effeciency of spirulina platensis cultured with different nitrogen regimes on larval development, growth and survival rate of white shrimp, litopenaeus vannamei n.r.

The blue-green algae spirulina platensis was cultured with different nitrogen regimes (nh_4cl, nh_4no_3 and kno_3) with concentrations of 0.010, 0.025 and 0.050 m and then fed to litopenaeus vannamei at 19 days post hatch (pli) to evaluate the nutritional quality. at the end of the experiment, growth and survival rate were determined, and the larval development was calculated. the maximum protein content was obtained in culture media containing nh_4no_3 followed by nh_4cl and kno_3 (p>0.05). moreover, in all s. platensis cultures, increases in nitrogen concentrations led to increases in protein content. the present study showed that, with the exception of shrimp larvae at 5 days post hatch, l. vannamei shrimp larvae fed on s. platensis cultured in nh_4no_3, as a nitrogen regime, generally developed significantly (p<0.05) faster to next stages compared with the other treatments. however, the survival rate (%) and total length (mm) of shrimp larvae fed on s. platensis did not show any significant difference (p>0.05) when the nitrogen was varied in terms of regimes. overall, the study points to the potential effectiveness of using nh_4no_3 as a nitrogen regime in s. platensis culture media in producing live food for the hatchery production of l. vannamei shrimp larvae.