• International Journal of Industrial Entomology and Biomaterials
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• 제8권1호
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• pp.33-41
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• 2004

The type of trichomes, their density and pattern of distribution on leaves of 16 genotypes of mulberry, belonging to both diploid and polyploid categories, were studied by scanning electron microscope. The present investigation was undertaken to find out the relationship of physical attributes, especially the density and trichome types with higher acceptability and better rearing performance by the silkworm Bombyx-mori L. Two types of trichomes glandular and non-glandular types were observed on both the leaf surfaces of all the mulberry genotypes studied. In general, greater densities of trichomes were observed on the abaxial surface than the adaxial surface of leaves in most of the genotypes. Distribution of glandular trichomes were more in abaxial surface and non-glandular trichomes were more in adaxial surface. Overall, distribution of glandular and non-glandular trichomes per unit area of leaf did not follow any regular pattern. When leaves of those genotypes were fed to silkworms, trichome density was found to be significantly negatively correlated with the survival of larvae i.e., effective rate of rearing, but trichome density did not influence the economic characters of rearing. As the distribution of glandular trichomes (GT) and non-glandular trichomes (NGT) did not follow any definite pattern, no relation could be established between the GT and NGT densities with silkworm rearing performance. However, the ratio of GT and NGT in a particular genotype influenced the rearing parameters, higher the ratios better the rearing performance. High GT and NGT ratio (＞1.00) was found positively significant when correlated with economic parameters viz., larval weight, single cocoon weight and single shell weight. The study is useful in screening different mulberry genotypes for their better acceptability to silk-worm and higher rearing performance at the early stage of selection without actually conducting the rearing.

• Fisheries and Aquatic Sciences
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• 제8권1호
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• pp.27-33
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• 2005

This is a subsequent study to our previous finding that Pacific oysters, Crassostrea gigas, gained a so-called upper plateau concentration, around 30,000 ng/g dry weight digestive gland for benzo(a)pyrene, showed reproductive behavior but produced their ensuing reproductive outputs damaged. A serial dilution of sediment elutriates from Jinhae Bay, Korea, where pollution was progressive, were exposed to gametes of the Pacific oyster for 0, 5, 10, 20, 30, and 60 min to detail the pollutant effects on very young specimens. There was an apparent critical dilution over which adverse effects are evident. This was $10\%$ of the present sediment elutriate, corresponding to 0.3 ng/g on the basis of total polycyclic aromatic hydrocarbons (PAHs) for the oyster. Within the dilution the embryonic development was not influenced by the duration of exposure to its gamete stage. At higher dilutions over the critical dilution, occurrence of abnormality increased dependent on the pollutant dilution and the duration of exposure. Similar trends were also found in larval mortality. However, overall, the chemical toxicity was more significant to morphogenesis than to survival, suggesting a potential recruitment of the pollutants-induced abnormal larvae in the wild population to threaten the population integrity.

• 한국잠사곤충학회지
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• 제36권1호
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• pp.69-75
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• 1994

경란전염은 숙주의 생식소 감염이 전제되므로 Nosema bombycis 감염 집누에를 대상으로 생식소의 발육에 수반된 란 및 정자 형성과 경란전염의 성립에 미치는 영향을 해부 및 조직병리학적 측면에서 구명하였다. 생식소의 감염경로는 도관을 통하지않고 체공에 접한 주변부의 피막조직이 먼저 감염된후 난소내부로 병세가 확산되었고, 감염시기는 다른 조직에 비하여 지연되므로 중증인 개체에 한하여 생식소의 감염은 인정되었으나 란 및 정자 형성이 저해되고 숙주는 성충화 전에 치사하였다. 생식능을 보유한 경증의 감염개체에서는 난소의 감염이 번데기 초기까지 인정되지 않았으나 경란전달은 가능하였다. 병원포자는 자력으로 이동할 수 없으며 성숙란에 대한 침입 가능성도 부정적인 것으로 판단되었으므로, 경란전염이 성립되는 란의 감염시기는 난소소관이 체공에 직접 노출되는 번데기 시기의 2~3일경 부터 난소난의 난각형성이 개시되기 전인 제10 발육단계까지의 기간이 될 것으로 추정되었다.

• 한국발생생물학회지:발생과생식
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• 제18권4호
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• pp.267-274
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• 2014

The immune system in teleost fish is not completely developed during embryonic and larval stages, therefore effective innate mechanisms is very important for survival in such an environment. However, the knowledge of the development of immune system assumed to be restricted. In many species, lysozymes have been considered as important genes of the first line immune defense. The early detection of lysozyme mRNA in previous reports, led to the investigation of its presence in oocytes. As a result, c-type lysozyme mRNA transcripts were detected in unfertilized oocytes indicating maternal transfer. Therefore, we investigated the expression patterns of lysozymes in flounder, including the matured oocyte. In our results, c-type lysozyme mRNA was first detected in unfertilized oocyte stage, observed the significantly decreased until hatching stage, and was significantly increased after hatching stage. On the other hand, g-type lysozyme mRNA transcripts were first detected at late neurula stage, and the mRNA level was significantly increased after 20 dph. It may be suggest that maternally supplied mRNAs are selectively degraded prior to the activation of embryonic transcription. This study will be help in understanding the maturation and onset of humoral immunity during development of olive flounder immune system.

• International Journal of Industrial Entomology and Biomaterials
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• 제37권2호
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• pp.73-81
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• 2018

The giant mealworm beetle, Zophobas atratus (Coleoptera: Tenebrionidae), is a tropical beetle. As this beetle can be used as an ingredient in animal feed, the effects of brewer's spent grain (BSG) on the development and nutritional value of Z. atratus were investigated. As results, there were no significant differences on the larval survival rate, body weight, and duration at different content of BSG, mixed with conventional feed, wheat bran (WB). Based on these results, BSG can be mixed with wheat bran as a Z. atratus food ingredient without any problems. The nutritional value was compared between 100% wheat bran control and 50% BSG experimental groups. The moisture, crude protein, carbohydrates, and amino acids were 1.1-1.4 times higher in the 50% BSG group. In the BSG group, the linoleic acid content was 1.6 times higher than that in the control group. In the wheat bran group, the oleic acid content was 38.4%, which was 1.3 times higher than that in the BSG group. As minerals, the control and BSG groups showed high potassium and phosphorus contents. In terms of hazardous materials, four heavy metals (lead, mercury, arsenic, and cadmium) and two microorganisms (Escherichia coli and Salmonella spp.) were not detected. There were no significant differences in developmental characteristics between the wheat bran and BSG mixed groups, and the nutritional values were better in the BSG mixed group. Therefore, BSG can be used as alternative food source for rearing Z. atratus.

• 한국환경농학회지
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• 제37권4호
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• pp.324-332
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• 2018

곤충은 변온동물로 육지생태계에서 주로 서식하면서, 식물의 생체량 조절, 종다양성 유지에 중요한 역할을 한다. 주변온도는 변온동물인 곤충의 생리적 반응속도, 뿐만 아니라 생존과 분포를 결정하며, 기후변화에 영향을 준다. 본 연구는 높은 온도에서 곤충의 적응성에 관련있는 유전자를 전사체를 이용하여 동정하였다. 고온에서 사육된 배추좀나방 유충의 지방체로부터 차세대 염기서열 분석법을 이용하여 전사체를 확보하였다. 대사중심인 지방체에서 구조단백질, 열충격단백질, 항산화단백질, 해독효소 들이 동정되었다. 이들 중에서 표피단백질(표피단백질, 키틴합성효소, 엑틴, 카이틴 합성), 스트레스관련단백질(시토크롬 P450), 열충격단백질, 한산화단백질은 발현이 증가되었으나, glutathione S transferase 발현은 오히려 감소되었다. 이상의 결과는 기후변화의 주요인인 온난화에 대한 해충의 생리적 대응과 온도적응을 이해하는데 필요한 기초자료를 제시한다.

• Fisheries and Aquatic Sciences
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• 제26권6호
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• pp.367-379
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• 2023

The rapid expansion of shrimp production requires a huge amount of protein sources from soybeans and wild-caught fishmeal; both are becoming a shortage. Meanwhile, catfish production and processing is a giant industry in Vietnam, which produce hundred thousand tonnes of protein- and lipid-rich by-products, annually. Using catfish by-products to gradually replace the traditional protein sources in shrimp aquaculture may bring triple benefits: 1) reducing pressure on wild fish exploitation for fishmeal, 2) reducing the environmental impacts of catfish by-products, and 3) increasing the value and sustainability of aquaculture production. In this study, we used catfish by-products to produce fish protein hydrolysate (FPH) and nano-hydroxyapatite (HA) as additives in feed for Pacific white shrimp (Litopenaeus vannamei). The supplement mixture of FPH and HA was added into the commercial diet (Charoen Pokphand Group [CP], 38% protein, and 6.5% lipid) to reach 38%, 38.5%, 40%, 43%, and 44% of the crude protein content. The survival and growth of shrimps were weekly assessed to day 55. The results showed that the shrimp growth was highest at 43% crude protein content in the feed as indicated by an increase of 124% and 112% in shrimp weight and length, respectively, compared to the commercial reference diet. No negative effects of adding the mixture of FPH and HA on the water quality were observed. Vibrio density was lower than 6.5 × 10³ CFU/mL, which is the lowest Vibrio density negatively affecting the shrimp growth and development. These findings indicate that the mixture of FPH and HA are promising additive components in feed for post-larval shrimp L. vannamei diets.

• Fisheries and Aquatic Sciences
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• 제26권11호
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• pp.649-659
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• 2023

The present study compared the structure of mixilliped of Fenneropenaeus chinensis between the larval and adult stage and investigated the effect of the structural difference on the immunity of F. chinensis. A fourteen day and a one-month long culture trial were conducted each with postlarvae and adults of F. chinensis in the biofloc, mixed water (50% biofloc:50% clear seawater) and seawater control. Immune-related genes mRNA expressions of postlarvae was analysed by quantitative reverse transcription polymerase chain reaction (qRT-PCR). And the analysis of adult stage immunity was carried out using phenoloxidase (PO) enzyme activation in haemocyte. In the postlarvae, the final body weights were 51.43 and 58.47 mg for the biofloc water and the control seawater, respectively. On the other hand, the final body weights of the adults were significantly different between biofloc water and seawater. The survival rate showed the opposite trend to the growth rate. Immune related genes mRNA expression levels in the postlarvae in the biofloc water were significantly lower than those in the seawater. While, the adult stage showed significantly higher PO enzyme activations in the biofloc water than in the seawater with the PO enzyme activation increasing proportionally to the biofloc concentration. This result is considerably explained by the observations of setal morphological structures of the third maxilliped: postlarvae have short serrulated setae that compose the small 'net' structure while adults had long and dense plumose setae. It is understood that the morphological difference of the maxilliped structure resulted in the different feeding abilities in the postlarvae and the adult F. chinensis to use bioflocs as food source.

• 한국양식학회지
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• 제8권4호
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• pp.317-326
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• 1995

북쪽말똥성게 유생기의 먹이효과를 알기 위하여 Chaetoceros calritrans, Pavlova lutheri 및 Isochrysis galbana의 3개 단독구와 이를 혼합 공급한(Chaetoceros + Pavlova, Pavlova + Isochrysis + Isochrysis + Chaetoceros) 3개 시험구 등 총 6개의 시험구에 대한 성장도, 생존율 및 발육 단계별 소요일수를 조사한 결과는 다음과 같다. 먹이 종류에 따른 유생의 성장은 8완기까지 Isochrysis+Chaetoceros의 혼합구, Isochrysis의 단독구 및 Chaetoceros의 단독구가 각각 $735{\mu}m$, $718{\mu}m$ 및 $701{\mu}m$로 성장이 좋았으며 Pavlova의 단독구는 642{\mu}m$로 저조하였다. 먹이 종류별 일간성장을에 있어서 유생초기(6완기) 에는 Isochrysis, 8완 초기부터는 Chaetoceros의 먹이효율이 높은 것으로 나타났다. 생존율에 있어서는 Chaetoceros의 단독구, Isochrysis+Chaetoceros의 혼합구, Isochrysis의 단독구 및 Pavlova의 단독구가 각각 $37.2\%,\;35.0\%,\;32.4\%,\;및\;18.4\%$로 나타났다. 북쪽말똥성게의 유생발육 단계별 소요일수에 있어 6완기 까지는 먹이종류에 따른 큰 차이가 없었으나, 8완 후기까지의 소요일수는 Chaetoceros의 단독구가 24일째로 가장 빨랐고 Isochrysis의 단독구는 27일, Pavlova의 단독구 및 혼합구는 $30\~33$일이 소요되었다.

• 한국잠사곤충학회지
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• 제50권1호
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• pp.27-32
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• 2012

점차 희소화되는 물방개류의 서식지내 복원 및 애완곤충 등 곤충산업 소재화를 목표로 실내 사육연구를 수행하였다. 물방개류는 자연상태에서 수초 줄기에 산란하는 습성을 지니고 있어 실내에서 안정적으로 대량생산을 하기 위해서는 인공산란매트 선발이 필요하며 인공산란매트는 사육상자 밑면에 깔아준 모래가 가장 좋은 것으로 나타났다. 또한 유충기(2 3령) 사육에 적합한 먹이원은 연중 안정공급시 가능한 먹이로서 날오징어를 선발하였다. 실내 사육시 개체간 공식행동이 강한 유충 사육을 위해 개체 집단사육시스템을 개발하였다. 또한 용화매트 선발 시험을 한 결과, 흙(자연매트)을 사용할 경우 표면이 쉽게 굳어 물방개유충이 파고들어가기 힘이 들어 용화율이 12~18% 저조하였고 또한 흙 관리 강도가 높았다. 그러나 발효톱밥을 용화매트로 사용할 경우 용화율 80%로 우수하여 물방개류의 용화매트로 가능함을 확인하였다.