• 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.

• Development and Reproduction
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• v.17 no.3
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• pp.247-255
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• 2013

The gonadsomatic index (GSI) of mottled skate was the highest in April, GSI and HSI showed a reverse phase for its reproductive cycle. The fish had one pair of egg capsules, having 1 to 7 fertilized eggs, and spawned all the year round. When surveying the reproductive characteristics of females over 63 cm in disc width, we found the spawning peak was between April to June, and the appearance ratio of egg capsules was the highest in May (32.1%). The eggs were hatched at $8^{\circ}C$, $13^{\circ}C$, $18^{\circ}C$, water temperature (12.8 to $24.2^{\circ}C$), and the best hatching temperature was $18^{\circ}C$. The number of fish hatched was 4 to 5 fish/egg capsules, and the hatching rate was 100%. The sex ratios of hatching larvae were 45.5% female and 54.5% male. Therefore this study will provide fundamental data and information for artificial reproduction of the mottled skate.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.4
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• pp.233-250
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• 1970

The present paper deals with the results of the observations on the characteristics of the eggs being ripen by injection of synahorin and the larvae of the black porgy. Mylio macrocehalus (Basilewsky). The adult fish used in the experiments, during May 11th to June 5th, 1970, were obtained from a fish-farm of the Atsumi Fish Culture Company in Aichi Prefecture, Japan, The results obtained are as follows: 1. The egg is colorless and buoyant, spherical in shape, measuring from $0.81\~0.96\;mm$ in dia-meter with a single oil globule, measuring $0.20\~0.23\;mm$. 2. Hatching took place within about 35 hours and 50 minutes after insemination of eggs at the water temperature $19.6\~22.5^{\circ}C$ (Mean, $20.6^{\circ}$). 3. The newly hatched larvae were 1.57 mm in total length, with the oil globule situated at the posterior part of the elongated oval-shaped yolk sac. Melanophores and xanthophores were distributed on the middle of the caudal region, and were scattered on the surface of the oil globule, but none on the yolk sac. 4. The diameter of the eggs ill each adult is distinguished into two types, large and small. The former is in the range of $0.811\~0.873\;mm$, the latter is $0.874\~0.963\;mm$. 3. The hatching rate of black porgy was in the range of $78.63\~95.19\%$ in large and $68.84\~74.80\%$ in small eggs. The mean hatching rate of total eggs was $79.80\%$. 6. The optimum temperature of hatching black porgy is in the range of $20\~26^{\circ}C$. The highest temperature limit of hatching the black porgy is from $26.71\~28.56^{\circ}C$. 7. The total length of hatched larvae is not maintained pararell to diameter of eggs and total length of the large larvae is from $1.976\~2.225mm$, and that of small larvae is $1.526\~1.90mm$. 8. The diameter of yolk sac of black porgy is in the range of $0.878\~0.979\;mm$ 9. The initial survived larva of the black porgy was $13.71\%$ in minimum, and $79\%$ in maximam. And the mean initial survived rate was $48.3\%$. 10. In conclusion, the biological characteristics of hatched larva of black porgy is seemed to be possible for large scale production of artificial seedlings. But experimental results make initial food the prime object believed to be supplemented.

• Korean Journal of Ichthyology
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• v.25 no.2
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• pp.82-89
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• 2013

The spawning behavior, development of eggs and larvae of the Five striped damselfish, Abudefduf vaigiensis were studied. The Five striped damselfish were caught at Dolsan Island, Yeosusi, Jeollanamdo from May in 2011. As a result of observation, male fish attracted female after cleaning the rock. Female left after spawning and male protected their eggs until they had hatched out. The fertilized eggs were elliptical in shape (mean long diameter: 1.06 mm; mean short diameter: 0.55 mm) and transparent. Larvae hatched at 53 hrs after fertilization in $24.5{\sim}26.5^{\circ}C$(mean $25.0^{\circ}C$). The newly hatched larvae were 2.55~2.86 mm (mean 2.71 mm, n=10) in total length and their mouth and anus were already opened. They began to eat rotifer and transformed to postlarva stage. 3 days after hatching postlarva was measured 2.74~2.97mm(mean 2.84 mm, n=10) in total length. 10 days after hatching postlarva was measured 3.85~4.20mm(mean 4.00 mm, n=10) in total length with dosal fin rays IV-5; ventral fin rays I-3; caudal fin rays 1~2.

• International Journal of Industrial Entomology and Biomaterials
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• v.1 no.2
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• pp.149-153
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• 2000

We have constructed a recombinant baculovirus, Autographa californica nuclear polyhedrosis virus (AcNPV), containing green fluorescent protein (GFP) gene from the jellyfish, Aequorea victoria, and transferred it into the domestic silkworm Bombyx mori larvae for the production of visible transgenic silkworm of living organism. When one day-old fifth instar female larvae were injected with the recombinant AcNPV of 1x10$^{5}$ plaque forming units, the bright glow of GFP was detected in the recombinant AcNPV-infected larvae and in the newly hatched larvae of the next generation. Our findings demonstrate that the viral replication was detected in the silkworm treated with the recombinant ACNPV and the gfp gene was expressed under the transcriptional control of the polyhedrin gene promoter, Furthermore, the gfp gene was transmitted to the next generation, suggesting that this system can be applied for the development of transgenic silkworms.

• Korean Journal of Ichthyology
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• v.21 no.4
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• pp.227-238
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• 2009

The egg development and morphological changes of larvae, juveniles and adults of Oryzias dancena were observed. Fertilized eggs were incubated at $25{\pm}1^{\circ}C$; the process of embryonic development was observed by light microscopy and based on diagnostic features of the developing embryos. The average time to hatch was 11 days after fertilization. The hatched larvae averaged $4.40{\pm}0.24mm$ in total length (TL). The yolk sacs of the larvae were almost absorbed at 3 days after hatching and $4.55{\pm}0.23mm$ TL. At 21 days after hatching, the larvae were $7.23{\pm}0.73mm$ TL and had reached the juvenile stage. First ovulation was about 9 weeks after hatching and at $22.58{\pm}2.73mm$ TL.

• Korean Journal of Ichthyology
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• v.29 no.3
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• pp.190-196
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• 2017

The egg and larval development of pale chub, Zacco platypus were determined by observation of laboratory reared larvae from hatching. The experimental adult fish were collected in Wicheon of Nakdong river in June 2016, The eggs and larvae were reared in the experimental tanks, and observed their morphological change. The egg diameter ranged from 1.68 to 1.78 mm ($mean{\pm}SD$, $1.73{\pm}0.07mm$, n =30). The eggs were hatch 70 hours after fertilization. The total length (TL) of the newly hatched larvae ranged from 5.39 to 5.42 mm ($5.40{\pm}0.02mm$, n=10). On the 8 days after hatching, 10 fin rays were formed in caudal fin at 7.89~7.93 mm TL ($7.91{\pm}0.02mm$, n=10). On the 44 days after hatching, the juveniles ranged from 16.1~16.5 mm TL ($16.3{\pm}0.28mm$, n=10).

• Korean Journal of Ichthyology
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• v.9 no.2
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• pp.178-185
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• 1997

From November 1996 to April 1997, the rockfish, Sebastiscus marmoratus (Cuvier et Valenciennes) was reared in laboratory, and observed eggs development and morphology of larvae. The eggs of this species are demersal and adhesive, and their diameter were varied within 0.76 to 0.82 mm. The color of yolk is light yellow in early developmental stage, and then turned to orange before hatching out. The yolk contained numerous tiny oil globules. Hatching began about 33 hours and 30 minutes after insemination at $10.0{\sim}14.5^{\circ}C$ of waters. The newly hatched larvae were elongated in shape and 1.62~1.68 mm in total length (TL) with 7~8+16=23~24 myomeres. The larvae absorbed yolk material and oil globule completely in 14 days after hatching and became postlarvae. The spawning season of adult rockfish may be supposed to be from February to March in the southern sea of Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.41 no.6
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• pp.478-484
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• 2008

To elucidate the spawning behavior and early life history of Liobagrus mediadiposalis, mature male and female fish were collected from a branch of the Seomjin River. Spawning was induced by injecting hormones, and then the spawning process and development of fertilized eggs, larvae, and juveniles were observed. Observations of spawning behavior showed that the female established a territory and built a spawning nest, and frequently pressed on the upper ventral part of the male to release her eggs. When spawning was finished, the fish supplied fresh water to the egg mass using their pectoral and caudal fins. Hatching began 189 h 20 min after fertilization at $21.5-23.5^{\circ}C$ (mean $22.7^{\circ}C$). The mean total length (TL) of newly hatched larvae was 7.18-7.39 mm (mean 7.31 mm). Their mouth and anus were already open and they had 14+24=38 myotomes. Eighteen days after hatching, the larvae were 12.71-13.79 mm (mean 13.27 mm) in TL and the yolk sac was absorbed completely. At 35 days after hatching, when all the fin-rays had formed, the juveniles were 15.84-17.92 mm (mean 16.33 mm) in TL.

• Development and Reproduction
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• v.20 no.2
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• pp.65-79
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• 2016

We observed the osteological development of larval and juvenile red spotted grouper (Epinephelus akaara) in order to generate data for the assessment of skeletal deformities and to inform phylogenetic systematics research. Larvae and juveniles were obtained from a aquafarm in Muan-gun, Jeolla-namdo Province, Korea. The average water temperature at the time of breeding was $23.0^{\circ}C$ and average water salinity was 33.0 psu. Freshly hatched fish larvae had not undergone any ossification, but ossification of the parasphenoid bone, which forms the base of the cranium, occurred as the juveniles reached an average body length (BL) of 2.49 mm. At the same time, ossification of the preopercle and opercle occurred in the operculum, and ossification of the maxilla, which forms the upper jaw, and the dentary bones, which form the lower jaw, began. In addition, ossification of the vertebra occurred by formation of 7 vertebral centra and the neural spine in the abdominal vertebra. When the juveniles reached an average (BL) of 5.22 mm, ossification of the nasal, lateral ethmoid, and alisphenoid bones occurred in the cranium; ossification of the endopterygoid and metapterygoid bones began in the palatine region; and ossification of the hypohyal and interhyal bones occurred in the hyoid arch. At an average (BL) of 20.9 mm, ossification of the basisphenoid bone in the cranium and the suborbital bone in the orbital region occurred. Ossification of the vertebra then occurred by the formation of long pairs of ribs from the third to the ninth abdominal vertebrae, completing osteological development.