Effect of repetitive dye extraction over yield and survival rate of the purple snail Plicopurpura pansa (Gould, 1853)

The purple snail is an important economic species because of the dye obtain ed from it in western Mexico. This dye has been used since ancient rimes to color ceremonial dresses purple. Other. snails produce dye, but Plicopurpu ra pansa dye extraction was done without killing the snail. Repetitive dye extraction is possible. The brat time between each milking, dye yield versu s milking frequency, and effect on survival was determined by repetitive mi lking snail groups several times (7, 14, 21, and 28 days). Mortality in the most frequently milked groups and dye yield reduction occurred (every 7 an d 14 days). When milking frequency occurred every 21 days, the best dye yie ld and 100% survival rate was observed. These results suggest wild populati ons can be exploited using optimum extraction sehedules, leaving at least 2 1 days between each dye extraction.