Potential of dhela in carp Poly culture system in ponds

Abstract

Dhela (Osteobrama cotio) is one of the most micronutrient rich small indigenous species in Bangladesh and gradually disappearing from the nature and considered as threatened species. So therefore it essential to conserve this species in nature as well need to find out the culture suitability in pond aquaculture. To assess the culture suitability of dhela along with large carps in polyculture systems in farmers pond of northeast region of Bangladesh, an experiment consisted of two treatments each with three replications was conducted for a period of 138 days from 16 July 2013 to 30 November 2013 at Rayghar village of Golapganj upazilla under Sylhet district. In the first treatment (T1) dhela, catla, rohu and mrigal were stocked 150, 75, 50 and 50, respectively. In the second treatment (T2) catla, rohu and mrigal were stocked 165, 110 and 110, respectively. All the treatments were subjected to same regime of feed and fertilizers. Yield of dhela was found 37.45 kg/ha in treatment T1. Production of dhela was very low because it did not took part breeding due to late stocking. Survival of dhela observed 83.56%. Total production of fish obtained in this experiment was 768.09 kg/ha and 806.64 kg/ha in treatment T1 and T2, respectively. There were no significant differences in total production between the treatments T1 and T2. Water parameter analysis shows that mean values of water temperature, transparency and dissolved oxygen were not significantly different among the treatments. Significantly difference (P < 0.05) was observed in the mean values of pH between the treatments. The total revenues per ha pond during study period were Tk. 94520 and Tk. 96720 in treatments T1 and T2, respectively. The net benefits from treatment T1 and T2 were Tk.44605 and Tk. 57515, respectively. Net benefit did not the show any significant differences between the treatments. However, from the result of the experiment it can be concluded that in view of low production dhela may be one of the good candidate species for carp plolyculture system considering its high nutritional value.