Larval growth, development, and survival of laboratory-reared Aplysia californica: Effectsof diet and veliger density

摘要

Over the last three decades, the California sea hare, Aplysia californica, has played an increasingly importantrole as a model organism in the neurosciences. Since 1995, the National Resource for Aplysia has supported agrowing research community by providing a consistent supply of laboratory-reared individuals of knownage, reproductive status, and environmental history. The purpose of the present study was to resolve the keybiological factors necessary for successful culture of large numbers of high quality larval Aplysia. Data from asequence of five experiments demonstrated that algal diet, food concentration, and veliger densitysignificantly affected growth, attainment of metamorphic competency, and survival of Aplysia larvae. Thehighest growth and survival were achieved with a mixed algal diet of 1:1 Isochrysis sp (TISO) and Chaetocerosmuelleri (CHGRA) at a total concentration of 250 x 10~3cells/mL and a larval density of 0.5-1.0 per mL Rapidgrowth was always correlated with faster attainment of developmental milestones and increased survival,indicating that the more rapidly growing larvae were healthier. Trials conducted with our improved protocolresulted in larval growth rates of >14 pm/day, which yielded metamorphically competent animals within21 days with survival rates in excess of 90%. These data indicate the important effects of biotic factors on thecritical larval growth period in the laboratory and show the advantages of developing optimized protocols forculture of such marine invertebrates.