Larval rearing of the giant Azorean barnacle,Megabalanus azoricus (Pilsbry, 1916): feeding trials,larval development and settlement on artificial substrata |
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| Authors: | Carla Nunes João Rodeia Bárbara Paulino Eduardo Isidro Mirko De Girolamo |
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| Institution: | MARE ‐ Marine and Environmental Sciences Centre, Universidade dos A?oresDepartamento de Oceanografia e Pescas |
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| Abstract: | A series of experiments were conducted to obtain an efficient larval rearing protocol for Megabalanus azoricus. The first part of this study investigates the effect of microalgae‐based diets on survival and larval development. Mono and mixed‐diets were tested at 20 ± 1°C, in a sequence of 11‐day feeding experiments. The second part presents a preliminary study on the influence of a biofilm on recruitment and use of oyster spat collectors in a mass rearing system. A photographic record of larval development and a brief reference to the diagnostic features that enable quick larval staging are also presented, along with morphometric measurements. Of the microalgae tested (Chaetoceros sp., Chloromonas sp., Dunaliella sp., T‐Isochrysis sp. and Skeletonema sp.) the mixed‐diet Skeletonema sp. with T‐Isocrysis sp. showed the highest survival percentages: total survival ranged from 79.7 to 85.7% and 69.7–80.0% of nauplii were in stage VI after 11 days of rearing. Cypris were also present, but only represented 5.3% of the survivors at most. In the mass rearing system juveniles were found settled in the collectors after 25 days, at 20 ± 1°C. However recruitment was less than 1%. Preliminary results showed no settlement preference towards collectors with biofilm. Nevertheless, this study provides the first record of M. azoricus settlement under laboratorial conditions and represent a starting point for future larval rearing studies. |
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| Keywords: | cirripede
Megabalanus azoricus
aquaculture larvae algal diets settlement |
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