River. Cunningham named this river "Mitchell" in honour of James Mitchell, the chief surgeon of Sydney Hospital, out of gratitude for his assistance with barometrical observations. The Namoi River Road Bridge, which was built at Manilla in 1886, has been placed on the Register of the National Estate. This bridge has eleven metal lattice truss spans and is one of the longest six or seven metal truss bridges completed in Australia by that time. Fauna The Namoi supports a wide range of fish and crustaceans, which include Murray cod, yellowbelly, silver perch, catfish (Tandanus tandanus) as well as yabbies (Cherax destructor). "Crawbob" is a regional name and may be called a "yabby" elsewhere in the state. Murray cod in the Namoi grow to a very large size, with fish of forty kilograms or larger being not uncommon. European carp and extensive irrigation practices have had adverse impact on the native fish population over the last forty years, and restocking programs have been undertaken, mainly by volunteers, to ensure the survival of the native fish population. The Namoi River snapping turtle or Bell's turtle (Elseya belli) is a species of turtle found only in the upper reaches of the Namoi River, Gwydir and Macdonald rivers on the North West Slopes. The platypus (Ornithorhynchus anatinus) is found in this river and can often be seen around Warrabah National Park, east of Manilla. See also Rivers of New South Wales List of rivers of Australia References External links Namoi region State of environment report 2008–2009 Tributaries of the Darling River North West Slopes