fa <p style="line-height:120%;"><a name="OLE_LINK8"><span style="color:black;">In order to</span></a> <span style="color:black;">estimate </span><span style="color:black;">responses</span><span style="color:black;"> of growth rate and growth hormone of <em>Clarias gariepinus</em> to stocking density, fish (initial weight 30.71 &plusmn; 0.89 g) were stocked in 120-L tanks at densities of 35, 65, 95, and 125 kg/m³ for 60 days. On day 30 and 60, the fish growth rates were measured, pituitary growth hormone (GH) mRNA levels and serum GH concentrations were examined by real-time qPCR and ELISA technique, respectively. <a name="OLE_LINK21"></a><a name="OLE_LINK20">From day 0 to day 30, there were significant decreases in specific growth rates and relative weight gains at higher densities (95 and 125 kg/m³) compared to that at lower densities (35 and 65 kg/m³), whereas no significant effects of stocking density on the two indexes during the day 30&minus;60 were detected.</a> On day 30, GH mRNA levels were unaffected by stocking density, <a name="OLE_LINK3">while</a> on day 60, GH mRNA levels were significantly lower at the density of 125 kg/m³ than in the two lower densities. Serum GH concentration increased with decreasing stocking densities but only significantly between 35 kg/m³ and the other treatments on day 30. However, there were no significant differences between two lower densities as well as between 65 kg/m³ and 95 kg/m³treatments on day 60. These results implied that effect of stocking density on SGR and RWG of <em>C. gariepinus</em> <a name="OLE_LINK147"></a><a name="OLE_LINK146">weren&rsquo;t </a>unif</span>orm in different growth periods and a weak positive correlation was observed between growth rate and GH in <em>C. gariepinus</em> in the present s<span style="color:black;">tudy.</span></p> Clarias gariepinus, Stocking density, Specific growth rate, Relative weight gain, Growth hormone, Real-time qPCR, ELISA 698 710 http://jifro.ir/browse.php?a_code=A-10-1941-2&slc_lang=fa&sid=1 X.M. Wang xiaomeiwem@yahoo.com 100319475328460020734 100319475328460020734 Yes J.W. Gao 100319475328460020735 100319475328460020735 No M. Xu 100319475328460020736 100319475328460020736 No B.L. Mo 100319475328460020737 100319475328460020737 No W. Dai 100319475328460020738 100319475328460020738 No CH.X. Chen 100319475328460020739 100319475328460020739 No