Cyprinus carpio Linnaeus, 1758 A native, widespread freshwater species of the lowland and lower hills, living in slow-flowing or stagnant water; abundantly supplemented by cultivated stocks (Bănărescu 1964; Manea 1985; Oțel 2007; Cocan & MireȘan 2018; Polyák et al. 2022; Nagy et al. 2023; Năstase & Năvodaru 2023). The koi, an ornamental breed selected in Japan, is worth mentioning as it is thought to originate from the Asian species Cyprinus rubrofuscus Lacépède, 1803 (Kottelat & Freyhof 2007). There are no precise data upon the introduction time, origin and distribution of koi in Romania; it is found in ornamental urban waterbodies (e.g. in Bucharest —A. Iftime obs.) as well as in some fishponds. While C. rubrofuscus is widely accepted as distinct from C. carpio (Kottelat & Freyhof 2007; Fricke et al. 2025; Froese & Pauly 2025), it seems to be very close to C. carpio; various aspects, including the overall genetic structure of C. carpio s. l.; (Xu et al. 2014; Tsipas et al. 2017; Xu et al. 2019; Zhu et al. 2023, Nielsen et al. 2010; Kuts et al. 2021) and the mix-up of domesticated koi, at least some strains thereof being admixed with European carps (de Kock & Gomelsky 2015), suggest its status as a valid species should be revised (as suggested by Zhu et al. 2023).

Published as part of Iftime, Alexandru & Oţel, Vasile, 2025, An annotated systematical checklist of the Romanian ichthyofauna, pp. 1-64 in Zootaxa 5654 (1) on page 10, DOI: 10.11646/zootaxa.5654.1.1, http://zenodo.org/record/15822021