The effect of different substrates on pearl oyster Pinctada martensii (Dunker) larvae settlement

In the present study, the effect of various substrata on the settlement of a pearl oyster, Pinctada martensii, was evaluated. The settlement of the larvae in the experiments with four different color substrata was compared and showed that deep color plastic sheets (red and blue) attracted significantly more larvae (P < 0.05) than light color (green and yellow). In addition, the influence of biofilm substrata was compared with that of non-film substrata of smooth or rough texture. Number of settled larvae was highest on biofilmed plastic sheets, either rough or smooth, then rough plastic sheets without film, the least recorded was on smooth plastic sheets without biofilm. Substrates of plastic sheets coated with tissue extracts of the same species appeared to attract larval settlement. The number of settled larvae on substrates with tissue extracts was significantly greater (P < 0.05) than that on the control.