• 한국수산과학회지
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• 제53권4호
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• pp.572-576
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• 2020

As grouper aquaculture production intensifies worldwide, hybrids are increasingly produced to induce heterosis of traits such as rapid growth and strong environmental adaptability. In this study, we compared the morphological characteristics of a hybrid grouper to those of its parent species Epinephelus moara and E. lanceolatus. The coefficients of external and skeletal traits evaluated using soft X-rays did not differ significantly among groups; however, several patterns were detected among measured traits. The body depth (BD), length of caudal peduncle (LCP), and pre-anal fin length (PAL) of the hybrid were the same as those of E. moara, whereas the pre-pectoral fin length (PPL) and interorbital width (IOW) of the hybrid were the same as those of E. lanceolatus. Traits that did not differ significantly among the three groups included pre-dorsal fin length (PDL), pre-ventral fin length (PVL), length of anal fin (LAF), and length of dorsal fin (LDF), whereas the depth of caudal peduncle (DCP) and snout length (SNL) showed intermediate traits, and eye diameter (ED) was significantly smaller in the hybrid. Therefore, intermediate traits such as DCP and SNL and specific traits such as ED may be used as indices for hybrid classification.

• 한국수산과학회지
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• 제36권2호
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• pp.136-143
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• 2003

The eggs of Favonigobius gymnauchen attached on the under side of a small stone were collected off Seongsan-eup Cheju-do in August, 2000 to investigate their development of egg, larvae and juveniles. The fertilized eggs were elliptical in shape (mean long axis: 1.50 mm; mean short axis: 0.57 mm) and transparent. There were filaments on one side of the egg membrane. Larvae hatched at 48 hrs 50 mins after morula stage with 25-26 myotomes in $22.8-28.5^{\circ}C\;(mean\;24.7^{\circ}C).$ The newly hatched larvae were 2.31-2.49 mm (mean 2.37 mm n=10) in total length (TL) and their mouth and anus were already opened. Their melanophores were appeared on the over gas globule, around anus and the part of caudal peduncle with 24-25 myotomes. At 4-5 days after hatching. larvae attained 3.81-4.07 mm (mean 3.96 mm, n=10) in TL and their yolk sac was completely absorbed. They began to eat rotifer and transformed to postlarvae stage. At 14 days after hatching, postlarvae attained 6.17-6.31 mm (mean 6.21 mm, n=10) in TL and their caudal notocord was flexed $45^{\circ}$ upward. At 24 days after hatching, postlarvae attained 8.69-9.10 mm (mean 8.87 mm, n=10) in TL had reached the juvenile stage. All fins were formed with the complete set of fin rays with the following counts: dorsal fin rays IV-I, 9-10; anal fin rays I, 9; pectoral fin rays 17; ventral fin rays: I, 5; caudal fin rays: 9+8= 17.

• 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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• 제8권1호
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• pp.14-21
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• 1996

Cottus poecilopus Heckel의 성적 이형을 조사하기 위하여 치악산 계류에서 1993년 1월 부터 1994년 4월까지 조사를 실시하였다. 연령별 암수의 체장 구성비에 있어서 수컷이 암컷 보다 다소 컸으며, 뒷지느러미, 배지느러미, 가슴지느러미의 길이와 입의 크기에 있어 수컷이 암컷보다 길다. 혼인색(nuptial color)과 생식적 유두(genital papilla)는 수컷에서만 존재한다. 암컷은 산란시 큰 수컷을 선호하며, 큰 수컷은 수정란을 보호하고 수류를 일으키는데 우세하며 수정난 생존에 유리하게 작용한다. 또한 큰 입은 산란장을 형성하거나 보호하는데 이점이 있다. 이러한 성적 형태의 차이는 본종의 성적 선택의 결과에 의해 기인된 것으로 생각된다.

• 한국발생생물학회지:발생과생식
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• 제17권3호
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• pp.187-198
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• 2013

In this study, we measured the morphometric and histological changes in the cyprinid loach, Misgurnus anguillicaudatus, during the early period of growth. Eyes, yolk length, yolk height, and yolk volume of the larva decreased for 16 days post hatching (DPH) (P<0.05). During 60 DPH (P>0.05), the most anterior extension of the head ${\times}$ the posterior end of the supraoccipital, the most anterior extension of the head ${\times}$ the origin of the dorsal fin, the most anterior extension of the head ${\times}$ the origin of the pectoral fin, the posterior end of the supraoccipital ${\times}$ the origin of the pelvic fin, and the origin of the dorsal fin ${\times}$ the ventral origin of the caudal fin gradually decreased, whereas the most anterior extension of the head ${\times}$ the dorsal origin of the caudal fin, the origin of the dorsal fin ${\times}$ the origin of the anal fin, the origin of the dorsal fin ${\times}$ the origin of the pectoral fin, and the insertion of the dorsal fin ${\times}$ the origin of the pelvic fin gradually increased (P<0.05). In the cyprinid loach, the retina is composed of six layers: the epithelial layer, ganglion cell layer, inner nuclear layer, inner plexiform layer, outer limiting membrane, and rod and cone layer (RCL). After hatching, part of the RCL gradually increased in density. The kidney and midgut epithelium were already formed in the cyprinid loach just after hatching and grew gradually in subsequent days.

• 수산해양기술연구
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• 제51권1호
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• pp.79-85
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• 2015

Three specimens of larvae (5.2~7.8 mm in standard length (SL)), of the family Scombridae, were collected from the southeastern waters off Jeju Island in August, 2014. These specimens were identified to Katsuwonus pelamis have melanophores distributed on the 1st dorsal-fin spines and post ventral margin on caudal peduncle. An analysis of the cytochrome oxidase submit I (COI) sequences (652 base pairs) of mitochondrial DNA showed that our specimens must be K. pelamis, because their sequences were concordant with those of the adult K. pelamis (genetic distance= 0.000~0.002), followed by Auxis rochei (genetic distance= 0.061~0.063) and Euthynnus affinis (genetic distance= 0.077~0.079). During the larval stage, K. pelamis differed from Thunnus spp. species in melanophores distribution period of 1st dorsal-fin spines, lower jaws and ventral margin on caudal peduncle. In conclusion, occurrence of K. pelamis larvae means Korean waters are potential spawning ground of K. pelamis.

• 한국어류학회지
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• 제18권1호
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• pp.27-35
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• 2006

한국산 칼납자루의 암컷은 산란시기가 되면 배지느러미 기부 부근에 돌출되어 신장되어 나타나는 배측융기가 형성된다. 이러한 배측융기는 직장(항문)부분과 내측산란관으로 구성되었다. 직장은 점막층, 점막하층, 근육층과 이들을 둘러싸는 다층의 표층으로 구성되어 있으며 특히 점막층에는 산성 점액다당류인 점액세포가 존재한다. 한편 내측산란관은 직장과 비슷한 구조를 가지고 있으나 점막층에는 점액세포가 존재하지 않는 특징을 보였다. 한편 외측산란관은 배측융기와 연결되지 않아 가늘고, 긴 관의 형태를 보이고 있으나 내측산란관과 달리 근육층이 존재하지 않아 점막층, 점막하층, 다층의 표피층으로 구성되어 있다. 이러한 결과로 보아 근육층을 가지는 내측산란관은 성숙란을 외측산란관으로 내보기 위해 연동운동과 관련있는 반면에 외측산란관은 근육층이 존재하지 않아 내측산란관으로부터 방출된 성숙란을 단지 이매패 속으로 전달하는 단순한 관의 역할을 하는 것으로 생각된다.

• 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.

• 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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• 제48권3호
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• pp.362-367
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• 2015

We followed the development of Pacific herring Clupea pallasii larvae after natural hatching in Korean coastal waters off Dadaepo, where the water temperature was $9^{\circ}C$. Twenty days after hatching, the larvae had (i) reached a total length (TL) of 10.8-12.2 mm, (ii) developed 9-11 dorsal fin rays, and (iii) branched melanophores along the dorsal line of the gut in the anterior half of the body and along the posterior half of the dorsal and ventral line. Thirty days after hatching, the larvae had reached 12.2-13.5 mm TL, and the number of dorsal fin rays had increased to 13-14. Thirty-five days days after hatching, the larvae had reached 14.0-14.7 mm TL, and the posterior ends of their notochords had begun to flex upward. Forty-five days days after hatching, the larvae had (i) reached 15.6-15.9 mm TL, (ii) a complete set of dorsal fin rays (15-16), (iii) 12-13 anal fin rays, and (iv) branched melanophores along the dorsal part of the lateral surfaces of the head behind the caudal terminus. Preflexion, flexion and postflexion stage larvae had TL values of 13.5 mm, 14.0-15.3 mm, and 15.6-15.9 mm, respectively.