Culter alburnus is an indigenous carnivorous fish which was originally distributed in central Taiwan, but was introduced into Feitsui Reservoir and its surrounding streams of northern Taiwan after 2000. From Apr. 2008 to May 2009, 14 monthly samples were collected in Jingualiao Stream by angling from 4 sampling sites: 2 sites were located above a check dam without Cul. alburnus, and 2 other sites were located below the dam where Cul. alburnus was present, having migrated upstream from the Feitsui Reservoir. The aim of this study was to evaluate the predation impacts of Cul. alburnus by comparing the compositions, abundances, and size-frequency distributions of fish communities above and below the check dam. In total, 2791 individuals of 18 fish species were collected, including 275 Cul. alburnus caught below the dam. A diet analysis showed that 11 of 30 Cul. alburnus (33.3%) had consumed a total of 26 fish, 23 of which were Candidia barbata. The abundance of Can. barbata was significantly greater above the dam. Additionally, the body size of Can. barbata collected above the dam averaged < 12.9 cm, whereas the body size of individuals below the dam averaged > 11 cm. We concluded that predation by the introduced Cul. alburnus resulted in a decrease in the total abundance and a change in the age structure of populations of native fish species, such as Can. barbata, that occupy mid- and surface waters. It is possible that predation by the introduced Cul. alburnus may also generate a trophic cascade effect on the animal communities in lotic waters. To conserve the freshwater biodiversity in Taiwan, we suggest that greater attention be given to the introduction of indigenous fish species by administrative agencies and the general public to prevent invasions by exotic species.
|頁（從 - 到）||1438-1445|
|出版狀態||Published - 2012|
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