Paradise Fish (Macropodus opercularis) in the Non-reproductive

The paradise fish, Macropodus opercularis (Linnaeus), belongs to the family Anabantidae in which most of the members are“bubble-nest” builders (Forselius 1957). This species is charac-terized by the presence of a labyrinthiform organ, which is derived from the 1st gill arch and enables the fish to breathe in the air (Lagler et al. 1977). Floating plants are usually dominant in spawning areas of the fish (Jan 1994). Plants or other sub-strates are necessary to hold the nest in place (Degani 1989). The fish sexually matures at approximately 6 mo, breeds well in aquaria, and reaches a maximum size of approximately 80-100 mm in standard length (Forselius 1957, Hall 1968). The paradise fish is native to China and near-by islands (Hall 1968). It is widely distributed in eastern Asia from the Yangtze River basin to Hainan I. in China, as well as Taiwan and North Vietnam (Freyhof and Herder 2002). The range of the fish s habitation is 20-30°N and 102-122°E,and its climatic temperature range of 16-26°C(Fishbase 2005) indicates that it is a subtropical and temperate fish. Indigenous to Taiwan, it is commonly known as the Formosan fighting fish, three-spot fish, and Chinese unicorn fish (Chen and Fang 1999, Shao and Chen 2003). Prior to the mid-1970s, the fish was widely distributed in lowland areas of Taiwan where it inhabited bodie