattern. Results indicated that fish-meat gels prepared from PM were superior to Alaska Pollock fish-meat gels with regard to gel strength, hardness, springiness, chewiness, cutting strength, and breaking force. In addition, although not matching in quality, PM exhibited a cohesiveness, whiteness, and expressible moisture content comparable to Alaska Pollock of both grades. Protein pattern analysis also showed that PM and Alaska Pollock fish-meat gels had similar protein profiles before and after gel preparation. Therefore, P. major is suggested as a potential substitute for Alaska Pollock in fish-meat gel production.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.41 no.4
• /
• pp.296-305
• /
• 2005

Acoustic target strength (TS) of 12 commercially important fish species caught in the Korean waters had been investigated and their results were presented. Laboratory measurements of target strength on 12 dominant fish species were carried out at a frequencies of 75 kHz by single beam method under the controlled condition of the water tank with the 241 samples of dead and live fishes. The target strength pattern on individual fish of each species was measured as a function of tilt angle, ranging from $-45^{\circ}$ (head down aspect) to $45^{\circ}$ (head up aspect) in $0.2^{\circ}$ intervals, and the averaged target strength was estimated by assuming the tilt angle distribution as N ($-5.0^{\circ}$, $^15.0{\circ}$). The 75 to fish length relationship for each species was independently derived by a least - squares fitting procedure. Also, a linear regression analysis for all species was performed to reduce the data to a set of empirical equations showing the variation of target strength to fish length and fish species. An empirical model for fish target strength(TS, dB) averaged over the dorsal aspect of 158 fishes of 7 species and which spans the fish length(L, m) to wavelength(${\lambda}$, m) ratio between 6.2 and 21.3 was derived: TS: 27.03 Log(L)-7.7Log(${\kanbda}$)-17.21, ($r^2$=0.59).

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.27 no.1
• /
• pp.64-68
• /
• 1991

In this paper, to percuss whether fish oil can substitute for marine fuel oil, the characteristics on the evaporation and ignition of 3 fish oils, Sardine oil, File fish oil and Alaska pollac oil, were investigated experimentally by suspending single fish oil droplel in hot atmosphere, and experiments on methanol and light oil were also carried out to compare the characteristics. The results abtained are summarized as follow; 1) Evaporation and ignition phenomena on the methanol and light oil by the present experimental method agreeded with the results of the earlier investigation. 2) The characteristic on evaporation and ignition of all 3 fish oils took the same pattern; in late stage of evaporation at atmospheric Temperature 55$0^{\circ}C$ droplet rapidly expanded and contracted, and then remained solid corbide, but in case of $650^{\circ}C$ rapidly expanded and ignitied, and then completly burned non-remained solid carbide. 3) As fish oil mixed with light oil (50% weight), in beginning stage of evaporation droplet depended on the characteristics of light oil, but in end stage depended on fish oil. 4) Ignition temperature of fish oil droplets was about 47$0^{\circ}C$, higher than about 25$0^{\circ}C$ of light oil, but atmospheric temperature to ignite droplet was about $650^{\circ}C$, lower than about 75$0^{\circ}C$ of light oil.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.25 no.4
• /
• pp.191-199
• /
• 1989

Research on the acoustic properties of fish has been carried out by a number of scientific workers from the earliest days of applying acoustic techniques to fish biomass estimates. This paper describes measurements of the target strength of Cyprinus Carpio, which measurements made at 50KHz in the experimental water tank. The results obtained are as follows: 1. The target strength(dB) of the fish has a directivity pattern quite similar to that of a transducer. The maximum value of target strength(dB) is obtained when the fish is insonified to its head-tail axis either from the dorsal or from the ventral side. 2. Empirical relationship between target strength(dB) and body length(cm) of the fish can be estimated as TS=20 Log L-65.4 where TS is the target strength of the fish and L is the body length of the fish. 3. The relationship between target strength(dB) and body weight(g) of the fish can be estimated as TS=6.7 Log W-53.7 where W is body weight of the fish.

• Fisheries and Aquatic Sciences
• /
• v.4 no.3
• /
• pp.138-143
• /
• 2001

Red sea bream, Pagrus major a fish species characterized by its dualistic feeding pattern, was investigated to study the synchronizing effect of light and food on the demand-feeding rhythm. Nocturnal and diurnal red sea bream, both in groups and individually, were exposed to restricted-feeding and Light-Dark cycles of different periods. The phase relationship between both zeitgebers was also studied. In some cases, food availability restricted to the light or dark phase contrary to that of the previous feeding phase changed a diurnal feeding pattern into nocturnal and vice versa, suggesting that food can be one of the switching factors that decides whether the circadian system of red sea bream is diurnal or nocturnal. However, the fact that the feeding pattern of some fish was unrelated with the phase in which food was available suggests that other internal and/or external-factors could be involved in the temporal flexibility of red sea bream.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.4
• /
• pp.413-422
• /
• 2011

An improved split-beam transducer for a 50 kHz fish-sizing echo sounder was developed. The main objective of this study was to minimize the side lobe level in the beam pattern and the distance between acoustic centers for adjacent transducer quadrants in the geometrical arrangement of array elements while maintaining a given number of transducer elements and beam width. To achieve these goals, a 32-element planar array transducer ($6{\times}6$ array with one element in each corner missing) was designed using the Dolph-Chebyshev shading function to suppress side lobes in the array beam pattern and fabricated by arranging the inter-element spacing to be substantially equal to half the wavelength using the transducer element of 0.4 times the wavelength in diameter. The performance characteristics of this split-beam transducer were evaluated in the experimental water tank of $5m{\times}5m{\times}6m$ (length${\times}$height${\times}$width). In this study, the design goal of the beam width and side lobe level for transmitting a beam pattern was initially set at $21^{\circ}$ and -30 dB, respectively. However, the measured beam width at 3 dB was $21^{\circ}$ in both directions with side lobe levels of -24.7 dB in the horizontal plane and -25.6 dB in the vertical plane. The averaged beam width at -3 dB of the receiving beam patterns for four receiving quadrants was $31.4^{\circ}$. The transmitting voltage response was 161.5 dB (re $1{\mu}Pa$/V at 1 m) at 50.23 kHz with a bandwidth of 2.16 kHz, and the averaged receiving sensitivity for four receiving quadrants was -178.13 dB (re 1 V/${\mu}Pa$) at 49.8 kHz with a bandwidth of 2.64 kHz.