• Journal of Marine Bioscience and Biotechnology
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• v.3 no.1
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• pp.1-6
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• 2008

Angola has a coastline of about 1,650 km long. Two diverging current namely, the Angola current with its warm water from the north and the cold Benguella Current in the south create a strong up-welling with a high productive ecosystem for marine resources. The area from Lobito to the mouth of the Cunene River, also known as the Southern fishing zone is by far the most productive of Angola's fishing zones. In 1977, the total potential of its marine fisheries sector was estimated at more than 700,000 tonnes per annum. In 2003, the Total Allowable Catch (TAC) established for demersal species was 57,600 tonnes and 160,000 tonnes for pelagic species. The most important resources are various marine demersal and pelagic fish including pilchard and the Cape and Cunene horse Mackerel (Tranchurus capensis and T. trecae). Sardinellas (Sardinella aurita and S. maderensis) are fished in parallel with horse mackerel. The rest of the catches are mainly demersal spp. and some deep water crustaceans. The demersal sppecies consist of Hake (Merluccius polli and M. capensis) and the large eye dentex spp. Tunas are caught at certain times of the year whilst some marine shrimp are also harvested from the Angolan waters. Angola also has several high value freshwater fish species, exploited by about 255 fishers. Tilapia sp. is among the most important and abundant fresh water fish found in Angola. Other species include the catfish (Clarias gariepinus) and fresh water prawns (Macrobrachuin rosenbergii). Some aquaculture ponds have been established in the country side, but due to lack of investment, proper training and the impact of civil war have seriously limited developments in the sub sector.

• Nutrition Research and Practice
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• v.15 no.6
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• pp.761-772
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• 2021

BACKGROUD/OBJECTIVES: Understanding the factors associated with fish consumption is necessary to determine strategies to improve the fish consumption particularly those high in omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA). The aim of this study was to analyse the correlation between a mother's perspective on fish and actual fish consumption in their children. SUBJECTS/METHODS: Two hundred thirty-one elementary school children grade 3-6 and their mothers in Surakarta were recruited using multi stage random sampling for this study. Data was collected in July and August 2017. A validated questionnaire consisted of 3 topics including knowledge related to the health benefits and organoleptic properties of fish and cooking technique-related attitudes on fish were used to measure the mother's response to the fish properties. A validated food frequency questionnaire and a food picture book of fish specifically designed for the survey were developed and used to assess fish consumption of the children. A χ² test was used to analyse the correlation between the mothers' perspective on fish and their children's fish consumption. RESULTS: The median fish consumption in children was 65 g/d with fried non-oily or lean fish, e.g., milkfish (locally called Bandeng) and catfish (locally called Lele) were consumed more than oily fish as well as processed fish products. Of all children, 31% met the fish consumption recommended by the Environmental Protection Agency-Food and Drug Administration 2017. There was no relationship between a mother's knowledge related to health benefits, organoleptic properties and cooking technique-related attitude toward fish and her child's fish consumption. CONCLUSIONS: The fish consumption of children is not influenced by their mother's perspective on fish. Nutrition education strategies are warranted to improve fish consumption and maintain the optimal benefits by consuming fish, including fish high in n-3 LCPUFA.

• Fisheries and Aquatic Sciences
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• v.27 no.6
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• pp.366-378
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• 2024

Application of commercial hormone failed to promote breeding in certain Pangasius species due to the differences of gonadotropin-releasing hormone specific peptide with species-specific bioactivities. Gonadotropin-releasing hormone (GnRH) is a hypothalamic decapeptide in the reproductive system that plays a crucial role in the regulation of reproductive processes. This study was performed to determine and analyse the GnRH genes from commercially important Pangasius sp., Pangasianodon hypophthalmus and Pangasius nasutus. The GnRH1 and GnRH2 genes were amplified and cloned into TOPO vector, followed by phylogenetic analysis of a complete open reading frame (ORF) of GnRH genes. The GnRH1 and GnRH2 genes of P. hypophthalmus and P. nasutus were detected at 300 bp and 360 bp, encoded for 81 and 87 amino acids, respectively. Amino acid sequence identities revealed high homology of P. hypophthalmus and P. nasutus GnRH1 and GnRH2 genes in comparison with other fish and vertebrates. Phylogenetic tree showed that fish from various families were aggregated into a group of the same order due to their highest identity similarities. It revealed that the vertebrate formed clusters and are grouped according to their GnRH decapeptide and GnRH-associated peptide (GAP) region, indicating a close relationship among GnRH decapeptide and GAP in different vertebrate species.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.2
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• pp.203-210
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• 1997

The aim of this study was to determine the effect of steroids and human chorionic gonadotropin (HCG) on in vitro maturation and ovulation of oocyte in Pseudobagrus fulvidraco. Oocytes were incubated in the media Leibovitz L15 supplemented with the various concentration of $17\alpha,\;20\beta-dihydroxy-4-pregnen-3-one(17\alpha20{\beta}OHP),\;17\alpha-hydroxyprogesterone(17{\alpha}OHP),\;progesterone(P_4),\;estradiol-17\beta(E_2)and\;HCG$. After 60 hours incubation, the maturation ability of oocyte was assessed by the appearance of germinal vesicle breakdown (GVBD). GVBD was significantly enhanced by the addition of $17\alpha20{\beta}OHP,\;17{\alpha}OHP,\;P_4\;and\;HCD(P<0.05)$. The highest CVBD was observed when $17\alpha20{\beta}OHP$ and HCG were supplemented to media. When oocytes were cultured for 16 hours in media containing $10\~1,000\;ng/ml\;17\alpha20{\beta}OHP,\;17{\alpha}OHP\;and\;P_4$, the rate of GVBD in oocytes cultured in the medium supplemented with 100 ng/ml $17\alpha20{\beta}OHP(65\%)$ was significantly higher than that with $17{\alpha}OHP\;(40\%)\;and\;P_4(35\%)$. The efforts of $17\alpha20{\beta}OHP$ and HCG on GVBD were assessed by various concentration of these hormones. When oocytes were cultured for 60 hours in various media containing $1\~1,000\;ng/ml\;17{\alpha}20{\beta}OHP\;or\;5\~1,000\;IU/ml$ HCG, the GVBD of oocytes was significantly increased in the medium with $10\~100\;ng/ml\;17\alpha20{\beta}OHP$ and 500 IU/ml HCT. When oocytes were cultured in the various media supplemented with $1\~1,000\;ng/ml\;17\alpha20{\beta}OHP\;or\;5\~1,000\;IU/ml$ HCG for 60 hours, the media with $1\~100\;ng/ml\;17\alpha20{\beta}OHP\;or\;50\~1,000IU/ml$ HCG significantly increased in the rate of ovulation. However supplementation with $1,000\;ng/ml\;17\alpha20{\beta}OHP$or 5 IU/ml HCG did not improve the rate of ovulation compared to controls. This results indicate that supplementation of steroid and HCG except $E_2$ can improve the in vitro maturation and ovulation of oocyte in P. fulvidrac; HCG and $17\alpha20{\beta}OHP$ may be more effective than other steroids on oocyte maturation and ovulation in P. fulvidraco.

• Korean Journal of Ichthyology
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• v.24 no.3
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• pp.183-190
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• 2012

The spawning site characters in the natural environment of bull-head torrent catfish, Liobagrus obesus, were investigated at the part of the Gosan stream in Korea from April to October 2010 and June 2011. The sex ratio of female to male was 1 : 1.02. Spawning season was from June to July with water temperature in approximately $23^{\circ}C$. The spawning sites were covered by the boulder used upper plate and were composed of gravel and sand. One male lies with the egg mass and guards the developing embryos in the hollow below the boulder. The environmental conditions of the spawning sites were $61.4{\pm}11.97$ (50~85) cm in depth, 0.58${\pm}0.067$ (0.48~0.72) m/sec in surface water velocity, $0.46{\pm}0.098$ (0.27~0.61) m/sec in middle water velocity, $0.27{\pm}0.083$ (0.14~0.41) m/sec in bottom water velocity. The boulder width as spawning sites was $26.2{\pm}5.32$ (20~38) cm in long axis, $20.5{\pm}2.97$ (16~25) cm in short axis and $11.1{\pm}4.02$ (5~19) cm in height. The hollow underneath the boulder was $9.8{\pm}2.32$ (6~14) cm in diameter and $2.8{\pm}1.10$ (1.5~5) cm in depth. The average number of eggs in ovary was $124{\pm}27.7$ (92~180). The matured egg size was $3.40{\pm}0.078$ (3.21~3.56) mm. The average number of spawning eggs in the spawning site was $99{\pm}12.9$ (81~122).

• Journal of Aquaculture
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• v.5 no.2
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• pp.117-126
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• 1992

Induced breeding and indoor rearing of the catfish, Silurus asotus were performed. Ovulation was induced by injection of 5 mg dried carp pituitary per kg body weight. Fertilization rates were $81.5\~98.0{\%}$ and hatching success was $67.0\~82.0{\%}$. There were no significant differences of daily growth rate (DGR) and food conversion ratio (FCR) between the groups fed extruded eel pellet and extruded carp pellet. No significant differences in DGR and FCR were also found between $3{\%}$ and $4{\%}$ daily feeding rates. DGR and FCR of small fry were slightly affected by dissolved oxygen (DO) level in aquaria. When the DO level maintained at $4.5\;mg/{\ell}$, the best result was obtained and DGR and FCR were $5.7{\%}$ and 0.65, respectively. At the higher level of DO, $5.5\;mg/{\ell}$, DGR and FCR were $5.52{\%}$ and 0.77, respectively, whereas at the lower level of DO, $3.5\;mg/{\ell}$, the DGR was decreased to $3.45{\%}$ and FCR was increased up to 1.01.

• Journal of fish pathology
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• v.3 no.1
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• pp.21-25
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• 1990

In inland aquaculture, a lot of fishes often died cause of touch of L. carteri which is attached on the net cage. In this works, the experiment were carried out on classification of species, toxin test, and extermination with some chemicals. A bryozoa from net cage in lake Okjeong is classified into the Phylactolaemata, Lophopodella carteri Hyatt. A bryozoa broke out firstly on the 30th of June with water temperature up to $31^{\circ}C$ and it reattached on the net with water temperature below $30^{\circ}C$. Size of bryozoa colony is about $0.8{\times}0.6{\sim}1.7{\times}1.5cm$. Water column of attachment was 0~5m and the peak is 2~3m. In toxin test on the israeli carp, goldfish and catfish touched with bryozoa for 1 minute at $25^{\circ}C$ of water temperature, a dead fish appeared at 20 minutes after touched. Mortality was 90% for israeli carp and 100% for goldfish at 100 minuties after touched, but catfish was not died at all. It was supposed that the toxin is from nematocyst being around tentacles and this toxin act a deadly poison on a israeli carp and goldfish. In extermination test, the bryozoa treated with 300ppm of formalin, 5% of sodium chloride, 5ppm of malachite green, 200ppm of potassium permanganate, 1000ppm of potassium iodide, 10ppm of DDVP for minute respectively, all of them were not effected.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.6
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• pp.445-454
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• 2004

A search for contraction and relaxation responses on the smooth muscles, antimicrobial and antioxidant activity in different body parts of 4 freshwater fish and 4 marine fish were conducted. The four freshwater fish studied were Sarotherodon niloticus (tilapia), Channa arus (snake head), Cyprinus carpio (Israel carp) and Siluru osotus (catfish), and the four marine fish were Scyliorhinus torazame (tiger shark), Ateiepus japonicus (tadpole fish), Mugil cephalus (gray mullet) and Thamnaconus modestus (file fish). Frozen samples were extracted with distilled water containing $1{\%}$ acetic acid. Antimicrobial activity against Bacillus subtilis and Eschrrichia coli was detected in extracts from several tissues in all species tested. Relatively high antimicrobial activity could also be detected in the bile extracts from C. carpio, M. cephalus, and T. modestus. Contraction and relaxation responses on smooth muscles could be detected in all species tested, especially in the intestine extracts. Antioxidant activity was also detected in extracts from several tissues in all species tested, while in the extracts from S. osotus, excluding livers and spleens, no antioxidant activity was detected. Results from this study suggest that fish are a potential source for the discovery of novel bioactive materials.

• Journal of fish pathology
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• v.10 no.2
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• pp.113-123
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• 1997

Concerned to the life cycle of Ichthyophthirius multifiliis, the biological characteristic of the parasites was studied in the rainbow trout (Oncorhynchus mykiss) and the Korean catfish (Silurus asotus) Under the experimental condition of $9^{\circ}C$- $28^{\circ}C$, tomitogenesis rate was positively proportional to water temperature, but not at over $28^{\circ}C$. The protomonts showed a high rate of tomitogenesis at $26^{\circ}C$ in comparision with other temperature conditions. Temperature affected tomitogenesis rate which resulted from the various conditions of salinity, pH and formalin concentration. The protomonts showed a high rate of tomitogenesis at pH 6.9 in comparision with other pH conditions at all temperatures tested. This result revealed that the opitimum pH for tomitogenesis was 6.9. The protomont had more tolerance against salinity and formalin concentration at low temperature ($18^{\circ}C$) than at high one ($22^{\circ}C$). Both trophont and protomont were not infective, but theront was infective.

• Journal of fish pathology
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• v.23 no.1
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• pp.85-98
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• 2010

Ministry of Agriculture, Fisheries and Food (MAFF) and National Fisheries Research and Development Institute (NFRDI) have inspected the hatchery-reared seeds of 22 marine species and 11 freshwater species for aquatic animal diseases in stock enhancement program in 2009. Results showed that total 12 local selfgovernments have been restocking the sea with cultured juveniles. Gyeongsangnam-do, Jeollanam-do, Jejudo and Chungcheongnam-do have a preference for marine species seeds to freshwater species. On the contrary, freshwater species were released mostly in Gyeonggi-do, Jeollabuk-do and Chungcheongbuk-do. In the marine species group, abalone was the most abundant as 24.5%, and then sea cucumber (15.2%), olive flounder (11.5%), swimming crab (5.6%), black sea bream and rockfish (6.8%), rock bream (5.1%), black rockfish (4.6%) and scorpionfish (4.5%) were followed. Crucian carp was the most abundant as 19.4%, and then eel (17.0%), Korean bullhead (12.3%), melanian snail (12.0%), catfish (8.4%) were followed in the freshwater species group. The total number of inspection cases in this study were 1,080 and disqualification cases were 19 by detection of aquatic animals pathogens such as red sea bream iridovirus (RSIV), koi herpesvirus (KHV) or white spot syndrome virus (WSSV).