Aquatic Invasive Species

Mozambique tilapia (Oreochromis mossambicus)

Description:

• Silver or pale olive (Trewavas, 1983) with large mouths (Yamamoto & Tagawa, 2000)
• Breeding males can be dark colored with white on the head and red on dorsal and caudal fins (Trewavas, 1983)
• Can reach 10-15 inches long (Yamamoto & Tagawa, 2000)

Habitat:

• Fresh and brackish water (Nico & Neilson, 2022; Mundy, 2005)
• Reservoirs, lakes, ponds, streams, and inshore with freshwater input (Mundy, 2005)
• Tolerant of high salinities (Nico & Neilson, 2022)

Impacts & Concerns:

• Outcompetes other fish for food, like the native striped mullet (Mugil cephalus) (Yamamoto & Tagawa, 2000; Randall, 1987)
• Colorful varieties of tilapia marketed as Hawaiian sunfish or Hawaiian perch (Yamamoto & Tagawa, 2000)
• Mozambique tilapia in the Ala Wai and Mānoa stream contained polychlorinated biphenyls (PCBs) which can be harmful to human health (Yang et al., 2008)

Introduction:

• Likely introduced as a hybrid from Singapore in 1951 and 1952 (Mundy, 2005)
• Stocked for use as baitfish, biocontrol, food, and recreation (Yamamoto & Tagawa, 2000)
• Displaced by later introduction of blackchin tilapia (Yamamoto & Tagawa, 2000)

Distribution in Hawaiʻi: (Mundy, 2005; Randall, 1987; Yamasaki et al., 2022; Carlton & Eldredge 2009)

• Kauai: Wailua River, Hulēʻia River, Keahua Stream, Kapahi Reservoir, Hanapēpē River, Anahola River, Lawai Stream, Kawaiʻele
• Oʻahu: Pearl Harbor, Ala Wai Canal, Mānoa Stream, Māʻiliʻili Stream, Honolulu Harbor, Kewalo Basin, Ala Wai Yacht Harbor, Kāneʻohe Bay, Nuʻuanu Reservoir, Kawa Stream, Kawainui Marsh
• Molokai: Kawela Stream, Kaunakakai
• Lanai: Not documented
• Maui: Lāhainā Stream, Kahului, Kūlanihākoʻi Gulch
• Big Island: ʻAlenaio stream, Kohala watershed

Regulations:

• Restricted for private and commercial use including research, zoological parks, aquaculture production or non-profit research (§4-71-6.5)
• Does not include individual possession of an animal as a pet

References:

• Carlton, J.T. & Eldredge, L.G. (2009). Marine bioinvasions of Hawaiʻi: The introduced and cryptogenic marine and estuarine animals and plants of the Hawaiian archipelago. Bishop Museum Bulletin in Cultural and Environmental Studies 4. Bishop Museum Press. 203pp.
• Hasan V., Pratama F.S., Malonga W.A.M. & Cahyanurani A.B. (2019). First record of the Mozambique tilapia, Oreochromis mossambicus Peters, 1852 (Perciformes, Cichlidae), on Kangean Island, Indonesia. Neotropical Biology and Conservation, 14(2): 207-211. https://doi.org/10.3897/neotropical.14.e35601
• Mundy, B.C. (2005) Checklist of the fishes of the Hawaiian Archipelago. Bishop Museum Bulletin in Zoology 6. Bishop Museum Press. 704pp.
• Nico, L. & Neilson, M. (2022). Oreochromis mossambicus (Peters, 1852): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/factsheet.aspx?SpeciesID=466
• Trewavas, E. (1983). Tilapiine Fishes of the genera Sarotherodon, Oreochromis, and Danakilia. The Dorset Press. https://doi.org/10.5962/bhl.title.123198
• Yamamoto, M. & Tagawa, A.W. (2000). Hawaiʻi’s native & exotic freshwater animals. Mutual Publishing.
• Yamasaki L.S., Iwai T.,Klinger-Bowen R. C., Weese D.A., Fowler C.E., Yacoub J.L., & Wong M.A. (2022). Identification of Nile tilapia (Oreochromis niloticus) and its hybrids in natural environments in Hawaii. Aquaculture, 550, e737805. https://doi.org/10.1016/j.aquaculture.2021.737805
• Yang, F., Wilcox, B., Jin, S., Alonso Aguirre, A., Rougée, L., Xu, Y., & Lu, Y. (2008). Detection and quantitative analysis of polychlorinated biphenyls in tilapia from Hawaiian waters. Chemosphere, 73(1), 133–137. https://doi.org/10.1016/j.chemosphere.2008.03.066