The effect of periphyton substrate density on production in freshwater polyculture ponds (original) (raw)

Effect of different amounts of feeds on growth and production of fishes in pond polyculture

Int. J. Agril. Res. Innov. Tech. 10(2): 128-136, December, 2020

An experiment was carried out to evaluate the effects of different amounts of supplementary feeds on growth and production of fishes in polyculture where four different species such as rui (Labeo rohita), mrigal (Cirrhinus mrigala), common carp (Cyprinus carpio) and tilapia (Oreochromis niloticus) were cultured in 6 ponds under three treatments, each with two replications. Eighty fish per decimal were stocked along with the stocking ratio of 1:1:1:1 in all the treatments. Supplementary feeds of rice bran and wheat bran (1:1), at the amount of 5% of body weight were applied in 2 ponds (treatment I) as well as at the amount of 3% of body weight were used in 2 ponds (treatment II) and 2 ponds (treatment III) were as control where no supplementary feed was used. Urea and T.S.P were applied fortnightly at the rate of 60 g decimal-1 and 90 g decimal-1 , respectively under all treatments. Physico-chemical and biological factors such as air and water temperature, transparency, rainfall, pH, dissolved oxygen, free CO2, total alkalinity, PO4-P and NO3-N, phytoplankton and zooplankton were studied fortnightly and the limnological conditions were more or less similar in the experimental ponds under three treatments. The calculated gross and net fish productions of fishes under treatment I, treatment II and treatment III were 8.87 and 7.33 ton ha-1 yr-1 , 7.12 and 5.58 ton ha-1 yr-1 and 4.69 and 3.16 ton ha-1 yr-1 , respectively. Percent increased of net fish productions of treatment I and treatment II were 231.97% and 176.59% higher than that of treatment III (control). The present study reveals that supplementary feeding in fish culture should be done along with fertilization because supplementary feeds are very important to enhance growth of fishes significantly.

Modeling the potential of periphyton based fish production in pond culture system

2011

To evaluate the potential of fish production from Periphyton-based aquaculture system, a simple dynamic simulation model was constructed. The model consists of three state variables, periphyton biomass (PB; g), fish biomass (FB; g) and nutrient stock and six rate variables (nutrient inflow, nutrient uptake by periphyton, periphyton grazing by fish, periphyton degradation rate, fish harvesting and mortality rates). In the model, it was assumed that PB is minimum before fish were stocked and that fish grazing would cease whenever PB would be lower than that minimum biomass. This model was implemented in Stella 8 and run with a timestep of 0.05 day. Parameter values were derived from the literature. We assumed a maximum periphyton density of 100 g dm m-2. PBmax was derived from this value by multiplying with the substrate area. Simulated PB increased from 10 g m-2 initially to 100 g m-2 after 24 days. Before day 30, periphyton productivity was greater than the consumption of the periph...

Percid Pond Production Techniques

Journal of Applied Aquaculture, 1994

Tremendous variation in survival and growth of percid fry stocked in ponds was addressed through manipulation of amounts and kinds of fertilizers added and stocking densities of fish. Ponds were filled with water from nearby eutrophic lakes less than one week prior to stocking. Survival in these ponds averaged 64%. whereas ponds filled one month before stocking averaged only 14%. Optimal inorganic fertilization was identified as weekly restoration to 600µg N/L (NH4 +NO3) and 30µg P/L as PO4-3. Organic fertilization gave variable results and water qualities. In one experiment, low organic fertilization alone (28 kg alfalfa meal/ha/week) provided survival and growth comparable to optimal fertilization with inorganic nutrients. Although similar in results, inorganic fertilization was more cost effective than the alfalfa meal. Low fish predation from low stocking or survival allowed Daphnia to overgraze algae. This resulted in a crash in both algae and zooplankton in the ponds. Doubling the initial stocking density increased harvests from 150.000 to 300,000 fish/ha and increased yield from 45 to 100 kg/ha.

Nutrients profile and fish growth of some fish culture ponds

2015

Carbon, nitrogen and phosphorus (CNP) ratio is a significant index of high yielding aquaculture. The study was performed to determine the nutrients profile of different aquaculture ponds and to evaluate the necessary nutrients amendment required for high fish growth in fish farming ponds of different nutrients status and culture practices. Ten ponds – four sewage–fed–fish farming ponds, two carp farming ponds, two large water bodies of carp poly culture and two pangas (Pangasius pangasius Ham.) monoculture ponds were considered in this study. Nutrients and water qualities, primary productivity, heterotrophic bacterial population and fish growth of all ponds were examined during four months culture period. The higher daily fish growth rate (1.71 – 1.75 g d<sup>–1</sup>) was found in the pangas cultured ponds due to favorable CNP ratios (49.6:6.5:1 and 56:6:1) developed by congenial nutrient profile compared to remaining fish cultured ponds suffered by eutrophic and oligot...