In a 100 days field trial we examined the growth of sea cucumbers Apostichopus japonicus in bottom culture underneath net pens of tiger puffer Takifugu rubripes at an experimental integrated multi-trophic aquaculture (IMTA) site. We tested the effects of multi-culture on growth in two experimental species. We also compared growth of experimental animals cultured directly with control single species. There was no significant difference in fish growth between polyculture and control group, the average weight of daily weight gain (Md-wg) of T. rubripes was 1.07 g/d and the specific growth rate (SGR) was 4.06%/d in polyculture group. The Md-wg of A. japonicus was (0.11±0.04) g/d and the SGR was (0.67±0.2)%/d in polyculture group. In control single group, the Md-wg of A. japonicus was (0.04±0.02) g/d and the SGR is (0.35±0.19)%/d. Sea cucumbers suspended directly below the tiger puffer net pens grew significantly faster than control individuals. This study demonstrated that A. japonicus is well suited to utilize the heavy fraction of waste from the tiger puffer while providing an additional valuable harvestable product.