• Title/Summary/Keyword: Ichthyoplankton

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Molecular Identification and First Morphological Description of Larvae and Juveniles of Neosalanx anderssoni (Salangidae) Collected from the Southwestern Sea of Korea (한국 서해 남부해역에서 채집된 도화뱅어, Neosalanx anderssoni (뱅어과) 자치어의 분자 동정 및 첫 형태기재)

  • Seo-Yeon Koo;Se-Hun Myoung;Jin-Koo Kim
    • 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).

First Morphological Description of Thryssa kammalensis (Engraulidae, Clupeiformes) Larvae and Juveniles Collected from the Southwestern Coasts of Korea (한국 서해 남부연안에서 채집된 청멸, Thryssa kammalensis (멸치과, 청어목) 자치어의 첫 형태 기재)

  • Hyeon-Jun Ryu;Se-Hun Myoung;Ho-Sun Sohn;Jin-Koo Kim
    • Korean Journal of Ichthyology
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    • v.36 no.3
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    • pp.273-281
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    • 2024
  • In June and July 2023, a total of 101 Thryssa kammalensis larvae and juveniles were collected during an ichthyoplankton survey using RN80 in the waters around the southwest coasts of Korea. When pre-flexion larval stage (3.77~10.20 mm NL, n=22), some individuals have pterygiophores of dorsal and anal fins, but no apparent fin rays were formed. Line-shaped melanophores were distributed in a row from below the opercle to the anal fin base. When flexion larval stage (12.13~16.69 mm SL, n=14), the number of dorsal and anal fin rays were 13~15 and 18~23. Dot and line-shaped melanophores were distributed in a row in the ventral portion of the abdominal cavity, and melanophores appeared on the caudal fin. When post-flexion larval stage (17.23~21.73 mm SL, n=20), all fin rays appeared, and the number of pectoral, pelvic, anal and dorsal fin rays were 7~9, 4~5, 29~31 and 14~15, respectively. Dot and line-shaped melanophores were distributed in a row from the posterior of the preopercle to the ventral portion of the abdominal cavity, oval-shaped melanophores were distributed along the anal fin base, and melanophores concentrated lower lobe of the caudal fin. When juvenile stage (18.43~25.98 mm SL, n=45), the number of pectoral, pelvic, anal and dorsal fin rays were completed as 12~15, 7~8, 30~33 and 14~15, respectively. Point-shaped melanophores of the ventral position of the abdominal cavity disappeared, it continued in a row along the anal fin base to the lower caudal peduncle. Our results suggest that Thryssa kammalensis may use the sea around Chilsan-do Island as spawning and/or nursery ground between June and July.