Influence of Water Alkalinity in Production of Stunted Fingerlings of Catla catla (Hamilton)

Abstract

Journal homepage: http://www.ijcmas.com Study was conducted for 90 days to know the effect of varying water alkalinity in production of stunted fingerlings of Catla catla in outdoor FRP tanks (1000 litre). Tanks filled up to 800 litre marks were grouped into three triplicated treatments and were stocked with catla seed (3.9g, 67±0.27mm) at 16nos per tank (20m -3 ). Three alkalinity levels, i.e. 80, 150 and 200 mg CaCO 3 L -1 were used and designated as Control, T-1 and T-2, respectively. Pond water (80 mgL -1 ) and bore well water (360 mgL -1 ) were used as the two sources to get the desired alkalinity level. Fishes were fed with powdered feed @ 8% of their respective biomass in all the treatments. The survival of catla decreased significantly (p<0.05) with the increase in alkalinity from control (97.92±3.61%) to T2 (89.58±3.61%). The average harvested body weight and length in T-1 (8.83±0.40g, 8.73±0.17cm) and T-2(8.28±0.19g, 8.65±0.10cm) were similar (p>0.05), but both were significantly lower than the control (9.64±0.12g, 9.02±0.02cm). Similarly, specific growth rate of T1 (0.91±0.05) and T2 (0.84±0.03) were similar and significantly lower than control (1.01±0.01). The biomass yield also reduced significantly with increase in alkalinity from control (151.00±4.63g) followed by T1 (132.43±6.06g) and T2 (118.77±7.56g). Such results indicated pronounced effect of increased alkalinity on suppressing fish growth and suggested possibility of manipulating this parameter as a tool for stunting of catla seed.

Effects of fish stocking density on growth and survival of Silver carp (Hypophthalmichthys molitrix) fry in Jashore, Bangladesh

“…The mean values of total alkalinity were found 155.78±2.518, 154.89±3.091 and 154.64±2.677 mg/l in T-1, T-2, and T-3, respectively. These results are relatively like those of (Sahoo et al 2020, Sarker et al 2019, Wurts 2002. From the above discussion we might conclude that all the experimental ponds for present experiment were most suitable for silver carp fish fry culture.…”