• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.5
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• pp.607-611
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• 2016

This study was conducted to investigate the effects of different water temperatures on growth, survival, biochemical composition, and blood physiological parameters of juvenile mandarin fish Siniperca scherzeri. Feed-trained juvenile fish were subjected to four water temperatures (20, 23, 26 and 29℃) with two replicate groups. The fish were fed to apparent satiation twice daily using a formulated diet containing 55% crude protein and 6% crude lipid. After the 8-week feeding trial, survival was >96% in all groups. Weight gain and feed efficiency of fish reared at 26 and 29℃ were higher than those reared at 20℃. The protein efficiency ratio, daily feed intake, and whole body proximate composition were not affected by water temperature. These results indicate that a suitable water temperature range for optimal growth and feed efficiency of juvenile mandarin fish is 26-29℃ under these experimental conditions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.4
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• pp.538-543
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• 2020

A feeding trial was conducted to investigate the effect of feeding frequency on the growth performance and body composition of juvenile mandarin fish Siniperca scherzeri. Triplicate groups of fish (initial fish weight, 7.5 g/fish) were fed to apparent satiation at one, two, three or four meals per day for 8 weeks. The results showed that weight gain of fish fed one meal per day was significantly (P<0.05) lower than those fish fed two, three or four meals per day. Feed efficiency of fish fed two meals per day was significantly (P<0.05) higher than other experimental groups. The plasma cholesterol content was significantly lower in fish fed one meal per day than those fed two, three or four meals per day. Consequently, we can conclude that feeding juvenile mandarin fish twice daily to apparent satiation is acceptable and sufficient to achieve good growth and feed efficiency, as fish performance was not remarkably enhanced when feeding increased from two to four times per day.

• Korean Journal of Ichthyology
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• v.29 no.2
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• pp.124-129
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• 2017

The feeding habits of the Siniperca scherzeri were studied using 332 specimens collected by trammel net in the Soyang Lake of Han River, from April to November 2014. Of 332 specimens, 197 contained food and 135 were empty. The standard length of individuals used in this study ranged from 107 to 321 mm. Mandarin fish mainly consumed fishes and shrimps. The main food items of fishes and shrimps were Hypomesus nipponensis and Macrobrachium nipponense. The proportion of fishes in prey items increased with increasing mandarin fish length, however shrimps decreased with growth. The seasonal difference were apparent, fishes were taken mainly all the seasons except June, July and October. There were higher rates of fishes for food items in downstream areas than in the upper and middle areas of the Soyang Lake.

• Journal of Aquaculture
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• v.10 no.4
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• pp.439-447
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• 1997

A specific disease syndrome, which led to massive mortality on the Korean mandarin fish fingerling (Sinperca scherzeri) at Chongpyong Inland Fisheries Institute was atudied. The causetive agent isolated from the diseased fish was identified as Aeromonas hydrophila on the basis of biochemical and physiological characteristics. Infection experiments in the Korean mandarin fish fingerling, weighting 3-4 g with A. hydrophila were conducted by immersion, oral administration, intramuscular injection, and injection of the soluble extracellular products secreted from it. Motality rate was higher virulence in intramuscular injection group than other experimental groups. In injection group of the soluble extracellular products, all fish treated with high concentration ($8{\times}10^9$ cfu/ml) were repidly killed into 3-6 hrs. There results show that the Korea mandarin fish fingerling has high susceptibility to A. hydrophila.

• Korean Journal of Ichthyology
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• v.30 no.2
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• pp.84-91
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• 2018

The study about maturity and spawning of Korean Mandarin fish, Siniperca scherzeri collected using the set net and gill net in Soyangho Lake from April to November 2014 was conducted. The number of individuals was 401 (female: 204, male: 197). The total length of females ranged from 113 mm to 365 mm and that of males was from 140 mm to 342 mm. The water temperature in May which is the start of spawning season indicated about $15^{\circ}C$ and gradually increased to July ($26^{\circ}C$). Gonadosomatic index (GSI) of females indicated 2.3%, 4.6% and 3.1%, respectively, in May to July. Males' value showed the similar pattern recording 8.0%, 6.6% and 4.5% in the same time. According to histological observations of gonadal tissue, the most of female in May had the gonadal tissue of maturing and mature stage. And the ovary of June was mostly in the stage of ripe and spawning and a number of individuals in July was recovery stage. In the case of male, a number of males in May showed in the stage of mature. The testis of June showed that mature sperm was releasing. And the testis of July was mostly in recovery stage. The total length at 50% group maturity was estimated 245.16 mm. As shown in the above, the main spawning period of S. scherzeri was May to June.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.756-761
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• 2017

This study investigated the growth of juvenile mandarin fish Siniperca scherzeri, reared at high water temperatures. Feed-trained juvenile fish were reared at four water temperatures: 27, 29, 31, and $33^{\circ}C$. The fish were fed to apparent satiation twice daily using pelleted diet. After 10 weeks of feeding trial, the survival exceeded 98% in all groups. The weight gain of fish reared at $31^{\circ}C$ was higher than for fish reared at the other temperatures. The feed efficiency and protein efficiency ratio of fish reared at 29 and $31^{\circ}C$ were higher than for the fish reared at 27 and $33^{\circ}C$. The daily feed intake of fish reared at 27 and $33^{\circ}C$ was higher than for the 29 and $31^{\circ}C$ groups. The whole body moisture content of fish reared at $33^{\circ}C$ was higher than in the $27^{\circ}C$ group. The whole body crude protein and lipid contents of fish reared at $27^{\circ}C$ were higher than in the $33^{\circ}C$ group. The results indicate that suitable rearing water temperature was $31^{\circ}C$ for optimal growth and feed efficiency of juvenile mandarin fish under the experimental conditions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.762-769
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• 2017

This study investigated the effects of stocking density on the growth of the mandarin fish Siniperca scherzeri, in small (1-year old, 50.2 g/fish) and large (2-years old, 173.1 g/fish) size (age) groups. Small and large fish groups were fed pelleted diets twice daily for 10 and 15 weeks, respectively. In the small group, at the end of the feeding, the weight gain of fish at a density of $4kg/m^3$ was lower than that of fish at densities of 3, 2 and $1kg/m^3$. However, fish stocking density did not affect feed efficiency. The daily feed intake of fish at a density of $4kg/m^3$ was lower than that fish at densities of 3, 2 and $1kg/m^3$. In the large fish group, the weight gain of fish at a density of $4.5kg/m^3$ was higher than that of fish at densities of 6, 3 and $1.5kg/m^3$. Again, fish stocking density did not affect feed efficiency. The daily feed intake of fish at a density of $4.5kg/m^3$ was higher than that of fish at densities of 6, 3 and $1.5kg/m^3$. Based on these results, the optimum stocking density for small (50.2 g/fish) and large (173.1 g/fish) mandarin fish is 3 and $4.5kg/m^3$, respectively.

• Journal of Aquaculture
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• v.18 no.2
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• pp.76-80
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• 2005

The early gonadal development and sex differentiation of the mandarin fish, Siniperca scherzeri was described from hatch to the 130th day post-hatch (DPH). Primordial germ cells were observed on the just hatched fry (5.10 mm in total length (TL)) and began to protrude into the peritoneal cavity between mesonephric duct and gut. The primordial gonad, with the formation of genital ridge, developed on the 8-10th DPH (10.77-12.47 mm TL). Ovarian differentiation was identified by the presence of ovarian cavity and meiotic oocytes from the 40th DPH (29.75 mm TL). Testicular differentiation was identified by the presence of spermatogonial cells with efferent duct also from the 40th DPH. Sex differentiation of the mandarin fish was identified as gonochoristic type.

• Korean Journal of Ichthyology
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• v.13 no.2
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• pp.129-135
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• 2001

Matured adults of Siniperca scherzeri were collected from Soyangdam and Hongchun river, Gangwon-do, Korea. The fertilized eggs were hatched and reared in the laboratory of the Korea Ocean Research and Development Institute. Osteological development of the larvae and juveniles of Siniperca scherzeri were investigated. Three days after hatching, the larva (6.12 mm in total length: TL) had partly ossified parasphenoid, clavicle, hyomandibular, preopercle, opercle and jaw bones with 7 to 8 canine teeth. The ascending process of premaxillary and ca 19 and 23 teeth on the premaxillary and dentary, respectively, were ossified at 10 days after hatching. Also at 10 days, the vertebral columns of the larvae (6.85 mm in TL) were posterioly ossified to the 5~7th vertebra, and ossification was completed in the juvenile (10.99 mm in TL) on the 22 nd day. Thus ossification began 3 days after hatching, and was completed 22 days after hatching.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.1-10
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• 1998

The early history of Korean mandarin fish, Siniperca scherzeri was studied to obtain some information required in aquaculture and reinforcement of natural population. During the period from June 1996 to July 1997, the mature adults of Siniperca scherzeri were collected from the middle Soyang Lake at Puksan - myon, Chunchon - shi, Kangwon - do, Korea. The eggs from females were obtained by injecting HCG or/and GnRH - a and fertilized by dry method in the laboratory. The fertilized eggs, measuring 1.70~2.10 mm in diameter and expanded to 2.20~2.66mm after absorption of water, were globosity, light orange yellow, separative, submergence and had one large oil globules of 0.5~0.7 mm. The blastodisc was formed in 1 hour and cleavage started in 1 hour 30 min. after fertilization, and the intervals of each stage of cleavage was about 50 min. at the water temperature of $21{\sim}24^{\circ}C$. Hatching occurred 131 hours 30 min. after fertilization and newly hatched larvae were 5.86~6.85 mm in total length(TL) and numerous stellate melanophores were distributed on the yolk and abdomen of caudal peduncle. The yolk was almost absorbed and the teeth development. 3 days after hatching, at 6.98~7.60 mm TL. The head spines and the teeth were largely developed and all fins were completely formed and became postlarva stage 15 days after hatching, at 10.10~12.90 mm TL. The body shape and the color pattern were similar to adult, 25 days after hatching, at 15.3~23.8 mm TL. In 5 months after hatching were reached at 154.10~175.02 mm TL and 49.32~82.67 g in body weight.