Effects of food availability, larval source and culture method on larval development of Balanus amphitrite amphitrite Darwin: implications for experimental design

Abstract

Effects of food concentration on larval development of Balanus amphitrite amphitrite Darwin (Crustacea: Cirripedia) were studied in three experiments designed to examine plasticity of survival, time of development and size: I, larvae from a single brood, cultured individually; II, larvae from multiple broods, cultured individually; III, larvae from multiple broods, cultured in groups (batch cultures). Nauplii were fed the diatom Skeletonema costatum (Grev.) Cleve at six concentrations ranging from 0 to 10 6 cells · ml −1 at 24 °C and 30%. salinity. Food concentration had a clear impact on larval survival and development time for B. a. amphitrite and larvae showed the same trends in survival, duration of development, and growth whether they were obtained from single or multiple parents and whether they were cultured individually or in batches. Nauplii of B. a. amphitrite failed to reach the cypris stage at algal concentrations ≤ 10 3 cells · ml −1. Development stopped at nauplius II when larvae were reared at 0–10 2 cells · ml −1 and stopped at nauplius III when larvae were reared at 10 3 cells · ml −1. Survival at 10 5 and 10 6 cells · ml −1 was higher than at 10 4 cells · ml −1. Larvae reared at the three highest food concentrations developed to the cypris stage. Development time from nauplius II to cyprid was similar ( p > 0.10) when larvae were maintained at 10 5 or 10 6 cells · ml −1, but was significantly longer when reared at 10 4 cells · ml −1. The sizes of B. a. amphitrite larvae at a particular stage were similar regardless of food concentration, developmental rate, larval source (from single vs. multiple broods) and the method of culture. In future studies that involve B. a. amphitrite larvae, larval source and method of culture can be selected solely on the basis of questions to be addressed.