CULTURE POTENTIALITY OF Mystus gulio IN SALINITY INTRUSION PRONE AREAS OF NOAKHALI COAST, BANGLADESH

Abstract

This experiment was aimed to assess culture potentiality of M. gulio in different culture systems in salinity prone areas of Noakhali coast, Bangladesh. Nine uniform earthen ponds (40 m 2 ) of Noakhali Integrated Agro Industries Limited were randomly divided in to three treatments, explicitly T1 (mono culture of M. gulio), T2 (poly culture with Oreochromis niloticus (60) and Rhinomugil corsula (40)) and T3 (poly culture with O. niloticus (40) and R. corsula (60). The fishes with (1.12±0.01g) initial weight held in triplicates groups hand-fed up to apparent satiation and were reared over a period of 120 days. Sampling of the experimental fishes along with the monitoring of the water quality parameters were measured on a monthly basis, pH of water (7.34±0.206, 7.30±0.134 and 7.4942±0.1400), nitratenitrogen

(0.05±0.013, 0.06±0.014 and 0.087±0.016 mgl ) and total alkalinity 70.33±3.473, 79.08±9.337 and 78.92±8.523 in T1, T2 and T3, respectively showed distinct variation between different treatments. Other properties like temperature, dissolved oxygen, transparency, salinity, nitrite-nitrogen, phosphate, ammonia did not exhibit any significance variance. All the water quality parameters measured during the study period was found within the acceptable range suitable for fish culture. At the end, the mean final weight of M. gulio (25.36±0.72 -1

g, 16.36±.07g and 20.57±0.03g), % weight gain (2158.69±51.32, 1349.24±36.84 and 1720.73±13.91), SGR (2.60±0.02, 2.23±0.01a and 2.42±0.01b % day ) were recorded in T1, T2 and T3 respectively where T1 showed significantly better growth performance followed by T3 and T2. Though significantly (P<0.05) better nutrient utilizations AFCR and APER was recorded in T2 (2.03±.05 and 1.6420±.0160) followed by T3 (2.1333±.03and 1.57±.0306) and T1 (2.95± 0.06 and 1.13±0.02) along with the highest gross production (kg ha -1 ) in T2 (3866.37±69.65) followed by T3 (3489.968±62.22) and in T1 (1682.50±21.93). However, considering the survival, net profit and BCR of T3 were found to be more efficient and profitable followed by T1 and T2. The significantly higher survival (%) of the fishes were recorded in T1 (77.90±1.00) followed by the T3 (75.06±1.007) and lowest in T2 (72.53±1.405). Significantly higher net profit (BDTha -1 -1 ) was found in T3 (158814.88±7584.83) over T1 (142599.76±11913.74) and T2 (129071.86±5498.3) However along with significantly (P<0.05) higher BCR were recorded in T1 (1.38±0 .04) followed by the T3 (1.30±0.01) and lowest in T2 (1.23±0.01). Therefore the results the study suggests that T3 (poly culture of M. gulio with O. niloticus (40) and R. corsula (60) is more beneficial with higher profitability for the fish farmer over the T1 and T2.