IMPACT OF SUBSTRATES AND FISH STOCKING DENSITY ON GROWTH AND PRODUCTION OF THE INDIAN MAJOR CARP, LABEO ROHITA (HAM.)

摘要

The effect of two substrates and four fish stocking densities on the growth and production of rohu (Labeo rohita) was investigated through a 70-day 2x2 factorial design experiment carried out in mud-bottomed outdoor 25 m~2 cement tanks. Bamboo and sugarcane bagasse were employed as substrates. Both the substrates affected (P<0.05) fish growth and production. Percentage increase in production was higher with the lowest fish density. Periphyton ash free dry matter did not differ significantly among substrates, but showed an increase with the progress of the experiment along with that of pigment content. Fish density did not affect pigment content of periphyton from the two substrates. Bagasse treatment recorded the highest plankton dry weight. A reciprocal relationship was noticed between fish density and plankton dry weight. Substrates reduced water temperature and dissolved oxygen. Bagasse substrate proved equally effective as bamboo in supporting periphyton and fish growth.