Partial Replacement of Fish Meal with an Aquatic Macrophyte, Ceratophyllum demersum in the Diet of Common Carp, Cyprinus carpio var. communis Fingerlings

Abstract

A 12-week feeding trial was conducted to investigate the nutrient utilization, growth performance, and hematological indices of Cyprinus carpio var. communis fingerlings fed diets based on aquatic macrophyte, Ceratophyllum demersum as a replacement of fish meal (FM). Six isonitrogenous and isocaloric diets containing graded levels of C. demersum 0%, 5%, 10%, 15%, 20%, and 25%, respectively, as replacer of FM were formulated. Total of 360 fingerlings with an initial weight of 3.65 ± 0.98 g were randomly stocked in 70 L plastic tanks water volume 60 L connected with a continuous flow-through system (1–1.5 L/min) for each treatment and were run in triplicate having 20 fish in each tank. At the end of the feeding trial, it was observed that the C. carpio var. communis fingerlings receiving 5% and 10% C. demersum in the diet showed improvements in live weight gain (LWG), specific growth rate (SGR), feed conversion ratio (FCR), and protein efficiency rate (PER). While further addition of C. demersum as a replacement of FM from 15% to 25% led to the progressive decline in the values of LWG, SGR, FCR, and PER. Hematological data also exhibited a linear declining trend beyond the 10% C. demersum replacement level. The fish fed with higher inclusions of C. demersum in each diet significantly (P<0.05) affected whole body composition with the lowest protein and fat amounts recorded at higher replacement levels significantly (P<0.05). The highest protein and fat contents were observed at 5% and 10% diets. Except serum glucose, cholesterol, alanine aminotransferase (ALT), and aspartate aminotransferase (AST), the other serum indices exhibited a decreasing trend with increasing inclusion of C. demersum in the diet. The results of the present study clearly demonstrated that the inclusion of 10% C. demersum did not affect the growth and other parameters of C. carpio var. communis fingerlings compared to the 50% FM diet. However, it is recommended that 10% FM can be substituted without compromising the growth and nutritional quality of fish.

Floating Aquatic Macrophytes in Wastewater Treatment: Toward a Circular Economy

“…In combination with Anabaena azollae, it efficiently removes nutrients even after complete nitrogen depletion. The species A. pinnata can effectively be used in the treatment of domestic and industrial effluents [8,109,110].…”

“…Wastewater consists of organic matter, nutrients, heavy metals, explosives, radioactive elements and specific organic and inorganic chemicals, including micropollutants and microorganisms, that are above the permissible level unless they pass through a treatment system [8][9][10]. Wastewater, according to its origin, can be broadly categorized as domestic, industrial, agricultural, leachate and stormwater discharge [9].…”

“…Economic advancement due to no or low energy consumption, eco-friendly attributes and operating flexibility make the biological treatment more feasible despite its minimal shortcomings [27,28] Phytoremediation is a biological treatment method using plants to eliminate contaminants from wastewater, groundwater and soil [29,30]. Subsequently, wherever possible, the extracted resources, along with the plants, will be used for other purposes, such as animal feed production [8], drug formulation [31], bioenergy production [32] and soil fertil-ity improvement and reclamation [33]. The suitability of macrophytes in post-treatment resource recovery and product development frames the floating phytoremediation process as a cradle-to-cradle (C2C) design, which is a novel approach to eliminate waste and create a circular economy.…”