design: High molecular weight DNA was extracted from juvenile, gemmule-grown sponges cultured as described above using the Fire Monkey High Molecular Weight DNA Extraction Kit followed by removal of short sequences using the Circulomics Short Read Eliminator Kit. The DNA size distribution was assessed by an Agilent Femto Pulse and concentration via Qubit. PacBio HiFi sequencing was performed at the West German Genome Center on a Sequel IIe.