The Prymnesium parva 12B1 genome sequence and gene models were not determined by the Joint Genome Institute (JGI), but were downloaded from FigShare (Wisecaver et al., 2023) on 10/9/2023. All published models are available as ExternalModels. In order to ensure this genome is comparable to those sequenced and annotated by the JGI, we applied standard filters to ExternalModels to produce the initial GeneCatalog. A total 2,875 of 24,965 external models were excluded based on one of the following classifications: 1) association with repetitive elements, 2) pseudogenes with internal stop codons, 3) alternative isoforms or overlapping transcript models, 4) alleles on secondary scaffolds, and 5) short models lacking functional annotation. Please note that this copy of the genome is not maintained by the authors and is therefore not automatically updated. In order to allow comparative analyses with other algal genomes sequenced by the JGI, a copy of this genome is incorporated into PhycoCosm. The JGI Annotation Pipeline was used to add functional annotation to the genes.