• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.4
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• pp.291-300
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• 1990

The lipid compositions including fatty acid sterol lipid class and the lipid component of the total lipid extracted from the flesh of some fresh water fishes I. e. mandarin cornet cat fish and Korean perch were compared. The levels of total lipid of flesh tissues from the fresh water fishes were high(7.4%) in cat fish but low(1.4-2.2%) in mandarin fish Korean perch and cornet fish. On the contrary the content of unsaponifiable matters found in total lipid was low(2.6%) in cat fish but high(6.0%-6.5%) in mandarin fish Korean perch and cornet fish. Total lipids were mainly composed of triglyceride(74.6-86.5%) as major component in each sample and the other lipid components of total lipid e. g. polar lipid free fatty acids and free sterol were the minor components, The major fatty acids in total lipid of each sample were{{{{ {C }_{16 { }:_{ }0 } }}}}(19.6-29.2%) {{{{ {C }_{16 { }:_{ }1 } }}}}(17.3-30.7%) and {{{{ {C }_{18 { }:_{ }1 } }}}}(16.8-29.2%) and additionally it chiefly consisted of {{{{ {C }_{14 { }:_{ }0 } }}}} and {{{{ {C }_{18 { }:_{ }2 } }}}} Particularly the contents of polyenoic acids in total lipid of cat fish were higher than those of the other fish samples. The level of cholesterol in total lipid was low (8.3mg/g) in cat fish but were high(36.9-59.9mg/g) in mandarin fish Korean perch and cornet fish. The contents of fractionated neutral lipid(NL) were higher than those of polar lipid(PL) in each sample. Particularly phospholipid content in PL was low(6.0%) in cat fish but were high(23.1-36.3%) in mandarin fish Korean perch and cornet fish. Neutral lipids were mainly consisted of triglyceride(84.5-93.4%) as amjor component in each sample and the other lipid components of neutral lipid e, g, free fatty acids and free wterol were exhibited as a minor components, The fatty acid compositon of neutral lipids was very resembled to total lipids. The phospholipid in mandarin cornet and cat-fish were mainly composed of phosphatidyl serine(23.1-49.8%) and phosphatidyl choline(20.8-45.3%) The relatively higher amounts of phosphatidyl serine were observed in mandarine cornet and cat-fist than in Korean perch, But phosphatidyl ethanolamine(42.3%) and phosphatidyl choline (49.9%) were the main phospholipid in Korean perch. The extraordinary high content of phos-phatidyl ethanolamine compared to other fishes was characteristics in phospholipid composition of Korean perch. The major fatty acids in phospholipid of each sample were {{{{ {C }_{16 { }:_{ }0 } }}}} (38.3-46.5%) {{{{ {C}_{18 { }:_{ }0 } }}}}(14.2-21.7) and C16:1(11.6-13.8%) and additionally it chiefly consisted of C18:2, C18:0 and C17:0 The major fatty acids in glycolipid of each sample were C16:0(28.8-40.1%) C18:1(5.4-29.9%) C18:0(5.1-28.9%) and C16:1(8.2-20.1%) and additio-nally it chiefly consisted of C14:0 and C20:1.

• Fisheries and Aquatic Sciences
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• v.26 no.4
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• pp.282-293
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• 2023

Nile perch and Nile tilapia are major commercial species in Uganda, and thus require continuous production. However, their production is impacted by anthropogenic activities such as fishing in breeding habitats. The aim of this study was to identify and characterize Nile perch and Nile tilapia fish breeding habitats on Lake Kyoga. Water quality, lake bottom, fish and vegetation type samples were collected from 20 sites in April of 2021 and 2022. Key informant interviews were conducted with experienced fishermen at five fish landing sites. The water quality parameters indicated significant difference within the sites using analysis of variance. Sandy and muddy bottom types were equally spread at 40% each by use of a pie chart. Fish gonads showed no significant difference among the 20 sites. Bivariate correlation analysis of the vegetation types indicated a strong negative correlation with Nile perch while Nile tilapia had a positive correlation. Principal component analysis of the water quality, fish gonads and habitat vegetation components cumulatively contributed 82.5% in characterizing a fish breeding habitat. Four sites for Nile perch and four sites for Nile tilapia were characterized as breeding sites on Lake Kyoga and are recommended for mapping and gazettement as breeding habitats for sustainable fisheries management.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.227-238
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• 2021

This study investigates the effect of perch type and height on the growth performance, footpad dermatitis (FPD), blood parameters, behavioral characteristics, and meat quality of broilers. A total of 912 one-day-old male Ross 308 broilers (48.23±0.264 g) were subjected to a three x two factorial design of three types of perch (wood, steel, plastic) and two levels of perch height (10→30 cm change, 10 cm fixed) over a five-week experiment. Growth performance, perch availability, litter quality, FPD incidence, serum biochemical parameters, and meat quality of the broilers were evaluated. There were no significant differences in the body weight, feed conversion ratio, and biochemical parameters (except for aspartate aminotransferase), pH, color, and water holding capacity. The incidence of FPD was significantly higher in the plastic perch group than in the wood and steel perch groups (P<0.05) at five weeks of age. Perch use was high in the order of wood, steel, and plastic groups in the daytime and nighttime at one, three, and five weeks of age (P<0.05). Perch use was higher in the 10 cm fixed group than the 10→30 cm group (P<0.05). The shear force of the breast significantly increased in the order of wood, steel, and plastic groups (P<0.05). In conclusion, the group with a fixed perch height of 10 cm had high perch usage. Additionally, the use of wooden perches was higher than that of other materials, and it lowered the incidence of FPD in broilers.

• Korean Journal of Organic Agriculture
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• v.29 no.4
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• pp.589-600
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• 2021

The present study investigated the effect of perch material type (wood and steel) on performance, blood characteristics, and feather pecking. A total of 1,700, one-day-old female Hy-Line brown chicks were evenly assigned to two treatments (wood and steel). The body weight and uniformity of birds were investigated over a 10-week experimental period. Blood characteristics and feather pecking was conducted at week 10. The wood perch treatment (WP) and steel perch treatment (SP) did not differ in their body weight, uniformity, and serum biochemical profile (except inorganic phosphorus) of pullets. Inorganic phosphorus on serum in WP significantly higher than that in SP (P<0.05). Blood corpuscle composition (leukocyte, erythrocyte, and Heterophil / Lymphocyte ratio) of pullets did not show any significant differences among treatments at week 10. Serum corticosterone and feather score that is stress and welfare indices were not affected by the type of perch material. In conclusion, our results suggest that performance, blood characteristics, and feather pecking of pullets were not affected by the perch material type. The results of this study can serve as basic data for investigating the effects of perch type on layer pullets.

• Journal of fish pathology
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• v.23 no.1
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• pp.17-25
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• 2010

We have identified an iridovirus CH-1 from sea perch Lateolabrax sp. healthy externally and imported from China to Korea. In a comparison of the nucleotide sequences of the five different genomic regions, the CH-1 appears to be closely related to the ISKNV, IVS-1 and Ehime-1 strains detected in China, Korea and Japan respectively. In quantitative comparison of the viral DNA, level of CH-1 in tissue of imported fish was 10,000 times lower than that of IVS-1 strain presented in the infected rock bream Oplegnathus fasciatus of moribund stage. It allowed us to speculate the possibility of the asymtomatic iridovirus infection in the culturing sea perch. Such possibility of asymptomatic infection was supported by result of no appearance of dead fish with typical symptoms of iridoviral disease in keeping experiment of the imported sea pearch in laboratory for more than three weeks. Such asymptomatic infections with iridovirus were also found in spleen of the culturing and externally healthy sea perch of Korea by the presence of the iridoviral DNA in nested PCR.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.3
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• pp.378-390
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• 2016

A concept of the perch landing assisted by thruster (PLAT) for a fixed wind aircraft is proposed in this paper. The proposed concept is applicable to relatively large unmanned aerial vehicles (UAV), hence can overcome the limitation of existing perch landing technologies. A planar rigid body motion of an aircraft with aerodynamic and thruster forces and moments is modeled. An optimal control problem to minimize the fuel consumption by determining the histories of thruster and elevator deflection angle with specified terminal landing condition is formulated and solved. A parametric study for various initial conditions and thruster parameters is conducted to demonstrate the practicability of the proposed concept.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.699-707
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• 1995

Eurasian yellow perch (Perca fluviatilis) and American yellow perch (Perca flavescens) are known to be endemic species in Eurasia and North America, respectively. The presence of endemic species on each continent suggests their independent evolutionary history. However, because of the morphological similarity, distribution pattern, and only recent fossil record, their divergence time and speciation of the two Perca species has long been controversial. Here, from the comparison of the entire nucleotide sequences of cytochrome b gene, large genetic divergence between the two Perca species is observed although they are morphologically similar each other. Among 1,140 base pairs, interspecific nucleotide differences are found at 130 sites $(11.4\%)$. The differences varies with codon position, showing 22 sites in the first, 5 sites in the second, and 103 sites in the third codon position. Considering the types of nucleotide changes, transitional differences are much more than transversional differences and its ratio turned out to be 5.19. The estimated divergence time of the two Perca species indicates that they were separated each other approximately in the late Miocene period, which implies the long history of speciation. With comparison of the inferred amino acid sequences, strong structural and functional constraints which seem to be maintained by the highly conservative amino acid residues or protein regions, as found in other taxonomic groups of organisms, are also recognized in the cytochrome b of the fishes examined.

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.339-347
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• 2003

The regional distribution and relative frequency of some endocrine cells in the pancreas of the Korean aucha perch, Coreoperca herzi Herzenstein belonging to the family Serranidae in order Perciformis, were observed using specific mammalian antisera against serotonin, insulin, glucagon, somatostatin and human pancreatic polypeptide (hPP) by peroxidase antiperoxidase (PAP) method. The pancreas was divided into four portions (principal and secondary islets, exocrine and pancreatic duct regions). In addition, the pancreatic islet regions were further subdivided into three regions (central, mantle and peripheral regions). Spherical to spindle or occasionally round to oval immunoreactive (IR) cells were demonstrated in the pancreatic islets and exoccrine portions, but no cells were detected in the pancreatic duct portions. In the principal islets, serotonin-IR cells were not detected but most of insulin-IR cells were located in the central regions and they were also demonstrated in the mantle and peripheral regions in moderate and rare frequencies, respectively. Glucagon- and hPP-IR cells were mainly situated in the mantle regions but the cells were also demonstrated in the peripheral regions in relatively lower frequency. Somatostatin-IR cells were evenly distributed in the central and mantle regions in a few frequency and cells were also demonstrated in the peripheral regions in rare frequency. Cell clusters were consisted of hPP-IR cells that were situated in the peripheral to mantle regions. In the secondary islet portions, serotonin-IR cells were randomly distributed throughout the whole pancreatic islet regions but lower frequency was detected in the peripheral regions compared to that in central and mantle regions where cells were detected in a few frequency, respectively. Insulin-IR cells were restricted to the central regions in numerous frequency and glucagon-IR cells were evenly distributed in the mantle and peripheral regions in moderate frequencies, respectively. Somatostatin-IR cells were observed in the central and mantle regions in moderate and a few frequencies, respectively. In addition, hPP-IR cells showed similar distributional patterns to those of glucagon-IR cells except cells were also located in the central regions in rare frequency. In the exocrine portions, only glucagon- and hPP-IR cells were demonstrated in rare and a few frequencies, respectively. In conclusion, the regional distribution and relative frequency of pancreatic endocrine cells of the Korean aucha perch showed general patterns, which were observed in other teleost. However, some species-dependent different distributional patterns and/or relative frequencies were also demonstrated especially to serotonin-IR cells. In pancreas of the Korean aucha perch, insulin-IR cells were the most predominant cell type followed by glucagon-, somatostatin-, hPP- and serotonin-IR cells.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.3
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• pp.188-199
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• 2013

This thesis is the fundamental study on the adaptation of escape device for reducing small size of fish in set-net. The escape devices for experiments were made the grid-type devices with three different slit sizes (15, 20 and 25mm). The experiments of size selectivity on escape devices were conducted by using two kinds of species as black rockfish (Sebastes schlegeli) and sea perch (Lateolabrax maculatusi) in the experimental tank. The size selectivity curve was fitted by using a logistic function and the parameters of selectivity curve were estimated by a maximum likelihood method. In the results; 50% selection ranges for the grid-type escape devices with three different slit sizes were; a black rockfish was 13.30, 19.22 and 22.06cm and a sea perch was 17.64, 20.91 and 22.78cm, respectively. The 50% selection range of a black rockfish was wilder than a sea perch about 1.1~1.3 time. Therefore, the small size of fish are able to reduce by using the grid type escape device. However, the optimum slit size of grid should be decided to consider the size of target species and economics of catches.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.4
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• pp.928-936
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• 2013

This thesis is the fundamental study on the adaptation of escape device for reducing small fishes in set-net. The escape devices for experiments were made the mesh-type devices with three different mesh sizes (60.6, 75.8 and 120.0mm). The experiments of size selectivity on escape devices were conducted by using two kinds of species as black rockfish (Sebastes schlegeli) and sea perch (Lateolabrax maculatusi) in the experimental tank. The size selectivity curve was fitted by using a logistic function and the parameters of selectivity curve were estimated by a maximum likelihood method. In the results; 50% selection ranges for the mesh-type escape devices with three different mesh sizes were; a black rockfish was 18.99 in mesh size 60.6mm and 21.96 in mesh size 75.8mm (120mm could not estimate). A sea perch was 22.02 in mesh 60.6mm and 24.46 in mesh size 75.8mm (120mm could not estimate). The 50% selection range of a black rockfish was wilder than a sea perch about 1.1~.2 time. Therefore, the small fishes are able to reduce by using the mesh type escape device. However, the optimum mesh size should be decided to consider the size of target species and economics of catches.