• Parasites, Hosts and Diseases
• /
• v.23 no.2
• /
• pp.221-229
• /
• 1985

The echinostomatid metacercariae encysted in the gill of the fresh water fish, Pseudorasbora larva were identified through obtaining adult worms after eBperimental infection to mice. In addition, a brief course of worm development and maturation was observed in this experimental host. The results were as follows: 1. The echinostomatid metacercariae were elliptical, golden yellow, 0.073∼0.078 mm long and 0.0541∼0.065 mm wide. Their head portions were characterized by the presence of a head crown armed with collar spines of total 24 in number and interrupted at the mid-dorsal side of the oral sucker. 2. The average rate of worm recovery froth 12 mice (on the 1-2lth postinfection days) was 19.4 % and the rate revealed no decrease in accordance with the increase of infection duration. The worms were collected chiefly from the lower part of the small intestine. 3. After the infection, their sexual maturation was attained in 5 days and their growth in size nearly completed in 7 days. The early growth curve of genital organs was S shape while that of nongenital organs was C form. In 5 day old worms, 1 or 2 eggs were found from their uteri and the stools of mice revealed echinostomatid eggs from the 5-6th postinfection day. 4. The 7 day old adult worms were ovoid in shape, 0.54-0.69 mm long and 0.29-0.34 mm wide, and characterized by a well developed head crown with 24 collar spines and vitelline follicles distributed from the acetabular level down to the posterior end of body. Based on these characters they were identified to be Echinochasmus japonicus Tanabe, 1926. From these results, it is verified that p. larva is one of the second intermediate hosts of 5. jatonicus in Korea.

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

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.33 no.5
• /
• pp.373-377
• /
• 2000

This study Investigated the effects of $estradiol-l7{\beta} (E_2)$, $17{\alpha}-methyltestosterone$ (MT) and high temperature (WT) on gonadal sex differentiation in black rockfish, Sebastes srhlegeli. fish were reared to oral adminstration of E, at nominal concentrations of $20, 40 and 60 {\mu}g/g diet$, and MT at nominal concentration of 20 and $50 {\mu}g/g$ diet from 56 days to 77 days after parturition. In the treatment of WT, water temperature of the breeding tanks ranged $27.0{\pm}0.5^{\circ}C$ more than $10^{\circ}C$ approximately, in comparison to the control and other experimental group, In the process of sex differentiation until 56 days after parturition, gonads were composed of mostly gonia cells, sexually undifferentiated. In contrast, 128 dal's after parturition, the ovaries were composed of ovarian cavity and lamellae, and oogonia and perinucleolus oocytes were distributed in the lamellae of ovary, and the testes were composed of a number of seminiferous tubule, and spermatogonia were distributed in the seminiferous tubule, and also melanophore scattered in the matrix layer of testis. In the sex ratio, more females than male were observed from $E_2$. treatment groups when compared to the control, but more males than females were observed from MT and WT treatment groups when compared to the control. In the results of the present study, the concentration and kinds of the sex steroid hormones, and also the rearing high temperature caused to the factor of sex determination in the process of sex differentiation of black rockfish.

• Journal of Life Science
• /
• v.25 no.7
• /
• pp.833-838
• /
• 2015

Multidrug-resistant super bacterial, fungal, viral, and parasitic infections are major health threaten pathogens. However, to overcome the present healthcare situation, among the leading alternatives to current drugs are antimicrobial peptides (AMPs), which are abundantly produced via various species in nature. AMPs, small host defense proteins, are in charge of the innate immunity for the protection of multicellular organisms such as fish, amphibian, reptile, plants and animals from infection. The number of AMPs identified per year has increased steadily since the 1980s. Over 2,000 natural AMPs from bacteria, protozoa, fungi, plants, and animals have been listed into the antimicrobial peptide database (APD). The majority of these AMPs (>86%) possess 11–50 amino acids with a net charge from 0 to +7 and hydrophobic percentages between 31–70%. This report classified AMP into several categories including biological source, biological functions, peptide properties, covalent bonding pattern, and 3D structure. AMP functions not only antimicrobial activity but facilitates cell biological activity such as chemotatic activity. In addition, fibroblastic reticular cell (FRC) originated from mouse lymph node stroma induced the expression of AMP in inflammatory condition. AMP induced from FRC contained whey acidic protein (WAP) domain. It suggests that the classification of AMP will be done by protein domain.

• Journal of Life Science
• /
• v.20 no.3
• /
• pp.356-364
• /
• 2010

This study was carried out to investigate the exposure pathway of PBDEs in human breast milk collected from new mothers residing in Chuncheon, a comparatively clean area in Korea. The congeners of PBDE in 22 human breast milk samples were analyzed using a high resolution gas chromatography with a high resolution mass detector. The residue level of ${\sum}PBDEs$ was higher in primipara subjects than in multipara subjects (p<0.05). The levels in this study were similar to those of people in some Asian and European countries, but were lower than those of people in north America. In the congener profiles, BDE-47 (mean contribution=36.1%) was predominant, followed by BDE-153 (27%), BDE-99 (11.7%), BDE-100 (11.1%), BDE-28 (7.9%) and BDE-183 (3.5%). The sum of BDE-47 and BDE-153 accounted for more than 50% of ${\sum}PBDEs$ in most samples. BDE-47 was highly correlated with ${\sum}PBDEs$ (r=0.94, p<0.001). No strong trend was observed between PBDE levels and a number of key biological factors (women's age, weight, height and body mass index) examined in this study, however, weak correlations were observed in PBDE levels measured against dietary habits, particularly in fish consumption frequency. It seems that Korean people might be exposed to multiple sources including products of PBDEs, and particularly food resources.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.31 no.5
• /
• pp.727-738
• /
• 1998

Seasonal species composition of fishery resources was determined using samples collected by a stow net from April 1995 through January 1996 at 9 stations off Youngkwang. Catch data obtained from a set net using strong tidal current could be used for a quantitative analysis of dominant species. Of the 98 species identified, assemblages were consisted of $52.0\%$ in fishes, $44.6\%$ in shrimps, $2.0\%$ in cephalopods, $1.4\%$ in crabs and <$0.1\%$ in gastropods. Thryssa kammalensis, Crangon hakodatei, Metapenaeus joynezi and Johnius grypotus predominated in abundance, consisting of $68\%$ in the number of individuals, The abundance and species composition fluctuated seasonally, and species could be distinguished by life history pattern with seasons. Seasonal variation in species composition was greater than the spatial variation in a sampling period, As the fine sediment was predominated in the study area, the species composition were significantly different from those of other coastal waters of West Sea, Korea.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.11 no.4
• /
• pp.31-35
• /
• 1982

The nutrition intake status of one hundred pre-school children, 5-year-old boys and girls, in Sok-Cho was surveyed. Subjects had two and half brothers and sisters. Breast-fed boys and girls were 48% and 40%, respectively. At the age of Six months, 70% of Subjects were Weaned. Percentage of total income spent for foods was $30{\sim}39%$. A varying number of foods were selected from 40 items. The food which children likeed best was fruit and icecream. Selected as liked food were straw berry, orange, apple, icecream, peach, grape, chocolate, youghurt and milk. Disliked foods were ginger, green onions, garlic, mushrooms and boiled rice mixed with orther cereals. Items which children have taken never before were kidney, slices of raw meat, liver, lotus rhizome and frech water fish. Insufficient caloric intakes were shown comprising 69~70% daily recommended dietary allowences for boys and girls. The total caloric intakes was composed of carbohydrate 65%, protein 11% and fat 23%, respectively. The cereal consumption was the highest (32.8%). There was a significant relationship (P<0.05) between the mother's knowledge on nutrition and the calorie. protein and calcium intake of boys. There was a significant relationship (P<0.05) between the mother's knowledge on nutrition and the caloric intake of girls.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.20 no.6
• /
• pp.629-636
• /
• 1991

Yellowtail fishes(Seriola quinqueeradiata) were submitted to the storages using ice-cooling($0^{\circ}C$), partial freezing($-3^{\circ}C$) and freezing $-20^{\circ}C$) method. Changes in the structures of muscle during storage at different temperatures were investigated. The ice-cooling and partial freezing storage caused early decomposition of glycogen granules and mitochondrial inner membrane, but it was accorded to much slower manner comparing with that of ice-cooling storage. The scars of ice crystals were appeared after three days of storage. The number and size of the crystal increased as progressing of the storage. They were circular and mostly located between fibers. When using the freezing storage, glycogen granules were mostly found from the muscle cell even after fourteen days of storage. Mitochonidral inner membrane maintained their integrity. The scars of ice crystals were also found, however, different from those of partial freezing storage. Their existing sites were random and their shapes were irregular. In many cases, they located in the fiber and had keen edges. Fibers were broken mostly at the Z-lines on fourteen days of storage. From these results, it was concluded that partial freezing storage can repress autolytic enzymic action and can reduce the physical damage from ice crystals which is caused by freezing.

• Korean Journal of Ichthyology
• /
• v.12 no.2
• /
• pp.101-110
• /
• 2000

Population ecology of Rhynchocypris keumgangensis have been investigated at upper part of the Han River in Korea from January to December, 1995. The habitat was low water temperature and clean area, and stream form was Aa. The major cohabitation fish was Phoxinus phoxinus. The total lengths in this population indicated that below 40 mm group is one year old, 40~65 mm group is two years old, 65~80 mm group is three year and the 80 mm longer group is regarded over four years old. There were no differences in total length distribution between the female and the male. The males became sexually mature, when longer than 45 mm and females longer than 65 mm in total length. Spawning season was from April to mid May with the water temperature in $11{\sim}14^{\circ}C$ and the properous period was April. The mean number of eggs in ovary was 1,616. The sex ratio all the year round of the female to the male was 1 : 0.75. The current velocity of the spawning ground was 44 (20~80) cm/sec and water depth was 35 (5~70) cm. Eggs were laied in 5~15 cm deep underneath the immaculate pebbles (2~6 cm). Sex ratio of the female to the male was 1 : 6.90 for spawning behavior.

• Korean Journal of Ichthyology
• /
• v.20 no.1
• /
• pp.28-35
• /
• 2008

Fishes by a set net in the coastal waters off Gwideuk, Jeju Island were studied to determine species composition and catch variation, 2004. The fishing period conducted by a set net in Gwideuk fishing ground were from April to December. A total of 45,473.2 kg including 21 species was caught during the survey period. Most of them consisted of fishes of 17 species and a few were cephalopods of 4 species. Dominant species were Trachurus japonicus and Siganus fuscescens, 44.3% in the total. And sub-dominant species were Sepioteuthis lessoniana, Seriola dumerili, Seriola quinqueradiata, Loligo bleekeri, Seriola lalandi accounting for 54.4%. Although the number of species had a tendency to decreased from July to December, the catch by a set net was higher in summer and autumn than in spring. Such catch variations were closely related to recruitment of dominant species and also the seasonal variation of fishing ground temperature.