• 한국발생생물학회지:발생과생식
• /
• 제22권1호
• /
• pp.39-53
• /
• 2018

The purpose of this study is to investigate the early life history of the Rhodeus fish, Rhodeus uyekii and R. ocellatus, in the Nakdong River to use as the preliminary data for the systematic study. The embryos used in the study were fertilized eggs (embryo) and larvae after artificial fertilization. The long diameter of the eggs of the R. uyekii was 3.39-3.97 mm (average $3.68{\pm}0.41mm$, n=30) and the short diameter was 1.36-1.55 mm (average $1.45{\pm}0.13mm$, n=30). The long diameter of the eggs of the R. ocellatus was 2.53-2.71 mm (average $2.62{\pm}0.12mm$, n=30) and the short diameter was 1.47-1.60 mm (average $1.53{\pm}0.09mm$, n=30). Hatching time was 48 hours for the R. uyekii and 50 hours for the R. ocellatus given that the average water temperature was $21.5^{\circ}C$. The hatched larvae were 4.95-5.00 mm (average $4.98{\pm}0.04mm$, n=5) for the R. uyekii and the total length was 3.66-3.69 mm (average $3.67{\pm}0.02mm$, n=5) for the R. ocellatus. R. uyekii was found to be 15.5-15.8 mm at total length (average $15.6{\pm}0.21mm$, n=5) on the 56 days after hatching with the number of dorsal fins being ⅲ-9, anal fins ⅲ-10, ventral fins ⅲ-5. The R. ocellatus was found to be 15.8-16.0 mm (average $15.9{\pm}0.14mm$, n=5) at total length on the 58 days with the number of dorsal fins being ⅲ-11, anal fins ⅲ-12 and ventral fins ⅲ-5 where the number of all fin stalks reached maximum.

• Fisheries and Aquatic Sciences
• /
• 제14권4호
• /
• pp.403-410
• /
• 2011

Scartelaos gigas is an amphibious mudskipper species that inhabits mud flats in Korea, China, and Taiwan. This fish is at risk of extinction because of its very restricted habitat and overexploitation. Information about this fish's reproductive characteristics is needed for species conservation. The sexual maturity and early life history of S. gigas were investigated through histological methods and direct observation of eggs in the wild, respectively. In total, 560 individuals of S. gigas were collected with the aid of fishermen from March 2003 to October 2003 at Jung-do Island, southwest Korea. Through microscopic observations of gonadal development, it was determined that S. gigas of both sexes were immature in April, but began to reach maturity in May, and were then fully mature by June, which was maintained until July. In August, some female fish developed early oocytes, but by September oocytes were observed to have degenerated and had been absorbed. Spawned eggs were elliptical and had an average size of 1.37 mm (long axis) by 0.69 mm (short axis). The newly hatched larvae (3.03 mm total length, TL) had an open mouth and anus, two melanophores near the anus, and one large melanophore between the 18th and 19th myomeres. The larvae (3.18 mm TL) showed absorption of the yolk and oil globule within 5 days after hatching and became prelarvae. This species should be considered vulnerable or conservation-dependent, and thus parental fish need to be protected from fishermen during the main spawning season (June).

• 한국수산과학회지
• /
• 제46권6호
• /
• pp.862-867
• /
• 2013

Since the industrial revolution, seawater has increased in temperature and acidity due to the increase in anthropogenic carbon dioxide in the atmosphere. To understand the effect of elevated $CO_2$ on the early life stages of fish, we reared fertilized eggs of black sea bream Acanthopagrus schlegelii under three $CO_2$ concentrations (400, 850 and 1550 ppm) for 3 weeks. The standard length and wet weight of black sea bream larvae declined with enhanced $CO_2$ concentration in the rearing water (P<0.05). However, chemical analysis using ICP-OES on internal tissues of black sea bream larvae indicated that the whole-body calcium concentration increased with $CO_2$ concentration in the rearing water. These conflicting results suggest that future experiments should examine the acid-base balance to investigate the formation of bone and otolith during larval growth.

• BMB Reports
• /
• 제44권3호
• /
• pp.187-192
• /
• 2011

TGF-$\beta$ activated kinase-1 (TAK1) plays a pivotal role in developmental processes in many species. Previous research has mainly focused on the function of TAK1 in model organisms, and little is known about the function of TAK1 in hymenoptera insects. Here, we isolated and characterized the TAK1 gene from Apis cerana cerana. Promoter analysis of AccTAK1 revealed the presence of transcription factor binding sites related to early development. Real-time quantitative PCR and immunohistochemistry experiments revealed that AccTAK1 was expressed at high levels in fourth instar larvae, primarily in the abdomen, in the intestinal wall cells of the midgut and in the secretory cells of the salivary glands. In addition, AccTAK1 expression in fourth instar larvae could be dramatically induced by treatment with pesticides and organic solvents. These observations suggest that AccTAK1 may be involved in the regulation of early development in the larval salivary gland and midgut.

• Environmental Analysis Health and Toxicology
• /
• 제24권1호
• /
• pp.1-8
• /
• 2009

In this study, we obtained the fertilized eggs from goldfish(Carassius auratus) and observed normal developmental stage(from fertilized eggs to larvae) in non-exposed groups. Goldfish embryos at 3 h postfertilization(hpf) were statically exposed for 1 h to either dimethylsufoxide(DMSO, 0.1%, v/v) or TCDD($0.5{\mu}g/L$). Toxicity and morphological changes were characterized from 3 to 120 h postfertilization(hpf). Egg mortality($0{\sim}48$ hpf) and hatching ratio($72{\sim}83$ hpf) in TCDD-exposed group were significantly different from control groups. However, pericardial edema was first observed at 72 hpf, followed by the onset of yolk sac edema and mortality. In addition, goldfish embryos-larvae exposed to TCDD significantly increased TCDD-related gene such as CYP1A($24{\sim}72$ hpf) and AhR2(72 hpf). This is the first study about in-depth characterization of TCDD-induced developmental toxicity in goldfish(Carassius auratus).

• 생명과학회지
• /
• 제12권4호
• /
• pp.407-415
• /
• 2002

동남참게 초기유생에 대한 다양한 먹이를 공급하여 먹이에 따른 어린게까지 소요 일수와 생존율을 수온 22$\pm$1$^{\circ}C$ 및 염분 24$\pm$1% 상태에서 조사한 결과는 다음과 같다. 무투여구에서는 5일만에 조에아 I~2기 상태에서 모두 사멸하였고, 살아있지 않은 먹이인 삶은 계란 난황 건조분말, 삶은 대두 건조분말, 인공배합사료 분말, 삶은 수수 건조분말, 새우 생육세편, 담치 외투막 생육세편를 공급한 실험구에세는 7~9일 까지 생존하였으며 유생의 형태는 조에아 2~3기 상태였다. 식물성 단세포인 C. ellipsoid, S. costatum, 및 C. gracilis를 각각 단독으로 공급하였을 때 각각 10, 18과 19일 까지 생존하였고, 유생의 형태는 조에아 3~5기 상태였고, 동물성 플랑크톤인 Artemia nauplii and rotifer를 공급하였을 때 각각 24일과 25일만에 치게로 변태하였고 이때의 생존율은 각각 43%와 25%이었다. 한편, 조류와 동물성 먹이를 혼합하여 공급하였을 때 단독공급시보다 모든 실험구에서 생존율이 높게 나타났고, 치게까지 도달하였다. 그 중에서 가장 효과가 좋았던 실험구는 규조류인 C. gracilis, Artemia nauplii and rotifer를 혼합공급한 실험구 이었고, 22일만에 치게로 변태하였으며 이때 생존율은 73%였다.

• 한국수산과학회지
• /
• 제9권4호
• /
• pp.273-280
• /
• 1976

1976년 6월 20일에 해운대 동백섬 연안에서 채집된 황아귀의 자어를 재료로 하여 초기생활사에 따른 형태변화 과정중 등지느러미 이극, 배지느러미, 색소포 및 소화관의 발적과정과 아가미, 새조 및 치아등의 형성과정에 관하여 관찰하였다. 1. 제1등지느러미 제1극의 원기는 부화직후인 2.7mm 전후에 생겨나 6.30mm 전후에서 극의 형태로 분화되며, 제2극은 5.82mm 전후에 원기가 나타나고 제3극은 6.45mm 전후에서 원기가 나타나 분화되는 것같다. 2. 배지느러미는 2.7mm 전후에 가슴지느러미의 바로 뒤쪽에서 원기가 나타나고, 처음에는 반원형으로 솟아나듯 하든 것이 차츰 발달함에 따라 뒤쪽으로 향해 곤봉상으로 길어지고, 전장 6.35mm 전후에서 전장의 1/2 정도의 크기로 발달하며, 가는 두 줄의 지느러미 줄기가 나타난다. 3. 색소포의 발달은 특히 미부에 있어서 2단계로 구분할 수 있는데, 부화직후(2.7mm 전후) 미부에 불규칙 9열로 분포하는 경우와 시일이 경과함에 따라 전장 4.25mm전후에는 뚜렷한 3개의 색소포군을 형성하는 경우를 들 수 있다. 4. 소화관은 부화직후인 2.7mm 전후에 창자의 시흔이 나타나기 시작하며 전장 5.4mm 전후에 난황이 축소되면서 창자의 굴곡등 소화관의 윤곽이 뚜렷해질 뿐만 아니라 입도 열리는 것 같다. 5. 아가미는 전장 6.35mm 전후에 시흔이 보이며 발달하기 시작하고 치아는 전장 6.25mm 전후에 원기가 나타나고 새조는 6.45mm 전후에 5개의 새조골을 볼 수 있다.

• 한국응용곤충학회지
• /
• 제38권2호
• /
• pp.85-91
• /
• 1999

본 종은 밤나무혹벌의 유충을 공격하는 외부기생, 단독기생성 천적으로 판명되었으며 성비는 도입종의 벌레혹에 기생하는 경우 1:1이었다. $15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$항온조건하에서 성충의 수명과 산란전기간은 온도가 낮을수록 길었다. 우화 직후 성충운 난소 내에 성숙한 알이 관찰되었으며 우화 4일 후에 피크에 달하였고 이후 점차 감소하는 경향이었다. 알은 장타원형으로 유배색이며, 밤나무혹벌의 유충체포위 혹은 충방내 벽에 낳았다. 산란된 후 3~5일 이내에 부화(15~22$^{\circ}C$)하였으며 노숙유충의 길이는 2.79mm이었다. 유충은 이듬해 3월부터 용화하며 암컷용의 길이는 2.25mm, 수컷용의 길이는 1.89mm로 용화 초기에는 유백색을 띠나 이후에는 흑색으로 변하였다. 강원도 춘천지방에서 밤나무혹벌의 벌레혹은 4월 중순에 형성되어 5월하순까지 성장하였으며 밤색긴꼬리좀벌의 성충은 4월 상순에 우화하기 시작하여 5월 상순에 종료되었다. 본 종은 년1세대 경과하였으며 성숙유충으로 월동하였다.

• 한국수산과학회지
• /
• 제46권6호
• /
• pp.970-972
• /
• 2013

We examined the relative growth of Microstomus achne during early life stages of laboratory-reared larvae and juveniles. Turning points in the relative growth of preanal length and upper jaw length against total length occurred during the settlement period (11.12-19.91 mm in total length). However, turning points in the relative growth of head length and eye diameter, as compared to total length, occurred during metamorphosis (17.57-22.47 mm in total length). Our results suggest that Microstomus achne concentrates its energy on the feeding apparatus (jaw) and digestive organs (intestine) rather than sensory or neural organs (eye, head) during early larval stage growth.

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