• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.2
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• pp.157-165
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• 1987

On January 16, 1986, mature adults of smooth lumpsucker, Aptocyclus ventricosus (Pallas) were collected from the coastal water of Okkye, Myongju-gun, Kangwon-do, Korea. The authors carried out artificial insemination on the boat. The eggs were incubated and the larvae were reared in laboratory. During the incubation period water temperature fluctuated between $7.5^{\circ}C$ and $21.4^{\circ}C$. The eggs of smooth lumpsucker are demersal and adhesive. The eggs diameters were varied from 2.28 to 2.36 mm. The hatching took place in ca. 725 hours after fertilization. The newly hatched larvae were 6.0-6.9 mm in total length. The features of the hatched larvae lie in the tadpole-like body form and in the well developed sucking disk, namely the ventral fins. 17 days after hatching, the larva attained 9.1 mm in total length. The gill opening retained a small opening at its upper part. Melanophores were developed on the tail. 31 days after hatching, the larva attained 10.6 mm in total length, and became juvenile. The first dorsal fin was disappeared. 105 days after hatching, the larvae attained 15.4-17.5 mm in total length.

• Korean Journal of Environment and Ecology
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• v.35 no.3
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• pp.285-293
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• 2021

This study was conducted to elucidate spawning period characteristics and early life development of eight barbel loach, Lefua costata (Balitoridae) at the Jusucheon stream, Okgye-myeon, Gangneung-si, Gangwon-do, Korea between January and December in 2018. The spawning period was estimated to be from May to August, considering the change in the gonad-somatic index, the appearance of young fry, and frequency distribution in egg diameter. It was a multi-spawning type. The gender ratio was 1:0.79 with 1,117 females and 879 males collected. The egg size was 0.24-0.93 mm, with mature and immature eggs found during the spawning period. The size of mature eggs was 0.71±0.02 mm, and the average number of fecundity was 1,786±818 (n=31). Observation of the egg development showed that the fertilized eggs were the sticky, gray, segregated, and demersal type with 0.76±0.03 mm in diameter. The hatching of the embryos began at about 34 hours (hatching rate 50%) after fertilization underwater temperature of 25℃. The average length of the newly hatched pre-larvae was 2.7±0.11 mm. The average length of pre-larvae at 4 days after hatching was 4.5±0.16 mm, and the yolk sac was completely absorbed and entered the post-larvae stage. At 20 days after hatching, the average length of post-larvae was 11.5±0.67 mm, and their fin rays were formed before they transitioned to the juvenile stage. At 100 days after hatching, the average length reached 49.8±2.60 mm, and the appearance and the lateral sideband patterns were similar to those of the adult fish.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.57-63
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• 2021

This study was carried out to clarify the egg, larvae and juveniles development of Carassius cuvieri in Nakdong River, Gyeongbuk. The amount of spawning of female C. cuvieri was about 30,400~44,900 (average 37,650±7,250). The egg shape was circular and the size was 1.24~1.37 mm (average 1.31±0.04 mm, n=30). At 100 hours after fertilization, more than of the total embryos were hatched. The newly hatched larvae had an 4.69~5.65 mm in total length (average 5.15±0.31 mm, n=10) and had egg yolk in the abdomen. At 3 days after hatching, the preflexion larvae absorbed all egg yolk was 6.27~6.70 mm in total length (average 6.59±0.08 mm, n=10). On the 10 days after hatching, the postflexion larvae were 8.71~8.92 mm in total length (average 8.81±0.07 mm, n=10), and the tip of the caudal fin was bent at 45°. On the 42 days after hatching, the total length of 15.1~16.8 mm (average 15.8±0.57 mm, n=10) was transferred to juvenile as the number of fins was (iii17 dorsal fins, iii4 anal fins) reached a constant number of each part.

• Korean Journal of Ichthyology
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• v.33 no.4
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• pp.262-272
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• 2021

The egg development and early life history of Tribolodon hakonensis that collected from the Seomjin River were studied. The fertilized eggs of the T. hakonensis were slightly adhesive and separated with a yellow yolk and no oil globule. The size of the eggs was an average of 2.89 mm (2.79~2.96) in diameter. Fifty percents of the embryos were hatched in about 63 hrs after fertilization at water temperature of 20℃. The newly hatched larvae showed average 6.92 mm (6.09~7.60) in total length. At 8 days after hatching, they were 13.75±0.67 mm (n=10) in total length and their yolk sacs were completely absorbed, opening mouth and anus (postflexion larvae stage). At 40 days after hatching, they became juvenile and reached 26.99±1.82 mm (n=10) in total length and all their fin rays were formed. At 137 days after hatching, the young fish were 72.63±10.7 mm (n=10) in total length and their body shape, color and behavior were similar to those of adult fish. The size of eggs and the larva after hatching significantly affected the initial growth among groups of genus Tribolodon, and the hatching time of fertilized eggs and the growth rate of the early life history according to the water temperate were different.

• Korean Journal of Ichthyology
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• v.17 no.1
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• pp.19-28
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• 2005

Osteolgical development of Korean striped bitterling, Acheilognathus yamatsutae (Cyprinidae), were investigated using cartilage and bone staining. The parasphenoid, dentary, pterygoid, ceratohyal, branchial arch and parts of the caudal skeleton were formed first as cartilaginous elements at $6.82{\pm}0.08mm$ total length (TL). Formation of frontal, parietal, and maxillary were notable at $7.76{\pm}0.09mm$ TL, and the proximal radial, scapula,and coracoid in the pectoral girdle were developed at this stage. At the same time, the neural and hemal spine were present in the caudal vertebra. The opercle and branchiostegals were observed at $9.68{\pm}0,14mm$, and the posttemporal was formed at $12.9{\pm}40.64mm$ TL, respectively. Ossification in the parasphenoid, pharyngeal bone, dentary, premaxillary, maxillary, and opercle began at about $9.68{\pm}0.14mm$ TL. The cleithrum, supracleithrum, urostyle, and caudal fin were calcified at this stage. The vertebral column was formed and ossified at $11.52{\pm}0.13mm$ TL, and the frontal, preopercle, subopercle, and hyomandibular were ossified at $15.30{\pm}0.68mm$ TL. This fish was late in developing the skeletal formation and ossification as compared with other fishes.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.5
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• pp.465-476
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• 1993

Rockfish, Sebastes inermis is a ovoviviparous fish distributed around the coastal waters of Korea and Japan. Naturally beared larvae obtained from female fish kept in the aquarium were reared for three months in the laboratory. The naturally healed larvae were 6.05mm in average total length(TL) with $8+18{\sim}19=26{\sim}27$ myomeres. Melanophores were distributed on the top of head, around the intestine tube and on the dorsal and ventral margins of the tail, but none on the pectoral fins. The larva(7.1mm in TL) consumed all the yolk and oil globule, in 7 days after bearing, and jaw bones were more rapidly ossified than vertebrae and cranium. In 21 days after bearing, the larvae averaged 8.50mm in TL and the caudal notochord flex $45^{\circ}$. Fin development in S. inermis larvae proceeds in the following sequence: caudal, pectoral, dorsal, anal and ventral fin. Individuals $17.6{\sim}20.8mm$ in TL($65{\sim}69$ days after bearing) are regarded as the juvenile stage. All fins bones was nearly completed in this stage.

• Korean Journal of Ichthyology
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• v.9 no.2
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• pp.186-194
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• 1997

Naturally beared larvae obtained from female fish kept in the aquarium were reared for 45 days in the laboratory. The naturally beared larvae were 3.19 mm in average total length (TL) with 9+15~16=24~25 myomeres. Melanophores were distributed on the dorsal margin of intestine tube, ventral margins of the tail and around the oil globule, but none on the top of head and on the pectoral fins. The larva (3.35 mm TL) consumed all yolk and oil globule in 5 days after bearing, and jaw bones and clavicle began to be ossified rapidly. In 22 days after bearing, the larvae averaged 6.30 mm TL and the caudal notochord flex $45^{\circ}C$. Fin development in S. marmoratus larvae proceeds in the following sequence : caudal, pectoral, dorsal, anal and ventral fin.

• Korean Journal of Ichthyology
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• v.12 no.4
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• pp.230-235
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• 2000

The purpose of the present study was to describe the morphological and skeletal development of the larvae and juvenile of Ilisha elongata(Bennett). The larvae(mean 5.02 mm in total length, TL) opened the mouth and anus with 36~38+15~16=51~54 myotomes, and anus located about 73.0% of TL. The clavicle of shoulder girdle was ossified. The larvae(mean 7.82 mm in TL) have all fin-fold differentiated and its caudal notochord began to flex. Parasphenoid of cranium and dentary of the lower jaw were ossified. The caudal notochord of the larva(mean 9.84 mm) was flexed $45^{\circ}$, and anus located about 67.0% of TL. The body height of the larvae(mean 23.32 mm in TL) were 18.0~20.0% of TL, and the aggregate numbers of all fin rays were completed. Ossification was completed in the larva of mean 26.52 mm in TL.

• Journal of the Korean Solar Energy Society
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• v.38 no.2
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• pp.33-43
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• 2018

PV/Thermal module is the combined system, which consist of a photovoltaic module and solar thermal collector that can obtain electrical power and thermal energy simultaneously. Thus the power generation can be increase by decreasing the temperature of photovoltaic module and thermal energy retrieved from module also can be used for heating system. In this study, Heat transfer performance of air type PV/Thermal module was confirmed with various bottom obstacles that can be installed easily to real photovoltaic module by CFD (computational fluid dynamics) analysis. Eight type obstacles were investigated according to the shape and arrangement. As a result, nusselt number represent heat transfer performance was increased about 86% compare with the basic type PV/Tthermal module that has no obstacle and triangle type obstacle had higher value than other types. But pressure drop was also increased with increment of heat transfer enhancement. Thus the performance factor considering both heat transfer and pressure drop was confirmed and V-fin type obstacle arranged in a row for Reynolds number below 9,600 and protrusion type obstacle arranged in zigzag for Reynolds number above 14,400 were shown higher performance factor than other types. From these results, V-fin type obstacle arranged in row and protrusion type obstacle arranged in zigzag were considered as a proper type for applying to real PV/thermal module according to operating condition. But the heat transfer performance can be changed by the geometric conditions of obstacle such as height, width, length and arrangement. Thus, it could also confirmed that the optimal condition and arrangement of this obstacle need to be found in further study.