• Journal of Aquaculture
• /
• v.11 no.2
• /
• pp.183-191
• /
• 1998

To substitute fromzed and freeze-dried food for live food in the development of the artificial seedling production of bivalve larvae, the dietary value of live T. suecica was compared with those of freeze-dried T. suecica, frozed T. suecica, live T. suecica (50%)+frozen T. suecica (50%), and live T. suecica (50%)+freeze-dried T. suecica (50%) in the rearing of oyster (Crassotrea gigas) and hen clam (Mactra chinensis) larvae, and manila clam (Tapes philipninarum) spats. Oyster larvae fed live T. suecica showed the highest growth (shell hight $231.9^{\mu}$m) and survival rate (72.6%) and those fed freeze-dried T. suecica showed the lowest growth (shell height $168.9^{\mu}$m) and survival rate (35.3%). However, in the hen clam larvae, there were not significantly different among diet group in growth and survival rate. The small spats of manila clam fed live t. suecica or live T. suecica (50%)+freeze-dried T. suecica (50%) showed higher growth and survival rate than those fed other diet group. In the case of large spats of manila clam, live T. suecica and live T. suecica (50%)+frozen T. suecica (50%) showed better growht. But, survival rates were not different among diet groups. Dietary valuse of frozen and dried T. suecica were different on species and growth stage, and frozen and freeze-dried T. suecica can be partially used as substitute food for T. suecica live T. succica in shellfish hatchery.

• Journal of Aquaculture
• /
• v.11 no.1
• /
• pp.19-29
• /
• 1998

An 18-week growth trial was conducted in flow-through aquarium system to evaluate the practical dietary protein sources for juvenile abalone (Haliotis discus hannai). Three replicate groups of the abalone averaging 0.11g were fed one of ten diets containing casein, white fish meal (WFM), meat meal (MM), feather meal (FM), blood meal (BM), soybean meal (SM), corn gluten meal (CGM), cotton seed meal (CSM), Undaria powder (UP), or wheat flour (WF) as a dietary protein source. In addition, these dietary protein sources were cmpared with algae such as raw Undaria or dried Laminaria. Weight gain of abalone fed the diets containing casein, WFM, SM, CSM, or UP was significantly higher (P<0.05) than those of abalone fed other diets, and this value of abalone fed FM, BM, CGM, or algae was lower than other groups. Shell length, shell width, body wt./shell length ratio, and body wt./shell width ratio of abalone fed casein, WFM, SM, CSM, UP, and WF were also highe (P<0.05) than those of other groups. There were no significant difference (P>0.05) in moisture and protein contents of soft body among all diets. The data obtained in this study indicate that each of the casein, WFM, SM, CSM or UP is good dietary protein source for juvenile abalone.

• The Korean Journal of Nuclear Medicine
• /
• v.1 no.2
• /
• pp.27-34
• /
• 1967

1. Within experimental chromatin, the total protein: DNA ratio did not vary in the same organs of control and irradiated rats. However, the amount of RNA and total protein associated with the DNA varied considerably among the different types of chromatin. In particular, the content of chromatin was the highest in the irradiated tissue, and the lowest in the chromatin control tissue. RNA and total protein ratio of chromatins from brain, liver, testis and spleen declined with experimental organs. 2. There was the same quantitative relationship between the amount of RNA and the amount histone-protein associated with DNA in each chromatin. 3. RNA:DNA ratio of chromatin showed a $1.5{\sim}2$ times increase in the irradiated organs except brain. However, RNA:DNA ratio was decreased in chromatin by irradiation. 4. Histone-protein:Residual protein ratio was greatly varied among the organs. However, the effect was not found by irradiation. 5. Priming activity of chromatins showed a higher value in testis and the activity was greater in organs with higher metabolic activity. 6. Inhibition of Actinomycin D observable in chromatin for testis, liver, spleen and brain declined without relationship between irradiated and non-irradiated conditions. Ammonium sulfate in DNA of chromatin from histone showed increased priming activity with dissociation by Electrostatics. It may give different effect of ammonium sulfate on stimulation by property of chromatins. 7. It is suggested that the results support a proposal that the higher sensitivity of radioactive in testis, spleen by irradiated showed a increase and decrease lower-sensitivity of radioactive from brain, liver than did priming activity under the radioactive conditions.

• The Korean Journal of Malacology
• /
• v.15 no.1
• /
• pp.57-62
• /
• 1999

Condition indices (Cl) are considered to be useful measurements of the nutritive and health status of bivalves although studies on Cl of bivalves are limited due to the lack of a standard formula for calculating Cl. This study attempts to generate Cl of the mussel, Mytilus coruscus inhabiting along the coastal area of Chuja Island in Cheju using three primary formulas. the formulas used in this study: (1) Cl-vol= [tissue dry weight (g) 1000] /shell cavity volume (ml). (2) Cl-wt= [tissue dry weight (g) 1000] / internal shell cavity capacity (g). (3) Cl-size= tissue wet weight (g)/[shell length (mm)]$\^$3/. Monthly condition indices calculated with the three formulas are compared using ANOVA, Duncan's multiple range test and Pearson correlation coefficient. In Chuja Island M. coruscus collected ranged from 50 to 180 mm in shell length. Monthly ranges of Cl-values were 67.48 to 140.61 (Cl-vol), 74.67 to 118.02 (Cl-wt) and 1.4 10$\^$-5) to 1.6 10$\^$-5/ (Cl-size). Cl-vol values in August were higher than two Cl-values in the other months. Monthly Cl-vol was significantly different from Cl-wt and Cl-size. (p<0.05). The results of this study suggest that volumetric condition index (Cl-vol) used in this study is acceptable as a standard measure to evaluate conditions of M. coruscus.

• The Korean Journal of Malacology
• /
• v.28 no.4
• /
• pp.305-312
• /
• 2012

Manila clam, Ruditapes philippinarum (SL; $32.74{\pm}2.18mm$, TW; $8.29{\pm}1.41g$, N; 450) were exposed to various concentrations of naphthalene for 20 weeks. Exposure concentrations of naphthalene established control, solvent control (ethanol), 30, 60, 90 and $120{\mu}g$ Nap $L^{-1}$ following results of 96h acute exposure. After exposure during 20 weeks, survival rate of the manila clam was lowed in 60, 90 and $120{\mu}g$ Nap $L^{-1}$ exposure group compared control group. Also, sex ratio of male was higher in $60{\mu}g$ Nap $L^{-1}$ exposure group (${\chi}^2=5.492$, P < 0.05) but lowed $90{\mu}g$ Nap $L^{-1}$ exposure group (${\chi}^2=4.214$, P < 0.05) and $120{\mu}g$ Nap $L^{-1}$ exposure group (${\chi}^2=30.118$, P < 0.05). Gonad development was delayed in female (> $60{\mu}g$ Nap $L^{-1}$) and male (> $30{\mu}g$ Nap $L^{-1}$). Intersex was 16.28% in female, 1.68% in male. In this result, naphthalene caused survival decrease, imbalance of sex ratio, delay of gonad development of the manila clam. Also, chronic exposure to naphthalene suggested abnormal effects in reproduction of the manila clam.

• Journal of Aquaculture
• /
• v.3 no.1
• /
• pp.65-77
• /
• 1990

The growth of ark shell, Anadara broughtonii was compared between two areas, $Gad\v{o}gdo$ in Jinhae Bay and Namhae located in the southern coast of Korea from May 1986 to October 1987. The ark shells in Namhae grew from 1.38$\pm$0.32 em to 7.20$\pm$0.30 em in shell length, while those in $Gad\v{o}gdo$ grew from 1.38$\pm$0.32 em to 6,41$\pm$0.30 cm in 17 months. Shell height, shell breadth and total weigth of the ark shells in Namhae were also greater than those from $Gad\v{o}gdo$. Bottom quality of $Gad\v{o}gdo$ showed negative skewness, and that of Namhae was positive skewness. Negative skewness of $Gad\v{o}gdo$ seems to be caused by the effect of strong tidal current. This may indicate that Namhae is better area than $Gad\v{o}gdo$ for the culture of the ark shell.

• The Korean Journal of Malacology
• /
• v.19 no.2
• /
• pp.125-132
• /
• 2003

Age and growth of the the Jedo venus clam, Protothaca jedoensis were investigated using samples from the subtidal zone of Boryeong, Chungcheongnam- do, Korea from January to December, 1999. The relationship between shell height and ring radius in each group was expressed as a regression line. Therefore, it could be recognized that there is a correspondence in the formation of each ring. Based on the monthly variation of the marginal index of the shell, it was suggested that the annual ring mark formation occurred during the period of February to March once a year. The relationship between shell height (SH) and total weight (TW) was represented by the non-linear equation: TW = 0.0007 SH$^{2.8919}$, and also in the relationship between shell length (SL) and shell height (SH), shell height (SH) and shell width (SW) were represented by the linear equations: SL=1.1067SH+1.778, SW=0.6758SH-0.9824. Growth curves for shell height and total weight fitted to the von Bertalanffy equation were expressed as: SH$_t$ = 81.546(1-e$^{-0.176(t+0.381)}$), TW$_t$ = 227.65(1-e$^{-0.176(t+0.381)})^{2.8919}$.

• Korean Journal of Veterinary Research
• /
• v.13 no.1
• /
• pp.5-12
• /
• 1973

Seventy two guinea pigs were divided into 3 groups; 24 each of control, unilateral thyro-parathyroidectomized and bilateral thyro-parathyroidectomized groups. After the intraperifoneal in jection of $16{\mu}Ci$ of radioactive calcium ($^{45}Ca$) $^{45}Ca$ uptake of various organs and tissues were measured at the 8th, 16th, 24th and 36th hours, respectively, 18 animals were slaughtered (6 from each group) each time. The results obtained were as follows: 1. It was shown that each organ and tissue of treated animals had higher $^{45}Ca$ uptake than the control group, and the bilateralectomized group, higher than the unilateralectomized group, generally. However, there were some exceptions of the findings. The unilateralectomized group had higher $^{45}Ca$ uptake than the bilateralectomized group in case of adrenal gland and femur at the 8th hour; adrenal gland and blood at the 16th hour; spleen, pancreas, adrenal gland, femur and skeletal muscle at the 24th hour; and pancreas, femur and skeletal muscle at the 36th hour, respectively. 2. $^{45}Ca$ uptakes of each organ and tissue were also determind with respect to time. The results were varied with each treatment group, but generally the highest uptake was shown at the 8th hour and decreased gradually thereafter. The differences were not, however, statistically significant. 3. Femur had shown the highest $^{45}Ca$ uptake and the next were blood, pancreas, liver, skeletal muscle and spleen respectively, and the least were adrenal gland and liver, even though there were some variations in the results. 4. The differences in $^{45}Ca$ uptake of each organ and tissue for the treatment group were statstically significant as compared with the test of the control group, except the spleen and blood at the 8th hour; liver at the 16th hour; adrenal gland, spleen, pancreas at the 24th hour; and spleen at the 36th hour.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.6 no.1_2
• /
• pp.65-75
• /
• 1973

Morphological variations of the Korean Oyster, Crassostrea gigas, were studied on the basis of the oyster samples collected from seven ecologically different areas in May and October of 1972 respectively. The sampling areas were Daecheon and Buan in the west coast, Namseong, Cha-myeon, Imyeong and Chubong in the south coast and Pohang in the east coast. The average sizes of the oysters of the west coast were smaller than those of the south coast as well as those of the east coast. The oysters of the east were largest in size, The oysters from subtidal habitats (Chubong and Pohang) had elongated shells and those from intertidal habitats (Buan, Namseong, Imyeong and Chamyeon) had slanted shells. The samples from subtidal habitats showed size variations depending on cultural methods applied. The oysters from Chubong reared by hanging method had their shells as compared to those from Pohang reared by bottom culture method. The ratio of shell height to shell length showed a great variation froms areas to areas with a significant differences. The fatness (meat weight / shell weight) of all the samples collected in October revealed higher value than those collected in May. The oysters from Chubong showed maximum fatness, and those of Pohang showed minimum fatness. Seasonal variations in fatness was not significant in Chubong. On the other hand, it was relatively significant in the oysters from Pohang, Chamyeon, Imyeong and Buan. Water content of the oyster meat was greater in October than in May. It also showed variations in the sampling areas with higher values in the oyster from Imyeong and Chamyeon than those from Chubong, Pohang and Daecheon.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.14 no.4
• /
• pp.217-220
• /
• 1981

A trematode, Cercaria tapidis which is parasitic to short necked clam, Tapes philippinarum was studied in terms of its morphology and incidence of infection rate. The host bivalve was collected from Solri near Gunsan from September 1980 to August 1981. Sporocysts were observed mainly in tissues of gonad of the short necked clams. Minimum infection rate ($0.85\%$) was found in May, while maximum infection rate ($23.27\%$) in December. The sporocyst is 1.1 mm long and 0.27 mm wide. Ellipsoidal body of cercaria is $283{\mu}m$ long and $120{\mu}m$ wide. Oral sucker is much larger than ventral sucker. Moderately small pharynx, a long esophagus, and a long intestine reaching to the posterior end of the body are distinctive. Globular excretory bladder is located at the posterior part of the body and bears numerous granules of various size. The flame-cell arrangement is represented by a formula 2[(3+3+3)+(3+3)]=30. Tail is five times body length.