Effect of the diet on growth and reproduction of Eisenia andrei (Oligochaeta, Lumbricidae) reared in individual cultures

The effect of some vegetable bulking agents (oak leaves, pine bark and pine needles) mixed with activated sewage sludge on the growth of Eisenia andre i, Bouche 1972, was studied in cultures comprising of isolated individuals. Four diets were prepared: diet 1-sewage sludge + oak leaves (3:1 proportio n, fresh weight); diet 2-sewage sludge + oak leaves (4:1); diet 3-sewage sl udge + pine bark(2:1) and diet 4-sewage sludge + pine needles (3:1). Twenty juvenile worms (10-20 mg, wet mass) were maintained individually in 0.5 L replicates of a given test diet. Earthworms developed to full sexual maturi ty on each diet. Cocoon production was monitored in the four dietary mixtur es; hatchling production was monitored in cocoons produced in diets 1, 2 an d 3. Growth (mean weight) and reproduction appeared to be inversely related acco rding to the identity of the sludge:bulking agent used for maintenance. Thu s, maximum growth and the least number of cocoons (all non-viable) were rec orded in the mixture of activated sewage sludge and pine needles. In contra st, the maximum reproduction rate and highest cocoon production was recorde d in the 3:1 sludge:oak leaves mixture.