• Korean Journal of Environmental Biology
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• v.23 no.1
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• pp.27-31
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• 2005

Early larval growth for total length (TL) and body weight (BW) in flesh prawn (Fenneropenaeus chinensis) was studied from hatching to 25 days after hatching. Mean total length at nauplius and zoea stages was 0.21-0.39 mm and 0.62-1.03 mm, respectively. Mean total length of mysis stage grew from 1.28 mm (9 days after hatching) to 5.98 mm (21 days after hatching). The increase of body weight during experimental period showed step by step growth pattern due to metamorphosis of this species. The relationship between BW and TL from hatching to 25 days after hatching was BW = 2E-5TL/sup 4.1707/ (r²= 0.9746).

• Korean Journal of Ichthyology
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• v.36 no.1
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• pp.10-19
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• 2024

This study investigated the early life history of Hemibarbus labeo from in Wicheon, stream Nakdonggang-River, and compared their characteristics with closely related species. In April 2021, egg formation and development of autonomous fish were observed in fertilized eggs collected at four spawning sites. The size of the fertilized egg was 1.93~2.39 (average 2.22±0.15, n=30) mm. The water temperature was 22.2~24.1°C, and the hatching time took 109~115 hours. Newly after hatching, the total length of the yolk-sac larvae was 7.50~8.80 (average 7.99±0.46) mm, and the mouth and anus did not develop and had difficulty in being yolk. 6 days after hatching, the preflexion larvae were fed with a total length of 9.49~10.2 (9.78±0.23, n=30) mm. 10 days after hatching, the flexion larvae was 9.97~11.9 (10.7±0.72, n=30) mm in total length, and the tail of the vertebrae began to bend. 20 days after hatching, the postflexion larvae was 12.6~15.2 (13.9±0.77, n=30) mm in total length, and the tailbone was completely bent to 45°. 29 days after hatching, the total length of the juvenile was 16.9~19.8 (18.1±0.91, n=30) mm, and the number of fins reached an integer with 10 dorsal fins, 9 anal fins, and 7 ventral fins. The distribution of melanophore, such as the head, the center of the body, and the upper part of the fin, was different from that of the allied species during the postflexion larvae period, so the morphological characteristics could be distinguished.

• Current Research on Agriculture and Life Sciences
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• v.20
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• pp.55-63
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• 2002

This experiment was to know properties of Sericin Jam that development, growth of silkgland, content of sericin and composition of amino acid in hemolymph. The characters of Sericin Jam can he seen form this experiment. Hatching ratio was 85% in Sericin Jam and 95% in Jam 120. Especially hatching period of Sericin Jam was longer than Jam 120 and also hatching of Sericin Jam was ununiform. The larval duration of Sericin Jam was 20 days and 23 hours, and Jaw 120 was 21 days and 22 hours. In Sericin Jam, middle silkgland contain a great p arts in silkgalod and posterior silkgand is short and no curves. The period of mounting to emergence was 12 days in Sericin Jam. The period of pupa was 7day. It is property of Sericin Jam that the period is short. Cocoon was very thin and light in Sericin Jam. Weight of cocoon shell of Sericin Jam is 2.7cg. The sericin protein quantity was 100% in cocoon shell of Sericin Jam, about 28% in cocoon shell of Jam 120, however the sericin ratio per Sericin Jam cocoon was 34.6% compare to cocoon shell of Jaw 120 in sericin protein quantity. The amino acids in hemolymph of Sericin Jaw was much hidtidine, lysine, glut amic acid. And the amount of almost amino acids were increased depends upon development at t he 5th instar.

• Korean Journal of Ichthyology
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• v.36 no.2
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• pp.120-128
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• 2024

In this study, the characteristics of the early life history were investigated for the Hypomesus nipponensis in the west coast Daeho Bay. Egg's were adhesive eggs that had the property of sinking in water in a circular shape. The size of mature eggs was 0.52~0.66 (average of 0.59±0.03, n=30) mm. The hatching time took 140 hours at a water temperature of 22~23℃. Immediately after hatching, the yolk sac larvae was 4.78~5.60 (average of 5.25±0.26, n=30) mm in total length, and the mouth and anus were not completely opened. On the 7 days after hatching, the preflexion larvae was 5.91~6.64 (6.32±0.21) mm in total length, and the mouth and anus were opened, and feeding activities were started. On the 25 days after hatching, the flexion larvae was 9.70~12.3 (10.2±0.63) mm in total length, and the end of the spine at the tail end began to bend upward. On the 42 days after hatching, the postflexion larvae was 14.1~18.8 (16.9±1.44) mm in total length, and the end of the spine at the tail was completely bent at 45°. On the 56 days after hatching, it reached the integer with 10 dorsal fins, 16 anal fins, 7 ventral fins, and 19 caudal fins. According to the study, there were spot-shaped melanophore vesicles under the pectoral fins during the incubation period, the different positions of the egg yolk compared to the battlefield, the deposition of melanophore vesicles on the back and under the body of the caudal part during the postflexion larvae period, and the absence of melanophore vesicles on the torso between the head and the starting point of the dorsal fin. It was distinguished from related species in that melanophore vesicles were deposited in one row from the back of the body to the caudal part during the juvenile period.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.19 no.1
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• pp.35-40
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• 2014

Hatching date, main spawning period and growth of juvenile marbled flounder (Pseudopleuronectes yokohamae) were determined by analysis of microstructure in otoliths. Marbled flounders were collected by a small beam trawl in Namhae from February 2011 to January 2012. The length (L, mm) was related to body weight (W, g); $W=9.76^*10^{-8}L^{4.39}$ ($r^2=0.93$). The length was also related to otolith radius (R, ${\mu}m$); L=0.0795R+0.2249 ($r^2=0.92$). The growth in length was represented by Gompertz growth curve; $L_t=135{\exp}\{-{\exp}[0.0103(t-116)]\}$ ($r^2=0.83$). The hatching date calculated from the number of daily growth increments in otoliths was between mid-December and mid-February.

• Korean Journal of Poultry Science
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• v.46 no.1
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• pp.1-10
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• 2019

The most important times during the development of young chicks are the days immediately prior to hatching and the days immediately after hatching, known as the perinatal period. A sufficient supply of nutrients during the perinatal period is a crucial during the late stage of embryonic development and the starvation period of the young chicks. The delayed post-hatch holding time can restrict the development of the gastrointestinal tract, reduce final body weight, impair muscle development, and change immunological capacities. These symptoms are deleterious to the development of young chicks. Therefore, the post-hatch holding time and its influence on the fitness of young chicks are major concerns to the poultry industry. The in ovo feeding is a practical technology for perinatal nutrition to optimize poultry production and for attenuating the stress experienced by fasting young chicks. This study will discuss in ovo feeding and its effect on the development of the chick embryo, the establishment of a healthy microbiota, and the improving immune response.

• Development and Reproduction
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• v.17 no.4
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• pp.345-351
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• 2013

This study examines the effects on fertilization rate (FR), hatching rate (HR), and normal individual rate after artificial fertilization using frozen thawed sperm according to the cryoprotectant (DMSO) concentration and the period of cryopreserved sperm of longtooth grouper, Epinephelus bruneus. Performing artificial fertilization using frozen-thawed sperm, after freezing the sperm at different DMSO concentration of 5.0%, 7.5%, 10.0% respectively, FR were (DMSO 5.0%: $99.5{\pm}0.8%$, DMSO 7.5%: $99.5{\pm}0.7%$, and DMSO 10.0%: $99.6{\pm}0.6%$). The results are not significantly different from the control fresh sperm (100%). HR also (DMSO 5.0%: $96.2{\pm}2.3%$, DMSO 7.5%: $95.3{\pm}3.6%$, 10.0%: $96.6{\pm}1.8%$) were not significantly different in each group. The normal individual rate after hatching using with control fresh sperm ($98.4%{\pm}0.5$) and DMSO concentration level of 5.0% ($97.8{\pm}0.1%$) were not significantly different. However, with 7.5% ($97.2{\pm}0.6%$) and 10.0% DMSO concentrations ($95.9{\pm}0.2%$) are lower than the normal individual rate after hatching observed in the control and 5.0% DMSO. Performing artificial fertilization using frozen-thawed sperm at different frozen period (2 days, 2 years, and 3 years), 10% DMSO FR and HR of 3 years (FR; $66.8{\pm}1.8%$, HR: $82.0{\pm}12.9%$) and 2 years (FR; $78.5{\pm}14.8%$, HR: $79.3{\pm}0.6%$) cryopreserved sperm were lower than control (FR; 100%, HR: $91.1{\pm}3.6%$) and 2 days cryopreserved sperm (FR; $99.6{\pm}0.6%$, HR: $96.6{\pm}1.8%$). These results suggest suitable DMSO concentration ranges of cryopreservation sperm for E. bruneus is 5 to 10% and with 2 to 3 years cryopreservation period, cryopreservation sperm can be useful for seed production.

• Journal of Aquaculture
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• v.10 no.4
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• pp.463-472
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• 1997

Floating and hatching rates, size and survival activity index(SAI) of spawned eggs of red spotted grouper, Epinephelus akaara were studied to understand egg qualities during the spawning periods in 1992, 1993 and 1995. The fish spawned from mid-July to mid-August when temperature ranged 23~$28^\circC$. Floating, fertilization and hatching rates were higher in the eggs from early to middle than those from late during the spawning period. SAI ranged 1.8~9.6, and it was closely related to survival rate until mouth operning time (SMOT). Egg diameter decreased gradually with the time of spawning, while diameter of oil globule was constant during the spawning periods. Induced spawnings were carried out with one injection of HCG over 5, 000 IU/kg body weight. Floating, fertilization and hatching rates of the induced spawning eggs were higher than those of untreated ones. Thus, induced spawning method with HCG was recommended for collecting fertilized eggs in bulk. Optimal time for the collection of high quality eggs was supposed to be from early to middle during the spawning periods. Considering that egg qualities were vulnerable within the period, hatchability, incidence of malformed larvae, SMOT and SAI were factors to be considered together to get good quality of eggs.

• Korean Journal of Ichthyology
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• v.12 no.3
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• pp.208-214
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• 2000

The egg development and morphological changes of larvae of the file fish, Thamnaconus modestus(Gunther), was investigated by artificial insemination. The fertilized egg was spherical in shape, colorless and adhesive with 0.63~0.67mm in diameter and yolk had 20~30 oil globules of various size (0.04~0.16 mm in diameter). The hatching occured at 53 hours after fertilization in $21.0\sim23.0^{\circ}C$ of water temperature. Hatched larvae measured 2.07~2.20 mm in total length with 5~6+17~18=22~24 myotomes. The 3~4 days after hatching larvae grew to the total length 2.62~2.77 mm, opened mouth and anus. The 5 days after hatching, total length of the larvae was 2.74~3.04 mm, the first dorsal fin was formed at the behind of head. After hatching 12~13 days larvae attained 3.78~3.99 mm in total length. This period formed rudimental dorsal fin and anal fin. Twenty days after hatching, larvae grew to 6.04~6.17mm in total length, at which time the dorsal, anal and caudal fin rays reached 19~20, 18~19 and 9~10, respectively.

• Korean Journal of Ichthyology
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• v.10 no.1
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• pp.1-10
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• 1998

The early history of Korean mandarin fish, Siniperca scherzeri was studied to obtain some information required in aquaculture and reinforcement of natural population. During the period from June 1996 to July 1997, the mature adults of Siniperca scherzeri were collected from the middle Soyang Lake at Puksan - myon, Chunchon - shi, Kangwon - do, Korea. The eggs from females were obtained by injecting HCG or/and GnRH - a and fertilized by dry method in the laboratory. The fertilized eggs, measuring 1.70~2.10 mm in diameter and expanded to 2.20~2.66mm after absorption of water, were globosity, light orange yellow, separative, submergence and had one large oil globules of 0.5~0.7 mm. The blastodisc was formed in 1 hour and cleavage started in 1 hour 30 min. after fertilization, and the intervals of each stage of cleavage was about 50 min. at the water temperature of $21{\sim}24^{\circ}C$. Hatching occurred 131 hours 30 min. after fertilization and newly hatched larvae were 5.86~6.85 mm in total length(TL) and numerous stellate melanophores were distributed on the yolk and abdomen of caudal peduncle. The yolk was almost absorbed and the teeth development. 3 days after hatching, at 6.98~7.60 mm TL. The head spines and the teeth were largely developed and all fins were completely formed and became postlarva stage 15 days after hatching, at 10.10~12.90 mm TL. The body shape and the color pattern were similar to adult, 25 days after hatching, at 15.3~23.8 mm TL. In 5 months after hatching were reached at 154.10~175.02 mm TL and 49.32~82.67 g in body weight.