• Asian-Australasian Journal of Animal Sciences
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• 제25권6호
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• pp.794-799
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• 2012

The cytochrome P450c17-I (CYP17-I) is one of the enzymes critical to gonadal development and the synthesis of androgens. Two single nucleotide polymorphisms (SNPs) were detected within the coding region of the CYP17-I gene in a population of 75 male Japanese flounder (Paralichthys olivaceus). They were SNP1 (c.C445T) located in exon2 and SNP2 (c.T980C (p.Phe307Leu)) located in exon5. Four physiological indices, which were serum testosterone (T), serum $17{\beta}$-estradiol ($E_2$), Hepatosomatic index (HSI), and Gonadosomatic index (GSI), were studied to examine the effect of the two SNPs on the reproductive endocrines of Japanese flounder. Multiple comparisons revealed that CT genotype of SNP1 had a much lower T level than CC genotype (p<0.05) and the GSI of individuals with CC genotype of SNP2 was higher than those with TT genotype (p<0.05). Four diplotypes were constructed based on the two SNPs and the diplotype D3 had a significantly lower T level and GSI. In conclusion, the two SNPs were significantly associated with reproductive traits of Japanese flounder.

• 한국수산과학회지
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• 제42권4호
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• pp.344-348
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• 2009

This study was conducted to investigate effects of dietary lipid level on growth and body composition of juvenile red sea bream in low temperatures. Duplicate groups of fish (initial body weight of 79 g) were fed one of three isonitronic diets (47% crude protein) containing different lipid levels (10%, 17% and 22%) for 25 weeks during the winter season. Weight gain and survival of fish fed 17% lipid diet were significantly (P<0.05) higher than those fish fed the 10% or 22% lipid diet. Protein efficiency ratio, daily feed intake, condition factor, hepatosomatic index and viscerasomatic index were not affected by dietary lipid level, but feed efficiency of fish fed 10% lipid diet was significantly (P<0.05) lower than those fish fed the 17% or 22% lipid diet. Proximate composition of the whole body, liver, viscera and dorsal muscle were not significantly different among all groups except for crude protein content of dorsal muscle. The contents of 16:0, 18:0, 20:4n-3 and 20:5n-3 of the whole body were significantly (P<0.05) affected by dietary lipid level. The results of this study suggest that an increased dietary lipid level from 10% to 17% can improve growth of juvenile red sea bream in low temperature periods.

• 한국수산과학회지
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• 제51권1호
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• pp.54-63
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• 2018

We investigated the effect of $CO_2$ exposure on the reproductive process of chameleon goby Tridentiger trigonocephalus. Rearing aquaria were exposed for 90 days to $CO_2$ gas through diffuser connected with pH controller maintaining at pH 7.2 ($156.31{\pm}7.90ppm$) in low treatment, and at pH 6.5 ($274.17{\pm}6.51ppm$) in high treatment. $CO_2$ treatment had no significant effects on survival rates although the value was decreased compared to the controls. In female fish, $CO_2$ treatment had no significant effects on gonadosomatic index (GSI), hepatosomatic index (HSI) and condition factor (CF). However, high $CO_2$ treatment decreased HSI and CF in males significantly compared to the controls (P<0.05). The spawning occurrence was 6 times in the low level $CO_2$ treatment, and 4 times in the high level $CO_2$ treatment although only once in the controls. For the histological observations, there was no significant difference in $CO_2$ treatments. However, in male fish, $CO_2$ treatment delayed the formation of sperm from spermatid compared to controls. These results suggest $CO_2$ may disrupt reproductive process by delaying gametogenesis in chameleon goby and it was more sensitive in males.

• 한국물환경학회지
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• 제23권1호
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• pp.144-154
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• 2007

The acute and chronic toxicity of ambient and effluent water discharged to Lake Shihwa were investigated by using Vibrio fischeri, Daphnia magna and Oryzias latipes. Physicochemical characteristics including biochemical oxygen demand (BOD) and nine heavy metals in a total of 15 water samples were evaluated and were satisfied with relevant Korean Water Quality Standards (KWQS) except for Hg in one sample. Acute toxicity was observed in five samples collected from three sampling locations. When impacts on reproduction and growth after chronic exposure were evaluated with D. magna, all the samples showed significant chronic effects. Reproduction appeared relatively more sensitive endpoint. In 21 days chronic tests on O. latipes, survival, mean egg number per female per day, hatching success rate and time to hatch were affected by increasing sample concentration. The organ-level changes such as gonadosomatic index (GSI), and hepatosomatic index (HSI), and molecular biomarker of vitellogenin (Vtg) induction that evaluated with O. latipes increased as exposure concentrations increased. It is noteworthy that the samples that did not exceed the KWQS resulted in acute and chronic toxicities. The results suggested that numeric criteria based on physicochemical parameters may not be protective of aquatic ecosystem. Acute and chronic toxicity tests with organisms representing different trophic groups should be supplemented in order to provide adequate level of environmental protection.

• 한국수산과학회지
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• 제56권6호
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• pp.861-869
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• 2023

This study aimed to evaluate the effectivity of full-fat black soldier fly Hermetia illucens (BSF) and defatted mealworm Tenebrio molitor (MW) larvae meal as a fish meal (FM) substitute in a low-fish meal (LFM) diet for juvenile olive flounder Paralichthys olivaceus. The LFM diet comprising 45% FM with tankage meal, poultry byproduct meal, soy protein concentrate and wheat gluten was the control diet. Three experimental diets were 10% FM in Con with BSF, MW and a mixture of both at the same ratio (designated as B10, M10 and B5M5, respectively). Four hundred and forty-fourth juvenile P. olivaceus (34.3±0.1 g) were randomly distributed into 12 tanks (425 L) in three replicate groups per treatment and fed the experimental diets for 15 weeks. At the end of the feeding trial, growth performance, survival, biological indices (condition factor, viscerosomatic index, hepatosomatic index), non-specific immune responses (lysozyme, myeloperoxidase) and intestinal histology (villi length and goblet cells) were not significantly affected by treatments. Feed utilization was significantly decreased in M10 compared to the control group. Alanine aminotransferase level was significantly higher in M10 than in the control group. Glucose level was significantly lower in B10 than in the control group. These results suggest that BSF and MW can be used as FM substitutes. However, considering feed conversion ratio and AST level, MW availability is thought to be lower than that of BSF, and feeding fish with a diet containing MW for an extended period is thought to adversely affect fish growth.

• Applied Microscopy
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• 제31권1호
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• pp.19-35
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• 2001

계절성 번식기 동안에 자성무지개송어 (Oncorhynchus mykiss)의 혈장내 $estradiol-17\beta$, 혈장성분, 전기영동상 그리고 미세구조 변화의 특징을 살펴보았다. 정상적인 자연조건에서 혈장내 $estradiol-17\beta$는 난황형성기(vitellogenic season)말인 9월에 peak를 나타내었고, 산란이 이루어진 시기 이후인 12월에는 서서히 감소하였으며, 난소의 재형성 초기인 2월과 3월에는 급격하게 감소하였다. 이러한 $estradiol-17\beta$의 변화 추이를 볼 때 이 호르몬은 자성 무지개송어에서 혈장내 calcium, phosphorus, glucose, albumin및 total protein수준의 증가에 의해서 증명된 것과 같이 난황전구물질(vitellogenin)의 생성을 자극하는 것으로 나타났다. Latematuring단계 혹은 산란중인 난모세포의 전기영동상(분자량이 각각 약 70,000과 200,000 Da)은 late perinucleolus단계의 난모세포의 전기명동상보다 훨씬 두껍고 진한 경향을 나타내었다. 이 단백질 2개의 전기영동상은 $estradiol-17\beta$ 호르몬 peak와 일치하는 추이를 나타내면서 SDS-PAGE에서 확인되었다. 생식소 숙도지수 일명 성성숙지수, [gonadosomatic indices(GSI)]는 10월로부터 그 이듬해 1월까지 유의성 있게 증가하는 경향을 나타내었고, 성숙난자의 급격한 수적인 증가와 일치하면서 1월에 가장 높은 peak를 나타내었다. 산란 전단계에서 estradiol-17 수준과 CSI간에는 정 (+)의 상관관계 (r=0.701, p<0.01)를 나타내었고, 간숙도지수 [hepatosomatic index (HSI)]는 번식시기인 12월에 가장 높은 수치를 나타내었다. 번식시기 (12월)에 생식소 자극호르몬 분비세포(gonadotropes)는 granules와 globules와 같은 생식소자극호르몬을 포함한 봉입체로 가득찬 상태를 나타내었다. 난황형성기에는 late perinucleolus 난모세포가 난황의 축적을 통해서 early maturing난모세포로 변형되는 과정이며, 이 시기의 난모세포는 late maturing단계로 되면서 난황으로 완전히 가득찬 상태로 확인되었다. 핵이주 단계에 있는 난모세포의 과립막세포의 미세구조를 살펴보면 팽창된 조면 내형질세망과 tubular cristae가 있는 간상의 미토콘드리아로 구성되어 있었다. 방사대 (zona radials)와 난황막 사이에 있는 미세융모(finger-like projections)는 각각 성장하면서 난황형성기에 pore canals을 이루면서 서로 연결되나, 난성숙기에 방사대가 더욱더 치밀하게 되면 수축되어 봉쇄되면서 위축되는 것으로 확인되었다. 방사대는 외측에 않은 homogeneous layer와 내측에 2개의 두꺼운 helicoidal layers (zona radiata interna and zona radials externa)총 3개의 구조물로 구성되어 있었다. 정상적인 환경조건에서 볼 때 난포는 난형성과 생식소에서 분비되는 스테로이드 흐르몬의 생성에 충분할 만큼 조직의 발달과 호르몬의 주기적인 분비에 영향을 주는 것으로 나타났다.

• 한국어류학회지
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• 제20권1호
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• pp.13-20
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• 2008

줄납자루를 이용한 외부생식형질의 정량화 가능성을 통하여 이를 어류의 생식관련 연구에 적용할 수 있는지 여부를 확인하기 위해 내부생식형질과 비교하였다. 줄납자루의내부생식형질은 GSI, HSI 및 생식소 발달단계를 이용하였으며, 외부생식형질은 암컷의 경우 산란관의 발현 및 산란관지수의 변화, 수컷의 경우 추성의 발현 및 수의 변화 그리고 꼬리지느러미와 등지느러미에 나타나는 혼인색의 발현 및 혼인색지수의 변화를 이용하였다. GSI와 HSI는 암컷과 수컷 모두 2월에 가장 높은 값을 나타냈으며, 생식소 발달단계는 암컷과 수컷 모두 2월에서 5월 사이에 완숙 및 방란 방정기의 조직상을 가진 개체들이 대부분을 차지하고 있었다. 산란관은 12월~5월 사이에 전 개체에서 신장되었으며, 산란관지수는 3월~4월 사이에 가장 높은 값을 나타냈다. 추성, 등지느러미 및 꼬리지느러미의 혼인색 발현율 및 각 지수들은 2월~5월(꼬리지느러미의 경우 2월~4월) 사이에 가장 높은 발현율과 값을 나타냈다. 이와 같은 결과들은 암컷과 수컷 모두 내부 및 외부생식형질이 동일한 변화를 보여주고 있는 것으로써, 추후 생식관련 연구를 수행하는 데 있어 보다 나은 자료를 제공할 것으로 생각된다.

• 한국어류학회지
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• 제7권2호
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• pp.150-159
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• 1995

1992년 5월부터 1993년 8월까지 부산 수영만 인근해역에서 채집된 망상어, Ditrema temmincki를 대상으로 조직학적 방법에 의해 생식주기와 군성숙도를 조사하였다. 조사된 결과는 다음과 같다. 본종의 군성숙도는 수컷은 체장 13.5cm, 암컷은 체장 12.5cm로 조사되었다. 생식소중량지수는 수컷은 10월, 암컷은 6월에 연중 가장 높은 값을 나타냈다. 정소의 내부조직상은 곡정세관형이며, 난소는 5∼6장의 난소습곡으로 이루어져 있는데, 곡정세관상피와 난소습곡상피에서 각각 정원세포와 난원세포가 유래한다. 생식주기는 수컷은 성장기(5∼8월), 성숙기(9∼10월), 교미기 (11∼12월), 퇴화 및 휴지기 (1∼4월)로 나눌 수 있으며, 암컷은 성장기 (9∼10월), 교미 및 성숙기 (11∼12월), 임신기 (1∼6월), 휴지기 (7∼8월)로 나눌 수 있다. 간중량지수는 암수 모두 4월에 최고치를 보여, 수컷에서는 생식소중량지수의 월변화와 역상관 관계를 보이고, 암컷에서는 정상관 관계를 보였다.

• 한국양식학회지
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• 제12권2호
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• pp.123-135
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• 1999

In order to investigate the effect of salinity on growth and osmoregulation of the sweetfish, Plecoglossus altivelis, the fish (post-larva, juvenile, adult) reared in seawater were directly transferred into the experimental rearing water of the different salinities (post-larva : $0\textperthousand$, $5\textperthousand$, $10\textperthousand$, $15\textperthousand$, $20\textperthousand$, $30\textperthousand$. juvenile : $0\textperthousand$, $\10textperthousand$, $20\textperthousand$, $30\textperthousand$. adult : $0\textperthousand$, $15\textperthousand$, $35\textperthousand$, respectively). Fish samples were taken in time courses after transfer for blood and body fluid collection. The changes of sodium, potassium concentration and osmolality of the body fluid and plasma, muscle water content, gonadosomatic index (GSI) and hepatosomatic index (HSI) in the experimental fish were observed in time courses. Growth rate of the post-larva in $\5~25\textperthousand$ were faster than in $0\textperthousand$ (P<0.05). Survival rate was very low in $0\textperthousand$ (P<0.05). No fish survived more than 50 days after transferred into $0\textperthousand$. The concentration of sodium, potassium and osmolality in body fluid of the juvenile sweetfish were slightly decreased at 0.25 day after the beginning of the maintainable level of sodium, potassium and osmolality were $36.4\pm6.2 mM/\ell, 47.5\pm0.7 mM/\ell, 366.3\pm19.1 mOsm/kg, respectively. Except potassium concetration, fish in $0\textperthousand$ and $10\textperthousand$ displayed the pattern of hypoosmotic regulation. Growth rate and survival rate of juveniles of $30\textperthousand$ are significantly low than other groups (P＜0.05). The concentration of sodium, potassium and osmolality in plasma of adult sweetfish were slightly decreased at 1 day after the beginning of the maintainable level of sodium, potassium and osmolality were $159.0\pm2.5 mM/\ell, 5.8\pm0.9 mM/\ell, 338.1$\pm13.3 mOsm/kg respectively. Compared with these values, fish in $0\textperthousand$ and $15\textperthousand$ displayed hypoosmotic regultion. Growth and survival rate of adult in $35\textperthousand$ are significantly low than other experimental groups. GSI was the highest in $15\textperthousand$ after 60 days. HSI was the lowest in $35\textperthousand$. With decreased salinities, oxygen consumption was found to be decreased in the other experimental groups compared to the more than $30\textperthousand$.

• 한국수산과학회지
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• 제37권6호
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• pp.462-468
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• 2004

In order to evaluate adaptation to the environment in released fish, digestive organ and body composition were compared among 1-year old cultured (CUL), released (REL) and wild (WIL) Black Sea Bream, Acanthopagrus schlegeli. Hepatosomatic index (HSI) of the REL was significantly lower than those of the CUL and WIL fish, but intestine weight index (IWI) of REL was significantly higher than those of the CUL and WIL fish. There were no significant differences in stomach weight index (SWI) and condition facto. (CF) among those different fish groups. The number of pyloric caeca of the REL and WIL fish were 4, but the $30{\%}$ of CUL fish was 3 counts. The moisture content of whole body in the WIL fish was significantly higher than the CUL and REL fish, but significant lowest in the crude lipid of whole body. The content of moisture and crude protein of dorsal muscle were no significant differences among the CUL, REL and WIL fish, but crude lipid content of WIL fish was significantly lower than the CUL and REL fish. Moisture content of CUL fish in the liver was significantly lower than the REL and WIL fish, and crude lipid was significant lowest in the WIL fish. Amino acid content of dorsal muscle in the WIL fish was highest in the total amino acid, EAA and E/A ratio, and CUL fish was highest EAA and E/A ratio in liver. EPA content in dorsal muscle of WIL fish was lower than CUL and REL fish, and the REL fish was highest in DHA content of the fatty acid. EPA content in liver of WIL fish was lower than CUL and REL fish, and DHA content in REL and WIL fish was highest and lowest. Crude protein content of CUL and WIL fish in the scale was significantly higher than REL fish, but there were no significant differences in contents of crude lipid and ash. Ca and P of scale were formed most of mineral and content of P in CUL fish was significantly higher than those of REL and WIL fish. There were no significant differences in Mg, K, Na and S of scale, but CUL fish was significantly lower than REL fish in C1. The results suggest that difference of digestive organs and body composition concluded it from differences of inhabitation environment and feed formulations.