Coldwater reattachment of colonial tunicate <i>Didemnum vexillum</i> fragments to natural (eelgrass) and artificial (plastic) substrates in New England

The colonial tunicate Didemnum vexillum Kott, 2002, was introduced to New England in the 1980s and by 2000 it was widespread. This highly invasive species spreads by larval release and fragmentation. We tested the ability of D. vexillum fragments to reattach to natural (eelgrass Zostera marina (Linnaeus, 1753)) and artificial (plastic container) substrates during late fall and early winter. On average, 77% of D. vexillum fragments reattached to eelgrass and plastic in water temperatures between 6 and 10°C. Eelgrass appeared to facilitate D. vexillum reattachment success in early winter but this tendency should be further investigated.