This study investigated cytogenetic and hematological and histological characteristics between diploid and spontaneous triploid on Cyprinidae (Crucian carp, Carassius auratus; crucian carp, C. cuvieri and common carp, Cyprinus carpio) in four major rivers of Korea. In our results, DNA contents of triploid Cyprinidae were 50% more than those of diploid Cyprinidae. Also, erythrocyte size of triploid Cyprinidae was 50% larger than those of diploid Cyprinidae. In all sampling rivers, sex ratios of C. auratus were biased to female, and especially, triploid groups of C. auratus were all female groups (p <0.05). In principle, sex ratios of C. cuvieri and common carp were equivalent between male and female.

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• In Bon Goo(Inland Aquaculture Research Center, National Institute of Fisheries Science (NIFS), Jinhae 51688, Korea)
• Sang Gu Lim(Aquafeed Research Center, NIFS, Pohang 37517, Korea)
• Hyun Woo Gil(Bio-Monitoring Center, Sejong 30121, Korea)
• In-Seok Park(Division of Marine Bioscience, College of Ocean Science and Technology, Korea Maritime and Ocean University, Busan 49112, Korea) Corresponding author
• Cheol Young Choi(Division of Marine Bioscience, College of Ocean Science and Technology, Korea Maritime and Ocean University, Busan 49112, Korea)