AnnelidaDB: a comprehensive platform of taxonomic and multi-omic resources across annelids

Annelids inhabit marine, freshwater, and terrestrial ecosystems and are important models for studying animal evolution, regeneration, and host-microbe interactions, yet their rapidly growing omics resources remain dispersed across repositories and publications. We developed AnnelidaDB (www.annelidadb.com), a species-centred database built on an updated phylogenetic framework that integrates genomes, mitochondrial genomes, transcriptomes, proteomes, epigenomes, single-cell datasets, host-associated symbiont genomes, and comparative synteny for Annelida. The current release covers 1121 species, including 152 species with nuclear genomes, 177 with mitochondrial genomes, 591 with transcriptome data, 5 with single-cell datasets comprising 209 802 cells, and 30 bacterial symbiont genomes. AnnelidaDB organizes these resources through 10 navigation directories and connects species, genome, gene, functional annotation, and gene-family records. Users can browse genomic assemblies, explore interactive single-cell atlases and 12 200 precomputed Oxford plots, run BLAST queries and search genes against the annelid-specific database, and submit chromosome-level data for syntenic analysis against 20 Annelida linkage groups. Sequences, annotations, and private results are available for download. As a comprehensive multi-omics resource dedicated to annelids, AnnelidaDB provides an accessible platform for comparative investigations of annelid genome evolution, adaptation, regeneration, and symbiosis.