en Biology & physiology Biology & physiology پژوهشي Orginal research papers <span style="LINE-HEIGHT: 115% FONT-FAMILY: "Times New Roman","serif" FONT-SIZE: 12pt mso-fareast-font-family: Calibri mso-ansi-language: EN-MY mso-fareast-language: EN-US mso-bidi-language: AR-SA" lang="EN-MY">An experiment was conducted to investigate the effect of collector materials and position on <i>Pinctada margaritifera</i> spat attachment. Settlement on polyethylene pipes (54.6%) was significantly<i> </i>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 <i>P. margaritifera</i> pediveliger larvae in a hatchery and may also be suitable for grow out in the ocean.</span> Pinctada margaritifera, Settlement, Spat, Collector 198 207 http://jifro.ir/browse.php?a_code=A-10-1-77&slc_lang=en&sid=1 F. Ehteshami ehteshamei@yahoo.com 10031947532846001334 10031947532846001334 Yes A. Christianus 10031947532846001335 10031947532846001335 No H. Rameshi 10031947532846001336 10031947532846001336 No Sharr Azni Harmin 10031947532846001337 10031947532846001337 No Che Roos Saad 10031947532846001338 10031947532846001338 No E. Abdolalian 10031947532846001339 10031947532846001339 No