• Fisheries and Aquatic Sciences
• /
• v.9 no.4
• /
• pp.160-166
• /
• 2006

We explored the possibilities of using the freshwater rotifer Brachionus angularis as a live food for small fishes cultured in fresh- or brackish waters. Brachionus angularis were collected from a reservoir for isolation and laboratory culture. Length and width of the lorica were $102.3{\mu}m$ and $76.6{\mu}m$, respectively, and those of amictic eggs were $64.4{\mu}m\;and\;47.9{\mu}m$, respectively. When their growth rates were examined at six different temperatures, i.e., 15, 20, 25, 30, 35, and $40^{\circ}C$, the highest daily growth rate of 0.801 was observed at $35^{\circ}C$, and growth was lower with decreasing temperature. Adaptation to salinity change was evaluated with two different modes of salinity increase: step-wise elevation lasting for short durations of 5 to 30 min or a long duration of 24 h. With the short duration modes, no individuals survived salinity higher than 10 psu, and the number of live individuals did not increase throughout the experiment. However, in the 24-h elevation, the number of individuals increased when salinity was elevated by 1 to 2 psu per day for the first 2 or 3 days, while no increase in number occurred at salinity increments higher than 3 psu per day. In addition, to assess the effect of different diets, four single-component diets (Chlorella vulgaris, Nannochloris sp., baker's yeast, or dry yeast) and three combination diets (C. vulgaris + Nannochloris sp. + baker's yeast + dry yeast; C. vulgaris 70% + baker's yeast 30%; C. vulgaris 30% + baker's yeast 70%) were used. The specific growth rates of B. angularis fed combination diets were higher than those of rotifers fed any single-component diet, with the highest rate of 0.648 in B. angularis fed a mixture of C. vulgaris, Nannochloris sp., baker's yeast, and dry yeast, and the lowest rate of 0.200 in those fed dry yeast only. Our results indicate that the freshwater rotifer B. angularis can be used for seedling production of both freshwater and brackish-water fishes that require small (less than about $120{\mu}m$) live food during their early stages.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.16 no.3
• /
• pp.202-210
• /
• 1983

In order to elucidate the taste compounds of Korean catfish, Parasilurus asotus, free amino acids, nucleotides and their related compounds, organic bases, sugars, organic acids and minerals in the extracts of Korean catfish were analyzed, and then evaluated by sensory test of synthetic extract prepared on the basis of the analytical data. Taste panel assessments of synthetic extracts prepared with each extractive component omitted were carried out by a triangle difference test, and changes in taste profile were assessed. In free amino acid composition, glycine was dominant occupying $25\%$ of total free amino acids. The other abundant free amino acids were lysine, taurine and alanine. Judging from the result of analysis of nucleotides, IMP was dominant showing about $70\%$ of total nucleotides while ATP, ADP, AMP, inosine and hypoxanthine were low in content. Among organic bases, total creatinine was abundant and its nitrogen content occupied more than $50\%$ of the total extractive nitrogen. The amount of betaine was 18mg/100g and trace amount of trimethylamine and trimethylamine oxide were detected. The main organic acids were succinic, butyric, propionic and valeric acid. On the other hand, oxalic, fumaric, maleic, tartaric and citric acids were analyzed in trace. As for the sugars, glucose was found to be the most abundant monosaccharide. Extremely small amounts of fructoae, inositol were also detected and ribose and arabinose were trace in content. $K^+,\;Na^+,\;PO_{4}^{3-}$ and $Cl^-$ were found to be the major ions and small amount of $Ca^{2+}$ were defected. The synthetic extract, prepared with about 40 pure chemicals based on the analytical data satisfactorily revealed the natural taste of the original extract except slight difference in meaty taste and mildness. From the results of omission test the major components which contribute to produce the taste were serine, IMP, succinic acid and $PO_{4}^{3-}$.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.10 no.2
• /
• pp.125-135
• /
• 1977

Recently, culture of Undaria pinnatifida, one of the representative esculent sea weed, has been prevailing in tile east and south coasta of Korea and reached the mass culture stage. In this study, compositional quality factors for food were studied and the contributory effects of blanching and pigment fixatives in the quality retention of cultured Undaria pinnatifida are discussed. When the place and time of harvesting were the same, cultured pinnatifida showed scarce difference in the chemical composition comparing to tile naturally grown Undaria pinnatifida, but cultured Undaria pinnatifida shelved a considerable difference depending upon the cultured places. In the chemical composition of Undaria pinnatifida, the alginic acid comprising about $40\%$ of the whole solid materials seemed to be responsible for the compositional puality. The chlorophyll and carotenoid content of the clutured Unaria pinnatifida were considerably lower than that of the naturally grown Undaria pinnatifida and wass inferior in puality by color to the naturally grown one. Dried Undaria pinnatifida contained a considerable amount of amino-N, mannitol, and soluble minerals and it is considered that these components play a great role in the relish effects. It could also be evaluated as a good albuminous source for food science the dried pinnatifida contains about $18\%$ of crude protein. In the analysis of free amino acid composition of dried Undaria pinnatifida, the naturally growm samples showed so what higher levels in all amino acid content than the cultured samples. The contents of theronine, alanine, and glutamic acid were major in quantity wherease histidine cysteine, tyrosine, and phenylalanine were minor. The contents of such amino acids like serine and proline were particularly low or undetectable. The results of amino acid analysis of the acid hydrolysates of dried Undaria pinnatifida in quantity of individual amino acid showed te same pattern as that of free amino acid. It is noticed that Undaria pinnatifida seemed to contain good quality protein since the contents of essential amino acids were considerably higher and uniform. By blanching the fresh sample, the water soluble components brought about cousiderable loss, and, particularly, it was noteworthy that both mannitol and soluble minerals apparently decreased. In the pigment analysis of the dried sample, blanching was effective to retain chlorophyll and carotenoid. The addition of pigment fixatives in blanching solution such as Ca-gluconate, Ca-carbonate, and Ca-hydroxide did not exhibit much effect on the pigment retention except that Ca-carbonate shelved some effect only in the early stage of storage.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.40 no.1
• /
• pp.3-10
• /
• 2014

Objectives: Although nerve growth factor (NGF) could promote the functional regeneration of an injured peripheral nerve, it is very difficult for NGF to sustain the therapeutic dose in the defect due to its short half-life. In this study, we loaded the NGF-bound heparin-conjugated fibrin (HCF) gel in the NGF-delivering implants and analyzed the time-dependent release of NGF and its bioactivity to evaluate the clinical effectiveness. Materials and Methods: NGF solution was made of 1.0 mg of NGF and 1.0 mL of phosphate buffered saline (PBS). Experimental group A consisted of three implants, in which $0.25{\mu}L$ of NGF solution, $0.75{\mu}L$ of HCF, $1.0{\mu}L$ of fibrinogen and $2.0{\mu}L$ of thrombin was injected via apex hole with micropipette and gelated, were put into the centrifuge tube. Three implants of experimental group B were prepared with the mixture of $0.5{\mu}L$ of NGF solution, $0.5{\mu}L$ HCF, $1.0{\mu}L$ of fibrinogen and $2.0{\mu}L$ of thrombin. These six centrifuge tubes were filled with 1.0 mL of PBS and stirred in the water-filled beaker at 50 rpm. At 1, 3, 5, 7, 10, and 14 days, 1.0 mL of solution in each tubes was collected and preserved at $-20^{\circ}C$ with adding same amount of fresh PBS. Enzyme-linked immunosorbent assay (ELISA) was done to determine in vitro release profile of NGF and its bioactivity was evaluated with neural differentiation of pheochromocytoma (PC12) cells. Results: The average concentration of released NGF in the group A and B increased for the first 5 days and then gradually decreased. Almost all of NGF was released during 10 days. Released NGF from two groups could promote neural differentiation and neurite outgrowth of PC12 cells and these bioactivity was maintained over 14 days. Conclusion: Controlled release system using NGF-HCF gel via NGF-delivering implant could be an another vehicle of delivering NGF to promote the nerve regeneration of dental implant related nerve damage.

• Journal of Aquaculture
• /
• v.13 no.1
• /
• pp.39-46
• /
• 2000

Successive management of prawn farm is strongly dependent upon monitoring of pond seawater quality which is generally influenced by an excessive food supplied sediment type and phytoplankton composition in the pond. For good condition of seawater quality it must need exchangning of fresh seawater by tidal current. Two distinct shrimp ponds Galha and Yunho which were different in seawater exchanging system and sediment type were selected to understand how some factors affected to seawater and sediment qualities in the pond. Prawn growth was also determined. Galha pond characterized by sand bottom with water exchanging by turn of the tidal current accumulated 1.8 mgS/g-dry as sulfide in sediment while Yunho pond mud- bottomed with seawater exchanging of pumping system showed 4.7mgS/g-dry when it was highest, Ammonia-N and hydrogen sulfide measured in the seawater were 0.31mg/${\ell}$ and 21.2 ${\mu}$${\ell}$/${\ell}$in Yunho and 0.10mg/${\ell}$and 10.8${\mu}$${\ell}$/${\ell}$in Galha pond respectively. Dissolved oxygen remained below 6.0mg/${\ell}$ in Galha and 5.0mg/${\ell}$in Yunho pond from June through August. Less growth of prawn was found in Yunho pond than in Galha pond. Prawn growth expressed as body length and weight were 138.3mm 22.9g in Yunho pond while they were length 158.2mm and 28.9g in Galha pond respectively when they were harvested in October. These results indicate that higher levels of ammonia-N and hydrogen sulfide and lower dissolved oxygen in bottom seawater of Yunho pond might affect the growth of cultured prawn.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.8
• /
• pp.1292-1300
• /
• 2020

Objective: To explore feed resources capable of replacing regular poor-quality fodder, this study was conducted to evaluate the effects of additives on the fermentation quality, in vitro digestibility and aerobic stability of mulberry leaves silage. Methods: The mulberry leaves were ensiled either untreated (control) or treated with 1×10⁶ cfu/g fresh matter Lactobacillus plantarum (L), 1% glucose (G), 3% molasses (M), a combination of 1% glucose and Lactobacillus plantarum (L+G), and a combination of 3% molasses and Lactobacillus plantarum (L+M). The fermentation quality and chemical composition were analyzed after 7, 14, 30, and 60 d, respectively. The 60-d silages were subjected to an aerobic stability test and fermented with buffered rumen fluid to measure the digestibility. Results: Inoculating lactic acid bacteria (LAB) resulted in more rapid increase in lactic acid concentrations and decline in pH of mulberry leaves silage as compared control. Higher acetic acid and lower ethanol and ammonia nitrogen concentrations (p<0.05) were observed in the LAB-inoculated silages as opposed to control during ensiling. The LAB-inoculated silages contained lower water-soluble carbohydrates compared with control during the first 14 d of ensiling, and lower neutral detergent fibre (p<0.05) concentrations as compared with non-LAB inoculated silages. Adding molasses alone increased (p<0.05) the digestibility of dry matter (DM). The aerobic stability of mulberry leaves silage was increased by LAB inoculation, whereas decreased by adding glucose or molasses. Conclusion: The LAB inoculation improved fermentation quality and aerobic stability of mulberry leaves silage, while adding glucose or molasses failed to affect the fermentation and impaired the aerobic stability. Inoculating LAB alone is recommended for mulberry leaves especially when ensiled at a relatively high DM.

• Parasites, Hosts and Diseases
• /
• v.34 no.1
• /
• pp.1-6
• /
• 1996

Mccroorchis spinuLosw Ando, 1918 (Digenea: Nanophyetidael is redescribed based on adult flukes recovered from experimental mice, rats and cats which were fed with metacercariae encysted in the muscle of the crayfish, Cambnroines similis. A total of 117 adult flukes were harvested from the small intestine of the experimental animals at S-21 days post-infection. The worm recovery rate was 31-37%, not significantly different among the three kinds of animals. The metacercariae were round, 0.18 mm in average diameter, encysted with two layers of thick walls, and possessing a stylets on the oral sucker and Y- shaped exc retory bladder. The adult flukes were oval, 0.66-0.71 mm long and 0.36-0.41 mm wide, and characterized by the presence of a stylet on the oral sucker, variable location of the ovary near the mid-portion of the body, bilobed seminal vesicle, and anterolateral location of two testes. These morphological features were a little different from the original description, hence, an emended version of M. spinulosw was given. M. spinuLosw is a new intestinal trematode of animals and possibly man in Korea.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.13 no.2 s.29
• /
• pp.111-118
• /
• 2007

Simple box budgets models are useful tools to understand the phenomena of natural system and to provide an insight into the complex processes including physical, chemical and biological processes occurring in natural system. Budgets of fresh water, salt and nutrients were estimated in order to clarify the characteristics of seasonal material cycle in the Masan Bay. Outflow volume of freshwater into system was approximately $307.4\times10^3\sim1,210\times10^3\;m^3/day$. Inflow masses of DIP and DIN were approximately $410.8\sim795.7\;kg/day$ and $4081.4\sim6525.3\;kg/day$, respectively. DIN is expected to accumulate in the system. The removal of nutrients from bottom sediments will contribute to the reduction of 21.0% of COD concentration in the system.

• Korean Journal of Environment and Ecology
• /
• v.30 no.2
• /
• pp.261-270
• /
• 2016

The concept of Eco-welfare emerged in the process of discovering the relationship between a healthy ecosystem and human wellbeing. The objective of this study is to offer basic data for eco-welfare policy realization by conceptualizing the 'National Park Eco-welfare' since national parks are appropriate places for eco-welfare to be optimally implemented. A pre-workshop and two rounds of Delphi surveys were conducted to determine the concept of the 'National Park Eco-welfare ' and the main elements to be included in ecosystem service. Through this study, the concept of 'National Park Eco-welfare' was defined as efforts to conserve the biodiversity and sustainability of the ecosystem and create harmony between 'National Park Ecosystem Welfare' and 'National Park Human Welfare'. To establish the direction of the National Park Eco-welfare policy, we identified the main elements of ecosystem services which are appropriate for the National Park. These are comprised of 3 elements (food, fresh water and genetic resources) from supply service, all elements from regulating service and supporting/habitat service and 4 elements (aesthetic information, recreation-based ecotourism, healing, and knowledge systems with educational values) from culture service. In this study, the concept of National Park Eco-welfare was established, and its policy objectives and scope were suggested. However, further studies are necessary to develop action plans areand thereby realize the policy.

• The Korean Journal of Zoology
• /
• v.32 no.4
• /
• pp.393-403
• /
• 1989

Using starch gel electrophoresis of proteins, we examined variation at 24 genetic loci in five species (three general of the Subfamily Danioninae (Class Pisces, Family Cyprinidae) inhabiting In Korea. The average degree of genic variation of the Subfamily Danioninae (A=1.8, P=16.5%, HD=0.043, HG=0.049) was far less than that of the fresh water fishes in general. But the degree of genic variation of A. chinensis (P=32.5 HD=0.100, HG=0.119) was highe, than other fishes and the value of O. biders was the lowest (P=4.2%, HD=0.008, HG=0.008). The average genetic similarities among the populations in each species of A. chinensis, Z. platypus, Z. temmincki MS type, Z. temmincki W type, and O. widens were S=0.902, 0.899, 0.990, 0.914, and 0.992, respectively. The average genetic similarity of A. chinensis to the other species was the lowest value of S=0.235, whereas that between two species of Z. temmincki was the highest of S=0.822. Genetically, Z. plypus is more similiar to O. widens than ho species of the same genus Zacco. Based on estimated divergent time of 5 species of the Subfamily Danioninae (7.6 to 0.9 million years) it is assumed that they are speciated during late Pliocene to middle Pleistocene epoch.