Genome Assembly and Annotation for the Okinawan Green Marine Spoon Worm Bonellia viridis (Polychaeta: Bonelliidae)

Bonellia viridis, an echiuran polychaete that inhabits infralittoral rocky habitats around the Atlantic, Mediterranean, and Southeastern Pacific coastlines, exhibits environmentally mediated sexual dimorphism: planktonic larvae develop into dwarf males after exposure to bonellin, a green pigment produced by adult females. Bonellin is a chlorin with a structure consistent with derivation from uroporphyrinogen III, the last universal precursor of all known tetrapyrroles, yet its biosynthesis remains unknown. Here, the de novo genome assembly for a single adult female specimen of B. viridis isolated from Okinawa has been generated (via Illumina sequencing) and found to comprise 429.95 Mb across 95,859 contigs, with an N50 of 6505 bp, recovering 83.3% of near-universal metazoan BUSCO orthologs. Homologs of all canonical enzymes of the heme biosynthetic pathway (termed hem genes) were identified across the genome. The genomic resources establish a foundation for research into the biochemical basis of pigment production, chemically mediated sex determination, and the distinct biology of B. viridis.