• 한국수산과학회지
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• 제54권4호
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• pp.467-479
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• 2021

The distribution and abundance of fish eggs and larvae were investigated from February to December 2020 along the coastal waters of Korea. The eggs and larvae were identified using the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) and 16s rRNA gene. During the study period, eggs of overall 45 taxa belonging to 26 families were collected and larvae of overall 39 taxa belonging to 23 families were collected. In Yeongil Bay, eggs of Engraulis japonicus, which accounted for 83.9% of the total population, was the most dominant species, followed by Sardinops sagax (4.0%), Repomucenus valenciennei (3.8%) and E. japonicus larvae, which accounted for 34.9% of the total population. These were followed by Sebastiscus marmoratus (31.0%). In Gomso Bay, E. japonicus eggs accounted for 61.7% of the total population, followed by Sillago japonica (14.0%), Johnius grypotus (8.8%) and Pholis fangi larvae, which accounted for 53.5% of the total population, followed by Ammodytes personatus (34.1%). In Jinhae Bay, E. japonicus eggs accounted for 86.0% of the total population, followed by Leiognathus nuchalis (4.1%), Konosirus punctatus (3.7%) and E. japonicus larvae, which accounted for 48.7% of the total population, followed by Parablennius yatabei (21.6%).

• 한국양봉학회지
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• 제33권4호
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• pp.261-268
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• 2018

Queen honey bees (Apis cerana) can be reared artificially on demand by the use of grafting technique. The technique consists of grafting young worker larvae into queen cell cups and raising in a queenless strong colony. As the age of grafted larvae for queen rearing exhibited several aspects related to quality and reproductive potential of queen, this study were conducted to investigate the influence of age of grafted larva on morphological characteristics and lifespan of queen, and the growth of colony she headed. Our results demonstrated that queens reared from young worker larvae (i.e., less than 1-day old larvae) were significantly larger in size (i.e., body weight and thorax width) than that of queens reared from 2-day old worker larvae. Moreover, queens reared from younger worker larvae initiated egg-laying earlier, stored more spermatozoa in spermatheca and had a longer lifespan compared to queens raised from older worker larvae. We also found a significant positive effect of queen grafting age on the production of worker and drone brood, adult worker population in colonies headed by queens reared from younger larvae. These findings suggested that rearing queens from brood grafted at the earliest possible age could increase the reproductive potential of queen as well as fitness of colony she head.

• 한국수산과학회지
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• 제52권1호
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• pp.67-73
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• 2019

We presented detailed morphological descriptions of the eggs, larvae and juvenile of Acanthaphritis unoorum based on specimens collected with bongo nets from Korean waters during the period May 2017-July 2018. We collected 18 individuals including eggs (n= 4, 0.77-0.85 mm in egg diameter), preflexion larvae (n= 6, 4.11-6.31 mm in standard length, SL), flexion larvae (n= 4, 6.60-7.82 mm SL), postflexion larvae (n= 3, 8.94-13.46 mm SL), and one juvenile (n= 1, 14.67 mm SL). The mitochondrial (mt) DNA 16S rRNA sequences of the eggs, and the cytochrome c oxidase subunit I (COI) sequences of the larvae were identical to those of A. unoorum adults (genetic distances <0.01). The A. unoorum larvae and the juvenile that we collected were morphologically similar to those of Dactylopsaron dimorphicum, but the A. unoorum specimens were readily distinguishable by the presence of lateral melanophores. This is the first record of A. unoorum in Korean waters. We propose a new Korean name for A. unoorum: "O-ri-bu-ri-nuntung-i".

• 한국양봉학회지
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• 제33권4호
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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.

• 한국해양학회지:바다
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• 제14권3호
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• pp.189-194
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• 2009

종속영양 와편의류인 Pfiesteria 종과 이와 유사한 형태의 Pfiesteria-like 종간의 생태적 지위차를 확인하기 위해, Pfiesteria piscicida, Cryptoperidininopsis brodyi, Stoeckeria algicida 3종에 전복유생(abalone larvae)을 투입하여 그들의 섭식 여부를 확인하고, 이들의 농도변화에 따른 전복 유생의 생존율 변화를 확인하였다. P. piscicida와 C. brodyi는 부화 1일차의 전복 유생을 직접 공격하여 치사 시킨 후 peduncle이라는 섭식기관을 이용하여 개체 전체를 섭식하는 것으로 밝혀졌다. 하지만 형태적으로 이들과 매우 유사하고 peduncle도 가진 S. algicida는 전복 유생을 직접 공격하거나 섭식하지 않았다. 전복 유생의 생존율은 P. piscicida와 C. brodyi의 초기 투입농도가 증가함에 따라 상대적으로 낮아졌다. 이러한 결과는 형태적으로 매우 유사한 종속영양성 와편모류일지라도 그들이 가지는 생태적지위는 매우 다르며, 보다 명확한 해양 생태계 먹이사슬을 이해하기 위해서는 종(species) 수준의 명확한 종 동정연구가 필요함을 제시해 준다.

• 대한수의사회지
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• 제21권1호
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• pp.43-47
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• 1985

Striking effects of hydrocortisone were observed on the behaviour of Toxocara canis larvae in 2 months old dogs. Four cross-breed dogs were used in this studies and each dog was inoculated 3000 infective eggs. The larvae were recovered from 2 dogs (contro

• 한국발생생물학회지:발생과생식
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• 제17권4호
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• pp.337-343
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• 2013

Post-thawed larval rearing in Pacific oyster Crassostrea gigas was performed to investigate the survival rate with time course in three kinds of larvae cryopreserved. The highest survival rate and larval activity index (LAI) of post-thawed larvae were obtained from the permeation in 0.2 M sucrose and 2.0 M ethylene glycol (EG) at $-1^{\circ}C/min$ in freezing speed showing the survival rates just after thawing of 63.8% in trochophore, 84.1% in D-shaped veliger and 56.3% in early umbo veliger. In post-thawed larval rearing with food supply, the larvae lasted their lives until 24 hours in trochophore, 75 hours in D-shaped veliger and 57 hours in early umbo veliger. The results suggested that each larval stage post-thawed revealed no more further development to subsequent respective stage.

• 한국임상수의학회지
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• 제21권3호
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• pp.248-252
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• 2004

DNase activity from infective larvae of the parasitic nematode Haemonchus contortus was characterized and compared to that from whole worm. DNase activity from infective larvae was detected throughout pHs 4-10, but high activity was detected under acidic conditions. The activity was not inhibited by 10 mM EDTA at pH 5.0, but was significantly inhibited at pH 7.0. The activity produced DNA, fragments with mixtures of 3'-hydroxyls (OH) and 3'-phosphates (P) at each pH with predominance of 3'-P. A unique DNase activity at 37 kDa was identified from infective larvae on zymograms. The 37 kDa DNase was detected only at pH 5.0, but not at pH 7.0, and this activity was not inhibited by EDTA at pH 5.0. These characteristics of the 37 kDa infective larval DNase resemble those of classic acidic DNases (e.g., DNase II). In contrast, 34, 36 and 38.5 kDa DNase activities were shown to be specific for whole worm. This result demonstrated that DNases in H contortus are regulated during development.

• 한국산림과학회지
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• 제9권1호
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• pp.45-48
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• 1969

야외 피해림지에서 봄철의 솔잎혹파리 유충밀도의 감소경향을 조사한것이다. (1) 해빙직후인 3월 12일의 유충수를 100으로 보았을 때 4월 15일은 29, 5월 4일에는 10 이하 이였다. (2) 봄철에 시기에 따라서 유충수가 점점 감소되는 것은 온도가 차차 높아지고 습도가 낮아 지는것이 큰 원인이라고 관찰되었다. (3) 지표토양에서 솔잎혹파리 유충을 선별 함에는 수선하는 방법이 가장 좋았다.

• 한국발생생물학회지:발생과생식
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• 제24권2호
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• pp.125-133
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• 2020

This study is intended to be used as the basic material for the taxonomic research by observing the stages of skeletal development of Luciogobius grandis larvae compared to the skeletal development patterns of the same fish family of Gobiidae. 3 days after hatching (DAH), the preflexion larvae was 4.01±0.11 mm (n=5) in average total length (TL) and the frontal began to ossify in the skull. 17 DAH, the advanced postflexion larvae was 5.37±0.05 mm (n=5) in average TL the supraoccipital and epiotic were ossified in the cranial bone. 36 DAH, the juvenile was 12.2±0.20 mm (n=5) in average TL and the urohyal was ossified in the hyoid arch. In addition to one hypural bone being ossified, the first, second, third and fourth were combined and were made three bone fragments and then, the bone ossification of all skeletons was completed.