Radix balthica were cultured in the presence or absence of predatory fish kariomone (Tincus tincus), from the first cell division up until either, first heart function, or first crawling activity. At this stage 150 embryos were pooled to create each of three samples per treatment group. RNA was extracted and sequenced (GenePool, Edinburgh University, UK - NBAF698) using both 24 M paired-end reads of 250 BP Miseq2(for transcriptome assembly) and 150 M 50 BP HiSeq SE (quantification). Data were trimmed to remove poor quality bases (<30) and adapters, using cut adapt. Trinity was then applied to the MiSeq data to assemble a transcriptome from which subsequent analysis will be performed.