METAMORPHOSIS OF LABORATORY-REARED LARVAE OF CONCHOLEPAS-CONCHOLEPAS (MOLLUSCA, GASTROPODA)

Metamorphosis of laboratory-reared larvae of the gastropod Concholepas concholepas was observed under the influence of K+ ions. After 64 h o f incubation at 10 degrees C, 58% of larvae metamorphosed in response to 20 mM K+ final concentration in seawater, 11 mM above ambient. No e ffect was observed at 15 mM K+. Likewise, larvae were unable to surviv e when exposed to 25 mM K+. Metamorphosed individuals of C. concholepa s migrated to the water-air interface within 28 h of their metamorphos is. This study reports the first successful experiment on the inductio n of metamorphosis in laboratory-reared larvae of C. concholepas. The advantages of mass production of larvae with metamorphic capacity of t his economically important resource, related to its eventual culture o n a pilot scale are discussed.