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Use of Coontail as a Natural Phytoremediation Feed Additive for Common Carp

Kiziloğlu Ümmühan, Yıldırım Önder, Çantaş İsmail Berat

Oceanological and Hydrobiological Studies

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2023

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Vol. 52, No. 1

102--110

EN

Ceratophyllum demersum is a submerged, rootless, free-floating macrophyte and natural aquatic phytoremediation. C. demersum has high efficiency in absorbing large amounts of nitrogen and phosphorus in the aquatic environment. In this study, the effects of a natural phytoremediation Ceratophyllum demersum meal, as a dietary supplement, on growth performance, feed utilization, and body composition of common carp (Cyprinus carpio L., 1758) were investigated. This was the first attempt to use coontail as a feed additive for common carp. Four isonitrogenous (38% crude protein), isolipidic (8% crude lipid), and isoenergetic (18 kJ g−1) diets were formulated control group (0%), CM5 group (5%), CM10 group (10%) and CM15 group (15%) in feed. Each dietary treatment was administered to triplicate in groups of 15 fish (~19 g). Carp were hand-fed to apparent saturation three times a day (09.00; 12.00 and 17.00). There was no difference between the control diet and 5% CM in terms of growth (final weight, weight gain, specific growth rate) and feed utilization (feed conversion rate, feed intake, feed efficiency) (p < 0.05). Increasing algae levels in diets improved protein levels in body compositions while decreasing lipid. There was no sign of appeared fish health indicators (disease or deformity) in all diet groups. This study results showed that instead of soybean meal, 5.75% and 6.07% as natural phytoremediation, C. demersum optimized the best growth and feed utilization performance in carp diets.

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Does fish stocking rate affect the photosynthesis of Lactuca sativa grown in an aquaponic system?

Jaszczuk Zuzanna Malwina, Brysiewicz Adam, Kozioł Agnieszka, Auriga Alicja, Brestic Marian, Kalaji Hazem M.

Journal of Water and Land Development

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2023

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no. 58

243--252

EN

The depletion of natural resources such as freshwater and cropland makes it necessary to find a new solution for sustainable food production. Aquaponic systems seem to be a great alternative to traditional agriculture, however, there are still many unknowns that need to be explored. It is already known how fish stocking affects water quality in aquaponic systems, but not how it affects the plants’ growth, and especially on chlorophyll fluorescence. In this study, we examined how the density of 0, 2, 4, 8, and 16 stocking fish in five aquaria affects lettuce growth. The first tank was only a hydroponic system with plants but without fish (control). In the remaining four aquaria - 2, 4, 8 and 12 specimens of common carp fry with an average weight of 20 grams (average 8.5-33.2 g) were placed in the aquaponic growing system. Physicochemical analysis of water was conducted to determine the levels of pH, electrical conductivity (EC), N-NO3, N-NO2, N-NH4, P-PO4, O2 and physiological parameters of plants (nitrogen balance index - NBI, chlorophyll content index - CCI, quantum yield - QY, flavonoid content - Flv) were analysed. The results showed that fish stocking density has different effects on plant physiological parameters, but in most cases, was insignificant. It seems that the greater number of fishes and higher density indirectly causes growth inhibition (lower photosynthetic efficiency) due to the increase of N-NO3 and a decrease of O2 in the water.

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A simple, rapid method for the production of soluble recombinant proteins from the duplicated growth hormone genes of the tetraploid common carp

Murakaeva A., Kohlmann K.

Environmental Biotechnology

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2011

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Vol. 7, No. 2

53-64

EN

The simple protein production method developed in the present study enables the production of large quantities of active recombinant common-carp growth hormone proteins in a few brief steps. With this method, the recombinant protein is obtained in a soluble form without the need for refolding. This method can be utilised for determining if the two common-carp growth hormones have similar functions in vitro and in vivo and what role each plays in growth regulation. If differences in activity exist, this method can also be used to produce intermediate forms of the two common carp growth hormones rapidly in order to determine which of the six amino acids that differ between the two proteins are responsible for the altered activity. Common carp has the same tetraploid ancestor as goldfish, and the products of the growth hormone paralogues in goldfish also differ. It would be interesting to understand how the same duplicated orthologues have evolved, and the methods elaborated in this study could be used for such comparative investigations.