• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.586-593
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• 1985

The rose bitterling, Rhodeus ocellatus (KNER) is commonly distributed in the fresh waters of Korea and Japan. On January 15, February 15, and March 18 in 1984, mature adults of rose bitterling were caught in the watercourse of Maeri, Kimhae, South Korea. The authors fertilized the eggs employing dry method in the laboratory on May 7, 16 and 25 in 1984. Hatched larvae were reared in small aquariums at $17{\sim}25.5^{\circ}C$ (average around $21.2^{\circ}C$). Mollusks, Anodonta woodiana in the gill chamber of which, rose bitterling lay eggs were caught in order to study natural spawning of the rose bitterling in the same watercourse. The eggs of this species are not adhesive and demersal. The size of the eggs varies from 2.54 to 2.75mm in long diameter and 1.45 to 1.65mm in short diameter. The eggs are cylindrical in form when they are extruded from ovipositor, immediately after entering water, but they acquire their distinctive form of a greatly elongated pear. Hatching took place in ca. 39 hours after fertilization. The newly hatched larvae were $2.65{\sim}2.70mm$ in total length possessing yolk sac and 13-14 myotomes. Thirteen days after hatching, the prelarvae attained 6.5 mm in total length, and the first melanophores appeared on the head, and the anterior part and sides of the yolk sac. One month after hatching, the postlarvae attained 8.5mm. in total length and emerged from the gills of the mollusks. Then the yolk sac was completely resorbed. Two months after hatching, the rose bitterling attained 14.4mm in total length, and entered the fingerling period of life. All the rays already present were the D. III, 11-12, A. III, 11-12, P. 10, V. 7. and a distinguishing, feature is the presence of a black pigment spot in the lobe of the dorsal fin.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.421-429
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• 2016

Tenebrio molitor larvae contain large amounts of proteins, lipids and other functional materials, enabling this insect to be used as an edible food source in animal feeds and for industrialization. Although many efforts have been made to set up mass rearing systems, few studies have been conducted to establish optimal rearing conditions for the production of high quality T. molitor larvae. Herein we investigated 1) the effects of additional diets on the survival and fecundity of the insect, 2) the relationship between oviposition period and the uniformity of larval size, 3) the effects of rearing density and temperature on insect development, and 4) the storage stability of eggs and pupae at low temperatures given possible temporary production discontinuation. The addition of carrot and zucchini to the traditional wheat bran diet significantly increased the survival and fecundity rate of adult T. molitor. Of the three different oviposition sampling periods (3, 7, and 14 days) used to investigate the uniformity of the hatched larvae in each treatment, the period of 3 and 7 days provided higher uniformity than the 14 days oviposition period. Larval development was faster at $30^{\circ}C$ than at 20, 25, and $35^{\circ}C$. Interestingly, oviposition rates were highest at $20^{\circ}C$ but showed much slower larval development and lower uniformity at $30^{\circ}C$. Regarding the effect of larval rearing densities (1, 10, 20, 30, 40, and 50 larvae per 90 mm diam. dish), larval weight was significantly reduced at higher rearing densities, but larval longevity and length were not influenced by rearing density. The 30 larvae/dish is suggested to be a reasonable density to be applied to mass production systems. When kept at $4^{\circ}C$, T. molitor eggs showed a significant reduction in hatching rate; however, when stored under the same conditions, pupae emergence rates remained high until 10 weeks, suggesting that storage at low temperatures is more suitable for the pupal stage than the egg stage. Our findings suggest that an increase in T. molitor adult survival and fecundity rates and a uniformity of hatched larval development can be achieved with the following recommendations: a combination diet (including wheat bran), a 7-day oviposition period; a larvae-rearing temperature of $30^{\circ}C$, a rearing density of 30 larvae/dish, and the storage of pupal stages at low temperatures in the case of rearing discontinuation. This study serves as a strong foundation for the successful mass production of high quality T. molitor larvae.

• Korean Journal of Ichthyology
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• v.9 no.1
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• pp.99-107
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• 1997

The early life history and reproductive ecology of Siniperca scherzeri were studied to obtain fundamental information in aquaculture and reinforcement of natural population in Soyang Lake, Buk-myon, Chunchon-shi, Kangwon-do from June to October 1996. Symptric species with adult fishes (+1 ages) of Siniperca scherzeri were 11 species belonging to 6 families and 10 genera and those with Juveniles (2~3 months) were 5 species belonging to 4 families and 5 genera. The sex radio of this species were 1 (female, 85) : 1.24 (male, 105). Adult and juvenile of this species were predominantly piscivores. Bluegill, Lepomis macrochirus, Zacco platypus, common carp, Cyprinus carpio, unidentified fish and shrimp were important components of the food items. The spherical eggs were demersal and separative without a colorless transparent chorion and slightly yellowish yolk containing one large oil globule (0.5~0.7mm). The egg just after fertilization were measuring 1.72~2.05mm (n=30), and expanded to 2.27~2.58mm (n=30) in diameter after 30 min. Hatching occurred 130~155 hrs after fertilization at water temperature of $20{\sim}25^{\circ}C$ and newly hatched larvae measuring 5.5~7.1mm in total length. In the newly hatched larvae, numerous branched malanophores were distributed on the yolk and abdomen of caudal peduncle. In ten-day old larvae, the yolk was mostly absorbed and the head spines and the teeth were well developed. All fin rays were formed and total length of the larvae were reached 13.6~15.6mm at 20 days after hatching. In fifty-five day old larvae were similar in both body shape and color to adult. The juvenile stage at 4 months after hatching were attained 86.4~95.3mm (n=7) in total length and 8.77~14.78g (n=7) in body weight.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.5
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• pp.458-464
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• 1993

From November 1992 to January 1993, the rockfish, Sebastes inermis was reared in the laboratory, and observed the developmental stage of the eggs and larvae squeezed from the parent fish. On December 4 1992, developing eggs at morula stage were obtained from female parent fishes($17.4{\sim}20.3mm$ in total lenght(TL)). The diameter of eggs ranged from 1.20 to 1.35mm(n=50), and oil globules in white color were found in the eggs. Hatching began about 55 hours after morula stage at the water temperature of $9.2{\sim}12.3^{\circ}C$. The newly hatched larvae measured from 2.90 to 3.35mm in TL with $8+12{\sim}13=20{\sim}21$ myomeres. Total lengths of the larvae will be from 5.75 to 6.15mm in 27 and 30 days after the hatching, respectively. Myomere number was $8+17{\sim}18=26$.

• Korean Journal of Ichthyology
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• v.26 no.1
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• pp.34-41
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• 2014

The present study describes the spawning ecology and early morphological development of Hemitripterus villosus. The natural spawning ground consisted of bedrock and pebbles was the intertidal coast at Taean (Chungnam) and its depth was about 5~10 m. Spawning period was mainly from the end of October to December, when the water temperature and salinity were $6.0{\sim}15.8^{\circ}C$ and mean 32.0‰, respectively. There were no difference of the body shape and color between female and male of Hemitripterus villosus, however its reproductive organs showed clear differences. The male had tube shaped genital papilla, which was connected with testis, and the female had seminal recepacle, which was the lower part of oviduct connected with ovary. Genital papilla of male came out of its body at spawning period and then male copulated. After copulation, female stored the sperm in its seminal recepacle and fertilized when it spawned. Fertilized eggs were reached 8 cells stage after fertilization at rearing water temperature $8.2{\sim}14.9^{\circ}C$. At 29 hours after fertilization, it reached morula stage, and at 146 hours after fertilization, its embryo was clearly formated. Hatching was begun from 1,488 hours (62 days) after fertilization with $8.2{\sim}14.9^{\circ}C$ water temperature. The newly hatched larvae were 12.99~15.46mm(mean $14.16{\pm}0.65$ mm) in TL (Total Length), and its mouth and anus were open. At 7 days after hatching, its yolk sac was completely absorbed and the myotomes were 15+25=40, measuring 15.23~15.54mm(mean $15.39{\pm}0.22$ mm, n=5) in TL. At 75~80 days after hatching, it was measured mean $30.06{\pm}0.76$ mm in TL, and it had reached the juvenile stage with the complete set of fin rays.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.343-349
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• 2007

Embryonic and larval developments on Pacific cod, Gadus macrocephalus are described from laboratory-reared specimens. The eggs (1.075~1.168 mm in diameter) were weakly adhesive, almost spherical in shape, transparent and unpigmented, showing a pale yellow yolk without oil globules. Hatching was occurred 220 hrs after fertilization at $9.8^{\circ}C$. The newly hatched larvae (3.72~4.40 mm in total length, TL) had 43~47 (11~13+32~34) myomeres, mouth and anus which was not yet opened. The yolk was completely absorbed at 4.58 mm TL, and transformed to postlarval stage. Locations of the anus and second dorsal fin origin, and distinctive growth of the larvae head were observed at 5.48 mm TL with melanophores in the gill cover and upper region of the occipital. In addition, melanophores were distinctive in the ventral region and caudal fin base at 6.88 mm TL. All fins were formed with a complete set of fin rays having the following counts (D. 3~7-12~14-13~14; A. 13-15) at 11.54 mm TL. Both lateral line and barbel of lower jaw were observed at 15.07 mm TL.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.239-246
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• 2009

To establish a database for artificial seed production of stone flounder Kareius bicoloratus, experiments were conducted to study the characteristics of spawning and fecundity of this species. Broodstocks were captured in the area of Gyeokryeolbiyeoldo, Chungnam, Korea in October 2003 and induced to natural spawning. The broodstock consisted of 12 females (34.5~51.0 cm total length and 540~2,200 g body weight) and 23 males (29.0~38.0 cm total length and 310~680 g body weight). Gonad development began in December and proceeded in the direction of the tail; measurements were made with the naked eye. The tank-held broodstock were reared for 3 months before spawning, which continued for 77 days from January 9 to March 27, 2004. Daylength during the spawning was recorded at the yearly shortest of 9.8~12.1 hours and the water temperature was maintained at $8.4{\sim}12.2^{\circ}C$. The total fecundity was 19,844,000 individuals, among which 15,433,000 individuals (77.8%) were produced during the mid-spawning period. The average bloating rate, egg-fertilization rate and hatching rate of the total number spawned reached 50.4%, 58.5% and 55.6%, respectively, and 93.8% of the hatched fry appeared normal. The number of total eggs in absolute fecundity per total length was proportional to both lengths, as was the number of total eggs in relative fecundity per total length. The number of total eggs in absolute fecundity per body weight was proportional to body weight as was the number in relative fecundity per body weight except that the number in relative fecundity per gram decreased after a peak in increased body weight at a certain point.

• Korean Journal of Agricultural Science
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• v.24 no.1
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• pp.16-20
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• 1997

Acrolepiopsis sapporensis Matsumura was reared on welsh onions in the laboratory in Taejon for observation on its bionomics; the adults were provided with 10% sugar solution. At controlled temperatures the stone leek minor female adult laid averages of about 103 at $15^{\circ}C$, 113 at $20^{\circ}C$ and 134 at $25^{\circ}C$. Adult lived for averages of about 10 days at $15^{\circ}C$, 8~9 days at $20^{\circ}C$ and $25^{\circ}C$ and 5 days at $30^{\circ}C$. The egg hatched in about 10~11 days at $15^{\circ}C$, 5~6 days at $20^{\circ}C$ and 5 days at $25^{\circ}C$. The larval stage lasted 25~26 days at $15^{\circ}C$, 11 days at $20^{\circ}C$ and 7~8 days at $25^{\circ}C$. The pupal stage lasted 13 days at $15^{\circ}C$, 9 days at $20^{\circ}C$ and 7~8 days at $25^{\circ}C$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.389-394
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• 1983

The right eye flounders, Limanda yokohamae Gunther widely distributed in the coastal waters of Korea and Japan. On Feburuary 3, 1983, the authors obtained a number of artificial fertilized eggs from the adult fishes(male: 285mm in total length; female: 297mm) caught by a trawl. The eggs of this species is demersal and adhesive, and the diameter of these eggs was varied in $0.71{\sim}0.80mm$. The egg capsule is colorless and transparent, and the eggs do not contain any oil globules, The hatching took place in 120 hour after fertilization at the water temperature $5.5{\sim}17.0^{\circ}C$. The newly hatched larvae were $2.64{\sim}2.72mm$ in total length with long trunk. Myotome number was $9{\sim}10+30{\sim}32=39{sim}42$ and yellowish brown melanophores were appeared. In 3 days after hatching out. The larvae attained 3.3mm in total length, and the mouth began to move. Xanthophore appeared also on the opereulum at this time. After 7 days the larvae attained 3.70mm in total length, and became the postlarvae absorbing the yolk completely.

• Korean Journal of Ichthyology
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• v.8 no.1
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• pp.83-89
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• 1996

The early life history of Korean bullhead, Pseudobagrus fulvidraco was studied to obtain some information required in aquaculture and reinforcement of natural population. The fertilized eggs were almost spherical in shape and demersal. The egg membranes were transparent with minute folds on the surface, causing them to stick to other substrates. Yolk is yellowish without oil droplets. The eggs just after fertilization were measuring $1.4{\pm}0.03mm$(1.3~1.5mm, n=10) and expanded to $1.7{\pm}0.08mm$(1.6~1.8mm, n=10) in diameter in 1.5 hr. The blastodisc was formed in 30 min and cleavage started in 1 hr after fertilization, and the intervals of each stage of cleavage was about 30 min at $25.0^{\circ}C$. The yolk from 32-cell stage to gastrula stage partly depressed and the depressed part moved clockwise. Hatching occurred in 53 hr after fertilization and hatched embryos had 18~19+20~21(38~40) myomeres measuring 4.2~4.3mm in total length. At the age 7 d after hatching, 4 pairs of barbels were already formed ; 1 pair on the posterior part of the nostril, 1 pair on the upper jaw, and 2 pairs on the lower jaw. And the posterior margin of caudal fin changed into two folds. The lateral band and the form of all fins were completed in 3 weeks.