Growth and survival of pink shrimp (Farfantepenaeus paulensis) postlarve in cages and pen enclosures

Technology for the culture of the pink shrimp Farfantepenaeus paulensis in low-cost cages and pen enclosures was developed together with artisanal fishermen of the Patos Lagoon estuary, southern Brazil. Although the production of postlarvae (PL) under laboratory conditions is well documented, survival and growth during the nursery phase cages and pen enclosures in the nature has not yet been analyzed. Therefore, the present study compared survival and growth of F. paulensis postlarvae reared either in cages or pens. Six cages (2.0 ´ 2.0 ´ 1.4 m) of PVC-coated polyester with a mesh size of 1.5 mm were stocked with 800 PL26 each. To assess the effect of the substrate, a 10 cm layer of sand was added to three of these cages to simulate a pen enclosure. No difference in the mean survival rate between cages (92.2%) and pens (88.7%) was found (P > 0.05). However, final weight of shrimp reared in pens (1.05 ± 0.05 g) was higher than those kept in cages (0.88 ± 0.12 g). The nursery phase of F. paulensis in cages and pens did not affect survival. Nevertheless, because of the higher growth rate of shrimp grown in pen enclosures, this kind of structure should be preferentially used in nursery rearing of this species