Production Performance and Nutritional Composition of <i>Perionyx excavatus</i> (perrier, 1872) Fed Different Composite Organic Food

Abstract

Perionyx excavatus is a potential earthworm species for vermicomposting, and of live feed for fish as it contains high quality protein with excellent amino acid profile. Its limited seasonal abundance in natural as well as the associated risk of bioaccumulation of toxic products in wild earthworm inflate large scale vermiculture of this species. To establish a suitable food composite for mass culture of that species, the present study evaluated the production performance and nutritional composition of P. excavatus fed on four different organic food composites namely, C, T 1, T 2 and T 3. Initially five adult wild earthworms were stocked in cemented tanks, and reared them with feeding respective organic composites at the rate of 10% of their body weight twice a week for 120 days. To determine the growth rate, newly hatched larvae of 0.12-0.16 mg collected from respective treatments was reared in the separate tubs at the stocking rate of 5 larvae tub -1 for 60 days. Temperature, pH, moisture, total nitrogen and organic carbon contents of rearing beds, and growth rate of earthworms were recorded at every fortnight. The treatment T 3 was found to be effective for production performance (2.508 ± 0.75 larvae week -1 ) while the T 2 gave higher growth rate (0.16 g·worm -1 ·week -1 ) to this earthworm species. The highest protein (48.36%) and moisture content (81.85%) were recorded in T 2 but T 3 contained the lowest protein (39.65%) and the highest lipid level (4.82%). The ash content was found not to be significantly different among all treatments. The results of this study demonstrated T 3 composition as good medium for reproduction, and T 2 composition as better food composite for rearing P. excavatus . The outcomes of this study may provide essential information towards the mass culture of this species.