Developmental toxicity and molecular responses of marine medaka (Oryzias melastigma) embryos to ciguatoxin P-CTX-1 exposure

Meng YAN, Priscilla T.Y. LEUNG*, Jack C.H. IP, Jin-ping CHENG, Jia-Jun WU, Jia-Rui GU, Paul K.S. LAM

*Corresponding author for this work

Research output: Journal PublicationsJournal Article (refereed)peer-review

28 Citations (Scopus)


Ciguatoxins are produced by toxic benthic dinoflagellates and cause ciguatera fish poisoning worldwide, but the toxic effects on developing marine fish have not been well investigated. The Pacific ciguatoxin (P-CTX-1), is a potent sodium channel agonist, which is one of the most toxic members among all CTXs. This study evaluated the toxic effects of microinjecting purified Pacific ciguatoxin-1 (P-CTX-1) on embryonic development of marine medaka Oryzias melastigma. A lower 96 h-LD50value was estimated for eleuthero-embryos (1.32 ng g−1) than that for embryos (1.71 ng g−1), indicating that P-CTX-1 is more lethal to newly hatched medaka larvae. P-CTX-1 induced detrimental effects during embryonic development, including hatching failure, abnormalities in physical development (caudal fin malformation and spinal deformities), internal damage (green coloration of the gall bladder and hemorrhaging), immune dysfunction, and altered muscle physiology (bradycardia and hyperkinetic twitching). The results of a transcriptional expression analysis of genes related to the stress/immune responses, cardiac and bone development, and apoptosis supported the observed developmental abnormalities. This study advanced the understanding of P-CTX-1 mediated toxic mechanisms in the development of early life stages of a fish, and thus contributed to the toxicity assessment of CTXs in marine ecosystems.

Original languageEnglish
Pages (from-to)149-159
Number of pages11
JournalAquatic Toxicology
Early online date10 Feb 2017
Publication statusPublished - Apr 2017
Externally publishedYes

Bibliographical note

Funding Information:
This project was supported by the State Key Laboratory in Marine Pollution (SKLMP) and the following funding sources: Collaborative Research Fund (C1012-15G to PKS Lam, LL Chan, YL Mak and JP Cheng); National Natural Science Foundation of China (41406184 to Meng Yan, 41576113 to PTY Leung and 21307102 to Jiajun Wu); and the 2014 GD-HK TCFS Program via Innovation and Technology Commission of the Hong Kong SAR Government (GHP/016/14SZ to PTY Leung); and Shenzhen Science and Technology Innovation Committee, ShenzhenKey Laboratory for the Sustainable Use of Marine Biodiversity (ZDSYSY20140509155229806). Mr. Jack CH Ip was partially supported by the SKLMP Internal Research Fund 2014-2015 (IRF/0015 to LL Chan).

Publisher Copyright:
© 2017 Elsevier B.V.


  • Ciguatoxin
  • Developmental toxicity
  • Embryo
  • Gambierdiscus
  • Medaka
  • Oryzias melastigma


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