• Title/Summary/Keyword: endangered freshwater fish

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Development of Eggs, Larvae and Juveniles of the Ladislavia taczanowskii from Hongcheongang-River (홍천강에 서식하는 멸종위기종 새미 Ladislavia taczanowskii의 난발생 및 자치어 형태발달)

  • Jae-Min Park;Seong-Jang Cho;Kyeong-Ho Han
    • Korean Journal of Ichthyology
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    • v.36 no.2
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    • pp.109-119
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    • 2024
  • This study was conducted to investigate the early life history by observing the egg development of Ladislavia taczanowskii in endangered fish and to use it as basic data for species conservation research. The broodstork used in the study was secured from the area of the Hongcheon River in Hongcheon-gun, Gangwon State. The broodstork, who was being raised in the laboratory, selected mature individuals in May 2021 and induced them to spawn by hormone injection. The size of the maturation egg was 1.50~1.79 (average 1.59±0.08, n=30) mm due to the circular invasive egg. The incubation time took 168 hours at 16.5℃ and 109 hours and 30 minutes at 25.5℃. Newly hatched larvae, the consonants had a total length of 5.55~6.31 mm (6.30±6.93, n=30) mm, and the mouth and anus did not open and had egg yolk. 5 days after hatching, the preflexion larvae had a total length of 9.91~10.8 (10.1±0.27, n=30) mm, and the mouth and anus opened, and feeding activities began. 8 days after hatching, the flexion larvae had a total length of 10.3~11.4 (10.8±0.38, n=30) mm, and the end of the vertebrae at the tail fin tip began to bend upward. 10 day after hatching, the postflexion larvae had a total length of 11.8~13.1 (12.3±0.43, n=30) mm, and the end of the vertebrae at the tail tip was completely bent at 45°. 18 days after hatching, the total length of the juveniles was 18.9~23.4 (20.4±1.69, n=30) mm, and the number of fins in each part was fin rays with 10 dorsal fins, 9 anal fins, 22 caudal fins, and 7 ventral fins. As a result of the study, the postflexion larvae showed differences in morphology from other Gobioninae fishes in the upper part of the tail's hypural, the shape of spots on the dorsal vertebrae, the vertical stripes developed on the head, and the irregularly deposited melanophore throughout the body.