• Korean Journal of Ichthyology
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• v.7 no.2
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• pp.171-176
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• 1995

Age and growth of Dictyosoma burgeri, sampled in the costal waters off Sanyang, Tongyeong, Ky$\breve{o}$ngnam during December 1992∼November 1993, were studied by otolith reading. Examination of outer margins of the otolith showed that the opaque zone as annulus was formed once a year with being mainly configured in November. Spawning period was estimated from January to March, with a peak in Feburary. Growth of the fish was expressed by the von Bertalanffy's equation as $L_t=23.5977(1-e^{-0.2542(t+2.1302)})$, $W_t=64.5892(1-e^{-0.2542(t+2.1302)})^{2.3002}$, where $L_t$ is total length in ㎝, $W_t$ is total weight in g and t is age.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.346-357
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• 2010

Characteristics of age and growth of the black rockfish, Sebastes inermis sampled in the Jeonnam Marine Ranching Area (JMRA) around Geumo Islands south of Yeosu were investigated using 642 otoliths from March 2009 to February 2010. The opaque zone was formed in September once a year and hence it was used as an annulus. The parturient period was December to January, and therefore the duration from fertilization to the complete formation of the opaque zone was nineteen months. From the parameters calculated using the average length when the year ring was formed, growth of S. inermis were expressed by von Bertalanffy growth equation as $L_t$=23.267 ($1-e^{-0.4406(t+1.1971)}$) for females and $L_t$=22.030 ($1-e^{-0.5312(t+0.6834)}$) for males when is total length in age t. Through the growth equations, the maximum length was determined as 23.27cm for females and 22.03cm for males and the growth factor as 0.4406/yr and 0.5312/yr, respectively. Finally, the growth of female S. inermis is larger than the one of male S. inermis.

• Journal of Fisheries and Marine Sciences Education
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• v.21 no.2
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• pp.230-236
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• 2009

Growth status of the Littleneck calm Ruditapes philippinarum (Adams et Reeve) in Komso Bay was investigated by 600 individuals from February 2003 to January 2004. Based on the monthly variation of marginal growth rate of the shellfish, it was suggested that ring formation occurres between January and March once a year and takes approximately 19 months (1.58 old ages) to form a complete ring. The relationship between the shell height(SH) and the total weight(TW) could be represented by the following equation $TW=2.8{\times}\;10^{-3}SH^{2.3648}$. And the relationship between the shell height(SH) and shell length(SL) as well as the shell width(SW) were represented by equations SL=1.0027SH+5.812 and SW=0.5121H+1.2849 respectively. Growth curves for shell height and total weight fitted to the Bertalanffy's equation were expressed as $SH_t=42.83(1-e^{-0.4595(t-0.59)})$ and $TW_t=20.17(1-e^{-0.4595(t-0.59)})^{2.3648.}$

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.929-939
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• 2015

We studied the characteristics of age and growth of the Goldeyes rockfish Sebasetes thompsoni in the Ulleungdo and Dokdo areas by using 730 otoliths from February 2013 to February 2014. The lowest value of the marginal index was found in June once a year. The spawning period was estimated as April. Therefore, the duration from fertilization to the complete formation of the first annual growth ring is fourteen months. From the parameters calculated using the weighted average length of the year ring formation, the growth of S. thompsoni was demonstrated by the von Bertalanffy growth equation as $L_t=34.68(1-e^{-0.2113(t+0.7683)})$ for females and $L_t=29.79(1-e^{-0.2163(t+1.7964)})$ for males, $L_t=32.84(1-e^{-0.25(t+0.57)})$ for combined sex. Comparing with growth performance index(${\Phi}$) from these 4 offshore areas, parameter of S. thompsoni in Ulleungdo area was 2.4087, that of in Tong-yeong was 2.2835, that of in Aomori was 2.4077 and in Niigata was 2.3927. As a result, the value of Dokdo and Ulleungdo areas showed the highest.

• Korean Journal of Ecology and Environment
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• v.43 no.1
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• pp.82-90
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• 2010

The ecological characteristics of the Korean Aucha perch, Coreoperca herzi, were determined in order to estimate stock of the mid-upper system of the Seomjin River. The age was determined by counting the otolith annuli. The oldest fish observed in this study was 5 years old. Relationships between body length (BL) and body weight (BW) were $BW=0.0195BL^{3.08}$ ($R^2=0.966$) (p<0.01). Relationships between the otolith radius (R) and body length (BL) were BL=3.882R+1.66 ($R^2=0.944$). The von Bertalanffy growth parameters estimated from a non-linear regression method were $L_{\infty}=19.68\;cm$, $W_{\infty}=188.64\;g$, $K=0.17\;year^{-1}$ and $t_0=-1.46$ year. Therefore, growth in length of the fish was expressed by the von Bertalanffy's growth equation as $L_t=19.68$ ($1-e^{-0.17(t+1.46)}$) ($R^2=0.997$). The annual survival rate (S) was estimated to be $0.666\;year^{-1}$. The instantaneous coefficient of natural mortality (M) of estimated from the Zhang and Megrey method was $0.346\;year^{-1}$, and instantaneous coefficient of fishing mortality (F) was calculated $0.061\;year^{-1}$. From the estimates of survival rate (S), the instantaneous coefficient of total mortality(Z) was estimated to be $0.407\;year^{-1}$.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.1
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• pp.9-16
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• 2013

The growth and production of Aulichthys japonicus (6.70~15.32 cm TL) were investigated in an eelgrass bed of Dongdae Bay, Korea throughout 2006. A total 888 A. japonicus were collected with a small beam trawl. Growth in fish total length was expressed by the von Bertalanffy's growth equation as: $L_t=24.8257(1-e^{-0.5583(t+0.4816)})$. The densities, biomass, daily, annual production, and P/B ratio were $0.01{\pm}0.009/m^{-2}$, $0.17{\pm}0.16g/m^2$, $0.00006{\pm}0.00006g$ AFDW/$m^2$/day, 0.02g AFDW/$m^2$/yr, and 0.12, respectively. Monthly variation in production of A. japonicus was large; the peak occurred at July, September and November 2006 (0.000182, 0.000127 and 0.000123 g AFDW/$m^2$/day), where as the lowest value was 0.000003g AFDW/$m^2$/day at April and May 2006. Monthly change in production of A. japonicus was positive correlated with number of individuals, biomass and growth rate.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.2 no.1
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• pp.21-30
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• 1997

The present study reports the density, growth and production of a razor clam, Sinollovacula constricta, which is known to be one of the important fishreies catches from the Korean tidal flat. The annual yield reached to about 6,000 metric tons per year till 1994. The study was conducted on the Hwaseong tidal flat located on the central west coast, 40 kilometers south-west from Seoul. The annual yield of the razor clam in this area reached to about 50% of the total catch from the whole Korean coast. Samples were colleted monthly at 14 occasions from May 1992 to August 1993. Density of S. constricta ranged from 92~165 individuals per square meter during the study period. General trend of decreasing density was observed when the animal became older, but an exception was the year class of 1991 whose density was lower than that of 1990. The size of the shell was clearly separated into two classes during fall and winter (from September to February), however, the maximum frequency of the length of small size classes moved to right after February. It indicates a fast growth of young clams from spring to summer. Fast growth of the shell could also be examined by the growth curve. The shell growth of the whole life span was described by the von Bertalanffy equation of $L_t=89.3{\times}[1{\exp}\{-0.58{\times}(t+0.73\}]$. The growth in flesh dry weight was well fitted to the Gompertz growth model with the equation, $W_t=5.00{\times}{\exp}\{-4.31{\times}{\exp}(-0.043{\times}t)\}$. The clam lost about 30% of the body weight during spawning in August. The annual production calculated based on the data from September 1992 to August 1993 amounted to 150 g $DW{\cdot}m^{-2}{\cdot}yr^{-1}$ which was 2~50 fold higher than those of other bivalves occurred in Korea. This estimate was patitioned by each year classes; 87.5 by 1992, 53.4 by 1991, 59.0 by 1990 and -30.0 g $DW{\cdot}m^{-2}{\cdot}yr^{-1}$ by 1989 year class.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.2
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• pp.82-87
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• 1983

The aging and growth of Spisula sachalinensis from Ingu over the period from December 1981 through November 1982 were studied. The rings on the shell were used as the character for age determination. The ring where the translucent zone shifts to the opaque one was regarded as an annulus. The time of its formation was estimated by monthly variations of marginal growth rate in the shell. It was formed once a year over the period from August through September. The shell length at the formation of the annulus was estimated by taking the mean shell length corresponding to each of the annual ring. From analysis of mean shell length at the formation of the annulus, von Bertalanffy's growth equation was estimated as follows; $l_t=126.38(1-e^{-0.262(t-0.656)})\;W_t=485.85(1-e^{-0.262(t-0.656)})^3$ Back-calculated shell lengths estimated from this equation was quite consistent with actual shell lengths.