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Vol. 47 No. 5, 2008
Zooplanktivory in the Endemic Freshwater Sardine, Sardinella tawilis (Herre 1927) of
Taal Lake, the Philippines
Rey
Donne S. Papa1,*, Roberto C. Pagulayan2, and
Alicia Ely J. Pagulayan1
1Department
of Biological Sciences and Research Center for the Natural Sciences,
University of Santo Tomas, Manila 1015, the Philippines
2Institute of Biology, University of the Philippines,
Diliman, Quezon City 1101, the Philippines. Current Address:
Center for Research and Development, Angeles University Foundation,
Angeles City, Pampanga 2009, the Philippines
Rey
Donne S. Papa, Roberto C. Pagulayan, and Alicia Ely J. Pagulayan (2008)
In this study, we compared the composition and relative abundance of
zooplankton found in the vicinity of Napayun I., Taal Lake, the
Philippines, with the zooplankton found in stomachs of the freshwater
sardine Sardinella tawilis
(Herre 1927) caught from the same location. Samplings were
conducted monthly from July 2003 to June 2004. Ninety percent of
the stomach contents were composed of relatively large-bodied adult
copepods; the remaining 10% contained cladocerans and rotifers.
Selectivity coefficients computed from comparing the fish diet with the
available prey from the environment showed a high preference for
copepods and a low to no preference for cladocerans and rotifers for
all 10 mo sampled of the 12 mo study. A high preference for
calanoid copepods noted in Apr.-June coincided with the peak spawning
of S. tawilis according to
previous studies. The preference for large prey such as
calanoids, despite the dominance of small-bodied zooplankton present
during that time may have been related to increased food intake during
spawning. These results indicate a preference for larger
zooplankton due to size-selective particulate feeding exhibited by
clupeids such as S. tawilis.
Key words: Sardinella
tawilis, Taal Lake, Zooplanktivory, Size-selective predation,
Copepods.
*Correspondence: Tel: 632-4061611 ext. 8297 or
4054. E-mail:rspapa@mnl.ust.edu.ph; reypaps@yahoo.com
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