Does female RNA content reflect viable egg production in copepods? A test with the Baltic copepod Acartia tonsa

Biomarkers are very useful for in situ assessments of zooplankton growth. In particular, RNA-based methods have been developed to estimate egg production in copepods. However, RNA–growth relationships can potentially depend on a variety of factors, such as egg quality. This study shows that in Acartia tonsa, female RNA-content reflects egg production irrespective of egg viability, implying that this growth proxy is not applicable for recruitment studies if the proportion of viable eggs fluctuates widely.