• Journal of Life Science
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• v.34 no.3
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• pp.191-198
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• 2024

To verify the nutritional value and safety of larvae fed with a soymilk residue-added food source, we compared and analyzed the nutritional components of and harmful substances in Tenebrio molitor larvae reared on wheat bran. Crude protein content based on dry weight was 1.2 times higher in the 10% soymilk residue-fed group (SR) (54.0%) than in the wheat bran-fed group (WB) (43.5%). Dietary fiber also tended to be 1.9 times more in the SR (4.9%) than the WB (2.5%). Among unsaturated fatty acids, the linoleic acid content was found to be 1.1-fold higher in the SR (32.9%) than in the WB (29.0%). Potassium, which was the most abundant among the macro minerals, was 1.1-fold more abundant in the WB (1,074.5 mg/100 g) than in the SR (1,014.0 mg/100 g). Among the micro minerals, zinc content was 1.2-fold higher in the SR (14.5 mg/100 g) than in the WB (11.9 mg/100 g). The results of the analysis of hazardous substances in the WB and SR revealed that the amount of heavy metals met the standards for heavy metals in edible insects, and food poisoning-inducing bacteria such as Escherichia coli and Salmonella spp. were not detected in all groups. These results indicate that mealworm larvae fed with 10% soymilk residue have abundant nutrients and are safe for intake. Thus, food sources with added soymilk residue has the potential to be used as feed ingredients.

• Journal of Bio-Environment Control
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• v.33 no.1
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• pp.55-62
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• 2024

This study aimed to compare the nutrient uptake rate, growth and yield of strawberry grown under the aquaponic and hydroponic systems in a plant factory. For aquaculture, 12 of fish (Cyprinus carpio cv. Koi) were raised in an aquaponics tank (W 0.7 m × L 1.5 m × H 0.45 m, 472.5 L) filled with 367.5L of water at a density of 5.44 kg·m^-3. The 30 seedlings of strawberry were planted in ports filled with perlite substrate and then were placed on the bed (W 0.7 m × L 1.5 m × H 0.22 m) at the top of the aquaponics system, and the 30 seedlings were planted in net-pots and then placed on the holes of acrylic plates (140 cm × 60 cm, Ø80 mm) on the bed (W 0.7 m × L 1.5 m × H 0.22 m) at the deep flow technique (DFT)- hydroponics. The pH and EC of the aquaponic solution was ranged from 4.3 to 6.9 and 0.32 to 1.14 dS·m^-1, respectively, while those of hydroponics were ranged from 5.1 to 7.5 and 1.0-1.8 dS·m^-1, respectively. The NO₃-N and NH₄-N concentration of the aquaponic solution were higher about 3.6 and 2.2 me·L^-1 than those of the standard hydroponic solution for strawberry cultivation. The P, Ca, Mg, and S ions in the aquaponic solution were also higher about 0.76, 3.1, 0.8, and 0.9 me·L^-1 than those of standard hydroponic solution, respectively, while the K and Fe were lower about 0.8 me·L^-1 and 0.5 mg·L^-1, respectively. The mineral contents of the strawberry leaves grown on aquaponics did not differ from that of hydroponics, and K content in the leaves were in an appropriate range. Uptake rates of T-N and P between the 58 and 98 days after transplant (DAT) were 1.5 and 1.9-fold higher in the aquaponics than those of hydroponics, respectively with no significant difference in the uptake rate of K. The crown diameter, plant height, and leaf length and width in the 98 DAT were significantly higher in aquaponics. The number of fruits per plant was significantly higher in aquaponics than those in hydroponics, and the fresh and dry weights of fruit and length and width of fruit were significantly higher in hydroponics. The results suggest that plants in aquaponics continuously utilize fertilizer components of solid particles from fish and feed wastes.

• Journal of Sericultural and Entomological Science
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• v.8
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• pp.11-25
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• 1968

Various formulae for estimation of leaf production in mulberry trees were investigated and obtained. Four varieties of mulberry trees were used as the materials, and seven characters namely branch length. branch diameter, node number per branch, total branch weight, branch weight except leaves, leaf weight and leaf area, were studied. The formulae to estimate the leaf yield of mulberry trees are as follows: 1. Varietal differences were appeared in means, variances, standard devitations and standard errors of seven characters studied as shown in table 1. 2. Y$_1$=a$_1$X$_1$${\times}$P$_1$......(l) where Y$_1$ means yield per l0a by branch number and leaf weight determination. a$_1$.........leaf weight per branch. X$_1$.......branch number per plant. P$_1$........plant number per l0a. 3. Y$_2$=(a$_2$${\pm}$S. E.${\times}$X$_2$)+P$_1$.......(2) where Y$_2$ means leaf yield per l0a by branch length and leaf weight determination. a$_2$......leaf weight per meter of branch length. S. E. ......standard error. X$_2$....total branch length per plant. P$_1$........plant number per l0a as written above. 4. Y$_3$=(a$_3$${\pm}$S. E${\times}$X$_3$)${\times}$P$_1$.....(3) where Y$_3$ means of yield per l0a by branch diameter measurement. a$_3$.......leaf weight per 1cm of branch diameter. X$_3$......total branch diameter per plant. 5. Y$_4$=(a$_4$${\pm}$S. E.${\times}$X$_4$)P$_1$......(4) where Y$_4$ means leaf yield per 10a by node number determination. a$_4$.......leaf weight per node X$_4$.....total node number per plant. 6. Y$\sub$5/= {(a$\sub$5/${\pm}$S. E.${\times}$X$_2$)Kv}${\times}$P$_1$.......(5) where Y$\sub$5/ means leaf yield per l0a by branch length and leaf area measurement. a$\sub$5/......leaf area per 1 meter of branch length. K$\sub$v/......leaf weight per 100$\textrm{cm}^2$ of leaf area. 7. Y$\sub$6/={(X$_2$$\div$a$\sub$6/${\pm}$S. E.)}${\times}$K$\sub$v/${\times}$P$_1$......(6) where Y$\sub$6/ means leaf yield estimated by leaf area and branch length measurement. a$\sub$6/......branch length per l00$\textrm{cm}^2$ of leaf area. X$_2$, K$\sub$v/ and P$_1$ are written above. 8. Y$\sub$7/= {(a$\sub$7/${\pm}$S. E. ${\times}$X$_3$)}${\times}$K$\sub$v/${\times}$P$_1$.......(7) where Y$\sub$7/ means leaf yield estimates by branch diameter and leaf area measurement. a$\sub$7/......leaf area per lcm of branch diameter. X$_3$, K$\sub$v/ and P$_1$ are written above. 9. Y$\sub$8/= {(X$_3$$\div$a$\sub$8/${\pm}$S. E.)}${\times}$K$\sub$v/${\times}$P$_1$.......(8) where Y$\sub$8/ means leaf yield estimates by leaf area branch diameter. a$\sub$8/......branch diameter per l00$\textrm{cm}^2$ of leaf area. X$_3$, K$\sub$v/, P$_1$ are written above. 10. Y$\sub$9/= {(a$\sub$9/${\pm}$S. E.${\times}$X$_4$)${\times}$K$\sub$v/}${\times}$P$_1$......(9) where Y$\sub$7/ means leaf yield estimates by node number and leaf measurement. a$\sub$9/......leaf area per node of branch. X$_4$, K$\sub$v/, P$_1$ are written above. 11. Y$\sub$10/= {(X$_4$$\div$a$\sub$10/$\div$S. E.)${\times}$K$\sub$v/}${\times}$P$_1$.......(10) where Y$\sub$10/ means leaf yield estimates by leaf area and node number determination. a$\sub$10/.....node number per l00$\textrm{cm}^2$ of leaf area. X$_4$, K$\sub$v/, P$_1$ are written above. Among many estimation methods. estimation method by the branch is the better than the methods by the measurement of node number and branch diameter. Estimation method, by branch length and leaf area determination, by formulae (6), could be the best method to determine the leaf yield of mulberry trees without destroying the leaves and without weighting the leaves of mulberry trees.

• Journal of Animal Science and Technology
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• v.45 no.6
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• pp.1007-1018
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• 2003

This study was conducted to investigate the effect of feeding of garlic stalk silage on performance and carcass characteristics of Hanwoo steers. Feeding trial was conducted with 27 heads of Hanwoo steers and these animals were divided into two groups of control(rice straw) and garlic stalk silage. Animals consuming rice straw were fed concentrates and rice straw for 22 months from the 5 months of age and animals consuming garlic stalk silage were fed concentrates, rice straw and garlic stalk silage for 22 months from the 5 months of age. Animals fed rice straw and garlic stalk silage were fed 1.34 and 1.47, 1.69 and 1.74, 1.65 and 1.66% concentrates to body weight for the growing period, fattening period and finishing period, respectively. Animals fed rice straw and garlic stalk silage as roughage sources were fed 1.37 and 1.38, 0.65 and 0.63, 0.43 and 0.43% roughages to body weight for the growing period, fattening period and finishing period, respectively. Also, animals fed garlic stalk silage were offered 0.22 and 0.33% garlic stalk silage to body weight for the fattening and finishing period, respectively. Animals fed rice straw and garlic stalk silage as a roughage sources did not differ in average daily gain during the whole feeding periods. Animals of control group consumed less concentrates and roughage than those fed garlic stalk silage during the whole feeding periods. However, feed efficiency was not significantly different between both treatments. Beef yield including backfat thickness, eye muscle area and carcass weight was slightly lower in the animals fed garlic stalk silage than in the animals fed rice straw even though there were no differences between both treatments. However, beef quality including beef color, fat color, texture, maturity and marbling score was slightly higher in the garlic stalk silage-fed animals than in the animals fed rice straw although there were not statistically different between both treatments. Animals consuming garlic stalk silage was significantly(p<0.05) lower in shear value than those fed rice straw. Amino acid composition including essential amino acid and non-essential amino acid was not different between animals fed rice straw and garlic stalk silage. Eye muscle area of animals fed garlic stalk silage contained slightly higher oleic acid, less linoleic acid and arachidonic acid and more linolenic acid than that of animals fed rice straw only as a roughage sources. So eye muscle area of animals fed garlic stalk silage contained more mono-unsaturated fatty acid than that of animals fed rice straw and $\omega$6/$\omega$3 ratio was narrower in the animals fed garlic stalk silage than in the animals fed rice straw. Economic income was higher by 20% in the animals fed garlic stalk silage than in the animals fed rice straw. Therefore, It may be concluded that feeding of garlic stalk silage as a roughage sources to steers during the fattening period seems to improve meat quality, fatty acid composition and economic income.

• Journal of Sericultural and Entomological Science
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• v.9
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• pp.67-87
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• 1969

1. Objectives and Importance. Many silkworms have been damaged by nuclear polyhedrosis virus diseases thoughout the country every year causing a decease in cocoon production by approximately ten per cent per year. The damage caused by the infections virus has occured in spite of complete disinfection. In this respect, it is well known it is impossible, at the present time, to protect the silkworm from these virus infections through chemical and physical control methods. Therefore, this author has attempted to solve this urgent problem from the view point of heredity and breeding, discovering the different resistances and heritabilities among 120 stains collected from throughout the country, and selecting the ones with highest resistance for the basic materials in the silkworm breeding. 2. Results of work 1) The strains with strong resistance to the nuclear polyhedrosis virus diseases are N$_4$, N$\sub$15/, N$\sub$48/, C$\sub$55/ and Em. the log ED$\sub$50/ values of them vary between 0.799 and 1.611. The susceptible strains are N$\sub$20/, C$\sub$62/, N$\sub$76/, N$\sub$79/ and C$\sub$108/, the log ED$\sub$50/ values of them vary between 5.159 and 7.258. (Reference Table 4) The Japanese strain with a log ED$\sub$50/, value of 3.770 is the strongest, followed by the Chinese strain with a log ED$\sub$50/ value of 3.564. The weakest is the European strain with a log ED$\sub$50/ value of 3.3381. The direction coefficient of the regression equation of the susceptibility varies between 0.1 and 0.6, the uniformness of the resistance of the preserved strains of this country is comparatively low. The hereditary henomena of the resistance of each strain and the conerete method of its application for silkworm breeding main the subjects for later studies. 2) The content of water and ash in silkworm has not been correlated with the capability for resistance to the virus diseases(Reference. Table 8). but it is very significantly correlated with mortality rate (in common reaning). In the case of the silkworms which have just completed the fourth moulting the content of water and ash is not related to the mortality rate. In the case of the silkworms which have just completed the third moulting, however, the water( +0.326) and ash (+0.362) registered a high significance. The ash content in the first ($\div$0.520) and second ($\div$0.386) moults is highly significant but water content in both cases is not significant (Reference Table 7). 3) The No. 205 strain proved to be the best in character among the various F$_1$ hybrids. No. 204 was very good in strength but a little lower in cocoon character than the control. No. 212 was a little low in coccon character and mortality was average, but the cocoon harvest was the best among all the varieties offered for (Reference Table 9). 4), In short, the above mentioned strains which are known to have strong resistance to the virus disease are expected to provide basic data for breeding strong varieties. It is proposed that continued research should be conducted on the characteristics of various strains for a satisfactory preservation of various characteristics.research should be conducted on the characteristics of various strains for a satisfactory preservation of various characteristics.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.2
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• pp.270-284
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• 1997

Effects of dietary carotenoids were investigated on the metaboβsm and body pigmentation of rainbow trout(Salmo gairdneri), masu salmon(Oncorhynchus macrostomos), eel(Anguilla japonica), rock fish(Sebastes inermis) and black rock fish(Sebastes schlegeli). Three weeks later after depletion, these fishes were fed diet supplemented with ${\beta}-carotene$, lutein, canthaxanthin', astaxanthin or ${\beta}-apo-8'-carotenal$ for 4 to 5 weeks, respectively. Carotenoids distributed to and changed in integument were analyzed. In the integument of rainbow trout. zeaxanthin, ${\beta}-carotene$ and canthaxanthin were found to be the major carotenoids, while lutein, isocryptoxanthin and salmoxanthin were the minor carotenoids. In the integument of masu salmon, zeaxanthin was found to be the major carotenoids, while triol, lutein, tunaxanthin, ${\beta}-carotene$, ${\beta}-cryptoxanthin$ and canthaxanthin were the minor carotenoids. In the integument of eel, ${\beta}-carotene$ was found to be the major carotenoids, while lutein, zeaxanthin and ${\beta}-cryptoxanthin$ were the minor carotenoids. In the integument of rock fish, zeaxanthin, ${\beta}-carotene$, tunaxanthin$(A{\sim}C)$ and lutein were found to be the major carotenoids, while ${\beta}-cryptoxanthin$, ${\alpha}-cryptoxanthin$ and astaxanthin were the minor carotenoids. Likely in the integument of black rock fish, ${\beta}-carotene$, astaxanthin and zeaxanthin were found to be the major carotenoids, whereas ${\alpha}-cryptoxanthin$, ${\beta}-cryptoxanthin$, lutein and canthaxanthin were the minor contributor. The efficacy of body pigmentation by the accumulation of carotenoids in the integument of rainbow trout and masu salmon were the most effectively shown in the canthaxanthin group and of eel, rock fish and black rock fish were the most effectively shown in the lutein group. Based on these results in the integument of each fish, dietary carotenoids were presumably biotransformed via oxidative and reductive pathways. In the rainbow trout, ${\beta}-carotene$ was oxidized to astaxanthin via successively isocryptoxanthin, echinenone and canthaxanthin. Lutein was oxidized to canthaxanthin. Canthaxanthin was reduced to ${\beta}-carotene$ via isozeaxanthin, and astaxanthin was reduced to zeaxanthin via triol. In the masu salmon, ${\beta}-carotene$ was oxidized to zeaxanthin. Lutein was reduced to zeaxanthin via tunaxanthin. Canthaxanthin was reduced to zeaxanthin via ${\beta}-carotene$. and astaxanthin was reduced to zeaxanthin via triol. In the eel, ${\beta}-carotene$ and lutein were directly deposited but canthaxanthin was reduced to ${\beta}-carotene$, and cholesterol lowering effect by Meju supplementation might be resulted from the modulation of fecal axanthin, astaxanthin and ${\beta}-apo-8'-carotenal$ were oxidized and reduced to tunaxanthin via zeaxanthin. In the black roch fish, ${\beta}-carotene$ was oxidized to ${\beta}-cryptoxanthin$. Lutein was reduced to ${\beta}-carotene$ via ${\alpha}-cryptoxanthin$. Canthaxanthin was reduced to ${\alpha}-cryptoxanthin$ via successively ${\beta}-cryptoxanthin$ and zeaxanthin. Astaxanthin converted to tunaxanthin via isocryptoxanthin and zeaxanthin, and ${\beta}-apo-8'-carotenal$ was reduced to ${\alpha}-cryptoxanthin$ via ${\beta}-cryptoxanthin$ and zeaxanthin.

• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.197-208
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• 1991

This study was conducted to estimated the genetic and phenotypic correlations between economic traits and certain other traits in Korean Native Ogol fowl The data analysis were the record of 450 pullets bred from 150 dams and 20 sires of Korean Native Ogol fowl at Chungnam National University from June 18, 1987 to April 6, 1989. The results obtained are summarized as follows ： 1 The genetic correlation coefficients of the economic traits and body shape components were as follows ： between body weight and shank length, breast width. breast girth, tibia length were 0.210~0.788, 0.231~0.826, 0.610~0.995 and 0.096~0.503 between age at first egg and shank length, breast width, breast girth, tibia length were 0.555~0.626, 0.149~0.270, 0.370~0.445 and 0.014-0.124. between number of egg production and shank length, breast girth, tibia length were -0.446~-0.167, -0.162~-0.320, 0.076~0.336 and 0.203~0.312 ： between egg weight and shank length, breast width, breast girth, tibia length were 0.132~0.498, 0.236~0.410, 0.148~0.775 and -0.019~0.593, respectively. 2. The genetic correlation coefficients of the economic traits and egg components were as follows ： between body weight and albumen weight, yolk weight, shell weight were 0.083~0.591, 0 110~0.541 and 0.336~0.782 between age at the first egg and albumen weight, yolk weight, shell weight were 0.476-0.692, 0.265~0.631 and 0.420~0.519 between number of egg Production and albumen weight, yolk weight, shell weight were -0.578~-0.240, -0.255~-0.060, -0.477~-0.313. between egg weight and albumen weight, yolk weight, shell weight were 0.825~0.939, 0.382~0.564, 0.374~0.337, respectively. 3. The genetic correlation coefficients of the economic traits and egg qualifies were as follows ： between body weight and egg shape index, shell thickness, albumen height, Haugh units were 0.215~0.367, 0.248~0.650, 0.161~0.624, 0.157~0.449. between number of egg production and egg shape index, shell thickness, albumen height, Haugh units were -0.384~-0.207, -0.557~-0.306, -0.555~-0.198, -0.582~-0.074 between egg weight and egg shape index, shell thickness, albumen height, Haugh units were 0.276~0.697, 0.290~0.627, 0.238~0.538, -0.207-0.020, respectively. 4. The genetic correlation coefficients of egg compositions and egg qualities were as follows ： between albumen weight and egg shape index, shell thickness, albumen height and Haugh units were 0.110~0.584, -0.380~-0.002, 0.239~0.887 and -0.195~0.279 ： between yolk weight and egg shape index, shell thickness, albumen height and Haugh units were -0.204~0.160, 0.294~0.133, -0.049~0.133 and -0.196~-0 136 ： between shell weight and egg shape index, shell thickness, albumen height and Haugh units were 0.127~0.503, 0.127~0.476, 0.140~0.273 and -0.172~0.233, respectively.

• Journal of Animal Science and Technology
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• v.44 no.3
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• pp.327-340
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• 2002

This study was conducted to investigate the effects of domestic clay minerals on feed efficiency, meat quantity, meat quality and economic traits in 24 head of Hanwoo steers(166.1kg in body weight) for 540 days from six to 24 months in age. Feeding trial was conducted with 4 treatment(six heads/treatment) which were T1(Control), T2(Control+Kaolinite), T3(Control+Bentonite), T4(Control+Illite). The results obtained are summarized as follows; The range of average daily gains were 0.682 to 0.713, 0.669 to 0.714, 0.690 to 0.840 and 0.699 to 0.756kg in growing, fattening, finishing and over-all period, respectively, and the gains were high in T1 for growing and fattening period but in clay mineral groups for finishing and over-all period, especially it was high in Illite and Bentonite groups. Concentrates and TDN intakes per unit of kg gains were lower in clay mineral groups than in control and was lower especially in Bentonite groups. In carcass characteristics, dressed carcass and fresh meat and retailed cut percent were not apparently difference by treatments, and yield index was 69.3, 68.9, 68.8 and 68.6 in T3, T2, T4 and T1, respectively. Marbling scores were 5.1, 4.6, 4.4 and 3.3 in T3, T2, T4 and T1, respectively, and the range of shear force by treatment was from 3.51 to 6.02kg/cm2. and were improved with significant difference(P<0.05) in clay mineral groups than in control. Also in palatability traits, panel test scores of juiciness, tenderness and flavor were improved in clay mineral feeding groups, especially the flavor was improved with highly significant difference(P<0.01) in clay mineral groups than in control. In total fatty acid contents, the rate of SFA(saturated fatty acid) in longissimus muscle of beef was higher in the order of T2, T3, T1 and T4 while the rate of MUFA(monounsaturated fatty acid) was high in the order of T4, T3, T1 and T2. The content of oleic acid which is major influential factor at the flavor of beef was higher in Illite groups than in any other groups. In composition of amino acids in longissimus muscles of beef, the rate of essential amino acids was high in the order of T1, T2, T3 and T4. and the rate of amino acids in clay mineral groups was smaller than in control.In chemical component in Gom-Tang(soup of bone) made by Hanwoo steer’s leg-bone, the ranges of crude protein, ether extract, and crude ash was 0.81 to 1.24, 0.17 to 0.35 and 0.07 to 0.09%, respectively. In mineral composition, the ranges of Ca, P, Na and Mg was 14.01 to 15.77, 11.45 to 16.40, 37.92 to 49.99 and 0.26 to 0.46ppm, respectively. Chemical composition were not apparently different but mineral composition was increased in clay mineral groups than in control. Income by treatments was 967,096 to 1,524,055 Won per head for 540 days and income of clay mineral groups in comparison with control’s increased by 23.7 to 57.6 percent, and especially it was higher in bentonite and(or) Illite groups than others. According to the above results it may be concluded that clay mineral to growing-fattening Hanwoo steers can be improved the meat quantity, meat quality and income. Especially the effect of bentonite and illite is large and can be recommended for usage to improve animal performance as feed additives of growing-fattening Hanwoo steers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.2
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• pp.79-92
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• 1992

This study was carried out to develop new techniques useful for cryopreservation, thawing and artificial insemination, and ultrastructural changes of cryopreserved spermatozoa in rainbow trout(Oncorhynchus mykiss) . Two extenders, such as Tyrode solution and Whittingham's $T_6$ solution, were used to preserve rainbow trout sperm in refrigerator $(-20,\;-40\;and\;-70^{\circ}C)$ or liquid nitrogen $%(-196^{\circ})$. Hand-stripped semen was diluted to 1:16 with two extenders, an then the semen were frozen after mixing semen and each extender containing 1M or 1.5M DMSO solution to 1:1. After 60 days cryopreserved semen was thawed in a $13^{\circ}$ water bath, and subsequently centrifugated. After centrifugation at 1,000 rpm for 5 min thawed semen was washed with extenders, and then fertilized with fresh eggs. The results obtained in these experiments were summarized as follows: After cryopreservation, over 75% of spermatozoa were appeared motile and the survival rate was high. Following cryopreservation by the addition of cryoprotectant such as DMSO, methanol and glycerol, the fertilization rate of the thawed spermatozoa appeared over $99\%$ compared with the control having $99\%$ of fertilization rate. There was no difference between the control and experimental groups such as $(-20^{\circ}C\;-40^{\circ}C\;and\;-70^{\circ}C)$ and $-196^{\circ}$ in fertilization rate. Following cryopreservation at $-196^{\circ}$ by the addition of 1M DMSO of cryoprotectant, each fertilization rate following 24 hours and hatching rate following 24 days showed $96\%$ and $8\%$ by the addition of BSA, but showed $98\%\;and\;10%$ by no addition of BSA. Following 2 months of cryopreservation by the addition of 1M DMSO of cryoprotectant, there were $10%$ of hatching rate at $-196^{\circ}\;and\;10\%\;and\;35\%,\;respectively,\;at\;-40^{\circ}C\;and\;-70^{\circ}C$. Following 2 months of cryopreservation by the addition of 1M methanol of cryoprotectant, there were $22\%$ of fertilization rate at $-20^{\circ}C,\;and\;28\%,\;at\;-70^{\circ}C$ Following 2 months of cryopreservation by the addition of 1M glycerol of cryoprotectant, there were $22\%$ of fertilization rate at $-20^{\circ}C$, and $33\%,\;at\;-70^{\circ}C$. pollowing 2 months of cryopreservation by the addition of 1.5M DMSO of cryoprotectant, there were $27\%$ of fertilization rate at $-20^{\circ}C,\;an\;36\%\;and \;35\%,\;respectively,\;at\;-40^{\circ}C\;and\;-70^{\circ}C$. Following 2 months of cryopreservation by the addition of 1.5M glycerol of cryoprotectant, there were $34\% \;of\;fertilization\;rate\;at\;-20^{\circ}C, \;and\;31\%\;and\;31\%,\;respectively,\;at \;-40^{\circ}C\;and\;-70^{\circ}$. Following 2 months of cryopreservation by the addition of 1.5M methanol of cryoprotectant, there were $28\%$ of fertilization rate at $-20^{\circ}C,\;and\;29\%\;and\;28\%,\;respectively,\;at\;-40^{\circ}C\;and\;-70^{\circ}C.$ From 10 days and 15 days following fertilization at $13^{\circ}C\;and\;10^{\circ}C$, respectively, the mortality rate of fertilized ova was markedly increased. The middle piece of spermatozoa had two set of central doublets, nine set of outer coarse fibres, and mitochondrial sheath. Spermatozoa went through morphological changes during storage, e.g. winding of flagella, detachment of the nuclear envelope and the plasma membrane from the nucleus of the sperm head. There were $1\%$ abnormal spermatozoa in fresh sperm and about $15\%$ during storage.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.3
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• pp.187-198
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• 1970

The author succeeded in rearing the young blue crab from the first stage of zoe ato the true crab shape, and during this time he observed their growth and metamorphosis. The relationships between the number of eggs carried by female crabs (E) and the carapace width (C) and body weight (W) are shown as follows: E= 27.9049C-281.8155, E=0.5682 W-116.4606. There are five zoeal stages and a megalopa in the complete larval development of the blue crab. Water temperature in rearing aquaria ranged from 21.4 to $25.2^{\circ}C$. The duration of each zoeal stage was two days on the average. After the fifth moulting, the zoea becomes megalopa and 5 to 6 days later the megalopa moults and develops into the first stage of adult crab shape. The carapace width of megalopa measured about 1.70 mm and the carapace length, from the tip of the rostrum to the posterior dorsal margin of the carapace, was about 2.78 mm on the average. The carapace width and length of the first crab, 18 days after hatching, measured about 4.48 mm and 2.62 mm respectively. After two days, the first crab moulted and grew into the second crab with about 6.47 mm in carapace width and 4.66 mm in carapace length. The larval rearing in the outdoor tank shelved better results than in the indoor aquarium. The highest mortality occurred when the first stage of zoea moulted into the second stage. Percentage of crabs which survived, from the first crab to the ninth crab stages, was about $55\%$. The relationships between rearing days (D) and the carapace width (C), carapace length (L) and body weight (W) of the crab stages during 40 days of rearing are shown as follows. Carapace width, Indoor: C=1.1250D+1.7227 Outdoor C=1.3465D -0.2449 Carapace length, Indoor: L=0.6654D+1.6712 Outdoor: L=0.7893D+0.6919 Body Weight, Outdoor: $$W=1.15e^{0.12423D}$$ Indoor: $$W=6.759\times10^{-2}D^{1.2598}$$ (9-19 day old crabs) Outdoor: $$W=4.136\times10^{-2}D^{1.6024}$$ (21-40 day old crabs) During the crab stage, the following relationships between the number of moulting times and the carapace width (C), carapace length (L) and body weight (W) were found as follows: $$C=5.2e^{0.28119N}$$ $$L=3.65e^{0.26372N}$$ $$W= 0.14e^{0.7037N}$$ The relationships between the carapace length (L) and the carapace width (C) and body weight (W) of the crab stages are shown as follows: Carapace length, mm Formula 2.62-27.17 L=1.6864C-1.0387 7.47-18.53 $$W=9.367\times10^{-5}C^{3.5567}$$ 22.11-27.17 $$W=3.406\times10^{-5}C{3.8571}$$