Gene Ontology manually annotated genes. The presence or absence of orthologs of essential oogenesis genes listed in Additional file 1 has been manually verified. The Gene Ontologies (GO) of genes that were present were determined by BLAST2GO and GO terms were subsequently condensed using the generic GO Slim subset. The histogram details the number of Pararge aegeria manually verified contigs (note, as has been observed for many de novo assemblies, for some genes multiple contigs were present in the transcriptome) for each GO term. FPKM estimates were used to compare the levels of transcripts found in the ovaries and as maternal transcripts in the egg. Using a Log2 fold change threshold of 1, genes were classified in the histogram as present in similar amounts in the egg and ovarian transcriptome (labelled Ubiquitous), used predominantly during oogenesis to make an egg, but not or hardly used as a maternal transcript (labelled Ovary), or highly concentrated in the egg as maternal transcripts (labelled Egg).