Carassius auratus (Linnaeus)

Chan, Jeffery C. F., Tsang, Alphonse H. F., Yau, Sze-man, Hui, Tommy C. H., Lau, Anthony, Tan, Heok Hui, Low, Bi Wei, Dudgeon, David & Liew, Jia Huan, 2023, The non-native freshwater fishes of Hong Kong: diversity, distributions, and origins, Raffles Bulletin of Zoology 71, pp. 128-168 : 134-135

Carassius auratus (Linnaeus)

( Fig. 6 , [LU])

Distribution. Lam Tsuen River, Siu Lek Yuen area (GBIF, 2021); Sham Tseng Settlement Basin, Tai Po Kau Nature Reserve; Shing Mun Reservoir (current survey).

Native range. Central China, South China, and Taiwan ( East Asia).

Remarks. This species is morphologically similar to the native Misgurnus anguillicaudatus , and has been known to hybridise with it in the wild ( You et al., 2009). DNA sequencing of the specimen from Shing Mun Reservoir ( Fig. 18 ) matched with multiple P. dabryanus purebreds and a single hybrid, suggesting the 12S RNA gene may not be sufficient to delineate hybrids of this species. The localities listed in the distribution also have records of M. anguillicaudatus , which may already be hybridising in Hong Kong. Alarmingly, M. dabryanus and M. anguillicaudatus are commonly sold admixed as live feeder fish and are sometimes released during Buddhist rituals. It is possible both species hybridised in the aquarium trade before release. Further genetic work is required to resolve this issue.

Distribution. Plover Cove Reservoir ( Dudgeon, 1983; Lai, 2011); Sandy Ridge Cemetery, Sha Ling, Ma Dai Stream, Cheung Po, Lin Ma Hang ( Wilson et al., 1997) ; Nam Long Shan area (within Ocean Park) (Maunsell Environmental Management Consultants Limited, 2006); Fung Lok Wai area ( CH 2M HILL Hong Kong Limited, 2008); Hok Tau Reservoir ( Lai, 2011); Lok Ma Chau Loop, Tse Koo Hang area, Ma Tso Lung area (Ove Arup & Partners Hong Kong Limited, 2013a); Ha Che area (Atkins China Limited, 2020); Tai Po Kau Nature Reserve, Tai Lam Chung Reservoir (AFCD, 2021c); Kam Tin River, Ho Pui River, Tong Fuk River, Ma Wat River, Lam Tsuen River, Wong Lung Hang, (DSD, 2021); Ng Tung River, Lai Chi Kok Park, Mui Tsz Lam Stream, Mui Wo River, Sheung Yue River, Shui Chuen O Stream, Tan Shan River, Shing Mun River, (GBIF.org, 2021); Tung Chung River ( Green Power, 2021); Mai Po Nature Reserve (WWF, 2021); Sam Dip Tam Stream, Kau Lung Hang Lo Wai, Fung Yuen Stream ( Tsang & Dudgeon, 2021a); Little Hawaii Stream; Lohas Park area, Deep Water Bay Stream, Kowloon Reservoir, Miu Shan Stream (current survey).

Native range. East Asia, including South China.

Figures

Fig. 6. Carassius auratus, Little Hawaii Stream.

Fig. 18. Synodontis eupterus, 112.6 mm SL, Tai Po Kau Nature Reserve.