• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.4
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• pp.349-355
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• 2019

Reproductive ecology of rabbit fish, Siganus fuscescens were investigated from samples collected monthly in the coastal waters off Jeju Island of Korea from February to December 2014. In male and female of S. fuscescens, the values of GSI were reached high values between July to August in which the water temperature was high, and then decreased until December. The occurrence of individuals which have mature eggs in ovary were higher from July to August. Therefore, a main spawning season was estimated from July to August, with the highest peak in July. Throughout histological observation of the ovary in the spawning period, S. fuscescens belong to an group-synchronous and has a one spawning season a year. Fecundity of ovary ranged from 380,000 to 2,600,000 during the spawning period. Size at 50% sexual maturity, determined from logistic equation, were 25.1 cm TL which is over two years.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.2
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• pp.169-175
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• 2014

The age and growth of rabbit fish, Siganus fuscescens were investigated from samples monthly collected in the coast of Jeju island, Korea from February to December 2012. Ages were determined from annuli in otoliths, and annuli were formed in one or two months immediately after spawning once a year. Also, main spawning period was estimated between July and August, thus rings were considered as annual marks. The von Bertalanffy growth equations estimated from a non-linear regression method were $L_t=37.24(1-e^{-0.33(t+1.24)})$ ($R^2=0.92$) for female and $L_t=31.44(1-e^{-0.45(t+1.23)})$ ($R^2=0.90$) for male, and the growth between female and male was different.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.4
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• pp.309-313
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• 2000

A experiment was carried out to measure the auditory threshold of dusky spinefoot Siganus fuscescens(Houttuyn) in the coast of Cheju Island by heartbeat conditioning technique using pure tones coupled with a delayed electric shock in order to investigate the hearing ability to audible sound. The audible range of dusky spinefoot extended from 80Hz to 800Mhz with a peak sensitivity at 200Hz. The mean auditory threshold levels of dusky spinefuot were 102dB, 96dB, 92dB, 95dB, 105dB and 121dB respectively in the range of measurement frequencies, As the frequency became higher than 300Hz, the auditory threshold increased rapidly.

• Korean Journal of Ichthyology
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• v.35 no.2
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• pp.101-112
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• 2023

The survey was conducted to find out the temporal variation of the fish species in the eelgrass beds in Punghwa-ri, Tongyeong-si, Gyeongsangnam-do from April 2021 to March 2022. In comparison with the results of previous study conducted 10 years ago, there was a significant difference in species composition and dominant species. In addition, this study found that subtropical fish species such as Siganus fuscescens, Plotosus lineatus, Petroscirtes breviceps, which were not reported in the previous study.

• Journal of Fisheries and Marine Sciences Education
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• v.12 no.2
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• pp.191-198
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• 2000

An experiment was carried out to obtain the fundamental data on the auditory thresholds of fishes for catching method using audible frequency sound, the auditory thresholds of dusky spinefoot Siganus fuscescens(Houttuyn) were measured in the presence of masking noise in the spectrum level range of 74 - 83dB re $1{\mu}Pa/{\sqrt{Hz}}$ by heartbeat conditioning technique using pure tones coupled with a delayed electric shock. The auditory critical ratios were about 23 - 34dB at measurement frequency range. The ratio increased almost linearly with increasing frequency from 200 to 500Hz. The noise spectrum level at the start of masking was about 61 - 73dB within the measurement frequency range. This suggests that hearing of dusky spinefoot is masked in the natural environment with the noise spectrum level above 70dB. The sound pressure level of which the signal sound of 100Hz is recognized by dusky spinefoot under the white noise of 70dB is above 98dB and the critical ratio of them is above 23dB.

• Korean Journal of Ichthyology
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• v.23 no.3
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• pp.225-233
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• 2011

This is the attempt to study the fish assemblages in eelgrass bed of Jeogu on Geoje Island, Korea. Samples were collected by surf net monthly from August 2009 to July 2010. A total 38 species, 2,335 individuals, and 5,289.8g of fishes were collected. The dominant species were Chaenogobius annularis, Gymnogobius heptacanthus, Rudarius ercodes, Siganus fuscescens, Ditrema temminckii, Takifugu niphobles, Aulichthys japonicus, Pseudoblennius cottoides, Syngnathus schlegeli, Sebastes schlegelii, Pterogobius elapoides, Urocampus nanus, Takifugu pardalis, Hypodytes rubripinnis which accounted for 94.2% of total number of individuals of fish collected. Eelgrass biomass showed a peak in August (DW 121.5g/m$^2$), low values in November (DW 74.9 g/m$^2$) to February (DW 49.3g/m$^2$), and started growing from May (DW 112.8g/m$^2$). Gymnogobius heptacanthus, Sebastes schlegeli, Takifugu niphobles, Syngnathus schlegeli, Urocampus nanus were collected year-round with no clear relationship to the biomass of eelgrass bed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.3
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• pp.277-283
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• 1999

For the purpose of leading horse mackerel Trachurus japonicus schools, mackerel Scomber japonicus schools and arrow squid Todarodes pacificus schools, which migrate to the Cheju coast and are caught by the set-net, to the set-net by attracting lamps, we made five attracting lamps and took a practical experiment in the Gwiduk and Dongbuk set-net fishing ground. In the set-net with two bag-nets, we compared the amount of catch of both bag-nets by the means of switching on and off the each attracting lamps in order, switching off the attracting lamps in order which had been switched on and moving an attracting lamp.In the bag-net with an attracting lamp, horse mackerel, mackerel and arrow squid were caught the most, on the other hand, yellow tail Seriola quinqueradiata, striped mullet Mugil cephalus were caught in large quantities in the bag-net without attracting lamp. File fish Stephanolepis cirrhifer, Dusky spinefoot Siganus fuscescens were caught evenly in both bag-nets regardless of an attracting lamp.This result indicates that the amount of horse mackerel, mackerel, arrow squid can be increased by the use of attracting lamps in the set-net fishing method.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.1
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• pp.65-72
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• 2004

Fish catch by a set net in Hamdeuk fishing ground off Jeju Island were studied to determine seasonal variation of species composition and catch from 1998 to 2000. A total 72,022.9 kg was caught during the survey period, including Scomber japonicus and Trachurus japonicus of $76.4\%$ in the total. The other dominant species were Siganus fuscescens, Loligo chinesis, Seriola dumerili, Sepioteuthis lessoniana, Sardinops melanostictus, and Seriola lalandi accounting to $20.0\%$ of the total. The fishing period conducted by a set net in Hamdeuk fishing ground were from May to November. The catch by a set net were higher in summer than in spring and autumn and closely related with the seasonal variation of sea water temperature. The catch was higher in 1998 than In 1999 and 2000, which was related to the sea water temperature in fishing ground.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.3
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• pp.407-415
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• 2014

Fish was caught by a set net in Gwideok, Jeju island that was studied to determine monthly variation of species composition and catch from May 2005 to October 2006. Total catch was 54 species, 44,118 individuals, and 2,152,423.7 g during survey period. Dominant species were Trachurus japonicus and Siganus fuscescens that held 91.3% of total individuals and 71.3% of total abundance. The highest individuals and abundance of catch were in July 2005, and the lowest individuals and abundance of catch were in October 2006 and in October 2005, respectively. As the result, temporal change in abundance have corresponded with changing water temperature.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.4
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• pp.301-314
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• 2023

Long term variations of fish assemblage in the coastal waters of Bukchon-ri were determined using samples collected by trammel net from 2012 to 2022. Water temperature increased by 0.4℃ in 2022 that was less then 2012. During the survey period, a total of 95 species (53 families and 15 orders) of fishes were identified, Scorpaeniformes (five families and 22 species) and Perciformes (25 families and 39 species) accounted for 73% of the total number. The number of species was higher in summer than winter, showing a peak in summer at 66 species and lower in winter and autumn at 45 species. The number of individuals and the biomass peaked in summer at 1,238 individuals and 280.1 kg, and were the lowest in autumn at 597 individuals and 155.4 kg. The annual diversity index, evenness index and richness index were appeared 2.11-2.80, 0.64-0.80 and 4.70-7.34 at each years. The dominance index were appeared highest in 2014 while 2021 were appeared the lowest in 2017. The subtropical fishes were identified total of 38 species (40.0%) and the number of species was higher in 2022 at 22 (52.4%) species and lower in 2015-2017 at each 10 (31.3-37.0%) species. The dominant species of subtropical fishes were appeared rabbit fish (Siganus fuscescens), boxfish (Ostracion immaculatus), smallscale blackfish (Girella melanichthys), flag fish (Goniistius zonatus), stripey (Microcanthus strigatus), rock porgy (Oplegnathus punctatus), and bluestriped angelfish (Chaetodontoplus septentrionalis) in study sites.