• 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.

• Fisheries and Aquatic Sciences
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• v.14 no.1
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• pp.55-61
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• 2011

Fish larvae were collected monthly with an ichthyoplankton net from 18 stations (including four stations located in eelgrass beds) in Gamak Bay and Yeoja Bay, southern Korea, in 2007. In total, 33 species of fish larvae were collected, of which Engraulis japonicus (48.5%), Tridentiger trigonocephalus (21.5%), and Omobranchus elegans (9.2%) were dominant. Dominant species varied seasonally: Hexagrammos otakii during December and January, Pholis nebulosa during January and March, Acanthogobius flavimanus in April, T. trigonocephalus in May, E. japonicus during June, July, September, and November, and Sillago japonica in August. Dominant species also differed between sites inside and outside the bays. Leiognathus nuchalis, O. elegans, and T. trigonocephalus were more abundant inside, while H. otakii was more abundant outside. From cluster analysis, three groups were identified according to sampling months (January-April, May-September, and October-December) and two groups according to station (inside and outside bays). The occurrence of small larvae of almost all major fish species indicated that the bays were used as spawning and nursery grounds. An exception was Lateolabrax japonicus, whose specimens were relatively large (>19 mm TL), suggesting that this fish may spawn offshore, with its juveniles approaching the bays with growth.

• Development and Reproduction
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• v.18 no.4
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• pp.311-319
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• 2014

Newly hatched black porgy larvae (Acanthopagrus schlegeli) swam to the surface, with the mouth and anus still closed and were 1.90-2.11 mm (mean, 2.0 mm) in total length (TL). The larvae were 2.71-2.94 mm TL (mean, 2.82 mm) on day 2 after hatching. At this time, about two-thirds of the yolk was absorbed, the bladder and intestines had formed, and the mouth and anus were open. Total length was 4.32-4.66 mm (mean, 4.45 mm) at the post-larval stage on days 5-6 after hatching, and the yolk and oil globule were almost absorbed. The end of the notochord began to flex, and 6-8 caudal fin rays were visible. The larvae were 15.37-16.1 mm TL (mean, 15.83 mm) at the juvenile stage on days 30-32 after hatching, and the number of rays in all fins was completely revealed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.5
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• pp.676-683
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• 2023

The development of the egg, larvae, and juveniles of Acheilognathus macropterus from the Wicheon stream of Nakdonggang River was investigated for early life history characteristics. The fish used in the study were collected from Wicheon stream located in Bian-myeon, Uiseong-gun, Gyeongsangbuk-do. The fertilized egg was 1.88±0.09 mm (n=30) in long diameter and 1.34±0.06 mm (n=30) in short diameter. After fertilization at a water temperature of 20℃, the egg took 31 h and 40 min to hatch. Newly hatched larvae had an average total length of 3.92±0.13 mm (n=30) and possessed a yolk sac the mouth and anus were not developed. Twenty days after hatching, the postflexion larvae had an average total length of 8.08±0.29 mm (n=30), with the tail tip fully bent at 45° and began feeding. Thirty-three days after hatching, the number of fin stems reached an integer with an average total length of 15.0±1.08 mm (n=30). In this study, differences in the egg size, hatching time, melanophore development period, and distribution location were confirmed between A. macropterus and allied species.

• Development and Reproduction
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• v.10 no.1
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• pp.47-54
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• 2006

The Tridentiger obscurus were collected of Ocheon-dong and Dolsan-do in Yeosu from Apirl to July 2003, and were carried to the laboratory to investigate their development of spawning habit, egg development, larvae and juveniles. The fertilized eggs were measured $0.86{\sim}1.07{\times}0.53{\sim}0.74\;mm$ in diameter. Hatching of the embryo began about 154 hrs 40 mins after fertilization in water temperature of $18.4{\sim}23.2^{\circ}C$(mean $21.2^{\circ}C$). The newly-hatched larvae were $2.72{\sim}2.87mm$(mean 2.83mm) in total length (TL), their mouth and anus were opened, and the yolk sac was completely absorbed. At 21 days after hatching, the postlarvae were $5.32{\sim}7.23mm$(mean 6.02mm) TL, and the tip of the caudal notochord was flexed $45^{\circ}$ upward. The juveniles stage was reached when all fin-rays were formed at 45 day after hatching, and $11.62{\sim}14.32mm$(mean 13.45mm) TL.

• Korean Journal of Ichthyology
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• v.13 no.1
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• pp.63-68
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• 2001

The skeletal development of the larvae and juvenile of red marbled rockfish, Sebasticus tertius (Barsukov et Chen) was studied based on individuals that were discharged and reared in the laboratory from April to May 1997. In 8 days after bearing, the postlarvae attained 4.42 mm in total length (TL), and its parasphenoid, premaxillary, maxillary, and clavicle were ossified for the first time at this stage. In 15 days after bearing, the postlarvae attained 5.23 mm in TL, and its pterotic, basioccipital, exoccipital, opercle, and preopercle were ossified, with one spine on the each cranium and preopercle. In 27 days after bearing, the postlarvae attained 8.81 mm in TL, its vertebra were posteriorly ossified to the 15th centrum, and five spines were formed on the preopercle. In 39 days after bearing, the juveniles attained 14.21 mm in TL, and the all bones were almost completed at this stage.

• Korean Journal of Ichthyology
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• v.36 no.1
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• pp.94-100
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• 2024

During ichthyoplankton survey in the southwestern sea of Korea, we collected six individuals of noodlefish larvae and juveniles between April and May 2023. They were identified as Neosalanx anderssoni by mitochondrial DNA cytochrome c oxidase subunit I or 16S ribosomal RNA sequences, and their external morphological traits were described for the first time. All six individuals have a slender and elongated body. When preflexion and flexion larval stages (10.24 mm notochord length, NL and 15.47 mm total length, TL, respectively), oval-shaped black melanophores were distributed in a row along the ventral side of the gut. However, when postflexion larval and juvenile stages (23.58~25.90 mm TL, and 29.20~31.26 mm TL, respectively), melanophores on the ventral side of the gut were disappeared, and dark spot-shaped melanophores appeared along the dorsal side of the gut in a single row. Also, from the postflexion larval stage (23.58 mm TL), two large black spots began to appear symmetrically on the caudal fin. Our results suggest that N. anderssoni may use coastal area as spawning and/or nursery ground unlike previous study (Kim and Park, 2002).

• Development and Reproduction
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• v.9 no.1
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• pp.7-13
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• 2005

The effects of various physicochemical stimuli in parturition induction were assayed on ovoviviparous freshwater melania snails, Semisulcospira libertina libertina and S. gottschei. Both of them did not respond to $NH_4OH$ and $H_2O_2$, but showed responses to the water temperature raising, serotonin and acetylcholine. S. gottschei showed stronger responses to the stimulants in parturition induction compared with S. libertina libertina. In case of S. libertina libertina exposed to $10^{-9}M$ acetylcholine, the number of newly born larvae and juveniles per adult and juvenile parturition rate were 68 individuals and 57.5%, which were the most among experimental groups, respectively. In the parturition induction with temperature raising of $9^{\circ}C$, S. gottschei bred 113 larvae and juveniles in which juvenile parturition rate was 56.3% and $10^{-12}M$ acetylcholine also induced very high juvenile parturition rate(61.7%) and 83 larvae and juveniles. It could be concluded that the treatment of acetylcholine has a high effectiveness in the parturition induction of S. libertina libertina and S. gottschei.

• Korean Journal of Ichthyology
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• v.13 no.2
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• pp.136-142
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• 2001

The ichthyoplankton were sampled during six different months (January, March, May, July, September and November 1998) to study seasonal variation and species composition of the ichthyoplankton in Sunchon Bay. During the study, fish eggs collected in May and July were identified as belonging to 4 species. The most of dominant species Engraulis japonicus accounted for 54.1% of the total fish eggs, followed by Leiognathus nuchalis (21.8%), Ilisha elongata (12.7%) and Konosirus punctatus (11.4%). The collected larvae and juveniles were identified into 12 taxa. 11 of which were identified to species level, and 1 taxa identif ied only to family level, respectively. The dominant species, Ilisha elongata, accounted for 48.9% of the total larvae and juveniles: it was followed by Pholis nebulosa at 31.8%. A species of Gobiidae and Thryssa hamiltoni accounted for 15.8% and 2.2% of the total, respectively. The 4 taxa constituted 98.7% of the total collected larvae and juveniles.

• Korean Journal of Ichthyology
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• v.17 no.1
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• pp.29-35
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• 2005

Fertilized eggs of Takifugu pardalis (Temminck et Schlegel) were collected on the coast of Jook-do in Tongyong, Korea, from March 1997 to June 1999, and hatched and reared in the laboratory to investigate osteological development of the larve and juveniles. The newly hatched larvae attained a mean of $3.13{\pm}0.05mm$ in total length (TL). Ossification first began in the parasphenoid, premaxillary and dentary. At 5 days after hatching, the postlarvae attained a mean of $3.82{\pm}0.03mm$ in TL, and their sphenotic, prefrontal, preopercle, opercle, maxillary, and articular were ossified. At 15 days, the postlarvae attained a mean of $7.84{\pm}0.06mm$ in TL, their nasal and posttemporal bones were ossified and the hyoid arch completed ossification. Ossification of all bones was completed in the juveniles (mean = $10.21{\pm}0.06mm$ in TL) at 21 days.