Comparing the biomass production of Tubifex tubifex cultured at cow dung and lettuce substrates

Having a diversity of necessary amino acids and fatty acids (W6 & W3) Tubifex worm (Tubifex tubifex) is a valuable food source for many ornamental fish species as well as larva of other fishes. Due to the risk of transferring pathogens, collection of these worms from natural environment is not recommended. We investigated the influence of culture substrate on biomass production of worms in a completely randomized design with two treatments (substrates) each with four replicates. The substrate treatments were organic fertilizer (cow dung) + sand with a height of 3 cm (treatment 1) and minced lettuce + sand with the same height (treatment 2). (The proportion of cow dung or lettuce to sand was 4:1 in all the treatments and the diameter of sand granules was 0.25 to 0.40 mm). The experimental units were small aquariums (length = 30 cm; width = 25 cm; height = 20 cm) adjusted to 100 ml/minute flow rate of water after preparing substrate treatments. Treatments 1 and 2 had 20.5 and 46.6 times increase respectively in the number of Tubifex worms at the end of a 45-days period of culture. The mean number of produced Tubifex worms was significantly different between the two treatments (P< 0.001).