Oreochromis niloticus (Linnaeus) (Fig. 35, [LU]) Distribution. Tai Chung Hau area, Lam Tsuen River, Kau Lung Hang Lo Wai area, Shuen Wan area, Sha Ling area, Tan Shan River, Pui O Stream, Tong Fuk River, Tai O River, Tai Ho River (Chan, 2001); Lung Mei area (Halcrow China Limited, 2007); Fung Lok Wai area (CH 2M HILL Hong Kong Limited, 2008); Tsang Tsui area (Metcalf & Eddy Limited, 2008); Sha Lo Wan area (Ove Arup & Partners Hong Kong Limited, 2009); Big Wave Bay Stream (DSD, 2010; current survey); Kong Nga Po area (Mott MacDonald Hong Kong Limited, 2013); Fanling area, Kwu Tung area (Ove Arup & Partners Hong Kong Limited, 2013b); Ho Pui Reservoir, Hok Tau Reservoir, Shing Mun Reservoir, Kowloon Reservoir, Plover Cove Reservoir, Pok Fu Lam Reservoir, Kowloon Reception Reservoir, Shek Lei Pui Reservoir (Lai, 2011; current survey); Sandy Ridge Cemetery (Ove Arup & Partners Hong Kong Limited, 2016); Mui Tsz Lam stream (AECOM Asia Company Limited, 2016a); Hung Shui Kiu area (AECOM Asia Company Limited, 2016b); Shan Ha Tsuen area, Muk Kiu Tau Tsuen area, Tai Tong area (Ove Arup & Partners Hong Kong Limited, 2017); Sung Shan New Village, Lin Fa Tei area, Ha Che area (Atkins China Limited, 2020); Yuen Long Town Nullah (Black & Veatch Hong Kong Limited, 2020a); Hong Po Road area (Black & Veatch Hong Kong Limited, 2020b); Nam Wa Po area (DSD, 2020); Shek Kiu Tau area (Mott MacDonald Hong Kong Limited, 2020); Pak Tin area (Tai Wai) (AECOM Asia Company Limited, 2021a); Lau Shui Heung Reservoir (AFCD, 2021c); Ma Wat River, Ping Yuen River, Pak Ngan Heung Stream, Ma Tso Lung Stream, Ngau Tam Mei River, Yuen Long Bypass Floodway, Ho Chung River, Kam Tin River, Ping Kong Stream, Cheung Po Stream, Wong Lung Hang Stream, Tai Tei Tong Stream, Shek Kong Stream, Ho Pui River, Deep Water Bay Stream (DSD, 2021); Wetland Park, Hang Tau area, Tin Shui Wai Park, Tai Po Kau Nature Reserve, Sheung Yue River, Tin Shui Wai River, She Shan River, Ting Kok area, Nam Sang Wai area, San Tin area, Kai Tak River, High Island Reservoir, Hung Shui Hang Irrigation Reservoir, Shan Pui River (GBIF.org, 2021); Tung Chung River (Green Power, 2021; current survey); Mai Po Nature Reserve (WWF, 2021); Kowloon Byewash Reservoir; Lam Tei Irrigation Reservoir, Tai Shui Hang area, Aberdeen Lower Reservoir, Aberdeen Upper Reservoir, Tai Tam Reservoir, Tai Tam Tuk Reservoir, Tai Tam Byewash Reservoir, Tai Tam Intermediate Reservoir (current survey). Native range. Africa. Remarks. The introduction of this species has not been as well documented as that of O. mossambicus. However, this species may have been misidentified as O. mossambicus in earlier studies. Presently, O. niloticus appears to be relatively abundant and has replaced O. mossambicus in numerous habitats. It differs from other Oreochromis spp. in that the caudal fin has black bars, and the upper margin of the dorsal fin is black or grey and never entirely fringed with red as in O. mossambicus, O. aureus, or hybrids (Trewavas, 1983).

Published as part of 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, pp. 128-168 in Raffles Bulletin of Zoology 71 on pages 146-147, DOI: 10.26107/RBZ-2023-0012, http://zenodo.org/record/7815765