• Journal of Nutrition and Health
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• v.17 no.4
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• pp.297-304
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• 1984

The effect of dietary fish oil ( mackerel oil : MO, eel oil : EO) on energy utilization in rats was studied with measurements of various tissue lipoprotein lipase( LPL ) and live and heart mitochondrial respiration. Fatty acid composition of mitrochondrial inner membrane matrix was also investigated. Dietary fat level was 10%( w/w) and reference groups were fed soybean oil (SO), repeseed oil ( RO) and beef tallow( BT ). Activity of LPL was about 60% higher in post-heparin plasma and 2 to 3 times higher in adipose tissue of BT group than fish oil or vegetable oil group. But there was no significant difference between fish oil and vegetable oil groups. Inclusion of EO above 2% (w/w) in dietary fat with fille oil of BT, markedly reduced both post -heparin plasma and adipose tissue LPL. Effects of MO and EO were not different in adipose tissue LPL, but EO was more effective than MO, in reducing post -heparin plasma LPL when mixed fat with varying amount of fish oil was used. Hepatic mitochondria isolated from fish oil-fed group showed the lowest rate of respiration but had P/O ratio comparable to SO and BT groups. On the other hand, cardiac mitochondria of fish oil group showed no difference in all the mitochondrial respiration parameters observed RO group had lowest P/O ratio both in hepatic and cardiac mitochondria. Fatty acid compositions of mitochondrial lipid differ between SO, RO, BT and MO groups, notably in the content of $C_{22:1}$ fatty acid.

• The Journal of the Acoustical Society of Korea
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• v.20 no.5
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• pp.100-109
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• 2001

The backscattered sound energy by fish depends on size and physical structure and, most important, on the presence or absence of a swimbladder. Target strength experiments of red seabream (Pagrus major) were conducted by using 38 (split-beam), 120 (split-beam) and 200 kHz (dual-beam) frequencies with live fishes confined in a net-cage and free swimming in tank without the cage, respectively. For 38, 120, and 200 kHz frequencies, target strength equations are expressed as a function of fish length：TS/sub 38kHz/=20 log/sub 1o(l)/-66.41, TS/sub 120kHz/＝20 log/sub 1o(1)/-71.80, and TS/sub 200kHz/＝20 log/sub 1o(1)/-73.94. To test the acoustic models by using Helmholtz-Kirchhoff ray approximation, predictions of target strength based on swimbladder morphometries are compared with target strength measurements. The target strength of whole fish depends on variations in swimbladder morphology than fish body morphology. In the mean time, when the fish is confined in the net cage, scattering length by the backscattered signal matched with the Gaussian PDF, while under the free-swimming condition, scattering length is close to the Rayleigh PDF.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.1
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• pp.120-127
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• 2015

Morphological properties of dark banded rockfish (Sebastes inermis) were analysed to investigate its acoustic scattering characteristics. Total of 18 live samples was prepared for X-ray photos and collected morphological coordinates of their body and swim bladder shapes. Kirchhoff-ray mode model was used to calculate acoustic scattering pattern for broad-band frequency range. Inclination of swim bladder ranged from 17 to 30 and the averaged value was about $25.2^{\circ}$ (S.D.(standard deviation)=3.15). There were no any tendency of increase or decrease in volume and area ratio of swim bladder to fish body and ranged from 2.2 % to 4.43 % and 14.85 % to 21.31 %, respectively. The averaged value of volume and area ratio was 3.13 % (S.D.=0.52) and 17.6 % (S.D.=1.5). $b_{20}$ values were -69.01 for 38 kHz, -69.83 for 70 kHz, -70.17 for 120 kHz and -70.93 for 200 kHz, recpectively. Broadband acoustic patterns of dark banded rockfish for 20 ~ 200 kHz were similar among samples and they reflected size and morphological properties of fish species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.6
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• pp.709-718
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• 2019

Cephalopods, such as the Japanese flying squid Todarodes pacificus and golden cuttlefish Sepia esculenta, are an important food source for all toothed whales, particularly bottlenose dolphins in costal and offshore waters around the Korean Peninsula. A controlled laboratory experiment was conducted to investigate the broadband acoustic backscattering from live individuals of these two cephalopod species using linear chirp signals (100-200 kHz). The backscattered echo signal was measured at about 1° intervals from -45° (head down) to +45° (head up) in the dorsal plane. The species-specific, frequency-dependent scattering characteristics were investigated by comparing the relationship between the wavelength-normalized backscattering cross-section (σ/λ²) and the wavelength-normalized fish length L/λ for each species. The estimated σ/λ² value for Japanese flying squid was 9.51 at an L/λ range of 12.79-30.27 (mean, 21.26). This was approximately 7% of the σ/λ² value (136.1) for golden cuttlefish at an L/λ range of 9.07-25.49 (mean, 15.77).

• Parasites, Hosts and Diseases
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• v.41 no.2
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• pp.117-120
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• 2003

A human Echinostoma hortense infection was diagnosed by gastroduodenoscopy. An 81-year-old Korean male, living in Yeongcheon-shi, Gyeongsangbuk-do and with epigastric discomfort of several days duration, was subjected to upper gastrointestinal endoscopy. He was in the habit of eating fresh water fish. Two live worms were found in the duodenal bulb area and were removed using an endoscopic forcep. Based on their morphological characteristics, the worms were identified as E. hortense. The patient was treated with praziquantel 10 mg/kg as a single dose. The source of the infection in this case remains unclear, but the fresh water fish consumed, including the loach, may have been the source. This is the second case of E. hortense infection diagnosed by endoscopy in Korea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.747-754
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• 1999

Food waste in school foodservices is an important factors in managing expense and in evaluating the acceptance of served meals. This study was undertaken to investigate the management of food waste and the opinion of dietitians in one hundred fourty nine elementary school foodservices, in Pusan, Korea. When serving places were compared, the classroom generated more leftover and plate waste than those of lunchroom(p<0.05). In rank for generating raw waste, the residue from vegetables was the highest in first order. Fruit, eggs, fish, and shell fish also left the most raw waste, respectively, in descending order. The residue that generated the most plate waste in the first and the second order was from soup and pot stew, and vegatables side dishes, respectively. The treatment process of food waste which was the most common in school foodservices was the fertilization by processing machine in order to make recyclable fertilizer(52.1%). Food waste at 30.8% of foodservices was processed for live stock feed. At 92.3% of investigated foodservices, food waste water was drained through a round net basket. Before treating as a waste, food residue was recycled at only 41.9% of foodservices. The main utilization of food residue was the production of soap from used oil. Most dietitians in school foodservices recognized that treating food waste was not so inconvenient, although, the problems of odor and hygiene were not solved. They also thought that the liquid residue(54.1%) and oil(30.4%) among food waste were primarily responsible for resulting environmental pollution.

• Journal of Microbiology and Biotechnology
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• v.33 no.2
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• pp.167-179
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• 2023

The rifampicin-resistant strain E9-302 of Edwardsiella ictaluri strain 669 (WT) was generated by continuous passage on BHI agar plates containing increasing concentrations of rifampicin. E9-302 was attenuated significantly by 119 times to zebrafish Danio rerio compared to WT in terms of the 50% lethal dose (LD₅₀). Zebrafish vaccinated with E9-302 via intraperitoneal (IP) injection at a dose of 1 × 10³ CFU/fish had relative percentage survival (RPS) rates of 85.7% when challenged with wild-type E. ictaluri via IP 14 days post-vaccination (dpv). After 14 days of primary vaccination with E9-302 via immersion (IM) at a dose of 4 × 10⁷ CFU/ml, a booster IM vaccination with E9-302 at a dose of 2 × 10⁷ CFU/ml exhibited 65.2% RPS against challenge with wild-type E. ictaluri via IP 7 days later. These results indicated that the rifampicin-resistant attenuated strain E9-302 had potential as a live vaccine against E. ictaluri infection. A previously unreported amino acid site change at position 142 of the RNA polymerase (RNAP) β subunit encoded by the gene rpoB associated with rifampicin resistance was identified. Analysis of the whole-genome sequencing results revealed multiple missense mutations in the virulence-related genes esrB and sspH2 in E9-302 compared with WT, and a 189 bp mismatch in one gene, whose coding product was highly homologous to glycosyltransferase family 39 protein. This study preliminarily explored the molecular mechanism underlying the virulence attenuation of rifampicin-resistant strain E9-302 and provided a new target for the subsequent study of the pathogenic mechanism of E. ictaluri.

• Journal of fish pathology
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• v.12 no.2
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• pp.73-81
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• 1999

To study the supplementaing effects of kugija, Lycium chinense, in commercial diet on the immune response of nile tilapia, Oreochromis niloticus, nonspecific immune responses were investigated. The activities of complement and lysozyme were higher in sera of the fish fed diet with kugija than control diet. The effects of kugija on vaccination of fish to Edwardsiella tarda were compared in three different vaccination methods after feeding kugija for ten weeks. Intraperitoneal injection and bath administration with formalin killed cells (FKC) and bath with extracellular products (ECP) after injection of FKC showed differences in immune responses of vaccinated fish. Bath administration with ECP after injection of FKC was more stimulated than any other methods in each of nonspecific and specific responses such as the activities of complement and lysozyme, antibody production and rosette forming cells. Moreover, cumulative mortality was significantly lower in the fish vaccinated with combination FKC and ECP after injection challenge with live E. tarda.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.37 no.3
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• pp.174-180
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• 2001

Dusky spinefoot, Siganus fuscescens live primarily in shore reefs with sea weeds, like around Jeju Island in Korean south sea. Therefore they are caught much by set net in the coast of Jeju Island. We carried out measurements of the dorsal aspect target strengths of Dusky spinefoot in order to study the influences of swim bladder for fishes. and have obtained some desired results though not sufficiently complete as comparison with target strengths of fishes before and after the air gas in the swim bladder of fish is taken off by an injector. The appropriate equations share the common form TS = A + 20 log L. TS = B + 20/3 log W where TS is the average dorsal aspect target strength in decibels. L is the fish total length in centimeters. W is the fish total weight in grams, and the coefficient A and B are determined by a least mean squares regression analysis. The results obtained before the air gas in the swim bladder of fish is taken off are TS = -63.16 + 20 log L TS = -50.50 + 20/3 low W and, the results obtained after the air gas in the swim bladder of fish is taken off are TS = -65.29 + 20 log L TS = -52.62 + 20/3 log W As above result, the differences of target strengths before and after the air gas is taken off from swim bladder are 2.12-2.13 dB, but the maximum difference of target strengths of both cases averaged according to the fish aspects from $-45^\circ$ to $45^\circ$ is 5.87 dB, and the average difference of them is 2.01 dB.

• Journal of Aquaculture
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• v.11 no.4
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• pp.495-503
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• 1998

The present study investigated the effects of Bisroot, that contains live bacteria (Bacillus polyfermenticus, Bacillus mesentericus, Streptococcus faecalis, & Bifidobacterium breve) and digestive enzymes (protease, lipase), on the growth, body composition and immune response of Nile tilapia fingerlings. One percent of the Bisroot was added to the experimenta feed. All exprimental fish were fed for 60 days. The weigh gains among the experimental fish were not significntly different (P>0.05). Hematocrit value, hemoglobin, total protein, glucose, GOT, and GPT were unaffected by Bisroot treatment. However, it was observed that glucose, GOT, and GPT value in the fish that were fed Bisroot, were lower than the control. The complement activity ($CH_50$) tended to be significantly increased by Bisroot treatment, but not lysozyme activity. Phagocytosis and respiratory burst activities of macrophages in the head kidney were enhanced by Bisroot. Therefore, the Bisroot diet enhances the cellular immune activities were enhanced by Bisroot. Therefore, the Bisroot diet enhances the cellular immune activities of non-specific immune responses. When fish were challenged with a virulent strain of Edwardsiella tarda, the Bisroot treated fish were more resistant than the control. The present results suggest that the introduction of Bisroot into the diet of Nile tilapia could increase their resistance against bacterial infection, reduce fish mortality, and offers economic benefits.