• 한국양식학회:학술대회논문집
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• 한국양식학회 2003년도 추계학술발표대회 논문요약집
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• pp.76-77
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• 2003

Olive flounder Paralichthys olivaceus larvae and early juveniles were reared for 43 days after hatching in order to observe the effects of starvation during development and metamorphosis. Morphological, histological and biochemical measurements were made to assess the nutritional condition during growth and starvation from pre-matamorphic through post-metamorphic phases. Two groups of fish were compared ; one with sufficient food supply and one under continuous starvation until death. Among morphometric analyses, both ratios of body height at anus/head height and pre-/post-anal lengths appeared to be sensitive to starvation during which substantial reduction was observed within a day of food deprivation. Histological variables as intestinal and rectal epithelial heights and gall bladder volume changed significantly with onset of starvation. The gut epithelial heights of starving fish decreased with advances in starvation, although they fluctuated during mid-metamorphic phase. In contrast, gall bladder volume increased remarkably soon after starvation. Ontogenetic changes in both gut epithelial height and gall bladder volume were evident, those associated with settlement and/or completion of metamorphosis. Abrupt decrease in the RNA/DNA ratios of starving fish were found right after onset of starvation. Even in the fed fish marked fluctuations in its ratios during metamorphosis were observed, evident by decreasing from late-metamorphic to post-metamorphic stages. These findings suggest that a combination of morphologically and histologically sensitive characteristics, and biochemical measurement could be utilized as a measure to evaluate nutritional condition related to starvation in wild olive flounder larvae and juveniles.

• 한국수산과학회지
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• 제50권3호
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• pp.287-295
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• 2017

Egg development and morphological change of larvae of the Sakhalin sole Limanda sakhalinensis were studied by observing specimens obtained in a rearing experiment from fertilized eggs to the juvenile stage. The wild broodstock was collected in January 2010 and kept in a circular water tank (${\O}1.5{\times}1m$) at a temperature of $14.5{\pm}0.5^{\circ}C$. Fertilized eggs ranged from 0.72 to 0.82 mm ($0.77{\pm}0.07mm$, $mean{\pm}SD$) in diameter. The eggs were spherical, transparent and adhesive demersal. The egg yolk was divided from the oocyte 10 min after fertilization (AF), and an embryo was formed in 36 h AF. More than 50% of the eggs hatched within 133 h AF. The mouth and anus did not open until $3.5{\pm}0.25mm$ total length (TL). At 4, days after hatching (AH), the fish became larvae 3.7 to 4.2 mm ($4.0{\pm}0.36mm\;TL$), yolk absorption was completed and the mouth began to open. The left eye moved upward and the nostril moved to the right at 39 days AH. These post-larvae ranged from 8.0 to 9.9 mm TL ($8.9{\pm}1.33mm\;TL$). At 50 days AH, the fish became juveniles ($12.4{\pm}1.20mm\;TL$) There were 70-72 dorsal fin rays, 55-56 anal fin rays, 11 pectoral fin rays, and 6 ventral fin rays and the juveniles adopted a benthic life.

• 한국수산과학회지
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• 제53권2호
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• pp.203-208
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• 2020

This study was carried out to clarify the larvae and juveniles of egg development and autonomous development of Hemibarbus longirostris from Korea, and to obtain basic data for species conservation and seed production. The shape of the egg was circular and sticky. The average size of the eggs was 2.01 mm (n=10). At 185 hours after fertilization, more than 50% of the total embryos were hatched. The newly hatched larvae had an average total length of 8.10 mm (n=5) and had egg yolk in the abdomen. At 3 days after hatching, the larvae absorbed all egg yolk was average total length 8.64 mm. On the 6 days after hatching, the caudal tip of the notochord started to curve upwards was average total length 10.9 mm. At 70 days after hatching, the average total length 37.9 mm. The number of fins was i 8-10 in dorsal fin, iii 7 in the anal fin, and ii 5 in the ventral fin.

• 한국어류학회지
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• 제12권2호
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• pp.146-153
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• 2000

본 연구는 1995년 5월과 6월에 부산시 해운대구 송정동의 조간대에서 6차에 걸쳐 소형 치어망(稚魚網)으로 Ocyneetes modestus 자치어(仔稚魚)를 채집하여, 실험실에서 사육하면서 형태발달 과정을 관찰하였다. 전기자어(前期仔魚)인 평균체장(平均體長) 6.28 mm 개체는 난황(卵黃)이 완전하게 흡수되어 있고, 근절(孵節)은 32~33개이다. 평균체장(平均體長) 7.36 mm 자어(仔魚)에서 처음으로 척삭(脊索)의 끝이 위로 굽어지기 시작하여, 평균체장(平均體長) 9.34 mm 이상의 개체에 달하면 완전하게 위로 굽어져 있다. 평균체장(平均體長) 10.08 mm 이상의 개체에서 모든 지느러미 줄기가 완전하게 정수에 달하여 치어기(稚魚期)로 이행한다. 평균체장(平均體長) 10.08 mm의 치어(稚魚)에서 눈의 윗부분인 머리의 동쪽에 1쌍의 수실모양의 피질 돌기가 형성되어 있다. 평균체장(平均體長) 14.00 mm 이상의 치어(稚魚)는 몸의 형태와 색체가 성어(成魚)에 닮아 있다. 국내 미기록 어종인 Ocyneetes modestus의 한국명을 머리부분에 수실모양의 피질 돌기가 1쌍밖에 없는 점에서 가시꺽정이와 비교하여 "민가시꺽정이"로 국명을 명명한다.

• 한국수산과학회지
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• 제41권6호
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• pp.478-484
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• 2008

To elucidate the spawning behavior and early life history of Liobagrus mediadiposalis, mature male and female fish were collected from a branch of the Seomjin River. Spawning was induced by injecting hormones, and then the spawning process and development of fertilized eggs, larvae, and juveniles were observed. Observations of spawning behavior showed that the female established a territory and built a spawning nest, and frequently pressed on the upper ventral part of the male to release her eggs. When spawning was finished, the fish supplied fresh water to the egg mass using their pectoral and caudal fins. Hatching began 189 h 20 min after fertilization at $21.5-23.5^{\circ}C$ (mean $22.7^{\circ}C$). The mean total length (TL) of newly hatched larvae was 7.18-7.39 mm (mean 7.31 mm). Their mouth and anus were already open and they had 14+24=38 myotomes. Eighteen days after hatching, the larvae were 12.71-13.79 mm (mean 13.27 mm) in TL and the yolk sac was absorbed completely. At 35 days after hatching, when all the fin-rays had formed, the juveniles were 15.84-17.92 mm (mean 16.33 mm) in TL.

• 한국발생생물학회지:발생과생식
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• 제21권3호
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• pp.287-295
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• 2017

This study was conducted to observe egg and larvae morphological development of carp to obtain basic data for resource conservation and taxonomic research. Brood carp used in the research (total length 67.3-75.5 cm, average $71.0{\pm}3.45cm$) were bred in a circular rearing aquarium ($600{\times}300{\times}100cm$) using a running water system from January to July, 2015. Breeding water temperature was maintained at $23.0-25.0^{\circ}C$(average $24.0^{\circ}C$). Fertilized carp eggs were translucent and globular, and their size was 1.75-1.89 mm (average $1.82{\pm}0.06mm$). Blastoderms formed 10 min after fertilization and reached the two-cell stage 30 min after fertilization. Then, the embryo turned dark and exhibited melanophores, and blood started flowing from the heart across the egg yolk at 42 hrs and 50 min after fertilization. Hatching began 70 hrs and 26 min after fertilization larvae emerged through the egg membrane, starting from the head. The length of prelarvae immediately after hatching was 5.23-5.38 mm (average $5.31{\pm}0.11mm$) the mouth and anus were closed, and the pectoral fin was formed. Postlarvae at 18 days after hatching had a total length of 11.9-13.9 mm (average $12.9{\pm}1.40mm$), separate anal fin and back membranes, and fin ray. Juveniles fish at 35 days after hatching had a total length of 29.9-30.2 mm (average $30.1{\pm}0.13mm$), with the body covered with scales, and the same number of fin rays, color, and shape as their broodstork.

• 한국발생생물학회지:발생과생식
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• 제24권4호
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• pp.307-316
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• 2020

The purpose of this study is to observe the early life history of Korean Lefua costata and use the result as basic taxonomic research data for balitorid fish. The fertilized eggs were light green color with completely circle shape and mean size was 1.21±0.06 mm (n=30). Immediately after hatching, the size of the larvae was 2.81±0.11 mm (n=5) in mean length, with egg yolk. On the 3rd day after hatching, the preflexion larvae had a mean length of 4.64±0.09 mm (n=5), and their mouth was opened to start feeding. On the 8th day after hatching, a mean length of the postflexion larvae was 9.43±0.46 mm (n=5), the distal part of the notochord was bent to 45°, and 16 fin rays were developed on the caudal fin. On the 31st day after hatching, a mean length of juveniles was 22.3±0.85 mm (n=5), and the number of fin rays was the same as that of adult fish with (iv8) dorsal fins and (iii8) anal fins.

• 한국발생생물학회지:발생과생식
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• 제20권1호
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• pp.31-40
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• 2016

This study was conducted in order to examine the egg development in red spotted grouper, Epinephelus akaara and the morphological development of its larvae and juveniles, and to obtain data for taxonomic research. This study was conducted in June 2013, and 50 male and female fish were used for the study. One hundred ${\mu}g/kg$ of LHRHa was injected into the body of the fish for inducing spawning, and the fish were kept in a small-sized fish holder ($2{\times}2{\times}2m$). Eggs were colorless transparent free pelagic eggs, 0.71-0.77 mm large (mean $0.74{\pm}0.02mm$, n=30), and had an oil globule. Hatching started within 27 h after fertilization. Pre-larvae that emerged just after hatching were 2.02-2.17 mm in total length (mean $2.10{\pm}0.11mm$), their mouth and anus were not opened yet, and the whole body was covered with a membrane fin. Post-larvae that emerged 15 days post hatching were 3.88-4.07 mm in total length (mean $3.98{\pm}0.13mm$), and had a ventral fin with two rays and a caudal fin with eight rays. Juveniles that were formed at 55 d post hatching, were 31.9-35.2 mm in total length (mean $33.6{\pm}2.33mm$), with red color deposited over the entire body, and black chromophores deposited in a spotted pattern. The number of fin rays, body color, and shape were the same as that in the adult fish.

• 한국어류학회지
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• 제19권4호
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• pp.332-342
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• 2007

이 연구는 경상북도 울진 연안 해역에서 2002년 1월, 4월, 7월 및 10월까지 계절별로 총 4회에 걸쳐 만조시에 채집된 부유성 난 자치어의 종조성, 양적변동을 연구하였다. 연구기간 동안 채집된 부유성 난은 총 7개 분류군이 출현하여 멸치, 정어리, 까나리, 참가자미속 어류, 앨퉁이, 보리멸, 기타 난 등으로 분류되었고, 출현량을 보면, 멸치 난이 연구기간 동안 출현한 부유성 난의 38.34%를 차지하여 가장 우점도가 높았으며, 보리멸 난이 25.84%를 차지하였다. 연구기간 동안 출현한 자치어는 총 7목 18과 25개의 분류군이 출현하였고, 멸치가 연구기간 동안 출현한 자치어의 90.46%를 차지하여 최우점종이었으며, 다음으로 조피볼락이 자치어의 2.04%를 차지하였다. 이들 2종이 차지한 비율은 92.49%이었으며, 나머지 23개 분류군은 7.51%를 차지하였다. 2002년 울진에서 계절별 종 다양도지수(H')는 0.0878~2.3855였고, 균등도지수는 0.0451~0.9300로 나타났다. 우점도의 경우는 0.3000~0.9914로 종 다양도지수와 균등도지수와는 반대 경향을 보였다. 정점별로 분석한 종 다양도지수는 0.3035~0.7440으로 정점 2에서 가장 낮은 값을 나타냈고, 정점 1에서 가장 높은 값을 보였다. 우점도의 경우는 0.8919~0.9669로 종 다양도지수와 균등도지수와는 반대 경향을 보였다. 계절별 군집의 유사도는 여름과 가을에 상대거리 차(0.010)가 가장 적어 군집상이 매우 유사하였고, 정점별로는 정점 1과 정점 4에서 가장 적은 상대거리 차(0.014)를 보여 군집상이 매우 유사하였다.

• 한국수산과학회지
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• 제41권6호
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• pp.471-477
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• 2008

Development of egg, larvae and juveniles for the Pacific mackerel, Scomber japonicus are described following natural fertilization in the indoor tank of $25^{\circ}C$ water temperature. Following a routine hormone treatment technique for the brood stock, male and female mackerels were artificially matured by intramuscular injections of LHRHa at a dosage of $400{\mu}g/kg$ body weight (BW)+Domperidone at a dosage of $4{\mu}g/kg$ body weight (BW) to induce maturation in a separate aquarium and induced natural spawning. Fertilized eggs were ca. 1.0 mm in diameter; spherical in shape with a single oil globule; pelagic and non-adhesive. Hatching occurs 41 hours after fertilization at $23-24^{\circ}C$. The newly hatched larvae was 3.03 mm in average total length (ATL), the mouth and anus were not open, oil globule located in posterior end of yolk sac, and preanal length was 42.8% of TL. The larvae measuring 2.89 mm ATL, almost absorbed yolk sac and oil globule material in 2 days after hatching, in which the mouth and anus were open. Melanophores, branch or star in shape were observed on the top of head, peritoneal region and along the ventral contour. In 13 days after hatching, the larvae was 6.88 mm ATL, its posterior end of notochord began to flex upward, finfold of caudal fin appeared, jaw teeth were already formed. In 19 days after hatching, the larvae was 7.71 mm ATL completed only caudal fin rays (9+8), and preanal length was 49.4% of TL. In 37 days after hatching, the larvae was 27.4 mm ATL already completed all the fins, and preanal length was 59.9% of TL.