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Vol. 45 No. 4, 2006
Effects of Temperature and Floating Materials on Breeding by the Paradise Fish (Macropodus opercularis) in the Non-reproductive Season
Wen-Bin Haung1,2,* and Fang-Lin Cheng2
1Graduate Institute of Biological Resources and Technology, National Hualien University of Education, Hualien, Taiwan 970
2Department of Science Education, National Hualien University of Education, Hualien, Taiwan 970
Wen-Bin Haung and Fang-Lin Cheng (2006) The paradise fish, Macropodus opercularis,
is native to Taiwan, and its reproductive season spans from Mar. to
Oct. This experiment was conducted to examine paradise fish breeding in
winter, a non-reproductive season, using different treatments of water
temperatures (23, 27, and 31°C) and floating materials (floating ferns,
green Styrofoam pieces, and no floating material). The fish built 1-3
bubble nests during the 20 d experimental period. A significant
negative correlation was found between the temperature and the
frequency of nest building, indicating that a high water temperature of
31°C was unfavorable for building nests. In the treatments with
floating ferns and green Styrofoam pieces, the fish built more nests
than in the treatment without floating materials. The sizes of the 1st
bubble nests built were significantly larger at 27 and 31°C than at
23°C. Floating materials played an important role after the fish
acclimated to the temperature. In the treatment with green Styrofoam
pieces, the fish built smaller-sized 2nd nests than in the treatment
without floating materials. One female in a tank treated at 27°C with
green Styrofoam pieces laid 421 eggs during the 20 d experimental
period. Two hundred and eighty larvae hatched the next day, for a
hatching rate of 66.5%. In short, the paradise fish can breed at
appropriate temperatures, such as 27°C, in winter, normally a
non-reproductive season, and artificial floating materials are
conducive to successful reproduction.
Key words: Bubble nest, Floating fern, Formosan fighting fish, Anabantidae, Reproduction.
*Correspondence: Tel: 886-3-8227106 ext. 2261. Fax: 886-3-8236935. E-mail:bruce@mail.nhlue.edu.tw
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