The objective of the first of three growth experiments was to test the use of P. redivivus at two feeding levels, 5000 and 10 000 nematodes larva−1 day−1 of culture water, in the rearing of S. petricola within the first 14 days after hatching. The two feeding levels of nematodes were compared with treatments fed Artemia nauplii at 200 and 600 Artemia larva−1 day−1 of culture water, and a commercially available finely ground dry food at 0.3 g tank−1 day−1. Based on previous observation this feeding rate was in excess of what the fish were able to consume.