Effects of culture conditions on larval growth and survival of stalked barnacles ( Pollicipes pollicipes )

Pollicipes pollicipes (Crustacea: Scalpelliformes) is a highly prized food in Portugal and Spain and consequently a species of considerable interest to aquaculture. Surprisingly, however, larval culture conditions for this barnacle have not been optimized. This study investigated the effects of temperature, diet, photoperiod and salinity on the growth and survival of P. pollicipes larvae. Temperature had a significant effect on specific growth rate (2.6-5.9% total width per day, from 11 to 24 degrees C), reducing mean development time to the cyprid from 25 days at 11 degrees C to 10 days at 24 degrees C, although this was accompanied by a significant increase in mortality to over 90% above 22 degrees C. Midrange temperatures (15-20 degrees C) maximized total survival (19-31% respectively). Algal diets of Tetraselmis suecica, T. suecica/Skeletonema marinoi and S. marinoi/Isochrysis galbana did not affect specific growth rate significantly, but survival (on average 39% in 15 days) and the proportion of high-quality healthy cyprids was significantly higher on the latter two diets (11-15% of initial number of larvae). Photoperiod did not significantly affect the survival, although specific growth rate was significantly higher at 24:0 and 16:8 L:D. Salinity (2040 g L-1 range) did not affect growth and survival significantly. The best growth and survival were accomplished using rearing temperatures of 15-20 degrees C, daily feeding with T. suecica/S. marinoi or I. galbana/S. marinoi and a photoperiod of 24:0 L:D.