Influence of the collector type and at-sea cultivation period on seeds recovery rate and growth out of Pteria hirundo in Southern Brazil

Abstract

The recovery rate of seeds and the growth of Pteria hirundo were evaluated in at-sea cultivation. It was evaluated a netlon collector and a red plastic netting collector, over cultivation periods of 60 and 90 days. Seeds were classified by size and were cultivated with occupation rates of 100% and 50% on the lantern plate. The recovery rates for netlon were 49.68% and 27.36% for 60 and 90 days, respectively. For the red collector, the recovery rates were 35.8% and 28.39% for the 60 and 90 days, respectively. No statistical differences were found between collectors for either the recovery rate or the growth rate during either experimental period. The recovery rate was statistically higher in the 60 days than in the 90 days. After the final growth stage, the seeds removed from the sea 165 days after fecundation presented a predominate size of 30 to 40 mm with a 90% survival rate, and those removed after 195 days after fecundation were greater than 40 mm. The time at-sea had a greater influence than the collector type. The netlon collector should be used with a 60 day period at-sea and a 100% occupation rate of the lantern plate surface.