| dc.description.abstract | The bilih fish (Mysincolez~cuspndangensiBs lkr) is a native and endemic fish living in open water of Singkarak Lake, West Sumatera. Extensive and unselected catching of up to one ton per day threatens the fish population and endangers its conservation. In the effort to conserve the bilih fish a research had been conducted exsilo at the Seameo Biotrop laboratory in Bogor from September 1997 to Jan~~a1r9i9 8. The objective of this research is to study the effect of natural and artificial feeds (phytoplankton and pellet, respectively) on the growth pattern, the development of gonads and oocytes, the gonadosomatic indexes and fecundity of the bilih fish. Eighty four bilih fish (67 males and 17 females) were divided into two treatment groups of 42 each. The first group was treated with natural feed (phytoplankton) containing 27.89 percent protein and the second group was treated with artificial feed containing 42 percent protein. One sample of two fish each was randoinly taken every two weeks for observation, measurement and analysis. Results of this research revealed that the growth pattern of the bilih fish differs between the inale and female fish under natural feeding but not under artificial feeding conditions. Under natural feeding condition the length and weight of the female and inale bilih fish ranged from 86.00 to 101.75 mm and 5.23 to 8.15 grams, 75.00 to 96.00 mm and 3.12 to 6.35 grams , while under artificial feeding it ranged from 87.00 to 120.05 rnm and 6.01 to 17.01 grams, 78.15 to 108.95 mm and 4.76 to 13.50 grains respectively. Under natural feeding the growth pattern for females and males were negative allometric, positive allometric, whereas under artificial feeding they were isometric. Under natural feeding the female gonads reached its maximum maturity at stage 111 and the male ones at stage IV, whereas under artificial feeding the female and male gonads reached maximum maturity at stage IV. The gonadosomatic indexes of females and males under natural feeding ranged from 1.01 to 9.73 percent and 0.88 to 6.18 percent, and under artificial feeding it ranged from 1.95 to 10.64 percent and 4.18 to 7.26 percent respectively. The total fecundity under artificial feeding were between 4.057 to 11.349 grains. The oocytes development was an asinchronism type with a tendency of partiel spawner. It is generally concluded that artificial feeding with high (42%) protein content promotes growth, gonadal development and fecundity of the bilih fish better than the natural feeding with a lower (27.89%) protein content. | id |
