• Fisheries and Aquatic Sciences
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• 제21권9호
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• pp.20.1-20.3
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• 2018

Hypoptychus dybowskii, the Korean sandlance, is widespread in cold areas of the North Pacific. Although H. dybowskii has been considered to occur on the coast of Hamgyeongnam-do in Korea, the species is also distributed along the coast of Goseong-gun, Gangwon-do, south of Hamgyeongnam-do in the eastern part of the Korean Peninsula on the basis of newly collected specimens. In addition, many Koreans confuse H. dybowskii and Ammodytes japonicus (= A. personatus for Korean specimens) because the Korean common name or dialect of both species is "Yang-mi-ri", yet the two species differ in their external morphology. Hypoptychus dybowskii differs from A. japonicus in the location of the origin of the dorsal fin and the number of dorsal and anal fin rays.

• 한국발생생물학회지:발생과생식
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• 제1권1호
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• pp.91-97
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• 1997

In order to study the reproductive physiology of Sand ell(Hypoptichus dybowskii) catched at kangwon-do, Wooamjin Bay, spawning and egg development were investigated in April and May, 1996. The observed spawning period was from the middle of April to the end of May with the water temperature above $8^{\circ}$C. Body size and colouration were distinguished between male and female. The type of testicular structure is lobular, and the ovary is a pair of sac-sahaped covering with a fibromuscula capsule and comprising a mature egg of average 86. The unfertilzed egg are demersal and adhesive, and their diameter were 1.65-1.95 mm. the colour of yolk is light yellow and contained a lot of tiny oil globules. The average spawned egg was 62 in sargasso weeds. Hatching was observed in 12 days after fertilization with the water temperature of 14 ${\pm}1^{\circ}$C. The average size of larva after hatching was 6.85${\pm}$0.23mm in total length, and larva were containing yolk including globule.

• Animal cells and systems
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• 제3권2호
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• pp.199-205
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• 1999

The nucleotide sequences of a 504 bp segment of the mitochondrial cytochrome b gene were analyzed to survey the intraspecific variation of the brown frog, Rana dybowskii, collected from nine populations in South Korea. Comparisons of sequence divergence of the cytochrome b gene suggest that the populations examined are clearly classified into two types (type 1 and type 2), diverged from each other by a high value of 14.3-15.9% sequence divergence. The two types are distributed allopatrically in most populations, but only one population occurs sympatrically. In the Tonghae population, their spawning grounds differ in that type 1 spawns in the puddle and type 2 spawns in the mountain creek. Based on the genetic divergences of the cytochrome b gene sequences, the phylogenetic status of Korean R. dybowskii is elucidated by comparing it with related brown frogs distributed in an area adjacent to the Korean Peninsula. Interspecific sequence divergences among type 1, type 2 and other related brown frog species (Russian R. dybowskii, R. pirica, R. ornativentris, R. chensinensis: 2n=24 chromosomes) used in this study ranged from 11.7 to 16.3%. R. dybowskii in Tsushima is very similar to our type 1 (sequence divergence＝0-1.6%) and R. chensinensis in western China is closest to our type 2 (sequence divergence＝6.8-7.5%).

• 한국동물학회지
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• 제31권2호
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• pp.87-94
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• 1988

전라남도 일대에서 서식하는 북방상개구리(R. dybowskii)와 참개구리(R. nigromaculara)를 채집하는 생체외배양에 의한 여포난자의 성숙을 유도하였다. 북방산개구리의 여포난자는 배양액(amphibian Ringer's soluion AR)에 첨가한 progesterone, 0.1 $\mu$g/2 ml에 의해 난자의 성숙(핵붕괴)이 유도 되었으며 참개구리의 난자는 1 $\mu$g/2 ml (frog pituitary homogenate FPH)을 얻어서 그 효과를 조사해본 결과 북방산개구리에서는 0.01 pituitary equivalent/2 ml에서, 참개구리는 0.1 pit equiv./2 ml에서부터 여포난자의 성숙이 일어났다. 난자의 성숙에 요하는 시간은 두 개구리에서 모두 9-15시간이었으며 호르몬에 대한 반응성, 성숙기간 등은 개구리 재료로 가장 많이 사용되는 법개구리(R. pipiens)와 거의 일치하였다. 특이하게 2개월 이후에 사용한 북방산개구리의 여포난자는 호르몬의 도움없이도 성숙이 일어났으며 성숙기간도 3시간으로 매우 빨라졌다. 난소조각을 배양했을 때 자발적으로 성숙을 일으키는 여포들은 자발적인 배란까지도 일으키는 것을 발견하였다.

• Journal of Ecology and Environment
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• 제45권1호
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• pp.10-16
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• 2021

Background: Ranavirus is an emerging infectious disease which has been linked to mass mortality events in various amphibian species. In this study, we document the first mass mortality event of an adult population of Dybowski's brown frogs (Rana dybowskii), in 2017, within a mountain valley in South Korea. Results: We confirmed the presence of ranavirus from all collected frogs (n = 22) via PCR and obtained the 500 bp major capsid protein (MCP) sequence from 13 individuals. The identified MCP sequence highly resembled Frog virus 3 (FV3) and was the same haplotype of a previously identified viral sequence collected from Huanren brown frog (R. huanrenensis) tadpoles in South Korea. Human habitat alteration, by recent erosion control works, may be partially responsible for this mass mortality event. Conclusion: We document the first mass mortality event in a wild Korean population of R. dybowskii. We also suggest, to determine if ranavirus infection is a threat to amphibians, government officials and researchers should develop continuous, country-wide, ranavirus monitoring programs of Korean amphibian populations.

• The Korean Journal of Ecology
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• 제23권4호
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• pp.309-313
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• 2000

Since specific types and physical characteristics of anuran calls can represent reproductive qualities of a calling male, anuran calls have been studied in context of mate choice. We in here report call types of Rana dybowskii and their variations from two different recording sites. Calls of R. dybowskii are classified to three types based on their physical characteristics and behavioral observations; 'A-call'functions to advertise locations of a calling male and to attract potential mates. A territorial male emits 'B-call'only during male-male interaction. 'C -call'is released when a male frog was clasped by another male. The A-call from two recording sites, Miwon and Wonju, shows high variations in their call characteristics.

• Journal of Microbiology and Biotechnology
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• 제25권6호
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• pp.910-917
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• 2015

A total of 646 strains, including green algae and diatoms, were isolated from 220 samples to screen microalgae with high lipid productivity (LP). The samples were obtained from nine habitats in Northern Xinjiang, China in June 2013. This study initially identified eight lipidrich strains, namely, Desmodesmus intermedius XJ-498, D. intermedius XJ-145, D. intermedius XJ-99, Monoraphidium pusillum XJ-489, M. dybowskii XJ-435, M. dybowskii XJ-151, Mychonastes homosphaera XJ-488, and Podohedriella falcata XJ-176, based on 18S rDNA sequencing. The strains were cultured in a photobioreactor for the same period. Results showed that the specific growth rate (day^-1) of M. pusillum XJ-489 was the highest (1.14 ± 0.06), and the biomass concentration (g/l) of D. intermedius XJ-99 was the highest (2.84 ± 0.3). Futhermore, the lipid content (%) of M. dybowskii XJ-151 was the highest (33.5 ± 4.38), and the lipid productivity (mg l^-1 day^-1) of My. homosphaera XJ-488 was the highest (86.41 ± 9.04). C16 to C18 accounted for 86% to 98% of the total lipid, and the biodiesel qualities of the selected algae corresponded to international standards. This study suggests that My. homosphaera XJ-488, D. intermedius XJ-99, and M. dybowskii XJ-151 are the most potential strains for biodiesel production among all the isolated strains.

• 대한수의학회지
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• 제36권1호
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• pp.11-21
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• 1996

활동기와 동면기에서 산개구리의 위상관내분비세포를 면역조직화학적으로 비교 관찰하였던 바, 5-HT, somatostatin, glucagon, Gas/CCK, Porcine CG 및 BPP 등 6종류의 내분비세포를 동정하였으며, 동면기의 산개구리 위장관에서는 활동기에 비해 내분비세포의 부위별 분포 및 출현빈도에 있어서 특징적인 소견을 관찰할 수 있었다. 즉 면역반응세포의 출현빈도는 동면기에서 현저하게 높았으며, 부위별 출현분포 특히, glucagon-, Gas/CCK-와 BBP-면역반응세포들은 활동기에 비해 동면기의 소화관에 보다 더 광범위하게 출현하였다. 항혈청에 대한 대부분의 내분비세포들은 동면기에서 보다 더 강한 면역반응을 나타내었으며, 특히 위저선부에서 내분비세포들은 표층점막상피의 바로 아래에 위치해 있었다. 이상의 결과에서 산개구리의 위장관내분비세포들은 동면기에서도 활발한 장호르몬을 합성하고 그들의 세포질내 축적되어지는 것으로 시사된다.

• 한국환경생태학회지
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• 제20권4호
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• pp.400-406
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• 2006

월악산국립공원의 송계계곡 일대의 양서 파충류 노상상해 현황을 파악하기 위하여 송계계곡을 300m간격으로 50개구간을 나눈 후 구간별로 2003년 1월부터 2005년 12월까지 조사를 실시하였다. 그 결과 송계계곡에서 확인된 양서류 10종중 4종이, 파충류는 12종중 7종이 차량에 의해 노상상해된 것으로 확인되었다 또한 가장 많이 차량에 의해 죽는 종은 북방산개구리(Rana dybowskii)로 전체 노상상해 개체수중 94.9%를 차지하였으며, 시기로는 4월${\sim}$5월경에 가장 많은 피해가 있는 것으로 나타났다. 따라서 북방산개구리를 보호하기 위해 생태이동통로 설치가 필요하며, 북방산개구리와 다른 양서류의 보호를 위해서 지속적인 모니터링을 실시해야 한다.

• Animal cells and systems
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• 제2권1호
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• pp.87-91
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• 1998

The present study investigated the involvement of the phospholipase C (PLC) and protein kinase C (PKC) signaling pathways during progesteroneinduced meiotic maturation in amphibian (Rana dybowskii) oocytes. Prosesterone-induced germinal vesicle breakdown (GVBD) of oocytes was significantly inhibited by a PKC inhibitor, staurosporine and a PLC inhibitor, U73122, in a dose-dependent manner. In contrast, U73343, an inactive analogue of U73122, was ineffective in suppressing GVBD. PKC activity in oocytes reached a maximum level at 30 min after progesterone stimulation and this elevated PKC activity was effectively suppressed by U73122 or staurosporine, suggesting that the activation of PKC enzyme is closely linked to PLC signaling during oocyte maturation. In addition, these inhib itors blocked the maturation promoting factor (MPF) activity which appeared in oocytes in response to progesterone, suggesting that PKC activation is an important signal for MPF activity. Therefore, this study demonstrates that the activation of PKC via PLC signaling is directly linked to an intracellular protein kinase cascade related to the appearance of MPF activity during meiotic maturation in amphibian (Rana dybowskii) oocytes.