Growth, survival, and swimming activity of vendace (Coregonus albula (L.)) larvae under different food conditions in the laboratory

The growth (dry mass and total length), survival, and swimming activity of vendace, Coregonus albula, larvae were studied at 12.5 degrees C in a laboratory for three weeks using four different live zooplankton levels. The survival rate of larvae receiving lower amounts of food was lower. A decrease in both dry mass and swimming activity preceded their starvation. With low food levels, the total biomass of larvae decreased from the beginning of the experiment in relation to the biomass of their zooplankton food. The specific growth rate (SGR) calculated from samples of larvae was positive while the growth rate of the whole population was negative due to starvation. The variability in size of the larvae increased as the food level increased. This was a result of the variability of the initial size and different growth rates of larvae. On the other hand, the observed size-selective mortality decreased the size variability of the larvae. Vendace larvae (age<11d) are expected to starve if the density of copepoda is smaller than 200 larva per liter. The results of this study may be useful in estimating the carrying capacity and starving mechanisms of larvae in nature.