• Journal of Life Science
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• v.20 no.4
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• pp.614-617
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• 2010

We sequenced a 522 bp fragment including the $tRNA^{Thr}$, $tRNA^{Pro}$ gene and the first half of the control region from 29 wild and cultured olive flounder specimens from Korea. Out of 522 nucleotide sites, 49 (9.4%) were variable, 23 haplotypes being found. Most haplotypes are unique in the wild population and only four were shared by cultured specimins. The nucleotide diversity and differences between wild and cultured populations were $0.025{\pm}0.013$ and $0.015{\pm}0.008$, and $12.94{\pm}6.00$ and $7.83{\pm}3.75$, respectively. Haplotype diversity was $0.98{\pm}0.02$ and $0.49{\pm}0.09$ in the wild and cultured populations, respectively. These results show that marked reductions of genetic variability in the hatchery strains were observed in the number of mitochondrial DNA haplotypes and haplotype diversity when compared to the wild populations. Furthermore, we detected significant population differentiation between both populations. The mtDNA sequencing technique used to evaluate the genetic variability of hatchery strains compared to that of the wild population is potential for genetic monitoring of olive flounder hatchery stocks.

• Journal of fish pathology
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• v.26 no.2
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• pp.99-110
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• 2013

Hatchery-reared seeds provides a key source of animal protein for human consumption and restocking for fishery management. For stock enhancement program, we have inspected the hatchery-reared seeds of 33 species in 2009, 44 species in 2010, 43 species in 2011 and 46 species in 2012 for legally designated diseases. Results showed that abalone was the most abundant in the marine species group and then sea cucumber, olive flounder, rockfish and swimming crab were followed. Crucian carp was the most abundant and then mandarin fish, Korean bullhead, melanian snail and Chinese mitten crab were followed in the freshwater species group. The number of inspection for black sea bream, rock bream, scorpionfish, black scraper, and eel has continuously decreased for four years. The inspection for flathead mullet has been carried out only in 2009. The total number of inspection cases for eight pathogens in this study were 8,476 and disqualification cases were 56 (0.67%) by detection of aquatic animals pathogens such as koi herpesvirus, white spot syndrome virus, red sea bream iridovirus or viral haemorrhagic septicemia virus.

• The Korean Journal of Malacology
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• v.19 no.1
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• pp.71-79
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• 2003

After the juvenile octopus individuals being discharged, it is hard to separately capture them because they attach strongly to the wall of the aquarium by the suckers on the arms. Therefore, anaesthetics (MS-222 or lidocaine-HCl) are usually used for capture from attachment. The anaesthetized time of the octopus by lidocaine-HCl was more faster 1.6 to 4.5 times under 200 ppm and 6.0 to 6.5 times in 300 to 500 ppm than those in MS-222. In the anaesthetized and recovery rates (%) by the exposed time, the juvenile octopuses were anesthetized by lower concentrations of lidocaine-HCl within the short time, and rapidly recovered from anesthesia. In the secondary anesthesia of the juvenile octopuses exposed with lidocaine-HCl by the elapsed time after the primary anesthesia, the anesthetized time was later in case of lower concentrations and long elapsed times, However, the anesthetized time was faster when their concentrations were higher and the elapsed time after anesthesia were shorter. Recovery from the secondary anesthesia was faster when the elapsed time was long in lower concentration, and was later when the elapsed time was shorter. In case of Octopus ocellatus, anaesthetic effects by lidocaine-HCl concentrations were better than those of MS-222. Doses of lidocaine-HCl and critical time for works at the indoor laboratory were proper in concentration of 100 ppm within 15 min.

• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.63-68
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• 2001

The skeletal development of the larvae and juvenile of red marbled rockfish, Sebasticus tertius (Barsukov et Chen) was studied based on individuals that were discharged and reared in the laboratory from April to May 1997. In 8 days after bearing, the postlarvae attained 4.42 mm in total length (TL), and its parasphenoid, premaxillary, maxillary, and clavicle were ossified for the first time at this stage. In 15 days after bearing, the postlarvae attained 5.23 mm in TL, and its pterotic, basioccipital, exoccipital, opercle, and preopercle were ossified, with one spine on the each cranium and preopercle. In 27 days after bearing, the postlarvae attained 8.81 mm in TL, its vertebra were posteriorly ossified to the 15th centrum, and five spines were formed on the preopercle. In 39 days after bearing, the juveniles attained 14.21 mm in TL, and the all bones were almost completed at this stage.

• The Korean Journal of Malacology
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• v.18 no.2
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• pp.77-82
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• 2002

This study was performed to find out the optimal kind of additive and concentration of ethylene glycol (EG) as the cryoprotectant on the D-shaped larvae of arkshell, Scapharca broughtonii. The larvae in straws was carried in the programed freezer set uo at 0$^{\circ}C$, frozen to -12$^{\circ}C$ by the freezing rate of -1$^{\circ}C$/min, held for 10 minutes, seeded at -12$^{\circ}C$, finally refrozen to -35$^{\circ}C$ by the freezing rate of -1$^{\circ}C$/min and then directly plunged into liquid nitrogen. The survival of larvae frozen in 1.0 M and 2.0 M ethylene glycol added with 0.5 M sucrose were high (50.5 ${\pm}$ 1.3% and 51.9 ${\pm}$ 1.7%, respectively) in the early D-shaped larvae cryopreserved in 1 M and 2 M ethylene glycol diluted with 0.2 M and 0.5 M fructose, glucose and sucrose. In the late D-shaped larvae were cryopreserved according to five concentrations of ethylene glycol added with 0.5 M sucrose, the survival of larvae frozen in 2.0 M ethylene glycol was the highest as 51.9 ${\pm}$ 1.7%. The morphological differences in cells between unfrozen and frozen-thawed D-shaped larvae were not found by the scanning and transmission electron microscopy.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.4
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• pp.302-306
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• 2000

Gonad and blood samples were taken from cultured greenling (Hexagrammos otakii), and changes of steroid hormone levels in serum were examined in relation to the gonadosomatic index (GSI). GSI of female and male were not changed significantly between March and August and then began to increase from September showing the highest value in January. Hepatosomatic index (HSI) of female was the highest in December,'then decreased gradually until May. $Estradiol-l7{\beta} (E_2)$ level in blood of female reached to the highest level in December, then decreased rapidly in January. The level was maintained low until August and started to increase In September. Testosterone (T) level in blood of female was similar to trend of $E_2$ in female. $17{\alpha}2{\beta}-dihydroxy-4-pregnen-3-one (17{\alpha}20{\brta}-OHP)$ level in blood of female reached to the maximum in January, and then decreased rapidly from Febuary and maintained low until July. T level in blood of male reached to the highest value in December, and it started to decrease from January and maintained low until July, after then increased again, while $17{\alpha}20{\beta}-OHP$ level of male was similar to trend of female's.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.5
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• pp.713-720
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• 1998

Experiments on the control of rockfish, Sebastes inermis reproduction were performed by artificially changed water temperature (WT) and photoperiod (PP). The experiments were divided into three conditions; artificial changes of both WT and PP delayed two months against their natural variations (Exp.I), natural WT and PP replaced with artificial light (Exp.II) and natural WT and PP (Exp.III) from September to April (220 days). Initial gonadosomatic index (GSI) in female groups of experiments was 0.2. Female GSI of responded group in Exp.I began to increase from December and reached the highest value in February with 15.0, while the un-responded group kept the lower value during the experimental period. Female GSI of Exp.II and Exp.III reached the highest values in January with 13.0 and 14.7, respectively. Male GSI of Exp,I reached the maximum in October, and that of Exp.II and III reached the maximum in November and then rapidly decreased. Among the experimental groups, male GSI did not show the different tendency. Monthly changes of hepatosomatic index in both sexes showed the reciprocal tendency with those of GSI. The control of WT and PP did not affect on the changes of HSI and condition factor of rockfish. From the histological observations, maturation of ovary was delayed by the changes of WT and PP, but that of testis was not influenced. Judging from the above results, the maturation and parturition of female rockfish could be delayed one or two months by artificial changes of WT and PP.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.659-663
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• 1999

Gametogenesis, reproductive cycle, condition factor, and meat weight rate of the surf clam, Tresus Keenae were studied by histological observations and morphometric data based on the samples which have been collected from the south coast of Korea, from January 1995 to February 1996. The annual ranges of the mean seawater temperature and specific gravity in habitat of the surf clam were $4.9\~24.9^{\circ}C$ and 1.0210$\~$1.0266, respectively. Monthly changes in the condition factor showed in a wide range from 0.2381 to 0.2827, began to increase in January and reached the first maximum (0.2827) in April. And then the value rapidly decreased in June, thereafter, reached the second peak (0.2812) in August. The condition factor of this species showed the two peaks, and gonadal development reached sexually mature and ripe conditions during the period of these two peaks. The meat weight rate ranged from $38.0\%$ to $46.4\%$, and its change showed a similar tendency with the condition factor. The reproductive cycle of this species can be divided into five successive stages: in both sex, multiplicative (December to January, July to August), growing (January to February, September to October), mature (February to April, September to November), spawning (April to June, September to November), and degenerative and resting stage (May to July, November to January).

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.187-188
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• 2003

Conadotropin releasing hormono analogs (GnRHa) have now been tested successfully a range of marine and freshwater species and been shown to be an effective strategy for improving milt quantity and quality (Mylonas and Zohar, 2001; Zohar and Mylonas, 2001; Lim et at, , 2002). Greenback flounder (Rhombosolea tapirina) is currently under consideration as a potential culture species in south-eastern Australia. (omitted)

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.277.1-277
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• 2000

No Abstract, See Full Text