• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.4
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• pp.184-188
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• 1987

The author studied to analyse the relationship between the body dimension of sea eel, Astroconger myriaster and the mesh size of fishing gears. The samples were caught by traps and pots during September, 1987 in the Southern Sea of Korea. The results obtained can be summarized as follows: 1. The relationship between total length L, body weight W and diameter D may be expressed as: W=3.58$\times$10 super(-4) L super(3.38) (r=0.99). D=0.07 L-0.59 (r=0.99). W=10.38 D super(2.76) (r=1.00). W=1/2$\times$D super(2).L. 2. The mesh size of traps and the hole diameter of post must be more than 29.2 mm and 18.6 mm, respectively.

• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.543-550
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• 2020

This study aimed to identify the characteristics of fish inhabiting Hapcheon Dam and surrounding rivers and the Bluegill population, an invasive species, and provide basic data. The survey of fish living in Hapcheon Dam and surrounding tributaries in the Ulsan area from 2016 to 2017 identified a total of 1,785 individuals of 30 species of 10 families and identified 8 Korea's endemic species (21.8% indigenization rate), 3 exotic species, and 2 ecosystem disturbance species. The comparison of this study with the past survey showed that 36 species of 12 families were reported in the past survey, but 14 species of them were not found in this study. We believe that a more detailed survey of Lake Hapcheon should identify most of them. The analysis of the length-weight relationship for the Bluegill population, identified as the dominant species in the Hapcheon Lake, showed that a large number of populations was in the stage of rapid growth as a large number of populations aged 1 to 2 years was found. Since the obesity level and the length-weight relationship were confirmed to be in good condition, it was necessary to prepare a plan to control the Bluegill population. We expect that this study's results can be useful data for understanding the growth and trends of the Bluegill population inhabiting the Hapcheon Dam and surrounding rivers.

• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.402-412
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• 2020

This study aims to examine the population characteristics of the fish and the bluegill (Lepomis macrochirus), designated as ecologically disturbing fish, living in four water dams in the Ulsan area and to provide basic data. The survey of fish living in 4 water dams and surrounding tributaries in the Ulsan area from 2016 to 2017 found a total of 1,987 individuals of 28 species of 9 families and identified 6 Korea's endemic species is (21.4% indigenous rate), 4 exotic species, and 2 ecosystem disturbing species. Based on the number of fishes identified, the dominant species was Lepomis macrochirus, and the subdominant species was Hemiculter eigenmanni. The investigation of the age structure of the L. macrochirus found in the 4 water dams in the Ulsan area showed a large population of 1 to 2 old, and the population was growing fast. Moreover, the analysis of the total length-weight relationship and obesity of the L. macrochirus population showed that the regression coefficient b of the total length-weight relationship was greater than 3.0, and the habitat of the L. macrochirus population was in good condition. Obesity had a positive slope, and the growth state was relatively good. The result of this study can be used as useful data to predict the trend of the L. macrochirus fauna inhabiting in 4 water dams in the Ulsan area.

• Development and Reproduction
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• v.10 no.4
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• pp.271-275
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• 2006

The objective of this study was to examine the early growth of haddock, Melanogrammus aeglefinus larvae from a series of reared specimens for provide information to developmental biology and more information on the aspect of aquaculture in the larvae of this species. Larvae were reared in the laboratory and sampled periodically for developmental study until 67 days after hatching. An increase in total length of fish indicated continuous growth, described by the growth expression of the type $TL=3.5374e^{0.0536X}(r^2=0.8759$, where TL is total length and X is at days after hatching) and $BW=0.0002e^{0.1858X}(r^2=0.8671$, where BW is body weight and X is at days after hatching), respectively. Pattern of body depth and pectoral fin length are instantaneous growth which expression of the type $BD=0.3545e^{0.0778X},\;r^2=0.9563$(where BD is body depth and X is at days after hatching) for body depth growth and the type $PL=0.0111e^{0.1591X},\;r^2=0.9194$(where PL is pectoral fin length and X is at days after hatching) for pectoral fin length growth. The relationship of body depth and total length expressed as $BD=0.2397X-0.5735(r^2=0.9957$, where BD is body depth and X is total length), and pectoral fin length and total length is $PL=0.1929X-1.3767(r^2=0.9882$, where PL is pectoral fin length and X is total length) pectoral fin length against body depth simultaneously recorded for juvenile haddock(PL=0.8117BD-0.9718, $r^2=0.9814$, where PL is pectoral fin length and BD is body depth). Relationship of body depth and body weight was expressed the type of $BD=-9.4734X^2+19.046X+1.3672,\;r^2=0.941$(where BD is body depth and X is body weight), and pectoral fin length and body weight expressed the type of $PL=6.379X^2+14.023X+0.3774,\;r^2=0.9494$(where PL is pectoral fin length and X is body weight). From this point view, growth characteristics of juvenile haddock in this experiment may be useful to establish a successful culture technique for rearing larval haddock.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.529-534
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• 1998

Age and growth of the yellow goosefish, Lophius litulon, were studied using samples collected from the southwestern waters of Korea. Vertebrae of the fish had relatively clear annuli on their surface. The opaque zone of vertebrae was formed once a year between March and April. The oldest fish observed in this study was 8 years old for females and 5 years old for males. The relationship between the radius (R) of vertebral centrum and total length (L) was as follows: L=12.7+4.8R for females and L=9.8+5.6R for males. The relationship between total length and body weight (W) was as follows : $W=0.0089L^{3.0311}$ for females and $W=0.0329L^{2.7752}$ for males. Growth in length of the fish was expressed by the von Bertalanffy's equation as $L_t=127.60(1-e^{-0.1228(t+0.3851)})$ for females and $L_t=82.23(1-e^{-0.1832(t+0.6431)})$ for males.

• Korean Journal of Ecology and Environment
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• v.54 no.1
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• pp.12-23
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• 2021

As fish communities are sensitive to natural environmental changes as well as anthropogenic pressures, their composition and characteristics help us to assess the aquatic ecosystem health. The fish fauna and the length-weight relationship of Zacco platypus in the Seomjin River system were investigated from July 2018 to May 2019. The collected species during the survey period were 49 species belong to 14 families including 19 Korean endemic and two endangered species. According to Bray-Curtis similarities, 14 sites were divided into four groups based on the fish community composition; two groups(group A, B) and two uncategorized sites(group C, D). There were significant differences between groups A and B(analysis of similarities, R=0.722, p=0.002). A similarity percentage analysis revealed that Z. koreanus(8.55%), Micropterus salmoides(6.90%), and Lepomis macrochirus (4.90%) contributed to these differences of fish assemblages between group A and B. Group A showed higher relative abundances of exotic species such as M. salmoides and L. macrochirus, while Z. platypus and Z. koreanus which are the common species in Korea, were the most dominant species in group B. Based on the length-weight relationship of Z. platypus, b values were varied from 2.82 to 3.80, indicating that growth patterns of the species were spatially different. This study could be served as baseline data for understanding fish fauna, assessing habitat characteristics based on the fauna, and identifying health conditions of Z. platypus in the Seomjin River system.

• Korean Journal of Environment and Ecology
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• v.27 no.6
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• pp.695-703
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• 2013

The fish fauna and population Zacco koreanus in the Cheonggye stream after the rehabilitation was investigation from April 2011 to May 2012. The collected species during the survey period were 24 species belonging to three families. Among them, Korean endemic species such as Rhodeus uyekii, Acheilognathus yamatsutae, Acheilognathus gracilis, Squalidus japonicus coreanus and Zacco koreanus were observed in the stations. Dominant species was Zacco platypus (St. 1, 3, 4) and Z. koreanus (St. 2). A total of species of A. gracilis, Hemibarbus longirostris, Gnathopogon strigatus, S. japonicus coreanus, Pseudogobio esocinus, Erythroculter erythropterus, and Tridentiger brevispinis were first observed this study with compared the previous data (2005, 2008). It seems that the introduction species of artificially to the Cheonggye stream were Cyprinus carpio (fancy carp), Carassius auratus (gold fish), Carassius auratus (chinese carp), Zacco temmincki, Z. koreanus and Misgurnus mizolepis. Calculation of the length-weight relationship of Z. koreanus showed the value of constant a as 0.000007 and b as 3.58, and condition factor (K) was 0.82 on average. The frequency analysis of total length indicated that the group 20~80mm in total length is represented by one year-old individuals, the group 90~120mm by two year-old individuals, and the group over 130mm by three year-old individuals. It is assessed that stable spawning occurred following the introduction to the Cheonggye stream.

• Korean Journal of Environment and Ecology
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• v.34 no.3
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• pp.216-223
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• 2020

This study investigated the ecological characteristics of Coreoperca herzi at Jaho stream from September 2018 to August 2019. This species inhabited riffle and midstream of the stream, where the riverbed structure was mostly covered with cobble and pebble. The depth of the habitat was 32-157 cm, and the velocity of stream fast at 0.64±0.28 (0.32-1.28) m/sec. The gender ratio of females to males was 1:0.95. The age according to the frequency analysis of total length indicated that the group with 42-80 mm in total length was one year old, the group with 80-130 mm was two years old, the group with130-200 mm was three years old, and the group over 200 mm was four years old. The total length of sexually mature fishes was 65 mm for females and 70 mm for males. The sexually mature individuals grown in nature had a smaller total length than those reared in a laboratory. The spawning season was from May to late July, and the water temperature was 18.4-26.4℃ during the period. The prosperous spawning season was from May to June, and the water temperature was 18.4-21.8℃ during the period. The average number of eggs in the ovaries was 462 (151-919) per mature female, and the matured eggs were yellowish and spherical with a mean diameter of 2.31±0.33 (1.93-3.10) mm. Calculation length-weight relation of Korean aucha perch showed the constant a as 0.00002 and b as 3.01, condition factor (K) as 1.76 (1.01-2.63) on average, and the slope was a positive value of 0.0005.

• Journal of Fisheries and Marine Sciences Education
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• v.8 no.1
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• pp.41-47
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• 1996

The fishing experiment was carried out in order to analyses the mesh selectivity for trawl cod - end in the Southern Korean Sea and East China Sea from June,1991 through December, 1992. The mesh selectivity was examined for the five kinds with opening mesh size, of which having mesh s izes 51.2mm, 70.2mm, 77.6mm, 88.0mm and 111.2mm. In this report, mesh selectivity were taken analyses trawl cod - end for Priacanthus macracanthus. The main results obtained were as follows : 1. The relation equations between total length(TL) and body height(BH), body girth(BG) and body weight(BW) were BH=0.256 TL+2.963, BG=0.620 TL+8.650 and $BW=7.34{\times}10^{-5}TL^{2.6956}$, respectively. 2. 50% selection length and selection factor of trial cod - end with opening mesh size having 51.2mm, 70.2mm, 77.6mm, 88.0mm were 94.8mm, 1.85 ; 159mm, 2.27 ; 204mm, 2.09 ; 217.3mm, 2.18, respectively. 3. Range of opening mesh size from 51.2mm to 88.0mm, parameters of master curve were slope 2.70, intercept - 5.7 and selection factor 2.11.

• Korean Journal of Environment and Ecology
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• v.33 no.3
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• pp.256-265
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• 2019

We investigated the ecological characteristics of Phoxinus phoxinus in the spring water in Eocheon stream from January to December 2016. The water temperature was $9.7{\sim}14.3^{\circ}C$ and remained below $15^{\circ}C$ throughout the year. The fishes cohabiting with minnow were Rhynchocypris kumgangensis (70.14%), Cottus koreanus (13.63%), Rhynchocypris oxycephalus (3.16%), Oncorhynchus mykiss (0.97%), Zacco koreanus (0.49%), and Iksookimia koreensis (0.24%). The sex ratio of female to male was 1:0.86. The frequency analysis of total length indicated that the fishes with the total length of 30 - 50 mm were one year old, those of 50 - 65 mm were two years old, those of 65 - 75 mm were three years old, and those of 75 mm or more were four years old. The sexually mature fishes were 50 mm or longer for female and 60 mm or longer for male. The spawning season was from April to July, and the water temperature was $12.3-14.3^{\circ}C$ during the period. The prosperous spawning season was from June to July, and the water temperature was $13.8-4.3^{\circ}C$ during the period. The average number of eggs in the ovaries was 508 per matured female, and the matured eggs were yellowish and spherical with a mean diameter of $1.58{\pm}0.13mm$. The length-weight correlation of P. phoxinus was $BW=0.000007TL^{3.09}$ with the constant a as 0.000007 and the parameter b as 3.09. The condition factor (K) was 0.99 (0.76 - 1.32) in average.