• Development and Reproduction
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• v.11 no.3
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• pp.227-233
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• 2007

The milt properties of filefish(Thamnaconus modestus) included physical properties of sperm and biochemical properties of seminal plasma. The physical properties of milt were $0.3{\pm}0.1\;mL{\cdot}fish^{-1}$ in sperm volume, $2.6{\pm}0.1{\times}10^7\;spermatozoa{\cdotg}mL^{-1}$ in sperm concentration and $73.3{\pm}6.7$ in spermatocrit. The biochemical properties of seminal plasma contained $9.8{\pm}0.9\;mmol{\cdot}L^{-1}$ potassium, $164.0{\pm}4.0\;mmol{\cdot}L^{-1}$ sodium, $151.0{\pm}1.2\;mmol{\cdot}L^{-1}$ chloride, $14.9{\pm}0.6\;mg{\cdot}dL^{-1}$ calcium, $7.2{\pm}0.1\;mg{\cdot}dL^{-1}$ magnesium, $1.0\;mg{\cdot}dL^{-1}$ glucose, $0.1\;g{\cdot}dL^{-1}$ total protein and $1.0\;mg{\cdot}dL^{-1}$ total lipid. The osmolality and pH of seminal plasma were $322.8{\pm}2.8\;mOsmol{\cdot}kg^{-1}$ and $7.7{\pm}0.1$, respectively. The spermatozoon of filefish consisted of three parts: head without acrosome, mid-piece with five mitochondria and flagellum with "9+2" pattern. The head of spermatozoon in longitudinal section was horseshoe-shaped, and $1.3{\sim}1.6\;{\mu}m$ long and $1.0{\sim}1.3\;{\mu}m$ wide.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.189-193
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• 1981

An apparatus for continuous measurements of sorption isotherm of dried food was manufactured to shorten the time required for equilibration. The apparatus was so designed that the temperature, air velocity and relative humidity in the experimental chamber could be controlled. The use of dynamic stream of conditioned air with a velocity of 0.2m/sec, instead of static atmosphere, allowed a faster equilibration of dried filefish muscle at $25^{\circ}C$. The mean time necessary for the equilibration of dried filefish muscle at the water activity of a given state to a higher water activity was about 45 hours. The monolayer moisture content of dried filefish muscle calculated from BET-equation was 0.092 kg water /kg dry matter at $25^{\circ}C$.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.05a
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• pp.573-574
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• 2002

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.2
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• pp.170-176
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• 2012

Genetic diversities, population genetic structures and demographic histories of the thread-sail filefish Stephanolepis cirrhifer were investigated by nucleotide sequencing of 336 base pairs of the mitochondrial DNA (mtDNA) control region in 111 individuals collected from six populations in Korean coastal waters. A total of 70 haplotypes were defined by 58 variable nucleotide sites. The neighbor-joining tree of the 70 haplotypes was shallow and did not provide evidence of geographical associations. Expansion of S. cirrhifer populations began approximate 51,000 to 102,000 years before present, correlating with the period of sea level rise since the late Pleistocene glacial maximum. High levels of haplotype diversities ($0.974{\pm}0.029$ to $1.000{\pm}0.076$) and nucleotide diversities (0.014 to 0.019), and low levels of genetic differentiation among populations inferred from pairwise population FST values (-0.007 to 0.107), support an expansion of the S. cirrhifer population. Hierarchical analysis of molecular variance (AMOVA) revealed weak but significant genetic structures among three groups ($F_{CT}$ = 0.028, p<0.05), and no genetic variation within groups (0.53%; $F_{SC}$ = 0.005, p = 0.23). These results may help establish appropriate fishery management strategies for stocks of S. cirrhifer and related species.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.17 no.1
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• pp.7-11
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• 1981

The author carried out an experiment to find out the responsing patterns of filefish, Stepha nolepis cirrhifer (Temminck et Schlegel) to the color lights. The experimental tank (360LX50WX55H cm) was set up in a dark room. Six Longitudinal sections each being 60 em intervals are marked in the tank to observe the location of the fish. Water depth in the tank was kept 50 em level. Light bulbs of 20W were placed at the both ends of the tank to be projected the light horizontally into the tank. Two different colored filters were selected in combination from four' colors-red, blue, yellow, and white, and were placed in front of the light bulbs to make\ulcorner different light of color. Light intensity were controlled by use of auxiliary filters intercepted between the bulb and the filter. The fish were acclimatized in the dark for 40 minutes prior to employ in the experiment. Upon turning on the light, the number of fish in each section was counted 40 times in every 30 seconds, and the mean of the number of fish in each section was given as the gathering rate of the fish. The results obtained are as follows: 1. Color of light, to which the fish gathered abundantly was found in the named order of blue, white, green, and red. 2. The differences of gathering rate upon arbitary combined two color lights were shown significant, and the differences increased remarkably in accordance with the lapse of illuminating period.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.147-153
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• 1983

To check the differences of the digestive enzymes by the bait habits and the proteolytic activities of the fissile extracts from the fish, omnivorous filefish (Navodon modestus), carnivorous cat shark (Scilliorhinus tarazame) and bloodsucking hag fish (Eptatretus burgeri) were sampled for this experiment. The activity of crude alkaline protease extracted from the muscle and the internal organs of the samples was determined with casein as substrate. The activity of the proteolytic enzymes showed remarkable differences by the organs of the fish. The optimum condition of the pretenses from the muscle revealed in range of pH 7.8-8.3, at $60-65^{\circ}C$, while those of the enzymes from the internal organs were at about pH 8.2, $45-55^{\circ}C$, but those of hag fish were at about pH 6.7, $45-55^{\circ}C$. The proteolytic activity of the enzyme of alimentary canal in filefish and in hag fish was 57 and 11 times stronger than that of muscle, respectively. The crude enzyme from the alimentary canal of file fish showed the strongest proteolytic activity in samples submitted and that of cat shark was the lowest. The activity of pancreatic alkaline protease in cat shark was 50 fold higher than that of muscle alkaline protease in the fish.

• Korean Journal of Food Science and Technology
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• v.14 no.4
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• pp.342-349
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• 1982

Filefish muscle in the form of thin plate $(5{\times}10{\times}0.4\;cm)$ was dried in a forced air dryer at $47.5^{\circ}C$ to study the relation between dehydration mechanism and water activity. The dryer was designed in such a way that the temperature, relative humidity and velocity of air could be controlled. The whole dehydration process of the filefish muscle was divided into two different drying rate periods, constant and falling rate period. During the constant drying rate period, the drying rate was proportional to the square root of air velocity under the conditions of constant temperature and relative humidity of air. The falling rate period was further divided into two different falling drying rate periods, first and second falling rate period. The first falling rate period was an unsaturated surface drying period caused by partial unsaturation of the drying surface with capillary condensed free water diffused from the internal part of the filefish muscle. At this stage he drying rate was mainly dependent on the relative humidity at constant air temperature, and case-hardening phenomenon started at the end of this stage. The moisture content and the water activity at which the second falling rate period started were not constant, because the drying rate of the first falling rate period was strongly dependent on the air humidity. The second falling rate period was again divided into two drying rate periods, former and latter period. The drying rates of both of these periods were independent on the external air humidity. During the former period of the second falling rate period, the dehydration was proceeded by diffusion and vaporization of capillary condensed free water in filefish muscle. The diffusion coefficient of water was $2.89{\times}10^{-10}m^2/sec\;at\;47.5^{\circ}C$. At this stage, the case-herdening continued until the water activity reduced to 0.7. The latter period of the second falling rate period started at the water activity of 0.45. The dedydration was proceeded by diffusion and vaporization of bound water, which adsorbed in multimolecular layers, through the hardened drying surface. The number of molecular layers was 4, and the diffusion coefficient of water during this stage was $4.38{\times}10^{-11}m^2/sec\;at\;47.5^{\circ}C$.

• Food Science and Preservation
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• v.15 no.6
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• pp.922-926
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• 2008

The effect of UV-C irradiation on microbial growth and the quality of imported dried filefish and octopus during storage was examined. Samples of imported dried filefish and octopus were irradiated at 0, 5, 10 and $20\;kJ/m^2$ and stored for 3 months at $20^{\circ}C$ or for 6 days at $4^{\circ}C$. Exposure times of 5 min 33 sec, 11 min 6 sec, and 22 min 12 sec were used. UV-C treatment of the imported dried filefish and octopus decreased the populations of aerobic bacteria, yeasts and molds in proportion to radiation dose. Compared to the control, total aerobic bacteria, and yeast and mold populations were significantly lower (1-2 log CFU/g) with UV-C treatment of $20\;kJ/m^2$. UV-C irradiation caused negligible changes in the Hunter color L, a and b values. These results indicate that UV-C irradiation could be useful in inhibiting microbial growth on imported dried fish without impairing quality during storage.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.1
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• pp.1-13
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• 1980

The purpose of the present study is to find the light intensity which induces maximum gathering rate and to observe the variation of the gathering rate both in daytime and at night by using three species of commercial fishes: filefish, Stephanolepis cirrhifer (Temminck et Schlegel), conger eel, Astroconger myriaster (Brevoort) and crucian carp, Carassius oarassius (Linnaeus). An experimental tank $(360L\times50W\times55Hcm)$ was set up in a dark room. An illumination system was attached to one end of the tank to control horizontal, light intensity. Six artificial light sources were prepared by combination of two light bulbs (5W, 150W) and seven filters. During the experiment water depth was maintained 50 cm level in the tank. The tank was marked into six longitudinal sections each being 60 cm long to observe the distribution of fish. The fish were acclimatized in dark condition for 40 minutes prior to the main experiment. Upon turning on the light, the number of fish .in each section was counted 40 times every 30 seconds, and the gathering rates were obtain from the average number of fish in each section. In filefish the light intensity inducing maximum gathering rate was 0.7 lx(0.5-1.1 lx), and there nab little difference between day and night. Gathering rate varied propotionally to the length of illumination time. In conger eel the light intensities inducing maximum gathering rate were 1.9 lx(1.2-2.9 lx) in daytime and 5.2 lx (3.2-7.7 lx) at night. Thus, there was a considerable difference between day and night, but the gathering rate remained almost unchanged regardless to the length of illumination time. In crucian carp gathering rate did not show a definite pattern hut fluctuated irregularly. The gathering rate, however, was slightly higher at 16.21 lx, and there was little difference between day and night.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.99-106
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• 1982

Vacuum-packed and seasoned-dried products of filefish, Navodon modestus, caught in large quantities in the coasts of Japan and Korea, were prepared tentatively and stored at $35^{\circ}C$ for $3\sim4$ months to test their keeping quality. Headed, eviscerated, ana skinned filefish were purchased from Tokyo central wholesale market and filleted. The fillets were seasoned with the seasoning powder prepared from sugar, sorbitol, salt, glutamate, 5'-ribonucleotide, and either beef flavor (Flava-Beef, Kyowa Hakko Kogyo Co. Ltd.), red pepper, or smoke flavor (Smok-EZ, Alpha Foods Co. Ltd.). After seasoning, the fillets were dried at $39\sim41^{\circ}C$ for several hours, vacuum-packed in the bag of plastic film, and cooked in water of $80^{\circ}C$ for 40 min. Two kinds of products different in moisture level were prepared : one containing moisture of $26\sim29\%$ and the other $40\sim46\%$. The moisture level, water activity, color value (L,a, and b values), texture, and viable counts of bacteria of these products were determined during storage at $35^{\circ}C$. From the results obtained, it became clear that the products could be preserved in good condition for $3\sim4$ months at $35^{\circ}C$, though they slightly decreased in the softness with decrease of moisture content and developed a pale brown during storage. Judging from organoleptic evaluation on the flavor, the products containing beef flavor as a seasoning was most desirable.