World Aquaculture Magazine -December 2021

WWW.WA S .ORG • WORLD AQUACULTURE • DECEMBER 2021 65 Species and Habitat Tubifex is a segmented worm, commonly called sludge worms, belonging to the Family Naididae of Order Oligochaeta of Class Clitellata of PhylumAnnelida. The important species belong to the tubificids are Tubifex tubifex , T. ignotus , T. longipenis , T. nerthus , T. newaenis and T. newfei. Identification of species is challenging as reabsorption of the reproductive organ takes place after mating because of environmental fluctuations. Tubifex worms inhabit the sediment of sewage ponds and outfalls and drainage areas of lakes and rivers, where they feed on detrital particulate organic matter. They are red because they contain hemoglobin. Tubificid worms can survive in low oxygen areas by exploiting the available oxygen by waving the hemoglobin rich tail end and can also exchange oxygen and carbon dioxide through the cuticle. A mong live fish foods, tubifex worms are preferred by the larvae of many foodfish and also forms an excellent broodstock diet for many food and ornamental fish species. Tubifex worms naturally inhabit sewage and sludge areas as they can tolerate poor water quality, but worms collected from these natural habitats are subject to contamination by persistent toxins and potential fish pathogens. The culture of tubifex in controlled conditions provides a favorable environment to ensure a low risk of contamination from pollutants and pathogens. Tubifex is a significant source of nutrition as a live food. The proximate composition of tubifex worms is: crude protein – 55-66 percent, crude lipid – 12-28 percent, ash – 8 percent, food values – 5575 cal/g on dry weight basis, total fatty acid content – 7.28 mg/100 mg dry weight, which includes 18 percent of ω-3 fatty acid (C18:3n3, C20:5n3) and 22 percent of ω-6 fatty acid (C18:2n6, C20:4n6), and total carotenoids – 15.0 ± 0.8 mg/kg. Tubifex: A Forever Nutritious Jewel in Aquaculture Thejaswini, Upasana Sahoo, Shamna N. and Babitha Rani A.M. Tubifex colony established on kitchen waste substrate. ( C O N T I N U E D O N P A G E 6 6 )