IN RELATION TO CLIMATE CHANGE ADAPTATION: ASSESSING THE POTENTIALITY OF CAGE CULTURE OF Mystus gulio IN NOAKHALI COAST, BANGLADESH

Abstract

Mystus gulio commonly known as long whiskered catfish (locally nona tengra), is a euryhaline fish, occurring mostly in brackish water of low salinity, or even in fresh water. An experiment was conducted for 120 days in floating cages to evaluate the survival and culture potentiality as climate change adaption. Nine uniform metal cages (36 feet ) set in a pond (27 decimal) of Noakhali Integrated Agro Industries Limited were randomly divided into three treatments with different stocking density, explicitly T1 (100 M. gulio/per cage), T2 (150 M. gulio/per cage) and T3 (200 M. gulio/per cage). Initial weights of fishes were (1.10±0.02 g), held in triplicates groups and hand-fed up to apparent satiation. Sampling of the experimental fishes was done and monitoring of the water quality parameters was measured on monthly basis. Recorded water quality parameters, temperature, transparency, dissolved oxygen, water pH, soil pH, salinity, nitrite, nitrate, ammonia, phosphate and alkalinity did not vary significantly (P˃0.05), but all within the acceptable limit for aquaculture. At the end, the mean final weight of M. gulio (19.59±0.105 g, 17.19±0.172 g and 13.28±0.140 g), % weight gain (1683.92±24.692, 1477.13±11.295 and 1085.94±18.980), SGR (2.40±0.012, 2.30±0.006 and 2.06±0.014 %day 3 -1 ) were recorded in T1, T2 and T3 respectively, where T1 shows better growth performance significantly than T2 and T3. Though significantly (P<0.05) better nutrient utilizations Apparent Food Conversion Ratio (AFCR) and Apparent Protein Efficiency Ratio (APER) were recorded in T1 (3.017±0.035 and 1.11±0.013) followed by T2 (3.10±0.025 and 1.07±0.009) and T3 (3.24±0.035 and 1.03±0.012) along with the highest gross production (kg cage ) in T2 (2.12±0.091) followed by the T3 (2.10±0.083) and lowest in T1 (1.65±0.116), however, considering the survival and production of M. gulio T2 was found to be more efficient and profitable followed by T3 and T1. Highest survival (%) were observed in T1 (84.33±5.686) followed by T2 (82.22±3.909) and T3 (79.00±2.291) with no significant differences (P˃0.05). Based on the present findings, floating cage with 150 fish perform better but not to expected level. It might be suggested that further research is needed for adapting M. gulio in cages as potential adaptation option to utilized vast salinity affected coastal area of Bangladesh. -1