• 한국어병학회지
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• 제20권3호
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• pp.257-267
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• 2007

The hypo-salinity effects on fertilized eggs, embryos and larvae were investigated in olive flounder (Paralichthys olivaceus) obtained from hatcheries in Cheju-Island, Yeosu and Chungnam. Those were treated to eight concentration; 0, 3.4, 6.7, 10.1, 13.4, 20.2, 27.4 and 33.6 ‰. It was not discrepancy in the survival rate and hatching success rate of fertilized embryos obtained from different regions. Also, in the larvae, the regional difference was not appeared. The survival rate and hatching ability of embryos significantly diminished in the lower groups than 13.4 ‰ compared to 33.6 ‰. After fertilization, namely embryos are tolerant of a wide range of salinity (13.4 - 33.6 ‰). Reduced salinity induced an increase of the malformed embryo and larvae including various deformities; irregular embryos membrane (or yolk sac depression), fin erosion and swim bladder inflation in the flounder embryo. The hatching success of embryos was significantly reduced in lower salinity than 13.4 ‰. Notably, the reduction of larval survival rate significantly was observed in ≤10.1 ‰ treated groups with the same manner of survival rates of the embryos. Additionally, olive flounder was found to be adequate model for measuring external impulses because there are no the regional differences.

• 한국발생생물학회지:발생과생식
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• 제23권3호
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• pp.239-253
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• 2019

We investigated the physiological responses of the river puffer, Takifugu obscurus, the tiger puffer, T. rubripes, a hybrids of the two (river puffer${\times}$tiger puffer) and a hybrid triploids to acute changes of salinity from 30 psu to 0 psu and from 0 psu to 30 psu. The blood and plasma factors of each species were elevated for 48, 72, or 96 hrs, and thereafter decreased due to hyper-osmoregulation and hypo-osmoregulation. In hyper-osmoregulation and hypo-osmoregulation, the cortisol concentration of river puffer, hybrids, hybrid triploids and tiger puffer increased for 12 or 48 hrs, and decreased thereafter. Chloride cells in the gill filaments of each species increased with increasing salinity, and melano-macrophages in the kidney tissue of each species increased with decreasing salinity. In conclusion, the hematological and stress responses of the hybrids were between those of the river puffer and tiger puffer, and the hematological responses of the hybrid triploids were higher than those of the other groups. The stress response of the hybrids was more sensitive than that of the hybrid triploids. In all groups, the histological responses of kidney in hyper-osmoregulation were more sensitive than those in hypo-osmoregulation.

• ALGAE
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• 제33권4호
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• pp.329-340
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• 2018

The present study was to determine the effects of salinity on the growth and nutrient bioextraction abilities of Gracilaria and Ulva species, and to determine if these seaweeds can be used for nutrient bioextraction under hypo- and / or hyperosmotic conditions. Two Gracilaria species, G. chorda and G. vermiculophylla, and two Ulva species, U. prolifera and U. compressa, were cultured at various salinity conditions (5, 10, 15, 20, 30, 40, and 50 psu) for 3 weeks. Results showed that the growth rates, nutrient uptake, tissue nutrient contents and nutrient removal were significantly affected by salinity and species. All four species were euryhaline with the highest growth rates at 20 psu. Among the four species, U. prolifera, U. compressa, and G. vermiculophylla showed potential to be used for nutrient bioextraction in estuaries and / or land-based fish farms due to their rapid growth, high nutrient uptake, high tissue carbon and nitrogen accumulation and removal capacities.

• ALGAE
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• 제36권2호
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• pp.137-146
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• 2021

Intertidal macroalgae are regularly exposed to hypo- or hypersaline conditions which are stressful. However, red algae in New Zealand are generally poorly studied in terms of salinity tolerance. Consequently, two native (Bostrychia arbuscula W. H. Harvey [Ceramiales], Champia novae-zelandiae [J. D. Hooker & Harvey] Harvey [Rhodymeniales]) and one introduced red algal taxon (Schizymenia spp. J. Agardh [Nemastomatales]) were exposed for 5 days in a controlled salt stress experiment to investigate photosynthetic activity and osmotic acclimation. The photosynthetic activity of B. arbuscula was not affected by salinity, as reflected in an almost unchanged maximum quantum yield (F_v/F_m). In contrast, the F_v/F_m of C. novae-zelandiae and Schizymenia spp. strongly decreased under hypo- and hypersaline conditions. Treatment with different salinities led to an increase of the total organic osmolyte concentrations with rising salt stress in B. arbuscula and Schizymenia spp. In C. novae-zelandiae the highest organic osmolyte concentrations were recorded at S_A 38, followed by declining amounts with further hypersaline exposure. In B. arbuscula, sorbitol was the main organic osmolyte, while the other taxa contained floridoside. The data presented indicate that all three red algal species conspicuously differ in their salt tolerance. The upper intertidal B. arbuscula exhibited a wide salinity tolerance as reflected by unaffected photosynthetic parameters and strong sorbitol accumulation under increasing salinities, and hence can be characterized as euryhaline. In contrast, the introduced Schizymenia spp. and native C. novae-zelandiae, which preferentially occur in the mid-intertidal, showed a narrower salinity tolerance. The species-specific responses reflect their respective vertical positions in the intertidal zone.

• 한국어류학회지
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• 제22권1호
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• pp.9-16
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• 2010

본 연구에서는 광염성 송사리 Oryzias dancena 성체 및 자어의 염분도 변화에 대한 내성 및 생존 능력을 평가하고자 다양한 염분도 변화 처리를 수행하였다. 담수로부터 고 염분도 조건으로의 급격한 염분도 증가 노출 처리에 대하여 O. dancena 성체는 $40^{\circ}/_{\circ\circ}$염분도 변화 폭까지 생존의 장애 없이 빠르게 적응할 수 있는 것으로 관찰되었으며, 단계적인 순치를 통할 경우 최대 $75^{\circ}/_{\circ\circ}$의 염분도 조건까지 생존이 가능하였다. 염분도의 감소 처리에서 O. dancena 성체는 $60^{\circ}/_{\circ\circ}$ 이상의 급격한 감소 폭에서도 우수한 생존율을 나타내였다. 성체와 달리 O. dancena 자어는 급격한 염분도 증가에 대한 삼투압 조절 능력 (hyper-osmoregulation)이 유의적으로 낮아 약 $15^{\circ}/_{\circ\circ}$ 이상의 염분도 증가에서는 생존에 큰 장애를 겪는 것으로 나타났다. 그러나 초기 발달 단계에 있는 자어의 염분도 변화에 대한 내성은 최초 염분도 처리 농도에 따라 염분도 변화에 대한 내성 폭이 크게 영향을 받는 것으로 관찰되었다. 초기 발달 단계에서 O. dancena 자어는 염분도 증가 보다는 염분도 감소 시 삼투압 조정 능력 (hypo-osmoregulation)이 더 높은 것으로 나타나 $40^{\circ}/_{\circ\circ}$에서 완전 담수로의 염분도 변화에서도 우수한 생존 능력을 보였다.

• Asian-Australasian Journal of Animal Sciences
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• 제27권4호
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• pp.479-487
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• 2014

Leptin plays an important role in energy homeostasis and reproductive function in fish, especially in reproduction. Migrating fish, such as salmonoids, are affected by external environmental factors, and salinity changes are a particularly important influence on spawning migrations. The aim of this study was to test whether changes in salinity affect the expression of leptin, estrogen receptors (ERs), and vitellogenin (VTG) in chum salmon (Oncorhynchus keta). The expression and activity of leptin, the expression of ERs and VTG, and the levels of estradiol-$17{\beta}$ and cortisol increased after the fish were transferred to FW, demonstrating that changes in salinity stimulate the HPG axis in migrating female chum salmon. These findings reveal details about the role of elevated leptin levels and sex steroid hormones in stimulating sexual maturation and reproduction in response to salinity changes in chum salmon.

• 환경생물
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• 제22권3호
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• pp.419-425
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• 2004

사육수의 담수화시 수용밀도에 대한 생리학적 반응을 비교하고자, 30마리와 60마리씩 실험수조에 수용하여 30분이내에 사육수를 담수로 교환하였다. 혈장의 Cortisol 농도는 실험개시시 30SW에서 $2.8\;ng\;mL^{-1}$,60SW는 $2.7\;ng\;mL^{-1}$로부터 30FW와 60FW는 24시간째 각각 $66.9\;ng\;mL^{-1}$, $314.1\;ng\;mL^{-1}$로 유의하게 높아졌다. 혈장의 Glucose농도는 60SW는 개시시 $15.8\;mg\;dL^{-1}$로부터 60FW는 3시간째 $257.7\;mg\;dL^{-1}$, 24시간째 $164.0\;mg\;dL^{-1}$로 개시시보다 높은 값으로 남아있었다. $Na^+$ 농도는 30SW와 60SW는 시간경과에 따라 차이를 보이지 않았으나, 30FW와 60FW는 시간경과에 따라 낮아지는 경향을 보였다. $Cl^-$농도는 60FW에서 개시시 $59.0\;mEq\;L^{-1}$로부터 3시간과 24시간째에 각각 $43.5\;mEq\;L^{-1}$, $30.0\;mEq\;L^{-1}$로 유의하게 낮아진 값을 보였다. 모든 실험구에서 생존율은 100%였다. 사육수를 24시간동안 담수로 교환시 사육밀도의 차이에 따른 혈장과 혈액학적 지표에서 다소 차이를 나타냈으며, 삼투압 조절 능력 및 생존율에서는 해수에서와 같은 경향을 보였다.

• 환경생물
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• 제24권4호
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• pp.380-386
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• 2006

30일 동안 15 psu에서 순화 사육한 양식 넙치(평균전장: 20.8cm,평균체중: 96.1g)를 사용하여 염분변화에 따른 혈액 학적 변화 (cortisol, glucose, $Na^+$, $Cl^-$, $K^+$, AST, ALT, hematocrit, RBC, hemoglobin) 및 생존율을 조사하였다. 사육수를 실험개시시 15 psu로부터 0 psu(group I, G I)와 35 psu(group II, G II)로 30분 이내에 교환하였다. 5일 동안 유지하였으며, 다시 사육수를 0 psu로부터 35 psu(G I)와 35 psu에서 0 psu(G II)로 교환하였다. G I구는 cortisol, glucose, $Na^+$, $Cl^-$, AST및 생존율 등에서 일반적인 stress 경향을 보였다. G II구는 35 psu에서 0 psu로 교환한 240시간째에 cortisol, glucose 및 AST에서 유의적으로 높아진 값을 보였다. 두 실험구에서 생존율은 35 psu에서보다 0 psu에서 낮아지는 것으로 나타났다. 본 연구 결과 고염분과 저 염분변화에 따른 cortisol, glucose, $Na^+$, $K^+$, $Cl^-$및 생존율에 대한 기초자료로 유용할 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제23권5호
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• pp.588-597
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• 2010

We investigated the effect of quercetin on growth and plasma cholesterol level and the effects of quercetin pretreatment (Diet 1, 0%; Diet 2, 0.25%; and Diet 3, 0.5% quercetin) for 30 and 60 days on oxidative stress induced by hypo-osmotic conditions (17.5, 8.75, and 4 psu) in olive flounder. The weights of flounder were higher with Diet 3 than with Diet 1 and 2, which indicated that a high concentration (Diet 3) of quercetin was very effective in growth. Total cholesterol levels were lower with Diets 2 and 3 than with Diet 1, leading us to hypothesize that quercetin removed low-density lipoproteins from circulation and thereby reduced total cholesterol. To understand the antioxidant role of quercetin, we measured the mRNA expression and activities of superoxide dismutase (SOD) and catalase (CAT) and the $H_2O_2$ concentration in quercetin-treated flounder exposed to osmotic stress. The $H_2O_2$ concentration and the SOD and CAT expression and activity levels were lower in flounder fed with Diets 2 and 3 than with Diet 1, suggesting that quercetin directly scavenges reactive oxygen species to reduce oxidative stress. Furthermore, the plasma lysozyme activity and osmolality were higher with Diets 2 and 3 than with Diet 1, indicating that quercetin increases immune function and helps to maintain physiological homeostasis. Plasma cortisol was lower with Diets 2 and 3 than with Diet 1, suggesting the quercetin protects against stress. These results indicate that quercetin has hypocholesterolemic and antioxidant effects, increases immune function, and acts to maintain physiological homeostasis.