|Home||Archived April 13, 2016||(i)|
|Southeast Ecological Science Center|
(Silver, Grass, Bighead, and Black Carps)
In general, the four species of Chinese carps require large riverine environments for successful reproduction (Nico and others, 2005). Both migration and spawning activities are initiated in response to a combination of physical and hydrologic changes, such as increasing water levels, flows, and water temperature (Yih and Liang, 1964; Jennings, 1988; Opuszynski and Shireman, 1995). However, the importance of any one factor may vary among different regions (Nico and others, 2005).
Spawning grounds are usually located in river reaches characterized by turbulent or whirlpool-like flow, often in the vicinity of islands or stream junctions (Yih and Liang, 1964; Nico and others, 2005). Reported current velocities of spawning areas in China ranged from 0.33-0.90 m/s with temperatures ranges of 19.2-29.0 °C (Yih and Liang, 1964).
The appropriate environment, particularly with regard to water turbulence and higher water temperatures, is considered critical because it apparently stimulates spawning and is necessary for successful early development of eggs (Nico and others, 2005). The eggs of Chinese carps are semibuoyant and are carried by currents until they hatch (Soin and Sukhanova, 1972).
Introduced populations have been known to successfully reproduce in artificial canals of sufficient length that somewhat mimic the flow of natural rivers, such as the Kara Kum Canal in Turkmenistan (Aliyev, 1976; Nico and others, 2005). Eggs or larvae of Chinese carps found in reservoirs suggest the possibility of spawning in these habitats (Tang, 1960a,b). Nevertheless, uncertainty remains as to whether spawning occurred within the reservoir or in a connected stream (Nico and others, 2005). If spawning does occur in such artificial habitats, it could have been triggered by fluctuations in water levels or wave actions that mimicked natural riverine environments.
|AccessibilityFOIAPrivacyPolicies and Notices|
|Home||Archived April 13, 2016|