Effects of sediment load on polyp extension of the juvenile cold-water coral Caryophyllia (Caryophyllia) huinayensis

The table shows the polyp behaviour of juvenile Caryophyllia (Caryophyllia) huinayensis during a 12-week sediment exposure experiment. Corals were exposed to a natural (0.0042 ml/l), a 100-fold and a 1000-fold increased sediment concentration and observed three times a week, two hours after feeding start and once a week without feeding, by illuminating only the targeted coral briefly with a spotlight torch. Polyp extension was categorized into three groups: A = polyp fully extended (polyp fully visible, 100 %), B = polyp partly extended (polyp partly visible, 50 %) and C = polyp fully retracted (polyp tentacles not visible, 0 %).