• 한국수산과학회지
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• 제30권1호
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• pp.132-138
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• 1997

동해안 한해성 조개인 북방대합의 자원 증대를 위한 기초 자료를 얻기 위하여 1994년 3월부터 1995년 5월까지 주로 조직학적 방법에 의해 생식소의 발달과정과 생식주기를 조사하였다. 북방대합은 자웅이체로서, 생식소는 해부학적으로 소화맹낭과 족부 근육 사이에 위치하였다. 비만도는 1994년 6월에 0.19로 가장 높았으며 11월에 최소값을 보였다. 생물학적 최소형은 각장 50.0mm였으며, 80.0mm 이상의 대형개체에서도 $10\%$ 미만의 성적으로 미분화한 개체가 관찰되었다. 성숙한 난모세포의 크기는 $50\~60{\mu}m$였으며, 성숙기의 정소에서 정소란이 관찰되었다. 북방대합의 생식주기는 분열증식기 ($10\~1$월), 성장기 ($2\~4$월), 성숙기 ($4\~6$월), 산란기 ($6\~7$월) 및 휴지기 ($8\~9$월)의 연속적인 5단계로 구분되었다.

• 한국양식학회지
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• 제17권1호
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• pp.30-38
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• 2004

본 연구는 2000년 1월부터 2001년 12월까지 쥐노래미, Hexagrammos otakit를 대상으로 산란시기를 간접적으로 추정하기 위하여 생식소중량지수(GSI)의 연간변화를 조사하였다. 또한 2000년 1월부터 12월까지 포란수, 산란횟수, 난경조성을 육안적 관찰로 연구하였다. 배우자 형성과정 중 생식세포 분화, 생식소발달 단계에 따른 생식주기, 군성숙도에 관해서 광학현피경으로 연구하였다. GSI의 연간변화는 암컷과 수컷에서 8월에 증가되기 시작하여 저수온기인 10∼11월에 최대값을 나타냈다. 생식연주기는 암컷에서 초기성장기(7월), 후기성장기(7∼8월), 성숙기 (9∼10월), 완숙 및 산란기 (9∼12월), 회복 및 휴지기(12월∼6월)로 구분되었고, 수컷에서는 성장기(6∼8월), 성숙기(8∼10월), 완숙 및 방정기(9∼12월), 회복 및 휴지기(12월∼5월)의 연속적인 단계로 구분할 수 있었다. 성숙 및 산란기인 9∼12월 사이의 난소내 난경조성의 조사 결과, 쥐노래미는 2∼3회 이상 산란하는 다회 산란어종으로 확인되었다. 번식력을 측정하는 총포란수와 성숙란수는 체장이 커질수록 포란수도 많아지고, 체중에도 비례하여 증가하였다. 단위 체장당 총포란수와 성숙란수는 체장의 증가에 따라 증가하였으나, 단위 체중당 포란수는 체중증가에 따라 감소하였다. 군성숙도 조사에서 50%이상 산란에 참여하는 개체는 암$.$수의 체장 19.1∼21.0cm 이었으며, 25.1cm 이상에서 전 개체가 산란에 참여하였으며, 생식에 가담하는 암ㆍ수의 연령은 1세부터였다.

• 한국수산과학회지
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• 제46권6호
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• pp.835-842
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• 2013

Flathead flounder Hippoglossoides dubius is a commercially important fish in the coastal waters of Gangwon Province, which is its spawning ground and breeding habitat. A total of 1,669 gonads were sampled monthly from February 2011 to May 2013 to investigate ecological characteristics, such as variations in maturation and spawning by gonad index, visual maturity stage, histological observations and oocyte diameter. Males were numerically dominant over females in the fishing grounds year round. The spawning season was from January to April, and the peak was from February to March. Oocyte number as a measure of fecundity was between 27,372 and 915,209 eggs with a length range of 26.0-48.7 cm TL, while the largest oocyte grew to 0.9-1.4mm in egg diameter during its spawning season. The relationship between fecundity and total length was $F=0.0016TL^{5.2539}$. The smallest mature lengths of the females and males were 28.4 and 22.6 cm respectively, and the 50% mature lengths of females and males were 32.9, 26.9 cm respectively.

• 한국패류학회지
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• 제27권3호
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• pp.273-282
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• 2011

The ultrastructural characteristics of germ cells during spermatogenesis and mature sperm morphology in male Pinctada martensii were investigated by transmission electron microscope observation. The morphologies of the sperm nucleus and the acrosome of this species are the oval shape and cone shape, respectively. Spermatozoa are approximately $47-50{\mu}m$ in length including a sperm nucleus (about $1.24{\mu}m$ in length), an acrosome (about $0.60{\mu}m$ in length), and tail flagellum (about $45-47{\mu}m$). The axoneme of the sperm tail shows a 9+2 structure. In P. martensii in Pteriidae, a special substructure showing a thick and wide triangular shape which is composed of electron-dense opaque material (occupied about 50% of all, the upper part of the acrosomal vesicle), appeared in the upper region (part) of the acrosomal vesicle, while the lower region (part) of the acrosomal vesicle is composed of electron-lucent material. Thus, this special structure, which exist in the upper part of the acrosomal vesicle in P. martensii, is somewhat different from those of other subacrosomal vesicle in other families in subacrosomal vesicles. Therefore, we assume that the existence of a special substructure showing a thick and wide triangular shape in the acrosomal vesicle of the spermatozoon can be used as a key characteristic for identification of P. martensii or other species in Pteriidae in subclass Pteriomorphia. The number of mitochondria in the midpiece of the sperm of this species are five (exceptionally sometimes four), as one of common characteristics appear the same number of mitochondria in the same families of superfamilyies. This species in Pteriidae does not contain the axial rod and satellite fibres which appear in the species in Ostreidae in subclass Pteriomorphia. These characteristics can be used for the taxonomic analysis of the family or superfamily levels as a systematic key or tools.

• 한국환경생태학회지
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• 제35권2호
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• pp.115-125
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• 2021

본 연구는 전라북도 순창군 복흥면 추령천 일대에서 2006년 2월부터 2007년 5월까지 가시납지리의 개체군 생태조사를 실시하였다. 가시납지리는 물의 흐름이 느리고 하상이 주로 모래, 뻘, 잔자갈의 비율이 높은 수역에서 서식하였다. 체장빈도분포법으로 연령을 추정한 결과, 체장 30~46mm 군은 만 1년생, 47~58mm 군은 만 2년생, 59~68mm 군은 만 3년생, 69mm 이상 군은 만 4년생 이상으로 추정되었다. 생식소성숙도지수(GSI)는 3월(암: 12.9%, 수: 5.0%)에 가장 높았고, 산란관길이/체장(Ovipositor length/Standard length)의 비율(%)은 4월(46.3%)에 가장 높았다. 성숙란인 1.6mm 이상 크기의 난경이 차지하는 비율은 5월(13.2%)에 가장 높게 나타났다. 산란기 특성을 종합적으로 분석한 결과 산란기는 3월부터 6월까지로 추정되었고 (수온 11.5~22.5℃) 조사기간 동안 성비는 1:1.13(♀:♂)이었다. 포란수는 318±174.5 (50~583)개, 성숙란수는 220±139.2 (50~406)개, 성숙난의 크기는 장경 2.04±0.110mm, 단경 1.55±0.100mm으로 나타났다. 가시납지리의 주요 먹이생물은 규조류(Bacilariophyceae)의 Fragilaria, Synedra, Navicular, Cymbella 등과 녹조류(Chlorophyceae)의 Cosmarium 같은 식물성플랑크톤이 주로 관찰되었다.

• Fisheries and Aquatic Sciences
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• 제23권6호
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• pp.16.1-16.10
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• 2020

This study was conducted in Lake Hayq between January and December 2018. The objectives of this study were to determine the growth, condition, sex ratio, fecundity, length at first sexual maturity (L₅₀), and spawning seasons of common carp (Cyprinus carpio). Monthly fish samples of C. carpio were collected using gillnets of stretched mesh sizes of 4, 6, 7, 8, 10, and 13 cm and beach seines of mesh size of 6 cm. Immediately after the fish were captured, total length (TL) and total weight (TW) for each individual were measured in centimeters and grams, respectively, and their relationship was determined using power function. Length at first maturity (L₅₀) was determined for both males and females using the logistic regression model. The spawning season was determined from the frequency of mature gonads and variation of gonadosomatic index (GSI) values of both males and females. Fecundity was analyzed from 67 mature female specimens. The length and weight relationship of C. carpio was TW = 0.015TL^2.93 for females and TW = 0.018TL^2.87 for males that indicate negative allometric growth in both cases. The mean Fulton condition factor (C_F) was 1.23 ± 0.013 for females and 1.21 ± 0.011 for males. The value of C_F in both cases was > 1 that shows both sexes are in good condition. Among the total 1055 C. carpio collected from Lake Hayq, 459 (43.5%) were females and 596 (56.5%) were males. The chi-square test showed that there was a significant deviation between male and female numbers from 1:1 ratio (χ²= 22, df = 11, P > 0.05) within sampling months. The length at first sexual maturity (L₅₀) for females and males were 21.5 and 17.5 cm, respectively. Males mature at smaller sizes than females. The spawning season of C. carpio was extended from February to April, and the peak spawning season for both sexes was in April. The average absolute fecundity was 28,100 ± 17,462. C. carpio is currently the commercially important fish while Nile tilapia fishery has declined in Lake Hayq. Therefore, this baseline data on growth, condition, and reproductive biology of common carp will be essential to understand the status of the population of carp and design appropriate management systems for the fish stock of Lake Hayq, Ethiopia, and adjacent countries.

• Animal cells and systems
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• 제13권3호
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• pp.345-350
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• 2009

We have isolated and characterized a new insect chicken type (c-type) lysozyme gene from the common cutworm, Spodoptera litura. The full-length cDNA of Spodoptera lysozyme is cloned by rapid amplification of cDNA ends PCR (RACE-PCR). The isolated cDNA consists of 1039 bp including the coding region for a 142-amino acid residue polypeptide, which included a signal peptide of 21-amino acid residue and a mature protein of 121-amino acid residue. The predicted molecular weight of mature lysozyme and its theoretical isoelectric point from amino acid composition is 13964.8 Da and 9.05, respectively. The deduced amino acid sequence of Spodoptera lysozyme gene shows the highest similarity (96.7%) to Spodoptera exigua lysozyme among other lepidopteran species. Amino acid sequence comparison with other the c-type lysozymes, Spodoptera lysozyme has the completely conserved $Glu^{32}$ and $Asp^{50}$ of the active site and eight Cys residues are completely conserved in the same position as that of other lepidopteran lysozymes.

• 한국발생생물학회지:발생과생식
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• 제13권2호
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• pp.123-132
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• 2009

웅어 Coilia nasus의 생식소중량지수(GSI), 비만도지수, 난소 발달, 군성숙도, 포란수를 2007년 1월부터 2007년 12월 까지 조직학적 관찰 및 형태 측정 분석에 의해 조사하였다. GSI와 비만도지수는 2월에 증가하기 시작하여 난소가 성숙해지는 6월에 최대에 이르며, 그 후 산란이 일어나는 7월에 급격히 감소하였다. 그러므로 GSI와 비만도지수의 월별 변화는 난소의 성숙 및 산란과 밀접한 관련을 갖는다. 암컷의 난소 발달 단계는 연속적인 5단계로 구분되었다. 초기성장기($2{\sim}$3월), 후기 성장기($3{\sim}$4월), 성숙기($5{\sim}$6월), 완숙 및 산란기($6{\sim}$7월), 회복 및 휴지기($12{\sim}$1월). 본 종의 성숙과 산란은 고수온-장일장인 $6{\sim}$7월 사이에 일어난다. 군성숙도 조사에서 50% 이상 산란에 참여하는 암컷 개체는 전장 $24.1{\sim}27.0$cm 이었으며, 30.1 cm 이상에서 전 개체가 산란에 참여하였다. 절대포란수에 있어서 총포란수와 송숙란수는 전장 및 체중이 커질수록 증가하였다. 상대포란수에 있어서 총포란수와 성숙란수는 전장에 비례하여 증가하였으나, 이들 난수는 최대 체중(126.0${\sim}$150.0 g)에 도달하면 상대포란수는 오히려 감소하는 경향을 보였다.

• 한국동물위생학회지
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• 제32권1호
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• pp.83-85
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• 2009

In a cross-sectional abattoir survey of bovine pulmonary diseases in Mymensingh, during September 2001 to April 2002, subclinical Dictyocaulus viviparous infection was found in mesoendemic level in Bangladeshi adult zebu cattle. The number of mature lung worms varied from $1{\sim}18$ in individual lungs. One to five mature lung worms were most frequent (74.2%) followed by 6 to 10(19.3%) and $11{\sim}18$ (6.5%). Of the total 123 mature worms collected from 31 lungs, there were 50 (40.7%) male and 73 (59.3%) female worms. The female lungworms (mean length 14.41mm) were significantly (P<0.01) larger than the male lungworms (mean length 11.28mm). The number of hydatid cysts varied from $1{\sim}80$ in individual lungs. One to five ($1{\sim}5$) cysts were recorded most commonly (76.0%) followed by $11{\sim}80$ (20.0%) and $6{\sim}10$ (4%). The size (diameter) of the hydatid cysts ranged from $2{\sim}12cm$. Of the total 203 hydatid cysts collected from 31 lungs 45 (22.2%) cysts were fertile and 158 (77.8%) cyst were sterile.

• Fisheries and Aquatic Sciences
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• 제21권11호
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• pp.34.1-34.13
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• 2018

Sexual maturity ($L_{50}$), the length at which 50% of fish in a size class are mature, is a key aspect of domestication of new fish species because it guides the procedure for identification of appropriate broodstock size for artificial spawning. In this study, the $L_{50}$ was determined for 1083 Barbus altianalis samples obtained from Lake Edward and the Upper Victoria Nile. Gonads of freshly killed samples were examined macroscopically and verified with standard histological procedures for the maturation stages that were used to determine $L_{50}$. Oocytes and spermatogenic cell sizes were compared for fish obtained from both water bodies. Results indicated that there were no variations in macro gonad features observed for fish from Lake Edward and Upper Victoria Nile. Similarly, there were no significant differences in oocyte sizes (P > 0.05) between the two populations but significant differences in spermatogenic cell sizes were noted (P < 0.05) except for spermatozoa (P > 0.05). This however did not suggest peculiar differences between the two populations for staging the gonads. Consequently, no staging variations were suggested for both populations in determination of $L_{50}$. Sexual maturity was found in the same class size of fork length (FL) 20-24.9 cm and 35-39.9 cm for males and females from both water bodies, respectively. At this FL, however, males were too small, and for good selection of vigor broodstocks for spawning and conservation purposes, they are better picked from class size of 30-34.9 cm FL and above. These findings were crucial for integration of appropriate breeding size in spawning protocol by farmers and fisheries scientists conserving wild B. altianalis populations.