First evidence of a specific association between a stylasterid coral (Cnidaria: Hydrozoa: Stylasteridae) and a boring cyanobacterium

The association between living Stylasteridae and boring organisms have been hypothesized since 1942, when Broch (1942) observed in Distichopora borealis forma japonica and in Distichopora foliacea “numerous, streak-like, straight canals crossing the skeletal substance in all directions…much narrower than the normal coenenchym canals of the coenosteum” suggesting that these canals are probably due to some parasitic micro-boring organisms. Subsequently, Cairns (1988) hypothesized that the rose-violet colour of the Australian Stylaster tenisonwoodsi was due to an encrusting or a boring alga.