Towards understanding the prospects of select macrophytes as potential fish feed

Aquaculture provides high-quality protein reasonably at cheap cost. But the intensive aquaculture is facing expensive feeding cost because the key aquadiet ingredient- fishmeal is becoming very costly. In this scenario application of aquatic plants as an alternative for fishmeal has the potential to revolutionize aquafarming in meeting protein demand globally. Macrophytes grow abundantly in all water bodies and are considered as a nuisance in most of eutrophic aquatic systems. In the current study the nutritional profile of five aquatic plants, namely Azolla cristata, Ceratophyllum demersum, Nelumbo nucifera, Nymphaea mexicana and Trapa natans , collected from the Dal Lake, Kashmir was evaluated. The proximate analysis was carried out as per standard methods of association of official analytical chemists (AOAC) and mineral analysis by atomic absorption spectroscopy. Results show that the crude protein lies in the range of 16–24% with Nymphaea mexicana showing the highest (24.13%) and Ceratophyllum demersum showing the lowest (16.07%) crude protein content. The crude lipid content ranges between 4–8% whereas ash content lies in the range of 11- 37.74% with C. demersum showing the highest (37.74%). Among the investigated macrophytes, the highest levels of potassium, magnesium, iron, manganese, cadmium and copper were recorded in C. demersum . Azolla cristata was rich in sodium and zinc, and Nelumbo nucifera in cobalt. Omega-6 and omega-3 fatty acids were present in all the investigated macrophytes except C. demersum. Our findings revealed that macrophytes are rich sources of fatty acids, protein and minerals besides their readily availability and high productivity and it is argued here in this paper they can prove as viable candidates for aquafeed in the future.