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Vol. 51 No. 8, 2012
Evaluation
of the Predatory Effects of an Introduced Fish, Culter alburnus, on the
Fish Community in a Small Stream of Northern Taiwan
Yuh-Wen Chiu1, Cheng-Wei Tso2, Bao-Sen Shieh3, Chi-Chang Liu4, Yao-Sung Lin2, and ShihHsiung Liang5,*
1National Museum of Marine Biology and Aquarium, Pingtung 944, Taiwan
2Institute of Ecology and Evolutionary Biology, National Taiwan Univ., Taipei 106, Taiwan
3Department of Biomedical Science and Environmental Biology, Kaohsiung Medical Univ., Kaohsiung 807, Taiwan
4Center for Teacher Education, National Taiwan University, Taipei 106, Taiwan
5Department of Biotechnology, National Kaohsiung Normal Univ., Kaohsiung 824, Taiwan
Yuh-Wen Chiu, Cheng-Wei Tso, Bao-Sen Shieh, Chi-Chang Liu, Yao-Sung Lin, and Shih-Hsiung Liang (2012) 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.
Key words: Predation, Fish Introduction, Culter alburnus, Candidia barbata, Taiwan.
*Correspondence: Tel: 886-7-7172930 ext. 7310. Fax: 886-7- 6051365. E-mail:shliang@nknucc.nknu.edu.tw
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