• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.63-70
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• 2012

This study was conducted to investigated the distribution, ecological character and life cycle of Black Soldier Fly(BSF), Hermetia illucens, to determine effects of BSF on composing ability to the livestock feces. The distribution of BSF was defined in all parts of the country in Korea. Its main habitat was found to be areas near cattle sheds, feces sheds, living waste dump grounds, and food waste dump grounds. Excellent species of the bio-conversion using the livestock feces were selected out of two kinds of solider flies(Hermetia illucens and Ptecticus tenebrifer). And effects of BSF on composing ability to the livestock feces were pig feces 0.5 g, cattle feces 0.43 g and chicken feces 0.3 g per a larvae of BSF. In the examination of the ability of BSF to decompose food waste, volume of the livestock feces decreased by weight pig feces 77, cattle feces 83.62 and chicken feces 80%. Observed characteristics of BSF larvae and pupae stage were by developmental stage may be summarized as follows: size and length of larvae and pupae of BSF were higher than in pig feces and mixed sawdust treatments. In order to develop artificial indoor rearing techniques, The pupation and emergence rate were not visible the difference but important factor of the mating and egg-laying was a sun light. And it was visible the difference in mating ratio. Mating rate of H. illucens by seasonal change was the highest from May to July. Mating mostly occurred between 10 : 00 and 12 : 00 during which light intensity is high. As the egg-laying medium for artificial egg collection, calf feed and food waste were most effective. The ratio of egg-laying medium is waste food : sawdust(1 : 1) in volume. For egg-laying materials, flower foam and wood with holes were used; holes sized 3 ~ 5 mm in diameter, 7 ~ 10 mm in depth were most preferred for egg-laying.

• Journal of Life Science
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• v.20 no.2
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• pp.190-196
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• 2010

Nowadays many people use antibiotics to protect processed foods from many pathogenic bacteria. The abuse of antibiotics, however, can run the risk of creating resistant forms of bacterium. Our study focus is on making new substances that can not only replace antibiotics but also be friendly to the environment. In our experiments, we used fermented citrus fruit, soil microbes and coenzyme Q10 as probiotics and prebiotics. Chickens in the experimental group were fed these substances via oral route while those in the control group were not. After specific time periods, blood and feces samples were collected to test for Salmonella spp.. It is interesting that fermented citrus fruit was the most effective in suppressing this bacterium. Furthermore, dissection of the experiment group chickens shows that their livers did not change to a yellow color, in contrast to the control group. The results confirmed our proposal that the chickens fed with these materials can be protected from infection by Salmonella and other pathogens. These probiotics and prebiotics are highly practical because they are natural substances that can be easily recycled in the environment. It can also be used as an animal feed ingredient because of its safety.

• Korean journal of applied entomology
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• v.37 no.2
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• pp.171-178
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• 1998

This study was conducted to investigate the effect of temperature on the development of amushroom-infesting sciarid fly, Bradysia sp. (Diptera: Sciaridae). Egg period was 12.1, 7.0, 4.4, 3.4, and3.2 days, larval period was 38.3, 26.5, 13.4, 13.2, 12.7 days and pupal period was 10.4, 7.1, 4.4, 3.3, 3.2days, and total development period from egg to adult emergence was 60.8,40.6, 22.2, 19.9, and 19.1 daysat 10, 15, 20,25, 28"C, respectively. Development threshold temperature (DT) and effective accumulativetemperatures (ET) were 3.8"C, 74.8DD in eggs, 1.2"C, 321.8DD in larva, and 3.1$^{\circ}$C, 76.5DD in pupa,respectively. The number of eggs laid per female was 107.9, 129.7, 131.8, 86.9, and 82.7 at respectivetemperatures. Preoviposition period was 6.6, 4.4, 2.2, 1.3, 1.8 days, oviposition period 1.5, 1.5, 1.1, 1.1,1.1 days, postoviposition period 2.0, 1.1, 0.9, 0.6, and 0.3 days at th'e temperature of 10, 15, 20, 25 and 28"C, respectively. The longevity of male and female at the temperature was 13.3, 7.8, 5.9,4.1, 3.4 days and10.4, 7.0, 4.2, 3.0, 3.3days, respectively. The optimum temperature for hatchability was estimated to the20$^{\circ}$C and adult emergence was highest at 20$^{\circ}$C. Pupation rate was 50.7, 68.4, 84.3, 86.5, 45.4% at 10, 15,20, 25, and 28"C, respectively. at 10, 15,20, 25, and 28"C, respectively.tively.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.122-131
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• 2023

This study was aimed to determine the effects of grow media on the mineral contents of the leaves and growth characteristics of strawberry grown under aquaponics system in a plant factory. For aquaculture, 12 fish (Cyprinus carpio) (total weight, 2.0 kg) were raised in an aquaponics tank (W 0.7 m × L 1.5 m × H 0.45 m, 472.5 L) filled with 367.5 L of water at a density of 5.44 kg·m^-3 and total 34 of strawberry seedlings were transplanted in the pots filed with 200 g of orchid stone, hydroball or polyurethane sponge in the growing bed (W 0.7 m × L 1.5 m × H 0.22 m) laid out with holly acrylic sheet (140×60 mm, Ø80) on the top of the system. The pH and EC of the aquaponic solution was ranged from 7.6 to 4.9 and 0.24-0.91 dS·m^-1, respectively. The concentration of NO_3-N was about 28% lower than that of the hydroponic standard solution, and K, Fe and B were 10, 27 and 3.8 times lower, respectively; however, the mineral contents of strawberry leaves were in the appropriate ranges with lower contents in the leaves grown with sponge media. The organic content (OM), nitrogen (N), phosphorus (P), and potassium (K) of the sludge were 61.5, 5.72, 8.92, and 0.24%, respectively. The leaf area, leaf number, and dry and fresh weights of shoot at 81 DAT were significantly higher in the hydroball, and the average number of fruits per plant was significantly higher in both the orchid stone and hydroball. There was no significant difference in the fresh and dry weights of fruits. Integrated all the results suggest that the orchid stone and hydroball media are more effective to utilize nutrients in solid particles of aquaponic solution, compared to the polyurethane sponge.

• Journal of Mushroom
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• v.13 no.2
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• pp.145-150
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• 2015

Mushroom sciarid fly Lycoriella ingenua (Dufour), syn. L. mali (Fitch) is one of the most common fly pests affecting the mushroom cultivation in Korea. This study was carried out to investigate the development at different temperatures and damages of L. ingenua in A. bisporus mushroom cultivation. Rearing of mushroom flies were carried out on mycelial culture in Petri dishes. The development of L. ingenua from egg to adult at the temperature of 16, 20, 24, $28^{\circ}C$ were 35.2, 25.8, 23.5, and 22.2 days, respectively. Adult flies invade mushroom farms and oviposit in freshly spawned compost. Damages are mainly caused by the larvae of 1-7 mm, which feed on growing mycelium and also developing stipes and caps of mushrooms. Adult flies spoil the appearance of the fruiting bodies, spread various fungal and bacterial disease, and transmit mites. The damages by mushroom flies increased without pest control causing yield loss of up to 27%.

• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.69-73
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• 2001

Observation of morphological changes during larval and juvenile stages of the halfbeak fish, Hyporhampus sajori (Temminck et Schlegel), was made based on samples of fertilized eggs collected on the shores of Youngil Bay, Phohang-shi, Korea, on May 27, 1991, and incubated in the laboratory. During the incubation period, water temperature fluctuated between $17.6^{\circ}C$ and $23.2^{\circ}C$. The newly hatched larvae were elongated and 7.0~8.50 mm in total length (TL) with 40~42+17~18 = 59~60 myotomes. Numerous melanophores were on the head, mid-dorsal part of the body, intestine, and the tail part of the notochord. Three days after hatching the larvae had attained 8.60~10.90 m in TL, had completely absorbed the yolk, and the caudal notochord was flexed $45^{\circ}$ upward. At this time, it was attained postlarvae stage. Thirty-seven days after hatching the postlarvae were 32.37~44.95 mm in TL and had reached the juvenile stage. All fins were formed with a complete set of fin rays with the following counts: dorsal fin rays 16~17; pectoral f in rays 6; ventral fin rays 12~14; caudal fin rays 11~12+11~12 = 22~24.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.4
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• pp.308-316
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• 1987

The flying fish, Prognichthys agoo, is widely distributed in the coastal waters of south-eastern Korea. On July 14, 1986, mature adults of flying fish were captured from U-do, Cheju-do. The eggs were stripped and fertilized by the wet method on the ship. The mature eggs are demersal and adhesive with 30-40 filaments. The egg diameter varied from 1.42 to 1.58 mm. The water temperature throughout incubation ranged from 23.70 to $27.82^{\circ}C$, and salinity was maintained at $30.75-33.76\%_{\circ}$. The hatching took place in 174 hours after fertilization. The newly hatched larvae measured 4.75-5.25 mm in total length possessing yolk sac and about 45-46 myotomes. The larvae cultured for ten days after hatching reached 11.45-12.60 mm in total length and entered the juvenile period of life. Twenty days after hatching, the juveniles measured 20.01 mm in mean total length, and the scales were formed behind the pectoral fin.

• The Korean Journal of Zoology
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• v.14 no.3
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• pp.125-131
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• 1971

In order to see if NaCl affected the the emergence rate and the SD action when treated it at the pupal stage of Drosophila melanogaster, an experiment was performed in which the resistibility to NaCl at the pupal stage was examined by the emergence rate and the effects of NaCl on the SD action was studied by k values. The four SD strains and two other strains (cn bw and Oregon-R) were used and NaCl media were prepared by adding NaCl at a concentration of 0.0M, 0.1M, 0.3M, 0.5M, 0.7M, and 1.0M to the standard media for the present experiment. The following conclusions were established: 1. The emergence rate (resistibility to NaCl) when treated NaCl at the pupal stage is significantly different not only among the strains but also among concentrations of NaCl. 2. The emergence rate decreases as concentration of NaCl increases but the rate of decrease shows rather constant so that the curves of decrease are not steep. 3. The emergence rate of the cn bw and Oregon-R strains shows higher value than of the four SD strains, implying that the resistibility to the NaCl is lower in the SD strains than in the two strains; not a few flies are emerged from the media of 1.0M of NaCl. 4. The difference in k values is not significant among concentrations of NaCl but among strains, the k values of the original SD strains are rather higher and constant but those of the recombinant SD strains are rather low and unstable. 5. The SD action is not affected by NaCl as far as once emerged from the culture media whether containing NaCl or not in any developmental stage. Thus such an experiment on NaCl effect is of little value to analyze the mechanism of the SD action in D. melanogaster.

• Journal of Life Science
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• v.31 no.6
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• pp.587-594
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• 2021

By 2050, 70% more food will be needed to fulfill the demands of a growing population. Among the solutions, cultured meat or clean meat is presented as a sustainable alternative for consumers. Scientists have begun to leverage knowledge and tools accumulated in the fields of stem cell and tissue engineering in efforts aimed at the development of cell-based meat. Cultured meat has to recreate the complex structure of livestock muscles with a few cells. Cells start to divide after they are cultured in a culture medium, which provides nutrients, hormones, and growth factors. An initial problem with this type of culture is the serum used, as in vitro meat aims to be slaughter free. Thus, it is contradictory to use a medium made from the blood of dead calves. The serum is expensive and affects to a large extent the production cost of the meat. A positive aspect related to the safety of cultured meat is that it is not produced from animals raised in confined spaces and slaughtered in inhumane conditions. Thus, the risk of an outbreak is eliminated, and there is no need for vaccinations and animal welfare issues. The production of cultured meat is presented as environmentally friendly, as it is supposed to produce less greenhouse gas, consume less water, and use less land in comparison to conventional meat production.

• Korean Journal of Ichthyology
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• v.35 no.4
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• pp.253-262
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• 2023

This study compared the results of observing the early life history of Gymnogobius urotaenia, which lives in Hwangbocheon Stream, an inflow stream on the east coast, with the differences between fish of the same Gobiidae fishes. In May 2022 and 2023, fertilized eggs and brood stork scattered under rocks were captured twice in Hwangbocheon Stream. The spawning amount was 827~1,540 and the orchid was a elliptical in shape with a size of 3.21×1.07 mm. The stage of ovulation observed in the laboratory was 16 cells, and hatching began after 193 hours. The breeding water temperature range was 18.8~19.3℃. Newly after hatching larvae, the yolk sac with a total length of 3.84~4.33 (average 4.10±0.17, n=30) mm, and the anus was not open. 6 days after hatching of incubation, the total length was 5.32~6.11 (average 5.67±0.25, n=30) mm, absorbing all egg yolk and transitioning to the preflexion larvae, ingesting food, and developing a keynote on the tail fin. 15 days after hatching, the end of the urostyle end was completely bent at 45° with a total length of 7.33~8.52 (average 7.81±0.46, n=30) mm and transitioned to postflexion larvae, and melanophore developed throughout the body. 38 days after hatching, the total length is 22.1~26.1 (23.8±1.36, n=30) mm and the number of fins (6 first dorsal fins, 11 second dorsal fins, and 11 anal fins, 12 ventral fins) is all the number of fin base became integer and transferred to the juvenile. As a result of the study, it was possible to distinguish the melanophore of postflexion larvae of G. urotaenia from other postflexion larvae Gobiidae fish in that they were distributed throughout the body of half the body and tail.