• Journal of Apiculture
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• v.33 no.4
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• pp.283-295
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• 2018

As Sacbrood virus (SBV), a causative agent of larval death and colony collapse in Apis cerana honey bee, is prevalent and poses one of the most significant threats to the Korean apiculture, development of methods to counter this viral disease is urgently needed. In this study we tested some SBV controlling methods, such as requeen, shook swam, adding Apis mellifera and spraying yogurt to SBV inoculated colony. Colony size measured by number of sealed brood and adult were evaluated every 15 days until two months while instances of recurrence were recorded up to five months after applying treatment methods. We also test the effects of yogurt on healthy and SBV-infected larvae at both in vitro reared larvae and colony level. Our result showed that all SBV controlling methods had similar success rates with respect to elimination of SBV clinical symptom up to 30 days post treatment. Mix-species and spraying yogurt method had similar pattern of sealed brood and adult number and higher than that of other SBV controlling methods up to 45 days post treatment. These two groups also showed the lower percentage of SBV recurrence (50% and 66.7%) at 120 days post treatment than other group that mostly colony had clinical symptom. Result on in vitro reared larvae challenged with yogurt showed that yogurt have neither harmless on healthy larvae nor remedial effect on SBV infected larvae. However, at colony level, colony in group received yogurt treatment removed significantly more SBV-infected larvae, SBV-killed larvae, and even healthy larvae in comparison to the control, suggested that yogurt could trigger the hygienic behavior of nurse bee. Our results recommended that it is practical in beekeeping by adding A. mellifera and spraying yogurt to control SBV in A. cerana colony.

• Korean Journal of Environmental Biology
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• v.23 no.1
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• pp.27-31
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• 2005

Early larval growth for total length (TL) and body weight (BW) in flesh prawn (Fenneropenaeus chinensis) was studied from hatching to 25 days after hatching. Mean total length at nauplius and zoea stages was 0.21-0.39 mm and 0.62-1.03 mm, respectively. Mean total length of mysis stage grew from 1.28 mm (9 days after hatching) to 5.98 mm (21 days after hatching). The increase of body weight during experimental period showed step by step growth pattern due to metamorphosis of this species. The relationship between BW and TL from hatching to 25 days after hatching was BW = 2E-5TL/sup 4.1707/ (r²= 0.9746).

• Parasites, Hosts and Diseases
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• v.51 no.3
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• pp.297-304
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• 2013

Trichinosis is a parasitic zoonosis caused by the nematode Trichinella spiralis. Anthelmintics are used to eliminate intestinal adults as well as tissue-migrating and encysted larvae. This study aimed to investigate the effects of ivermectin and myrrh obtained from the aloe-gum resin of Commiphora molmol on experimental trichinosis. Ninety albino mice were orally infected with 300 T. spiralis larvae. Drugs were tested against adult worms at day 0 and day 5 and against encysted larvae on day 15 and day 35 post-infection (PI). Mature worms and encysted larvae were counted in addition to histopathological examination of muscle specimens. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), total protein, albumin, globulin, urea, and creatinine values were estimated. Significant reductions in mean worm numbers were detected in ivermectin treated mice at day 0 and day 5 PI achieving efficacies of 98.5% and 80.0%, while efficacies of myrrh in treated mice were 80.7% and 51.5%, respectively. At days 15 and 35 post-infection, ivermectin induced significant reduction in encysted larval counts achieving efficacies of 76.5% and 54.0%, respectively, while myrrh efficacies were 76.6% and 35.0%, respectively. AST, ALT, urea, and creatinine levels were reduced, while total proteins were increased in response to both treatments compared to their values in the infected non-treated mice. Ivermectin use for controlling T. spiralis could be continued. Myrrh was effective and could be a promising drug against the Egyptian strains of T. spiralis with results nearly comparable to ivermectin.

• International Journal of Industrial Entomology and Biomaterials
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• v.23 no.1
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• pp.107-113
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• 2011

Infection effect of $Nosema$ $bombyics$ on the midgut of silkworm $Bombyx$ $mori$ and subsequent appearance of spores and the performance of larvae was studied. Autopsy of larvae showed white pustules on the surface of midgut at 5 days of post infection (pi). At later stage, important organs like midgut, silk gland and gonads reduced in size and all these organs showed white pustules. Light microscope observation of pustules revealed enormous spores. Spore multiplication was at a faster rate in young larvae. Infection of the adult larvae resulted in pebrinized pupa and moths. Larval weight, cocoon weight and cocoon shell ratio reduced as the post infection period increased. Transverse sections of midgut showed $N.$ $bombycis$ infection limited to a few columnar cells at 3-5 days of pi. At 7 days pi, cell volume increased, cells were swollen and elongated. Heavily infected cells looked like sacks filled with parasite and the apical region of certain cells were bulging into the gut lumen. Later at 8-9 days of pi, spores or its developing stages leaked into the lumen either freely or enclosed within the globules of host cytoplasm. Besides columnar cells, development of $N.$ $bombycis$ was observed in the regenerative cells and rarely in goblet cells. Development of $N.$ $bombycis$ was also observed in both longitudinal and circular muscles at the late pi period. The histopathological changes, deformities and spore production time in the host were all influenced by the spore dosage and age of the host.

• Animal cells and systems
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• v.14 no.1
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• pp.25-30
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• 2010

We employed a new and improved differential display reverse transcription-polymerase chain reaction (DDRT-PCR) method, which involves annealing control primers (ACPs), to identify the genes that are specifically or prominently expressed in olive flounder (Paralichthys olivaceus) juveniles (35 days post-hatch; dph) compared to larval-stage (dph 21) flounder. Using 60 ACPs, we identified eight differentially expressed genes (DEGs) and basic local alignment search tool (BLAST) searches revealed eight known genes. Gene expression levels were confirmed by RT-PCR. Phosphoglucose isomerase (PGI) was highly expressed at 21 dph, while nephrosin, myosin light chain (MLC), myosin heavy chain (MHC), carboxypeptidase A, chymotrypsin B, fish-egg protein, and matrix protein were expressed at 35 dph. PGI, MLC, and MHC expression was further analyzed by RT-PCR. The differentially expressed genes identified in this study may provide insights into the molecular basis of development in olive flounder.

• Korean Journal of Environmental Biology
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• v.22 no.2
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• pp.300-307
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• 2004

The chloroacetanilide herbicide alachlor (2-chloro-2', 6'-diethyl-N-(methoxymethyl)-acetanilide) and organochlorine insecticide endosulfan (6, 7, 8, 9, 10, 10-hexachloro-l, 5, 5a, 6, 9, 9a-hexahydro-6, 9-methano-2, 3, 4-benzodioxathiepin-3-oxide)are the highly toxic agricultural chemicals. Bombina orientalis is one of the most common amphibians in the world and comprises a large proportion of their total number. B. orientalis spawns in the farming regions at Spring when the massive application of agricultural chemicals occurs. These chemicals in farmland may threaten the reproduction of this frog. Therefore, we examined the embryotoxic and survival effects of alachlor and endosulfan at various concentrations in B. orientalis embryos. The survival rates of embryos at 312h post fertilization treated with alachlor and endosulfan were decreased with concentration dependent manner. Also, developmental malformations appeared by alachlor and endosulfan in B. orientalis embryos. The malformations showed in order of frequency with bent trunk, tail dysplasia, bent tail, thick-set body and ventral blister in alachlor treated embryos. The exposure of endosulfan produced 7 types of severe external malformations with tail dysplasia, pectoral blister, bent trunk, bent tail, cephalic dysplasia, ventral blister, and thick-set body. Following exposure to alachlor and endosulfan the types of malformations were diverse, suggesting these chemicals target multiple events in embryonic and larval development in this species. These results suggested that alachlor and endosulfan were detrimental for survival and development of B. orientalis embryos.

• Ocean Science Journal
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• v.41 no.4
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• pp.201-205
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• 2006

Larval specimens of Halicampus punctatus were collected off Ulsan and Uljin in December 2002 (three specimens) and off Ulsan in December 2003 (one specimen). These specimens are characterized by the following morphological characteristics: rings, 14 + 35 = 49; subdorsal rings, 1 + 3 = 4; dorsal fin rays, 19 - 20; pectoral fin rays, 14 - 15; anal fm rays, 9; head length (HL), 5.8 - 6.7 in the standard length; snout length, 1.9 in HL; snout depth, 3.7 - 5.2 in snout length. The number of caudal fin rays 9 is less than those of the other species in the same genus 10. Wide stripe bands composed of small pigments are shown in the trunk and the tail. Melanophores are not found in the dorsal fin, the pectoral fin, and the anal fin except the caudal fin. The supraoccipital crest is on the head. The frontal ridge is on the dorsal side of front trunk. The blanched ridges on the opercular are fused with a main ridge like a tree branch. A few branched ridges that are small and narrow on the trunk and the tail are fused with the main ridges. We report these specimens as the first record in Korea and name them 'Byeol-sil-go-ki' in Korean.

• Development and Reproduction
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• v.18 no.4
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• pp.311-319
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• 2014

Newly hatched black porgy larvae (Acanthopagrus schlegeli) swam to the surface, with the mouth and anus still closed and were 1.90-2.11 mm (mean, 2.0 mm) in total length (TL). The larvae were 2.71-2.94 mm TL (mean, 2.82 mm) on day 2 after hatching. At this time, about two-thirds of the yolk was absorbed, the bladder and intestines had formed, and the mouth and anus were open. Total length was 4.32-4.66 mm (mean, 4.45 mm) at the post-larval stage on days 5-6 after hatching, and the yolk and oil globule were almost absorbed. The end of the notochord began to flex, and 6-8 caudal fin rays were visible. The larvae were 15.37-16.1 mm TL (mean, 15.83 mm) at the juvenile stage on days 30-32 after hatching, and the number of rays in all fins was completely revealed.

• Korean journal of applied entomology
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• v.28 no.2
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• pp.82-87
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• 1989

Mass production of Spodoptera litura nuclear polyhedrosis virus (SINPV) was carried out on massively reared host insects. The yield of SINPV was maximal with $6.7{\;}\times{\;}10^9$ PIBs per larva on the 8th day post inoculation, when 5th instar larvae were inoculated with $1.1{\;}{\times}{\;}10^7$ PIBs per ml, and 2 g of artificial diet was sufficient for food consumption of a larva. The moribund larvae were more suitable for handling and mass production of virus than the completely dead larvae. The larvae, when treated with methoprene ($Manta^{\circledR}$), prolonged their larval period and consequently became bigger to result in higher yield(about 15%) of virus.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.4
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• pp.374-381
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• 2021

A newly recorded chaetodontid species, Chaetodon speculum Cuvier, 1831 was collected in July, 2021 from Pohang, Korea. Its body color is yellow with black stripe across the eyes and a large spot occupying one fourth of the upper part of the body. C. speculum is very similar to congeneric species, C. zanzibarensis, but it can be distinguished by the size of the spot, shape of the lateral line, number of longitudinal line scales and geographic distribution. C. speculum is readily identified between post-larval stage and adult stage because of its similar external shape. Molecular analysis based on mitochondrial DNA COI sequences showed our specimen perfectly matched C. speculum. Therefore, we propose the new Korean name, "Heug-jeom-na-bi-go-gi" for C. speculum.