Larval Growth and Metamorphosis of Conus (Castropoda: Toxoglossa) in Hawaii

Abstract

The planktotrophic larvae of Conus lividus, C. quercinus, C. flavidus, C. striatus, and C. marmoreus were reared through metamorphosis in the laboratory and were described and figured . Minimum planktonic periods of these species were found to be 50, 30, 23, 20, and 10 days, respectively. The lecithotrophic larvae of C. pennaceus metamorphosed within 24 hours of escape from their egg capsules. Early post-hatching growth rate s of planktotrophic veligers were related to hatching size and the developmental state of the velum at hat ching. In C. pennaceus, metamorphosis was induced by the presence of a biological film. Substratum texture had no effect on rates of metamorphosis. The lecithotrophic larvae of C. pennaceus were observed to ingest unicellular algae. Experiments showed that this facultative feeding may improve the survival of C. pennaceus when the larval period is artificially prolonged.