From experience, When I first got my tubastrea it had polyps on the bottom facing downward that were not connected by tissue. I could not reach these polyps to feed them, so I fed the polyps I could reach on the top and sides. The polyps on the bottom withered and died after a month or so. However my coral was fed daily and quickly grew new flesh which eventually spread back to the bottom, producing new polyps. Again, I cannot reach these new polyps to feed them, only the top and sides are fed, but now that the tissue connects them to the rest, the polyps on the bottom continue to grow and multiply. This may be anecdotal, but I believe its a reasonable conclusion to draw from my observations.