• International Journal of Industrial Entomology and Biomaterials
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• 제11권2호
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• pp.99-105
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• 2005

We investigated oviposition and colony development of Bombus ignitus and B. terrestris depending on different pollen. In five kinds of pollen blend, the colony development in fresh-freezing pollen blend produced in Korea (Korea-FFP) was the best performance, although egg-laying characteristics is lower than that of pollen blend for oviposition imported from Korppert company (Kopport-FOP). The Kopport-FOP proved that it was suitable to use for oviposition of bumblebees. The Korea-FFDP, freezing dried-fresh pollen blend produced in Korea, is lower rather than the Korea-FDP although it is similar to the KopportFOP in colony development. It is not efficient to use commercial pollen for bumblebee because it is expensive in cost. The dried pollen blend for honeybee feeding imported from China (China-DP) was not suitable for rearing of bumblebee because it did not form colony although the worker emerged. In types of pollen, the oviposition and colony development of B. ignitus were not affected by the fresh-freezing pollen and dried-freezing pollen. This result also indicated that dried pollen, dried in the shade for 5 - 6 days, is possible to use as commercial pollen for bumblebee reproduction.

• 한국수산과학회지
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• 제53권4호
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• pp.506-514
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• 2020

We investigated seed management and feeding regime of larval red spotted grouper Epinephelus akaara using live food organisms. Fertilized eggs were produced in March 2020 by manipulating photoperiod and water temperature. Broodstock (F0) produced approximately 0.30×10⁶ eggs, of which 0.25×10⁶ were fertilized; first-generation broodstock (F1) produced 2.00×10⁶ eggs, of which 1.90×10⁶ were fertilized. Larvae were reared at temperatures of 21.0-24.5℃. The feeding regime consisted of rotifers Artemia, and commercial pellet feed. From 5-8 days after hatching (dah), rotifers collected from high-density incubation tanks were fed to grouper larvae at a density of 10-20 individuals/mL. From 9-30 dah, rotifers collected from low-density incubation tanks were fed to larvae at a density of 10-20 individuals/mL. Newly hatched Artemia were provided from 20-24 dah and enriched Artemia from 25-50 dah. Commercial pellet feed was given starting at 13 dah. The average mouth size in hatchlings was 263.4±3.7 ㎛ at 5 dah, 406.7±21.0 ㎛ at 11 dah, and 856.9±136.6 ㎛ at 21 dah. At 1 dah, larvae had a mean total length of 1.95±0.06 mm. At 66 dah, the mean TL was 4.0 cm. The final number of surviving red spotted grouper larvae was 218,380 fishes.

• 한국패류학회지
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• 제32권2호
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• pp.95-102
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• 2016

본 연구에서는 육상 수조에서 중간 양성 시 공급되는 상업용 북방전복 배합사료를 저수온이 유지되는 동계기간에 공급량을 다르게 할 시 성장특성을 조사하였다. 실험어는 1년생 전복치패 (평균 각장 $29.14{\pm}2.56mm$, 중량 $2.9{\pm}0.6g$) 를 사용하였으며, 실험구는 총체중에 대한 일일 먹이공급율 (the daily feeding rate about total weight, DFW) 을 각 수조에 수용된 실험전복 치패 (250 마리) 총체중의 0.75%, 1.50%, 2.25%. 3.00%. 3.75%, 4.50%로 공급되도록 총 6개 구간을 설정 (0.75 DFW, 1.50 DFW, 2.25 DFW, 3.00 DFW, 3.75 DFW, 4.5 DFW) 하였으며, 실험구는 모두 2반복으로 실시되었다. 실험기간인 동계기간에 평균수온은 $9.7{\pm}3.27^{\circ}C$이었으며. 월별 각장과 각장 성장률 (AGRSL) 및 순간성장률 (SGRSL) 은 1월에는 1.50 DFW 와 2.25 DFW, 3.75 DFW 가 0.75 DFW, 3.00 DFW 보다 유의적으로 높았으며 (P < 0.05), 월별 체중변화 3월에 3.75 DFW 가 모든 실험구보다 유의적으로 높았고 (P < 0.05), 월별 중중률변화에서는 3.75 DFW 가 실험구보다 0.75 DFW 와 1.50 DFW 보다 유의적으로 높았다 (P < 0.05). 열단위성장계수 (TGC) 에서는 1월부터 급격히 낮아졌으며, 3.75 DFW 가 모든 실험구보다 높은 값을 보였다, 1월에는 3.75 DFW 가 0.75 DFW, 1.50 DFW 보다 높았으며 (P < 0.05), 다른 실험구와 유의적 차이는 없었다. 2월에는 3.75 DFW 가 2.25 DFW, 4.50 DFW 를 제외한 모든 실험구보다 유의적으로 높았고 (P < 0.05), 3월에는 3.75 DFW 가 4.50 DFW 를 제외한 모든 실험구보다 높았다 (P < 0.05). 월별 사료효율에서는 12월에 0.75 DFW 가 모든 실험구보다 유의적으로 높았으나 (P < 0.05), 이후 1월을 제외한 2월과 3월에는 모든 실험구간 유의적 차이는 없었다. 따라서, 본 연구에서는 북방전복 치패를 육상수조에서 동계기간 내 사육 시 상업용 배합사료는 일정량 이상을 공급하는 것이 육중량을 유지 또는 일부 증가시킬 수 있으며, 향후 동계기간의 사료공급율에 따른 육중량의 변화가 수온상승기에 가져올 수 있는 성장 변화를 연결하여 조사할 필요가 있을 것으로 판단된다.

• 수산해양기술연구
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• 제51권1호
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• pp.1-8
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• 2015

The common octopus, which has a high growth rate and high market price, is a prime candidate for commercial marine aquaculture operations. We evaluated the effectiveness of two types of shelters (pipe and tire types) for juvenile common octopus growing out in flow-through seawater tanks. Growth rates were evaluated in two experiments. The first experiment (Experiment 1) ran for 72 days, and the second (Experiment 2; replicated) ran for 46 days. Each trial included 40 octopuses fed a diet of frozen sardine (Sardinops melanostictus) and swimming crab (Portunustri tuberculatus) at 3-8% of body weight once every 3 days. In the two experiments, the respective specific growth rates were 0.3 and 0.04%/day in pipe-type shelters and 0.00 and 0.88%/day in tire-type shelters, while the respective percentage survivals were 80 and 80% in pipe-type shelters and 70 and 90% in tire-type shelters. Shelter type had little influence on the growth rate (P < 0.05).

• 한국잠사곤충학회지
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• 제13권2호
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• pp.135-139
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• 1971

1. Ecdysterone의 숙화 촉진작용은 5령 성식기이후에 유효하다. 2. Ecdysterone은 누에의 숙화를 촉진하고 또 초숙잠과 종숙잠간의 시차폭을 축소시킨다. 3. Ecdysterone의 숙화 촉진작용은 Ecdysterone의 식하량과 비례한다. 4. Dodecyl alcohol 주제의 DAT는 등족작용을 촉진한다. 5. Ecdysterone과 Dodecyl alcohol의 병용은 숙화와 등족을 촉진하여 자연상족을 가능케 하며 상족기술 개량에 공헌할 줄 믿는다.

• International Journal of Industrial Entomology and Biomaterials
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• 제8권2호
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• pp.123-127
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• 2004

Normally, silkworms, Bombyx mori, generate offspring by sexual activity. As we known, the hybrids of the first generation of the silkworm have higher cocoon production than pure lines. During the sericulture production, many processes are related with sex control. For example, sex sorting in the egg grainages, rearing of only male silkworm to save the mulberry leaf consumption and increase silk output and quality. Therefore it is very interested in understanding the sex control of the silkworm in theory and practice. Chinese sericultural scientists have been being engaged in the researches in the fields of artificifial parthogenesis, dispermic androgenesis, sex-limited varieties, sex linkage balanced lethal strain and high temperature sensitive male stocks for several decades and gained substantial achievement. Some of the achievements have been used in the commercial production. In this review, the authors introduced that the methods for control of the silkworm sex, and regulate the silkworm sex ratio according to different producing aim in the world and especially in China.

• Journal of Microbiology and Biotechnology
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• 제16권8호
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• pp.1248-1254
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• 2006

The effect of Spirulina platens is and probiotics as feed additives on the growth of the shrimp Fenneropenaeus chinensis was investigated in comparison with a control. The shrimp were cultured in rearing tanks in a seawater pond for 35 days from September 1, 2004. As regards the water quality, the probiotic treatment (T2, commercial diet and 3% probiotics) produced a lower TDN (total dissolved nitrogen) and TDP (total dissolved phosphorus), making it effective in water quality improvement. Nonetheless, the phytoplankton flora succeeded from diatoms to cyanobacteria, regardless of the feed additives. Treatment T3, including 3% S. platensis, produced the highest mean body weight, which was 39% higher than that for all the other treatments (P<0.05). Accordingly, it was found that the use of Spirulina and probiotics as feed additives increased the shrimp body weight and improved the water quality, respectively.

• International Journal of Industrial Entomology and Biomaterials
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• 제17권2호
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• pp.169-172
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• 2008

Indian tropical tasar silkworm, Antheraea mylitta D is reported to have forty four ecoraces by way of their adoption to different topographical and vegetational conditions. Of late, another ecorace 'JATA' - univoltine under in-situ condition has been explored which is localized in Thakurmunda area of the foot hills of Simlipal biosphere (Mayurbhanj district) of Orissa, India. The ecorace 'Jata' exhibits superior economic characters over widely commercialized ecoraces of Daba and Sukinda. The cocoon production of localized 'Jata' ecorace is depleting day by day in in-situ condition. In the present study, efforts were made to stabilize the ecorace 'Jata' under ex-situ condition at Ranchi (Jharkhand), where the 'Jata' ecorace silkworms were reared on Terminalia tomentosa for four successive generations during 2006 and 2007 and the cocoons were preserved in grainage house under prevailing climatic conditions. The results indicated change in voltinism behaviour of the 'Jata' ecorace from univoltine to bivoltine. The rearing performance and grainage efficiencies indicate the tendency of 'Jata' ecorace towards acclimatization and stabilization under Ranchi climatic conditions. The 'Jata' ecorace manifests the prospects for acclimatization, stabilization and commercial exploitation.

• Fisheries and Aquatic Sciences
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• 제14권4호
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• pp.411-416
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• 2011

We investigated the nutritional status of the melania snail (Semisulcospira gottschei) using RNA/DNA ratios to evaluate the effect of feeding conditions (artificial versus natural) on the reaction times of the snails in a time course following starvation. In the short experiments (48 h), the RNA/DNA ratios of the artificial feeding groups were significantly higher than those of the natural groups. While two RNA/DNA ratio peaks were observed in the artificial food group during daytime, the natural food group showed a higher ratio at night. Under starvation conditions, the RNA content decreased whereas the DNA content was constant. The RNA/DNA ratios of the freshwater snail in both groups dramatically decreased after starvation and remained constant until the end of the experiment. We verified that the RNA/DNA ratio serves as an index of nutritional condition with respect to the effect of dietary differences. These results are important for understanding optimized aquaculture rearing conditions for this important commercial freshwater snail.

• International Journal of Industrial Entomology and Biomaterials
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• 제28권2호
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• pp.32-38
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• 2014

Food consumption and conversion efficiency of eri silkworm Samia ricini Donovan were studied during $4^{th}$ and $5^{th}$ larval instars by feeding castor leaves fortified with 100, 200, 300, 400 and 500 ppm concentrations of aqueous extracts of cyanobacteria Anabaena variabilis. The nutritional indices viz., ingesta, digesta, approximate digestibility (%), reference ratio and efficiency parameters like ECI and ECD were recorded which were significantly high at 400 ppm concentration treated batches of $4^{th}$ instar larvae over control batches. The decline in nutritional efficiency parameters of $5^{th}$ instar treated larvae might be due to higher utilization of the digested food for metabolic activities. Significant difference of ECI to cocoon % and non-significant difference of ECD to cocoon% and shell were observed between the treatments and control. Cyanabacteria feed supplement contains antibiotic and nutritions factors which has reflective effect on the biological parameters in eri silkworm and therefore has greater application in commercial eri silkworm rearing.