Micropterus dolomieu Lacepède, 1802 Micropterus dolomieu commonly known as smallmouth bass is a freshwater, benthopelagic species. It inhabits shallow rocky areas of lakes, clear and gravel-bottom runs and flowing pools of rivers, cool flowing streams and reservoirs fed by such streams. Its young feed on plankton and immature aquatic insects while adults take in crayfish, fishes, and aquatic and terrestrial insects (FishBase 2012). Native to North America: St. Lawrence-Great Lakes system, Hudson Bay and Mississippi River basins from southern Quebec Photo credit: Wikimedia Commons (User: Duane Raver) in Canada to North Dakota and south to northern Alabama and eastern Oklahoma in the USA; it has been introduced widely as a sport fish. Smallmouth bass has been recorded as being invasive Clanwilliam Rock Catfish Austroglanis( gilli), the VU Clanwilliam Redfin and its predatory impacts have caused decline in populations of (Barbus calidus), and the VU Clanwilliam Yellowfish (Labeobarbus native species of fish. capensis). Smallmouth bass was introduced for angling to South Africa and Introduced alien fishes (Oncorhynchus mykiss, Salmo trutta and now inhabits several river systems including the Berg, Breede smallmouth bass) have caused reduction in populations of the EN and Olifants-Doring river system that includes the Rondegat Treur River Barb (Barbus treurensis) in the Blyde River system. River recognized as South Africa’s most important catchment Alien fish species (Lepomis macrochirus, Tilapia sparrmanii and for the conservation of freshwater fish (8 of the 10 species are smallmouth bass) are a major threat to the Critically Endangered both endemic and threatened). See below for list of native and Tradou Redfin (Pseudobarbus burchelli) which only occurs in the endemic species under threat by smallmouth bass in South Africa. Tradouw catchment of the Breede River system. Predatory impacts of smallmouth bass has been associated with Smallmouth bass are also a major threat to the EN Berg River Redfin the reduction in populations of several endemic cyprinid species (Pseudobarbus burgi) that occurs only in the Berg River system and including Cape Kurper (Sandelia capensis); the Endangered (EN) to the Near Threatened Slender Redfin Pseudobarbus( tenuis) that Barnard’s rock-catfish (Austroglanis barnardi), the EN Berg-breede occurs in the Gourits River system River Whitefish (Barbus andrewi), the EN Clanwilliam Sawfin In the Eastern Cape River systems introduced fish such as largemouth (Barbus serra), the EN Clanwilliam Sandfish (Labeo seeberi), the and smallmouth bass and the sharptooth catfish Clarias( gariepinus) EN Fiery Redfin (Pseudobarbus phlegethon), the Vulnerable (VU) are a major threat to the EN Eastern Cape Rocky (Sandelia bainsii) References:

Darragh J Woodford, N Dean Impson, Jenny A Day & I Roger Bills (2005): The predatory impact of invasive alien smallmouth bass, Micropterus dolomieu (Teleostei: Centrarchidae), on indigenous fishes in a Cape Floristic Region mountain stream, African Journal of Aquatic Science, 30:2, 167-173 Click here to view archives of previous weeks’ species