Comparative study on growth performance of Thai Sharpunti (Puntius gonionotus) using two different weeds Duck weed (Lemna minor) and Azolla fern (Azolla pinneta)

The comparative growth performance study of Thai Sharpunti (Puntius gonionotus) was conducted from 20th March to 18th May, 2012by using duck weed (Lemna minor ) and Azolla fern (Azolla pinneta ) as in earthen pondof the Department of Aquaculture, Bangladesh Agricultural University, Mymensingh. Duck weed and Azolla fern were supplied as dietary feed in two separate treatments and each with three replications. Fifteen fingerlings of Thai sharputi was stocked in each pond. Average size and weight of Thai sarputi were 5.75 cm and 21g in T 1 and 5.50 cm and20g in T 2 , respectively. The ranges of physico-chemical parameters viz, water temperature (25.00 to 33.50 0 C), air temperature (31.00 to 34.50 0 C), transparency (28 to 34 cm),dissolved oxygen (6.00 to 7.20 mg/l), free CO 2 (2.00 to 3.33 mg/l), pH (6.9 to 7.45), total alkalinity (48 to 61 mg/l), phosphate-phosphorus (1.40 to 2.50 mg/l) and nitrate-nitrogen (2.13 to 3.20 mg/l) were within the productive range. Initial body weight, final body weight, weight gain, survival rate, specific growth rate(SGR), food convertion ratio (FCR), percent weight gain, average daily gain (ADG) were observed as21 and 20g, 356g and 308g, 335 and 288g, 90 and 85%, 558and 480% per day, 5.28 and 6.10, 1595 and 1440%, 5.58 and 4.80g in both the treatments,respectively. Calculated gross and net fish production in T 1 with duck weed were 2.40 and 2.08 ton/ha/yr and in T 2 with Azolla fern were 2.26 and 1.94 ton/ha/yr, respectively. It was found that the net fish production in T 1 was 1.32 times higher than T 2 (P?0.01, 0.05). The present study showed influence of duck weed as dietary feed on the production of Thai Sharpunti (P. gonionotus ) was positively significant. So it might be concluded that duckweed had better effect as dietary feed than Azolla fern on monoculture of Thai sharpunti. Res. Agric., Livest. Fish.2(2): 369-374, August 2015