Evaluation of selected substrates for collection of hatchery reared black-lip pearl oyster (Pinctada margaritifera) spat

An experiment was conducted to investigate the effect of collector materials and position on Pinctada margaritifera spat attachment. Settlement on polyethylene pipes (54.6%) was significantly higher (P < 0.05) than on plastic baskets (25%). Significantly higher (P < 0.05) spat catch was recorded from the collectors which were installed on lower height of settlement tank than upper. The number of dead spat after settlement on pipe (1.4%) and basket (1.5%) were not significantly different (P > 0.05). Possible factors causing the pattern of settlement reveals that it could be related to the material used in collector, reaction to light and gravity force. These results indicated that polyethylene pipes positioned horizontally in the third bottom part of the tank are suitable for the settlement of P. margaritifera pediveliger larvae in a hatchery and may also be suitable for grow out in the ocean.